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1 (function() {
2
3 /**
4  * Version of this script. If the server returns a version larger than
5  * this, it is a sign we should reload to upgrade ourselves.
6  *
7  * @type {Number}
8  * @const
9  * @private */
10 var SCRIPT_VERSION = 2021021300;
11
12 /**
13  * The current backend URL.
14  *
15  * @type {!string}
16  * @private
17  */
18 var backend_url = "/analysis.pl";
19 var backend_hash_url = "/hash";
20
21 /** @type {window.ChessBoard} @private */
22 var board = null;
23
24 /** @type {boolean} @private */
25 var board_is_animating = false;
26
27 /**
28  * The most recent analysis data we have from the server
29  * (about the most recent position).
30  *
31  * @type {?Object}
32  * @private */
33 var current_analysis_data = null;
34
35 /**
36  * If we are displaying previous analysis or from hash, this is non-null,
37  * and will override most of current_analysis_data.
38  *
39  * @type {?Object}
40  * @private
41  */
42 var displayed_analysis_data = null;
43
44 /**
45  * Games currently in progress, if any.
46  *
47  * @type {?Array.<{
48  *      name: string,
49  *      url: string,
50  *      hashurl: string,
51  *      id: string,
52  *      score: Object=,
53  *      result: string=,
54  * }>}
55  * @private
56  */
57 var current_games = null;
58
59 /** @type {Array.<{
60  *      from_col: number,
61  *      from_row: number,
62  *      to_col: number,
63  *      to_row: number,
64  *      line_width: number,
65  *      arrow_size: number,
66  *      fg_color: string
67  * }>}
68  * @private
69  */
70 var arrows = [];
71
72 /** @type {Array.<Array.<boolean>>} */
73 var occupied_by_arrows = [];
74
75 /** Currently displayed refutation lines (on-screen).
76  * Can either come from the current_analysis_data, displayed_analysis_data,
77  * or hash_refutation_lines.
78  */
79 var refutation_lines = [];
80
81 /** Refutation lines from current hash probe.
82  *
83  * If non-null, will override refutation lines from the base position.
84  * Note that these are relative to display_fen, not base_fen.
85  */
86 var hash_refutation_lines = null;
87
88 /** @type {!number} @private */
89 var move_num = 1;
90
91 /** @type {!string} @private */
92 var toplay = 'W';
93
94 /** @type {number} @private */
95 var ims = 0;
96
97 /** @type {boolean} @private */
98 var truncate_display_history = true;
99
100 /** @type {!string|undefined} @private */
101 var highlight_from = undefined;
102
103 /** @type {!string|undefined} @private */
104 var highlight_to = undefined;
105
106 /** The HTML object of the move currently being highlighted (in red).
107  * @type {?Element}
108  * @private */
109 var highlighted_move = null;
110
111 /** Currently suggested/recommended move when dragging.
112  * @type {?{from: !string, to: !string}}
113  * @private
114  */
115 var recommended_move = null;
116
117 /** If reverse-dragging (dragging from the destination square to the
118  * source square), the destination square.
119  * @type {?string}
120  * @private
121  */
122 var reverse_dragging_from = null;
123
124 /** @type {?number} @private */
125 var unique = null;
126
127 /** @type {boolean} @private */
128 var enable_sound = false;
129
130 /** @type {!number} @private */
131 var delay_ms = 0;
132
133 /**
134  * Our best estimate of how many milliseconds we need to add to 
135  * new Date() to get the true UTC time. Calibrated against the
136  * server clock.
137  *
138  * @type {?number}
139  * @private
140  */
141 var client_clock_offset_ms = null;
142
143 var clock_timer = null;
144
145 /** The current position being analyzed, represented as a FEN string.
146  * Note that this is not necessarily the same as display_fen.
147  * @type {?string}
148  * @private
149  */
150 var base_fen = null;
151
152 /** The current position on the board, represented as a FEN string.
153  * Note that board.fen() does not contain e.g. who is to play.
154  * @type {?string}
155  * @private
156  */
157 var display_fen = null;
158
159 /** @typedef {{
160  *    start_fen: string,
161  *    pv: Array.<string>,
162  *    move_num: number,
163  *    toplay: string,
164  *    scores: Array<{first_move: number, score: Object}>,
165  *    start_display_move_num: number
166  * }} DisplayLine
167  *
168  * "start_display_move_num" is the (half-)move number to start displaying the PV at.
169  * "score" is also evaluated at this point.
170  */
171
172 /** All PVs that we currently know of.
173  *
174  * Element 0 is history (or null if no history).
175  * Element 1 is current main PV, or explored line if nowhere else on the screen.
176  * All remaining elements are refutation lines (multi-PV).
177  *
178  * @type {Array.<DisplayLine>}
179  * @private
180  */
181 var display_lines = [];
182
183 /** @type {?DisplayLine} @private */
184 var current_display_line = null;
185
186 /** @type {boolean} @private */
187 var current_display_line_is_history = false;
188
189 /** @type {?number} @private */
190 var current_display_move = null;
191
192 /**
193  * The current backend request to get main analysis (not history), if any,
194  * so that we can abort it.
195  *
196  * @type {?AbortController}
197  * @private
198  */
199 var current_analysis_xhr = null;
200
201 /**
202  * The current timer to fire off a request to get main analysis (not history),
203  * if any, so that we can abort it.
204  *
205  * @type {?Number}
206  * @private
207  */
208 var current_analysis_request_timer = null;
209
210 /**
211  * The current backend request to get historic data, if any.
212  *
213  * @type {?AbortController}
214  * @private
215  */
216 var current_historic_xhr = null;
217
218 /**
219  * The current backend request to get hash probes, if any, so that we can abort it.
220  *
221  * @type {?AbortController}
222  * @private
223  */
224 var current_hash_xhr = null;
225
226 /**
227  * The current timer to display hash probe information (it could be waiting on the
228  * board to stop animating), if any, so that we can abort it.
229  *
230  * @type {?Number}
231  * @private
232  */
233 var current_hash_display_timer = null;
234
235 var supports_html5_storage = function() {
236         try {
237                 return 'localStorage' in window && window['localStorage'] !== null;
238         } catch (e) {
239                 return false;
240         }
241 }
242
243 // Make the unique token persistent so people refreshing the page won't count twice.
244 // Of course, you can never fully protect against people deliberately wanting to spam.
245 var get_unique = function() {
246         var use_local_storage = supports_html5_storage();
247         if (use_local_storage && localStorage['unique']) {
248                 return localStorage['unique'];
249         }
250         var unique = Math.random();
251         if (use_local_storage) {
252                 localStorage['unique'] = unique;
253         }
254         return unique;
255 }
256
257 var request_update = function() {
258         current_analysis_request_timer = null;
259
260         let handle_err = () => {
261                 // Backend error or similar. Wait ten seconds, then try again.
262                 current_analysis_request_timer = setTimeout(function() { request_update(); }, 10000);
263         };
264
265         current_analysis_xhr = new AbortController();
266         const signal = current_analysis_xhr.signal;
267         fetch(backend_url + "?ims=" + ims + "&unique=" + unique, { signal })
268                 .then((response) => response.json().then(data => ({ok: response.ok, headers: response.headers, json: data})))  // ick
269                 .then((obj) => {
270                         if (!obj.ok) {
271                                 handle_err();
272                                 return;
273                         }
274
275                         if (delay_ms === 0) {
276                                 process_update_response(obj.json, obj.headers);
277                         } else {
278                                 setTimeout(function() { process_update_response(obj.json, obj.headers); }, delay_ms);
279                         }
280
281                         // Next update.
282                         if (!backend_url.match(/history/)) {
283                                 var timeout = 100;
284                                 current_analysis_request_timer = setTimeout(function() { request_update(); }, timeout);
285                         }
286                 })
287                 .catch((err) => {
288                         if (err.name === 'AbortError') {
289                                 // Aborted because we are switching backends. Abandon and don't retry,
290                                 // because another one is already started for us.
291                         } else {
292                                 console.log(err);
293                                 handle_err(err);
294                         }
295                 })
296                 .finally(() => {
297                         // Display.
298                         document.body.style.opacity = null;
299                 })
300
301 }
302
303 var process_update_response = function(data, headers) {
304         sync_server_clock(headers.get('Date'));
305         ims = headers.get('X-RGLM');
306         var num_viewers = headers.get('X-RGNV');
307         var new_data;
308         if (Array.isArray(data)) {
309                 new_data = JSON.parse(JSON.stringify(current_analysis_data));
310                 JSON_delta.patch(new_data, data);
311         } else {
312                 new_data = data;
313         }
314
315         var minimum_version = headers.get('X-RGMV');
316         if (minimum_version && minimum_version > SCRIPT_VERSION) {
317                 // Upgrade to latest version with a force-reload.
318                 location.reload(true);
319         }
320
321         // Verify that the PV makes sense.
322         var valid = true;
323         if (new_data['pv']) {
324                 var hiddenboard = new Chess(new_data['position']['fen']);
325                 for (var i = 0; i < new_data['pv'].length; ++i) {
326                         if (hiddenboard.move(new_data['pv'][i]) === null) {
327                                 valid = false;
328                                 break;
329                         }
330                 }
331         }
332
333         if (valid) {
334                 possibly_play_sound(current_analysis_data, new_data);
335                 current_analysis_data = new_data;
336                 update_board();
337                 update_num_viewers(num_viewers);
338         } else {
339                 console.log("Received invalid update, waiting five seconds and trying again.");
340                 setTimeout(function() { location.reload(true); }, 5000);
341         }
342 }
343
344 var possibly_play_sound = function(old_data, new_data) {
345         if (!enable_sound) {
346                 return;
347         }
348         if (old_data === null) {
349                 return;
350         }
351         var ding = document.getElementById('ding');
352         if (ding && ding.play) {
353                 if (old_data['position'] && old_data['position']['fen'] &&
354                     new_data['position'] && new_data['position']['fen'] &&
355                     (old_data['position']['fen'] !== new_data['position']['fen'] ||
356                      old_data['position']['move_num'] !== new_data['position']['move_num'])) {
357                         ding.play();
358                 }
359         }
360 }
361
362 /**
363  * @type {!string} server_date_string
364  */
365 var sync_server_clock = function(server_date_string) {
366         var server_time_ms = new Date(server_date_string).getTime();
367         var client_time_ms = new Date().getTime();
368         var estimated_offset_ms = server_time_ms - client_time_ms;
369
370         // In order not to let the noise move us too much back and forth
371         // (the server only has one-second resolution anyway), we only
372         // change an existing skew if we are at least five seconds off.
373         if (client_clock_offset_ms === null ||
374             Math.abs(estimated_offset_ms - client_clock_offset_ms) > 5000) {
375                 client_clock_offset_ms = estimated_offset_ms;
376         }
377 }
378
379 var clear_arrows = function() {
380         for (var i = 0; i < arrows.length; ++i) {
381                 if (arrows[i].svg) {
382                         if (arrows[i].svg.parentElement) {
383                                 arrows[i].svg.parentElement.removeChild(arrows[i].svg);
384                         }
385                         delete arrows[i].svg;
386                 }
387         }
388         arrows = [];
389
390         occupied_by_arrows = [];
391         for (var y = 0; y < 8; ++y) {
392                 occupied_by_arrows.push([false, false, false, false, false, false, false, false]);
393         }
394 }
395
396 var redraw_arrows = function() {
397         for (var i = 0; i < arrows.length; ++i) {
398                 position_arrow(arrows[i]);
399         }
400 }
401
402 /** @param {!number} x
403  * @return {!number}
404  */
405 var sign = function(x) {
406         if (x > 0) {
407                 return 1;
408         } else if (x < 0) {
409                 return -1;
410         } else {
411                 return 0;
412         }
413 }
414
415 /** See if drawing this arrow on the board would cause unduly amount of confusion.
416  * @param {!string} from The square the arrow is from (e.g. e4).
417  * @param {!string} to The square the arrow is to (e.g. e4).
418  * @return {boolean}
419  */
420 var interfering_arrow = function(from, to) {
421         var from_col = from.charCodeAt(0) - "a1".charCodeAt(0);
422         var from_row = from.charCodeAt(1) - "a1".charCodeAt(1);
423         var to_col   = to.charCodeAt(0) - "a1".charCodeAt(0);
424         var to_row   = to.charCodeAt(1) - "a1".charCodeAt(1);
425
426         occupied_by_arrows[from_row][from_col] = true;
427
428         // Knight move: Just check that we haven't been at the destination before.
429         if ((Math.abs(to_col - from_col) == 2 && Math.abs(to_row - from_row) == 1) ||
430             (Math.abs(to_col - from_col) == 1 && Math.abs(to_row - from_row) == 2)) {
431                 return occupied_by_arrows[to_row][to_col];
432         }
433
434         // Sliding piece: Check if anything except the from-square is seen before.
435         var dx = sign(to_col - from_col);
436         var dy = sign(to_row - from_row);
437         var x = from_col;
438         var y = from_row;
439         do {
440                 x += dx;
441                 y += dy;
442                 if (occupied_by_arrows[y][x]) {
443                         return true;
444                 }
445                 occupied_by_arrows[y][x] = true;
446         } while (x != to_col || y != to_row);
447
448         return false;
449 }
450
451 /** Find a point along the coordinate system given by the given line,
452  * <t> units forward from the start of the line, <u> units to the right of it.
453  * @param {!number} x1
454  * @param {!number} x2
455  * @param {!number} y1
456  * @param {!number} y2
457  * @param {!number} t
458  * @param {!number} u
459  * @return {!string} The point in "x y" form, suitable for SVG paths.
460  */
461 var point_from_start = function(x1, y1, x2, y2, t, u) {
462         var dx = x2 - x1;
463         var dy = y2 - y1;
464
465         var norm = 1.0 / Math.sqrt(dx * dx + dy * dy);
466         dx *= norm;
467         dy *= norm;
468
469         var x = x1 + dx * t + dy * u;
470         var y = y1 + dy * t - dx * u;
471         return x + " " + y;
472 }
473
474 /** Find a point along the coordinate system given by the given line,
475  * <t> units forward from the end of the line, <u> units to the right of it.
476  * @param {!number} x1
477  * @param {!number} x2
478  * @param {!number} y1
479  * @param {!number} y2
480  * @param {!number} t
481  * @param {!number} u
482  * @return {!string} The point in "x y" form, suitable for SVG paths.
483  */
484 var point_from_end = function(x1, y1, x2, y2, t, u) {
485         var dx = x2 - x1;
486         var dy = y2 - y1;
487
488         var norm = 1.0 / Math.sqrt(dx * dx + dy * dy);
489         dx *= norm;
490         dy *= norm;
491
492         var x = x2 + dx * t + dy * u;
493         var y = y2 + dy * t - dx * u;
494         return x + " " + y;
495 }
496
497 var position_arrow = function(arrow) {
498         if (arrow.svg) {
499                 if (arrow.svg.parentElement) {
500                         arrow.svg.parentElement.removeChild(arrow.svg);
501                 }
502                 delete arrow.svg;
503         }
504         if (current_display_line !== null && !current_display_line_is_history) {
505                 return;
506         }
507
508         var zoom_factor = document.getElementById("board").getBoundingClientRect().width / 400.0;
509         var line_width = arrow.line_width * zoom_factor;
510         var arrow_size = arrow.arrow_size * zoom_factor;
511
512         var square_width = document.querySelector(".square-a8").getBoundingClientRect().width;
513         var pos, from_y, to_y, from_x, to_x;
514         if (board.orientation() === 'black') {
515                 pos = document.querySelector(".square-h1").getBoundingClientRect();  // FIXME: margin?
516                 from_y = (arrow.from_row + 0.5)*square_width;
517                 to_y = (arrow.to_row + 0.5)*square_width;
518                 from_x = (7 - arrow.from_col + 0.5)*square_width;
519                 to_x = (7 - arrow.to_col + 0.5)*square_width;
520         } else {
521                 pos = document.querySelector(".square-a8").getBoundingClientRect();  // FIXME: margin?
522                 from_y = (7 - arrow.from_row + 0.5)*square_width;
523                 to_y = (7 - arrow.to_row + 0.5)*square_width;
524                 from_x = (arrow.from_col + 0.5)*square_width;
525                 to_x = (arrow.to_col + 0.5)*square_width;
526         }
527
528         var SVG_NS = "http://www.w3.org/2000/svg";
529         var XHTML_NS = "http://www.w3.org/1999/xhtml";
530         var svg = document.createElementNS(SVG_NS, "svg");
531         svg.setAttribute("width", /** @type{number} */ (document.getElementById("board").getBoundingClientRect().width));
532         svg.setAttribute("height", /** @type{number} */ (document.getElementById("board").getBoundingClientRect().height));
533         svg.setAttribute("style", "position: absolute");
534         svg.setAttribute("position", "absolute");
535         svg.setAttribute("version", "1.1");
536         svg.setAttribute("class", "c1");
537         svg.setAttribute("xmlns", XHTML_NS);
538
539         var x1 = from_x;
540         var y1 = from_y;
541         var x2 = to_x;
542         var y2 = to_y;
543
544         // Draw the line.
545         var outline = document.createElementNS(SVG_NS, "path");
546         outline.setAttribute("d", "M " + point_from_start(x1, y1, x2, y2, arrow_size / 2, 0) + " L " + point_from_end(x1, y1, x2, y2, -arrow_size / 2, 0));
547         outline.setAttribute("xmlns", XHTML_NS);
548         outline.setAttribute("stroke", "#666");
549         outline.setAttribute("stroke-width", line_width + 2);
550         outline.setAttribute("fill", "none");
551         svg.appendChild(outline);
552
553         var path = document.createElementNS(SVG_NS, "path");
554         path.setAttribute("d", "M " + point_from_start(x1, y1, x2, y2, arrow_size / 2, 0) + " L " + point_from_end(x1, y1, x2, y2, -arrow_size / 2, 0));
555         path.setAttribute("xmlns", XHTML_NS);
556         path.setAttribute("stroke", arrow.fg_color);
557         path.setAttribute("stroke-width", line_width);
558         path.setAttribute("fill", "none");
559         svg.appendChild(path);
560
561         // Then the arrow head.
562         var head = document.createElementNS(SVG_NS, "path");
563         head.setAttribute("d",
564                 "M " +  point_from_end(x1, y1, x2, y2, 0, 0) +
565                 " L " + point_from_end(x1, y1, x2, y2, -arrow_size, -arrow_size / 2) +
566                 " L " + point_from_end(x1, y1, x2, y2, -arrow_size * .623, 0.0) +
567                 " L " + point_from_end(x1, y1, x2, y2, -arrow_size, arrow_size / 2) +
568                 " L " + point_from_end(x1, y1, x2, y2, 0, 0));
569         head.setAttribute("xmlns", XHTML_NS);
570         head.setAttribute("stroke", "#000");
571         head.setAttribute("stroke-width", "1");
572         head.setAttribute("fill", arrow.fg_color);
573         svg.appendChild(head);
574
575         svg.style.top = pos.top;
576         svg.style.left = pos.left;
577         svg.style.pointerEvents = 'none';
578         document.body.appendChild(svg);
579         arrow.svg = svg;
580 }
581
582 /**
583  * @param {!string} from_square
584  * @param {!string} to_square
585  * @param {!string} fg_color
586  * @param {number} line_width
587  * @param {number} arrow_size
588  */
589 var create_arrow = function(from_square, to_square, fg_color, line_width, arrow_size) {
590         var from_col = from_square.charCodeAt(0) - "a1".charCodeAt(0);
591         var from_row = from_square.charCodeAt(1) - "a1".charCodeAt(1);
592         var to_col   = to_square.charCodeAt(0) - "a1".charCodeAt(0);
593         var to_row   = to_square.charCodeAt(1) - "a1".charCodeAt(1);
594
595         // Create arrow.
596         var arrow = {
597                 from_col: from_col,
598                 from_row: from_row,
599                 to_col: to_col,
600                 to_row: to_row,
601                 line_width: line_width,
602                 arrow_size: arrow_size,
603                 fg_color: fg_color
604         };
605
606         position_arrow(arrow);
607         arrows.push(arrow);
608 }
609
610 var compare_by_score = function(refutation_lines, invert, a, b) {
611         var sa = compute_score_sort_key(refutation_lines[b]['score'], refutation_lines[b]['depth'], invert);
612         var sb = compute_score_sort_key(refutation_lines[a]['score'], refutation_lines[a]['depth'], invert);
613         return sa - sb;
614 }
615
616 /**
617  * Fake multi-PV using the refutation lines. Find all “relevant” moves,
618  * sorted by quality, descending.
619  *
620  * @param {!Object} data
621  * @param {number} margin The maximum number of centipawns worse than the
622  *     best move can be and still be included.
623  * @param {boolean} invert Whether black is to play.
624  * @return {Array.<string>} The FEN representation (e.g. Ne4) of all
625  *     moves, in score order.
626  */
627 var find_nonstupid_moves = function(data, margin, invert) {
628         // First of all, if there are any moves that are more than 0.5 ahead of
629         // the primary move, the refutation lines are probably bunk, so just
630         // kill them all. 
631         var best_score = undefined;
632         var pv_score = undefined;
633         for (var move in data['refutation_lines']) {
634                 var line = data['refutation_lines'][move];
635                 var score = compute_score_sort_key(line['score'], line['depth'], invert, false);
636                 if (move == data['pv'][0]) {
637                         pv_score = score;
638                 }
639                 if (best_score === undefined || score > best_score) {
640                         best_score = score;
641                 }
642                 if (line['depth'] < 8) {
643                         return [];
644                 }
645         }
646
647         if (best_score - pv_score > 50) {
648                 return [];
649         }
650
651         // Now find all moves that are within “margin” of the best score.
652         // The PV move will always be first.
653         var moves = [];
654         for (var move in data['refutation_lines']) {
655                 var line = data['refutation_lines'][move];
656                 var score = compute_score_sort_key(line['score'], line['depth'], invert);
657                 if (move != data['pv'][0] && best_score - score <= margin) {
658                         moves.push(move);
659                 }
660         }
661         moves = moves.sort(function(a, b) { return compare_by_score(data['refutation_lines'], data['position']['toplay'] === 'B', a, b) });
662         moves.unshift(data['pv'][0]);
663
664         return moves;
665 }
666
667 /**
668  * @param {number} x
669  * @return {!string}
670  */
671 var thousands = function(x) {
672         return String(x).split('').reverse().join('').replace(/(\d{3}\B)/g, '$1,').split('').reverse().join('');
673 }
674
675 /**
676  * @param {!string} start_fen
677  * @param {Array.<string>} pv
678  * @param {number} move_num
679  * @param {!string} toplay
680  * @param {Array<{ first_move: integer, score: Object }>} scores
681  * @param {number} start_display_move_num
682  * @param {number=} opt_limit
683  * @param {boolean=} opt_showlast
684  */
685 var add_pv = function(start_fen, pv, move_num, toplay, scores, start_display_move_num, opt_limit, opt_showlast) {
686         display_lines.push({
687                 start_fen: start_fen,
688                 pv: pv,
689                 move_num: parseInt(move_num),
690                 toplay: toplay,
691                 scores: scores,
692                 start_display_move_num: start_display_move_num
693         });
694         var splicepos = null;
695         if (scores !== null && scores.length >= 1 &&
696             scores[scores.length - 1].score !== undefined &&
697             scores[scores.length - 1].score !== null &&
698             (scores[scores.length - 1].score[0] === 'T' ||
699              scores[scores.length - 1].score[0] === 't')) {
700                 splicepos = scores[scores.length - 1].score[1];
701         }
702         return print_pv(display_lines.length - 1, splicepos, opt_limit, opt_showlast);
703 }
704
705 /**
706  * @param {number} line_num
707  * @param {?number} splicepos If non-null, where the tablebase-spliced portion of the TB starts.
708  * @param {number=} opt_limit If set, show at most this number of moves.
709  * @param {boolean=} opt_showlast If limit is set, show the last moves instead of the first ones.
710  */
711 var print_pv = function(line_num, splicepos, opt_limit, opt_showlast) {
712         var display_line = display_lines[line_num];
713         var pv = display_line.pv;
714         var move_num = display_line.move_num;
715         var toplay = display_line.toplay;
716
717         // Truncate PV at the start if needed.
718         var start_display_move_num = display_line.start_display_move_num;
719         if (start_display_move_num > 0) {
720                 pv = pv.slice(start_display_move_num);
721                 var to_add = start_display_move_num;
722                 if (toplay === 'B') {
723                         ++move_num;
724                         toplay = 'W';
725                         --to_add;
726                 }
727                 if (to_add % 2 == 1) {
728                         toplay = 'B';
729                         --to_add;
730                 }
731                 move_num += to_add / 2;
732                 if (splicepos !== null && splicepos > 0) {
733                         --splicepos;
734                 }
735         }
736
737         var ret = '';
738         var i = 0;
739         var in_tb = false;
740         if (opt_limit && opt_showlast && pv.length > opt_limit) {
741                 // Truncate the PV at the beginning (instead of at the end).
742                 // We assume here that toplay is 'W'. We also assume that if
743                 // opt_showlast is set, then it is the history, and thus,
744                 // the UI should be to expand the history.
745                 ret = '(<a class="move" href="javascript:collapse_history(false)">…</a>) ';
746                 i = pv.length - opt_limit;
747                 if (i % 2 == 1) {
748                         ++i;
749                 }
750                 move_num += i / 2;
751         } else if (toplay == 'B' && pv.length > 0) {
752                 var move = "";
753                 if (splicepos === 0) {
754                         move += "(TB: ";
755                         in_tb = true;
756                 }
757                 move += "<a class=\"move\" id=\"automove" + line_num + "-0\" href=\"javascript:show_line(" + line_num + ", " + 0 + ");\">" + pv[0] + "</a>";
758                 ret = move_num + '. … ' + move;
759                 toplay = 'W';
760                 ++i;
761                 ++move_num;
762         }
763         for ( ; i < pv.length; ++i) {
764                 var move = "<a class=\"move\" id=\"automove" + line_num + "-" + i + "\" href=\"javascript:show_line(" + line_num + ", " + i + ");\">" + pv[i] + "</a>";
765                 if (splicepos === i) {
766                         ret += " (TB: ";
767                         in_tb = true;
768                 }
769
770                 if (toplay == 'W') {
771                         if (i > opt_limit && !opt_showlast) {
772                                 if (in_tb) {
773                                         ret += ")";
774                                 }
775                                 return ret + ' (…)';
776                         }
777                         if (ret != '') {
778                                 ret += ' ';
779                         }
780                         ret += move_num + '. ' + move;
781                         ++move_num;
782                         toplay = 'B';
783                 } else {
784                         ret += ' ' + move;
785                         toplay = 'W';
786                 }
787         }
788         if (in_tb) {
789                 ret += ")";
790         }
791         return ret;
792 }
793
794 /** Update the highlighted to/from squares on the board.
795  * Based on the global "highlight_from" and "highlight_to" variables.
796  */
797 var update_board_highlight = function() {
798         document.getElementById("board").querySelector('.square-55d63').classList.remove('nonuglyhighlight');
799         if ((current_display_line === null || current_display_line_is_history) &&
800             highlight_from !== undefined && highlight_to !== undefined) {
801                 document.getElementById("board").querySelector('.square-' + highlight_from).classList.add('nonuglyhighlight');
802                 document.getElementById("board").querySelector('.square-' + highlight_to).classList.add('nonuglyhighlight');
803         }
804 }
805
806 var update_history = function() {
807         if (display_lines[0] === null || display_lines[0].pv.length == 0) {
808                 document.getElementById("history").innerHTML = "No history";
809         } else if (truncate_display_history) {
810                 document.getElementById("history").innerHTML = print_pv(0, null, 8, true);
811         } else {
812                 document.getElementById("history").innerHTML =
813                         '(<a class="move" href="javascript:collapse_history(true)">collapse</a>) ' +
814                         print_pv(0, null);
815         }
816 }
817
818 /**
819  * @param {!boolean} truncate_history
820  */
821 var collapse_history = function(truncate_history) {
822         truncate_display_history = truncate_history;
823         update_history();
824 }
825 window['collapse_history'] = collapse_history;
826
827 /** Update the HTML display of multi-PV from the global "refutation_lines".
828  *
829  * Also recreates the global "display_lines".
830  */
831 var update_refutation_lines = function() {
832         if (base_fen === null) {
833                 return;
834         }
835         if (display_lines.length > 2) {
836                 // Truncate so that only the history and PV is left.
837                 display_lines = [ display_lines[0], display_lines[1] ];
838         }
839         var tbl = document.getElementById("refutationlines");
840         tbl.replaceChildren();
841
842         if (display_lines.length < 2) {
843                 return;
844         }
845
846         // Find out where the lines start from.
847         var base_line = [];
848         var base_scores = display_lines[1].scores;
849         var start_display_move_num = 0;
850         if (hash_refutation_lines) {
851                 base_line = current_display_line.pv.slice(0, current_display_move + 1);
852                 base_scores = current_display_line.scores;
853                 start_display_move_num = base_line.length;
854         }
855
856         var moves = [];
857         for (var move in refutation_lines) {
858                 moves.push(move);
859         }
860
861         var invert = (toplay === 'B');
862         if (current_display_line && current_display_move % 2 == 0 && !current_display_line_is_history) {
863                 invert = !invert;
864         }
865         moves = moves.sort(function(a, b) { return compare_by_score(refutation_lines, invert, a, b) });
866         for (var i = 0; i < moves.length; ++i) {
867                 var line = refutation_lines[moves[i]];
868
869                 var tr = document.createElement("tr");
870
871                 var move_td = document.createElement("td");
872                 tr.appendChild(move_td);
873                 move_td.classList.add("move");
874
875                 var scores = base_scores.concat([{ first_move: start_display_move_num, score: line['score'] }]);
876
877                 if (line['pv'].length == 0) {
878                         // Not found, so just make a one-move PV.
879                         var move = "<a class=\"move\" href=\"javascript:show_line(" + display_lines.length + ", " + 0 + ");\">" + line['move'] + "</a>";
880                         move_td.innerHTML = move;
881                         var score_td = document.createElement("td");
882
883                         score_td.classList.add("score");
884                         score_td.textContent = "—";
885                         tr.appendChild(score_td);
886
887                         var depth_td = document.createElement("td");
888                         tr.appendChild(depth_td);
889                         depth_td.classList.add("depth");
890                         depth_td.textContent = "—";
891
892                         var pv_td = document.createElement("td");
893                         tr.appendChild(pv_td);
894                         pv_td.classList.add("pv");
895                         pv_td.innerHTML = add_pv(base_fen, base_line.concat([ line['move'] ]), move_num, toplay, scores, start_display_move_num);
896
897                         tbl.append(tr);
898                         continue;
899                 }
900
901                 var move = "<a class=\"move\" href=\"javascript:show_line(" + display_lines.length + ", " + 0 + ");\">" + line['move'] + "</a>";
902                 move_td.innerHTML = move;
903
904                 var score_td = document.createElement("td");
905                 tr.appendChild(score_td);
906                 score_td.classList.add("score");
907                 score_td.textContent = format_short_score(line['score']);
908
909                 var depth_td = document.createElement("td");
910                 tr.appendChild(depth_td);
911                 depth_td.classList.add("depth");
912                 if (line['depth'] && line['depth'] >= 0) {
913                         depth_td.textContent = "d" + line['depth'];
914                 } else {
915                         depth_td.textContent = "—";
916                 }
917
918                 var pv_td = document.createElement("td");
919                 tr.appendChild(pv_td);
920                 pv_td.classList.add("pv");
921                 pv_td.innerHTML = add_pv(base_fen, base_line.concat(line['pv']), move_num, toplay, scores, start_display_move_num, 10);
922
923                 tbl.append(tr);
924         }
925
926         // Update the move highlight, as we've rewritten all the HTML.
927         update_move_highlight();
928 }
929
930 /**
931  * Create a Chess.js board object, containing the given position plus the given moves,
932  * up to the given limit.
933  *
934  * @param {?string} fen
935  * @param {Array.<string>} moves
936  * @param {number} last_move
937  */
938 var chess_from = function(fen, moves, last_move) {
939         var hiddenboard = new Chess();
940         if (fen !== null && fen !== undefined) {
941                 hiddenboard.load(fen);
942         }
943         for (var i = 0; i <= last_move; ++i) {
944                 if (moves[i] === '0-0') {
945                         hiddenboard.move('O-O');
946                 } else if (moves[i] === '0-0-0') {
947                         hiddenboard.move('O-O-O');
948                 } else {
949                         hiddenboard.move(moves[i]);
950                 }
951         }
952         return hiddenboard;
953 }
954
955 var update_game_list = function(games) {
956         document.getElementById("games").textContent = "";
957         if (games === null) {
958                 return;
959         }
960
961         var games_div = document.getElementById('games');
962         for (var game_num = 0; game_num < games.length; ++game_num) {
963                 var game = games[game_num];
964                 var game_span = document.createElement("span");
965                 game_span.setAttribute("class", "game");
966
967                 var game_name = document.createTextNode(game['name']);
968                 if (game['url'] === backend_url) {
969                         // This game.
970                         game_span.appendChild(game_name);
971
972                         if (current_analysis_data && current_analysis_data['position']) {
973                                 var score;
974                                 if (current_analysis_data['position']['result']) {
975                                         score = " (" + current_analysis_data['position']['result'] + ")";
976                                 } else {
977                                         score = " (" + format_short_score(current_analysis_data['score']) + ")";
978                                 }
979                                 game_span.appendChild(document.createTextNode(score));
980                         }
981                 } else {
982                         // Some other game.
983                         var game_a = document.createElement("a");
984                         game_a.setAttribute("href", "#" + game['id']);
985                         game_a.appendChild(game_name);
986                         game_span.appendChild(game_a);
987
988                         var score;
989                         if (game['result']) {
990                                 score = " (" + game['result'] + ")";
991                         } else {
992                                 score = " (" + format_short_score(game['score']) + ")";
993                         }
994                         game_span.appendChild(document.createTextNode(score));
995                 }
996
997                 games_div.appendChild(game_span);
998         }
999 }
1000
1001 /**
1002  * Try to find a running game that matches with the current hash,
1003  * and switch to it if we're not already displaying it.
1004  */
1005 var possibly_switch_game_from_hash = function() {
1006         var history_match = window.location.hash.match(/^#history=([a-zA-Z0-9_-]+)/);
1007         if (history_match !== null) {
1008                 var game_id = history_match[1];
1009                 var fake_game = {
1010                         url: '/history/' + game_id + '.json',
1011                         hashurl: '',
1012                         id: 'history=' + game_id
1013                 };
1014                 switch_backend(fake_game);
1015                 return;
1016         }
1017
1018         if (current_games === null) {
1019                 return;
1020         }
1021
1022         var hash = window.location.hash.replace(/^#/,'');
1023         for (var i = 0; i < current_games.length; ++i) {
1024                 if (current_games[i]['id'] === hash) {
1025                         if (backend_url !== current_games[i]['url']) {
1026                                 switch_backend(current_games[i]);
1027                         }
1028                         return;
1029                 }
1030         }
1031 }
1032
1033 /**
1034  * If this is a Chess960 castling which doesn't move the king,
1035  * move the rook instead.
1036 */
1037 var patch_move = function(move) {
1038         if (move === null) return null;
1039         if (move.from !== move.to) return move;
1040
1041         var f = move.rook_sq & 15;
1042         var r = move.rook_sq >> 4;
1043         var from = ('abcdefgh'.substring(f,f+1) + '87654321'.substring(r,r+1));
1044         var to = move.to;
1045
1046         if (move.to === 'g1') {
1047                 to = 'f1';
1048         } else if (move.to === 'g8') {
1049                 to = 'f8';
1050         } else if (move.to === 'b1') {
1051                 to = 'c1';
1052         } else if (move.to === 'b8') {
1053                 to = 'c8';
1054         }
1055
1056         return { from: from, to: to };
1057 }
1058
1059 /** Update all the HTML on the page, based on current global state.
1060  */
1061 var update_board = function() {
1062         document.body.style.opacity = null;
1063
1064         var data = displayed_analysis_data || current_analysis_data;
1065         var current_data = current_analysis_data;  // Convenience alias.
1066
1067         display_lines = [];
1068
1069         // Print the history. This is pretty much the only thing that's
1070         // unconditionally taken from current_data (we're not interested in
1071         // historic history).
1072         if (current_data['position']['history']) {
1073                 var start = (current_data['position'] && current_data['position']['start_fen']) ? current_data['position']['start_fen'] : 'start';
1074                 add_pv(start, current_data['position']['history'], 1, 'W', null, 0, 8, true);
1075         } else {
1076                 display_lines.push(null);
1077         }
1078         update_history();
1079
1080         // Games currently in progress, if any.
1081         if (current_data['games']) {
1082                 current_games = current_data['games'];
1083                 possibly_switch_game_from_hash();
1084         } else {
1085                 current_games = null;
1086         }
1087         update_game_list(current_games);
1088
1089         // The headline. Names are always fetched from current_data;
1090         // the rest can depend a bit.
1091         var headline;
1092         if (current_data &&
1093             current_data['position']['player_w'] && current_data['position']['player_b']) {
1094                 headline = current_data['position']['player_w'] + '–' +
1095                         current_data['position']['player_b'] + ', analysis';
1096         } else {
1097                 headline = 'Analysis';
1098         }
1099
1100         // Credits, where applicable. Note that we don't want the footer to change a lot
1101         // when e.g. viewing history, so if any of these changed during the game,
1102         // use the current one still.
1103         if (current_data['using_lomonosov']) {
1104                 document.getElementById("lomonosov").style.display = null;
1105         } else {
1106                 document.getElementById("lomonosov").style.display = 'none';
1107         }
1108
1109         // Credits: The engine name/version.
1110         if (current_data['engine'] && current_data['engine']['name'] !== null) {
1111                 document.getElementById("engineid").textContent = current_data['engine']['name'];
1112         }
1113
1114         // Credits: The engine URL.
1115         if (current_data['engine'] && current_data['engine']['url']) {
1116                 document.getElementById("engineid").setAttribute("href", current_data['engine']['url']);
1117         } else {
1118                 document.getElementById("engineid").removeAttribute("href");
1119         }
1120
1121         // Credits: Engine details.
1122         if (current_data['engine'] && current_data['engine']['details']) {
1123                 document.getElementById("enginedetails").textContent = " (" + current_data['engine']['details'] + ")";
1124         } else {
1125                 document.getElementById("enginedetails").textContent = "";
1126         }
1127
1128         // Credits: Move source, possibly with URL.
1129         if (current_data['move_source'] && current_data['move_source_url']) {
1130                 document.getElementById("movesource").textContent = "Moves provided by ";
1131                 var movesource_a = document.createElement("a");
1132                 movesource_a.setAttribute("href", current_data['move_source_url']);
1133                 var movesource_text = document.createTextNode(current_data['move_source']);
1134                 movesource_a.appendChild(movesource_text);
1135                 var movesource_period = document.createTextNode(".");
1136                 document.getElementById("movesource").appendChild(movesource_a);
1137                 document.getElementById("movesource").appendChild(movesource_period);
1138         } else if (current_data['move_source']) {
1139                 document.getElementById("movesource").textContent = "Moves provided by " + current_data['move_source'] + ".";
1140         } else {
1141                 document.getElementById("movesource").textContent = "";
1142         }
1143
1144         var last_move;
1145         if (displayed_analysis_data) {
1146                 // Displaying some non-current position, pick out the last move
1147                 // from the history. This will work even if the fetch failed.
1148                 if (current_display_move !== -1) {
1149                         last_move = format_halfmove_with_number(
1150                                 current_display_line.pv[current_display_move],
1151                                 current_display_move);
1152                         headline += ' after ' + last_move;
1153                 }
1154         } else if (data['position']['last_move'] !== 'none') {
1155                 // Find the previous move.
1156                 var previous_move_num, previous_toplay;
1157                 if (data['position']['toplay'] == 'B') {
1158                         previous_move_num = data['position']['move_num'];
1159                         previous_toplay = 'W';
1160                 } else {
1161                         previous_move_num = data['position']['move_num'] - 1;
1162                         previous_toplay = 'B';
1163                 }
1164
1165                 last_move = format_move_with_number(
1166                         data['position']['last_move'],
1167                         previous_move_num,
1168                         previous_toplay == 'W');
1169                 headline += ' after ' + last_move;
1170         } else {
1171                 last_move = null;
1172         }
1173         document.getElementById("headline").textContent = headline;
1174
1175         // The <title> contains a very brief headline.
1176         var title_elems = [];
1177         if (data['position'] && data['position']['result']) {
1178                 title_elems.push(data['position']['result']);
1179         } else if (data['score']) {
1180                 title_elems.push(format_short_score(data['score']));
1181         }
1182         if (last_move !== null) {
1183                 title_elems.push(last_move);
1184         }
1185
1186         if (title_elems.length != 0) {
1187                 document.title = '(' + title_elems.join(', ') + ') analysis.sesse.net';
1188         } else {
1189                 document.title = 'analysis.sesse.net';
1190         }
1191
1192         // The last move (shown by highlighting the from and to squares).
1193         if (data['position'] && data['position']['last_move_uci']) {
1194                 highlight_from = data['position']['last_move_uci'].substr(0, 2);
1195                 highlight_to = data['position']['last_move_uci'].substr(2, 2);
1196         } else if (current_display_line_is_history && current_display_line && current_display_move >= 0) {
1197                 // We don't have historic analysis for this position, but we
1198                 // can reconstruct what the last move was by just replaying
1199                 // from the start.
1200                 var position = (data['position'] && data['position']['start_fen']) ? data['position']['start_fen'] : null;
1201                 var hiddenboard = chess_from(position, current_display_line.pv, current_display_move);
1202                 var moves = hiddenboard.history({ verbose: true });
1203                 last_move = moves.pop();
1204                 highlight_from = last_move.from;
1205                 highlight_to = last_move.to;
1206         } else {
1207                 highlight_from = highlight_to = undefined;
1208         }
1209         update_board_highlight();
1210
1211         if (data['failed']) {
1212                 document.getElementById("score").textContent = "No analysis for this move";
1213                 document.getElementById("pvtitle").textContent = "PV:";
1214                 document.getElementById("pv").replaceChildren();
1215                 document.getElementById("searchstats").innerHTML = "&nbsp;";
1216                 document.getElementById("refutationlines").replaceChildren();
1217                 document.getElementById("whiteclock").replaceChildren();
1218                 document.getElementById("blackclock").replaceChildren();
1219                 refutation_lines = [];
1220                 update_refutation_lines();
1221                 clear_arrows();
1222                 update_displayed_line();
1223                 update_move_highlight();
1224                 return;
1225         }
1226
1227         update_clock();
1228
1229         // The score.
1230         if (current_display_line && !current_display_line_is_history) {
1231                 var score;
1232                 if (current_display_line.scores && current_display_line.scores.length > 0) {
1233                         for (var i = 0; i < current_display_line.scores.length; ++i) {
1234                                 if (current_display_move < current_display_line.scores[i].first_move) {
1235                                         break;
1236                                 }
1237                                 score = current_display_line.scores[i].score;
1238                         }
1239                 }
1240                 if (score) {
1241                         document.getElementById("score").textContent = format_long_score(score);
1242                 } else {
1243                         document.getElementById("score").textContent = "No score for this line";
1244                 }
1245         } else if (data['score']) {
1246                 document.getElementById("score").textContent = format_long_score(data['score']);
1247         }
1248
1249         // The search stats.
1250         if (data['searchstats']) {
1251                 document.getElementById("searchstats").innerHTML = data['searchstats'];
1252         } else if (data['tablebase'] == 1) {
1253                 document.getElementById("searchstats").textContent = "Tablebase result";
1254         } else if (data['nodes'] && data['nps'] && data['depth']) {
1255                 var stats = thousands(data['nodes']) + ' nodes, ' + thousands(data['nps']) + ' nodes/sec, depth ' + data['depth'] + ' ply';
1256                 if (data['seldepth']) {
1257                         stats += ' (' + data['seldepth'] + ' selective)';
1258                 }
1259                 if (data['tbhits'] && data['tbhits'] > 0) {
1260                         if (data['tbhits'] == 1) {
1261                                 stats += ', one Syzygy hit';
1262                         } else {
1263                                 stats += ', ' + thousands(data['tbhits']) + ' Syzygy hits';
1264                         }
1265                 }
1266
1267                 document.getElementById("searchstats").textContent = stats;
1268         } else {
1269                 document.getElementById("searchstats").textContent = "";
1270         }
1271
1272         // Update the board itself.
1273         base_fen = data['position']['fen'];
1274         update_displayed_line();
1275
1276         // Print the PV.
1277         document.getElementById("pvtitle").textContent = "PV:";
1278
1279         var scores = [{ first_move: -1, score: data['score'] }];
1280         document.getElementById("pv").innerHTML = add_pv(data['position']['fen'], data['pv'], data['position']['move_num'], data['position']['toplay'], scores, 0);
1281
1282         // Update the PV arrow.
1283         clear_arrows();
1284         if (data['pv'].length >= 1) {
1285                 var hiddenboard = new Chess(base_fen);
1286
1287                 // draw a continuation arrow as long as it's the same piece
1288                 var last_to;
1289                 for (var i = 0; i < data['pv'].length; i += 2) {
1290                         var move = patch_move(hiddenboard.move(data['pv'][i]));
1291
1292                         if ((i >= 2 && move.from != last_to) ||
1293                              interfering_arrow(move.from, move.to)) {
1294                                 break;
1295                         }
1296                         create_arrow(move.from, move.to, '#f66', 6, 20);
1297                         last_to = move.to;
1298                         hiddenboard.move(data['pv'][i + 1]);  // To keep continuity.
1299                 }
1300
1301                 var alt_moves = find_nonstupid_moves(data, 30, data['position']['toplay'] === 'B');
1302                 for (var i = 1; i < alt_moves.length && i < 3; ++i) {
1303                         hiddenboard = new Chess(base_fen);
1304                         var move = patch_move(hiddenboard.move(alt_moves[i]));
1305                         if (move !== null) {
1306                                 create_arrow(move.from, move.to, '#f66', 1, 10);
1307                         }
1308                 }
1309         }
1310
1311         // See if all semi-reasonable moves have only one possible response.
1312         if (data['pv'].length >= 2) {
1313                 var nonstupid_moves = find_nonstupid_moves(data, 300, data['position']['toplay'] === 'B');
1314                 var response;
1315                 {
1316                         var hiddenboard = new Chess(base_fen);
1317                         hiddenboard.move(data['pv'][0]);
1318                         response = hiddenboard.move(data['pv'][1]);
1319                 }
1320                 for (var i = 0; i < nonstupid_moves.length; ++i) {
1321                         if (nonstupid_moves[i] == data['pv'][0]) {
1322                                 // ignore the PV move for refutation lines.
1323                                 continue;
1324                         }
1325                         if (!data['refutation_lines'] ||
1326                             !data['refutation_lines'][nonstupid_moves[i]] ||
1327                             !data['refutation_lines'][nonstupid_moves[i]]['pv'] ||
1328                             data['refutation_lines'][nonstupid_moves[i]]['pv'].length < 2) {
1329                                 // Incomplete PV, abort.
1330                                 response = undefined;
1331                                 break;
1332                         }
1333                         var line = data['refutation_lines'][nonstupid_moves[i]];
1334                         hiddenboard = new Chess(base_fen);
1335                         hiddenboard.move(line['pv'][0]);
1336                         var this_response = hiddenboard.move(line['pv'][1]);
1337                         if (this_response === null) {
1338                                 console.log("BUG: ", i);
1339                                 console.log(data);
1340                                 console.log(line['pv']);
1341                         }
1342                         if (response.from !== this_response.from || response.to !== this_response.to) {
1343                                 // Different response depending on lines, abort.
1344                                 response = undefined;
1345                                 break;
1346                         }
1347                 }
1348
1349                 if (nonstupid_moves.length > 0 && response !== undefined) {
1350                         create_arrow(response.from, response.to, '#66f', 6, 20);
1351                 }
1352         }
1353
1354         // Update the refutation lines.
1355         base_fen = data['position']['fen'];
1356         move_num = parseInt(data['position']['move_num']);
1357         toplay = data['position']['toplay'];
1358         refutation_lines = hash_refutation_lines || data['refutation_lines'];
1359         update_refutation_lines();
1360
1361         // Update the sparkline last, since its size depends on how everything else reflowed.
1362         update_sparkline(data);
1363 }
1364
1365 var update_sparkline = function(data) {
1366         if (data && data['score_history']) {
1367                 var first_move_num = undefined;
1368                 for (var halfmove_num in data['score_history']) {
1369                         halfmove_num = parseInt(halfmove_num);
1370                         if (first_move_num === undefined || halfmove_num < first_move_num) {
1371                                 first_move_num = halfmove_num;
1372                         }
1373                 }
1374                 if (first_move_num !== undefined) {
1375                         var last_move_num = data['position']['move_num'] * 2 - 3;
1376                         if (data['position']['toplay'] === 'B') {
1377                                 ++last_move_num;
1378                         }
1379
1380                         // Possibly truncate some moves if we don't have enough width.
1381                         // FIXME: Sometimes width() for #scorecontainer (and by extent,
1382                         // #scoresparkcontainer) on Chrome for mobile seems to start off
1383                         // at something very small, and then suddenly snap back into place.
1384                         // Figure out why.
1385                         var max_moves = Math.floor(document.getElementById("scoresparkcontainer").getBoundingClientRect().width / 5) - 5;
1386                         if (last_move_num - first_move_num > max_moves) {
1387                                 first_move_num = last_move_num - max_moves;
1388                         }
1389
1390                         var min_score = -100;
1391                         var max_score = 100;
1392                         var last_score = null;
1393                         var scores = [];
1394                         for (var halfmove_num = first_move_num; halfmove_num <= last_move_num; ++halfmove_num) {
1395                                 if (data['score_history'][halfmove_num]) {
1396                                         var score = compute_plot_score(data['score_history'][halfmove_num]);
1397                                         last_score = score;
1398                                         if (score < min_score) min_score = score;
1399                                         if (score > max_score) max_score = score;
1400                                 }
1401                                 scores.push(last_score);
1402                         }
1403                         if (data['score']) {
1404                                 scores.push(compute_plot_score(data['score']));
1405                         }
1406                         // FIXME: at some widths, calling sparkline() seems to push
1407                         // #scorecontainer under the board.
1408                         $('#scorespark').unbind('sparklineClick');
1409                         $('#scorespark').sparkline(scores, {
1410                                 type: 'bar',
1411                                 zeroColor: 'gray',
1412                                 chartRangeMin: min_score,
1413                                 chartRangeMax: max_score,
1414                                 tooltipFormatter: function(sparkline, options, fields) {
1415                                         // score_history contains the Nth _position_, but format_tooltip
1416                                         // wants to format the Nth _move_; thus the -1.
1417                                         return format_tooltip(data, fields[0].offset + first_move_num - 1);
1418                                 }
1419                         });
1420                         $('#scorespark').unbind('sparklineClick');
1421                         $('#scorespark').bind('sparklineClick', function(event) {
1422                                 var sparkline = event.sparklines[0];
1423                                 var region = sparkline.getCurrentRegionFields();
1424                                 if (region[0].offset !== undefined) {
1425                                         show_line(0, first_move_num + region[0].offset - 1);
1426                                 }
1427                         });
1428                 } else {
1429                         document.getElementById("scorespark").textContent = "";
1430                 }
1431         } else {
1432                 document.getElementById("scorespark").textContent = "";
1433         }
1434 }
1435
1436 /**
1437  * @param {number} num_viewers
1438  */
1439 var update_num_viewers = function(num_viewers) {
1440         var text = "";
1441         if (num_viewers === null) {
1442                 text = "";
1443         } else if (num_viewers == 1) {
1444                 text = "You are the only current viewer";
1445         } else {
1446                 text = num_viewers + " current viewers";
1447         }
1448         if (display_fen !== null) {
1449                 var counter = Math.floor(display_fen.split(" ")[4] / 2);
1450                 if (counter >= 20) {
1451                         text = text.replace("current ", "");
1452                         text += " | 50-move rule: " + counter;
1453                 }
1454         }
1455         document.getElementById("numviewers").textContent = text;
1456 }
1457
1458 var update_clock = function() {
1459         clearTimeout(clock_timer);
1460
1461         var data = displayed_analysis_data || current_analysis_data;
1462         if (!data) return;
1463
1464         if (data['position']) {
1465                 var result = data['position']['result'];
1466                 if (result === '1-0') {
1467                         document.getElementById("whiteclock").textContent = "1";
1468                         document.getElementById("blackclock").textContent = "0";
1469                         document.getElementById("whiteclock").classList.remove("running-clock");
1470                         document.getElementById("blackclock").classList.remove("running-clock");
1471                         return;
1472                 }
1473                 if (result === '1/2-1/2') {
1474                         document.getElementById("whiteclock").textContent = "1/2";
1475                         document.getElementById("blackclock").textContent = "1/2";
1476                         document.getElementById("whiteclock").classList.remove("running-clock");
1477                         document.getElementById("blackclock").classList.remove("running-clock");
1478                         return;
1479                 }       
1480                 if (result === '0-1') {
1481                         document.getElementById("whiteclock").textContent = "0";
1482                         document.getElementById("blackclock").textContent = "1";
1483                         document.getElementById("whiteclock").classList.remove("running-clock");
1484                         document.getElementById("blackclock").classList.remove("running-clock");
1485                         return;
1486                 }
1487         }
1488
1489         var white_clock_ms = null;
1490         var black_clock_ms = null;
1491
1492         // Static clocks.
1493         if (data['position'] &&
1494             data['position']['white_clock'] &&
1495             data['position']['black_clock']) {
1496                 white_clock_ms = data['position']['white_clock'] * 1000;
1497                 black_clock_ms = data['position']['black_clock'] * 1000;
1498         }
1499
1500         // Dynamic clock (only one, obviously).
1501         var color;
1502         if (data['position']['white_clock_target']) {
1503                 color = "white";
1504                 document.getElementById("whiteclock").classList.add("running-clock");
1505                 document.getElementById("blackclock").classList.remove("running-clock");
1506         } else if (data['position']['black_clock_target']) {
1507                 color = "black";
1508                 document.getElementById("whiteclock").classList.remove("running-clock");
1509                 document.getElementById("blackclock").classList.add("running-clock");
1510         } else {
1511                 document.getElementById("whiteclock").classList.remove("running-clock");
1512                 document.getElementById("blackclock").classList.remove("running-clock");
1513         }
1514         var remaining_ms;
1515         if (color) {
1516                 var now = new Date().getTime() + client_clock_offset_ms;
1517                 remaining_ms = data['position'][color + '_clock_target'] * 1000 - now;
1518                 if (color === "white") {
1519                         white_clock_ms = remaining_ms;
1520                 } else {
1521                         black_clock_ms = remaining_ms;
1522                 }
1523         }
1524
1525         if (white_clock_ms === null || black_clock_ms === null) {
1526                 document.getElementById("whiteclock").replaceChildren();
1527                 document.getElementById("blackclock").replaceChildren();
1528                 return;
1529         }
1530
1531         // If either player has twenty minutes or less left, add the second counters.
1532         // This matches what DGT clocks do.
1533         var show_seconds = (white_clock_ms < 60 * 20 * 1000 || black_clock_ms < 60 * 20 * 1000);
1534
1535         if (color) {
1536                 // See when the clock will change next, and update right after that.
1537                 var next_update_ms;
1538                 if (show_seconds) {
1539                         next_update_ms = remaining_ms % 1000 + 100;
1540                 } else {
1541                         next_update_ms = remaining_ms % 60000 + 100;
1542                 }
1543                 clock_timer = setTimeout(update_clock, next_update_ms);
1544         }
1545
1546         document.getElementById("whiteclock").textContent = format_clock(white_clock_ms, show_seconds);
1547         document.getElementById("blackclock").textContent = format_clock(black_clock_ms, show_seconds);
1548 }
1549
1550 /**
1551  * @param {Number} remaining_ms
1552  * @param {boolean} show_seconds
1553  */
1554 var format_clock = function(remaining_ms, show_seconds) {
1555         if (remaining_ms <= 0) {
1556                 if (show_seconds) {
1557                         return "00:00:00";
1558                 } else {
1559                         return "00:00";
1560                 }
1561         }
1562
1563         var remaining = Math.floor(remaining_ms / 1000);
1564         var seconds = remaining % 60;
1565         remaining = (remaining - seconds) / 60;
1566         var minutes = remaining % 60;
1567         remaining = (remaining - minutes) / 60;
1568         var hours = remaining;
1569         if (show_seconds) {
1570                 return format_2d(hours) + ":" + format_2d(minutes) + ":" + format_2d(seconds);
1571         } else {
1572                 return format_2d(hours) + ":" + format_2d(minutes);
1573         }
1574 }
1575
1576 /**
1577  * @param {Number} x
1578  */
1579 var format_2d = function(x) {
1580         if (x >= 10) {
1581                 return x;
1582         } else {
1583                 return "0" + x;
1584         }
1585 }
1586
1587 /**
1588  * @param {string} move
1589  * @param {Number} move_num Move number of this move.
1590  * @param {boolean} white_to_play Whether white is to play this move.
1591  */
1592 var format_move_with_number = function(move, move_num, white_to_play) {
1593         var ret;
1594         if (white_to_play) {
1595                 ret = move_num + '. ';
1596         } else {
1597                 ret = move_num + '… ';
1598         }
1599         ret += move;
1600         return ret;
1601 }
1602
1603 /**
1604  * @param {string} move
1605  * @param {Number} halfmove_num Half-move number that is to be played,
1606  *   starting from 0.
1607  */
1608 var format_halfmove_with_number = function(move, halfmove_num) {
1609         return format_move_with_number(
1610                 move,
1611                 Math.floor(halfmove_num / 2) + 1,
1612                 halfmove_num % 2 == 0);
1613 }
1614
1615 /**
1616  * @param {Object} data
1617  * @param {Number} halfmove_num
1618  */
1619 var format_tooltip = function(data, halfmove_num) {
1620         if (data['score_history'][halfmove_num + 1] ||
1621             (halfmove_num + 1) === data['position']['history'].length) {
1622                 // Position is in the history, or it is the current position
1623                 // (which is implicitly tacked onto the history).
1624                 var move;
1625                 var short_score;
1626                 if ((halfmove_num + 1) === data['position']['history'].length) {
1627                         move = data['position']['last_move'];
1628                         short_score = format_short_score(data['score']);
1629                 } else {
1630                         move = data['position']['history'][halfmove_num];
1631                         short_score = format_short_score(data['score_history'][halfmove_num + 1]);
1632                 }
1633                 if (halfmove_num === -1) {
1634                         return "Start position: " + short_score;
1635                 } else {
1636                         var move_with_number = format_halfmove_with_number(move, halfmove_num);
1637                         return "After " + move_with_number + ": " + short_score;
1638                 }
1639         } else {
1640                 for (var i = halfmove_num; i --> -1; ) {
1641                         if (data['score_history'][i]) {
1642                                 var move = data['position']['history'][i];
1643                                 if (i === -1) {
1644                                         return "[Analysis kept from start position]";
1645                                 } else {
1646                                         return "[Analysis kept from " + format_halfmove_with_number(move, i) + "]";
1647                                 }
1648                         }
1649                 }
1650         }
1651 }
1652
1653 /**
1654  * @param {boolean} truncate_history
1655  */
1656 var set_truncate_history = function(truncate_history) {
1657         truncate_display_history = truncate_history;
1658         update_refutation_lines();
1659 }
1660 window['set_truncate_history'] = set_truncate_history;
1661
1662 /**
1663  * @param {number} line_num
1664  * @param {number} move_num
1665  */
1666 var show_line = function(line_num, move_num) {
1667         if (line_num == -1) {
1668                 current_display_line = null;
1669                 current_display_move = null;
1670                 hash_refutation_lines = null;
1671                 if (displayed_analysis_data) {
1672                         // TODO: Support exiting to history position if we are in an
1673                         // analysis line of a history position.
1674                         displayed_analysis_data = null;
1675                 }
1676                 update_board();
1677                 return;
1678         } else {
1679                 current_display_line = {...display_lines[line_num]};  // Shallow clone.
1680                 current_display_move = move_num + current_display_line.start_display_move_num;
1681         }
1682         current_display_line_is_history = (line_num == 0);
1683
1684         update_historic_analysis();
1685         update_displayed_line();
1686         update_board_highlight();
1687         update_move_highlight();
1688         redraw_arrows();
1689 }
1690 window['show_line'] = show_line;
1691
1692 var prev_move = function() {
1693         if (current_display_line &&
1694             current_display_move >= current_display_line.start_display_move_num) {
1695                 --current_display_move;
1696         }
1697         update_historic_analysis();
1698         update_displayed_line();
1699         update_move_highlight();
1700 }
1701 window['prev_move'] = prev_move;
1702
1703 var next_move = function() {
1704         if (current_display_line &&
1705             current_display_move < current_display_line.pv.length - 1) {
1706                 ++current_display_move;
1707         }
1708         update_historic_analysis();
1709         update_displayed_line();
1710         update_move_highlight();
1711 }
1712 window['next_move'] = next_move;
1713
1714 var next_game = function() {
1715         if (current_games === null) {
1716                 return;
1717         }
1718
1719         // Try to find the game we are currently looking at.
1720         for (var game_num = 0; game_num < current_games.length; ++game_num) {
1721                 var game = current_games[game_num];
1722                 if (game['url'] === backend_url) {
1723                         var next_game_num = (game_num + 1) % current_games.length;
1724                         switch_backend(current_games[next_game_num]);
1725                         return;
1726                 }
1727         }
1728
1729         // Couldn't find it; give up.
1730 }
1731
1732 var update_historic_analysis = function() {
1733         if (!current_display_line_is_history) {
1734                 return;
1735         }
1736         if (current_display_move == current_display_line.pv.length - 1) {
1737                 displayed_analysis_data = null;
1738                 update_board();
1739         }
1740
1741         // Fetch old analysis for this line if it exists.
1742         var hiddenboard = chess_from(current_display_line.start_fen, current_display_line.pv, current_display_move);
1743         var filename = "/history/move" + (current_display_move + 1) + "-" +
1744                 hiddenboard.fen().replace(/ /g, '_').replace(/\//g, '-') + ".json";
1745
1746         let handle_err = () => {
1747                 displayed_analysis_data = {'failed': true};
1748                 update_board();
1749         };
1750
1751         current_historic_xhr = new AbortController();
1752         const signal = current_analysis_xhr.signal;
1753         fetch(filename, { signal })
1754                 .then((response) => response.json().then(data => ({ok: response.ok, json: data})))  // ick
1755                 .then((obj) => {
1756                         if (!obj.ok) {
1757                                 handle_err();
1758                                 return;
1759                         }
1760                         displayed_analysis_data = obj.json;
1761                         update_board();
1762                 })
1763                 .catch((err) => {
1764                         if (err.name === 'AbortError') {
1765                                 // Aborted because we are switching backends. Abandon and don't retry,
1766                                 // because another one is already started for us.
1767                         } else {
1768                                 console.log(err);
1769                                 handle_err();
1770                         }
1771                 });
1772 }
1773
1774 /**
1775  * @param {string} fen
1776  */
1777 var update_imbalance = function(fen) {
1778         var hiddenboard = new Chess(fen);
1779         var imbalance = {'k': 0, 'q': 0, 'r': 0, 'b': 0, 'n': 0, 'p': 0};
1780         for (var row = 0; row < 8; ++row) {
1781                 for (var col = 0; col < 8; ++col) {
1782                         var col_text = String.fromCharCode('a1'.charCodeAt(0) + col);
1783                         var row_text = String.fromCharCode('a1'.charCodeAt(1) + row);
1784                         var square = col_text + row_text;
1785                         var contents = hiddenboard.get(square);
1786                         if (contents !== null) {
1787                                 if (contents.color === 'w') {
1788                                         ++imbalance[contents.type];
1789                                 } else {
1790                                         --imbalance[contents.type];
1791                                 }
1792                         }
1793                 }
1794         }
1795         var white_imbalance = '';
1796         var black_imbalance = '';
1797         for (var piece in imbalance) {
1798                 for (var i = 0; i < imbalance[piece]; ++i) {
1799                         white_imbalance += '<img src="' + svg_pieces['w' + piece.toUpperCase()] + '" alt="" style="width: 15px;height: 15px;" class="imbalance-piece">';
1800                         white_imbalance += '<img src="' + svg_pieces['b' + piece.toUpperCase()] + '" alt="" style="width: 15px;height: 15px;" class="imbalance-inverted-piece">';
1801                 }
1802                 for (var i = 0; i < -imbalance[piece]; ++i) {
1803                         black_imbalance += '<img src="' + svg_pieces['b' + piece.toUpperCase()] + '" alt="" style="width: 15px;height: 15px;" class="imbalance-piece">';
1804                         black_imbalance += '<img src="' + svg_pieces['w' + piece.toUpperCase()] + '" alt="" style="width: 15px;height: 15px;" class="imbalance-inverted-piece">';
1805                 }
1806         }
1807         document.getElementById('whiteimbalance').innerHTML = white_imbalance;
1808         document.getElementById('blackimbalance').innerHTML = black_imbalance;
1809 }
1810
1811 /** Mark the currently selected move in red.
1812  * Also replaces the PV with the current displayed line if it's not shown
1813  * anywhere else on the screen.
1814  */
1815 var update_move_highlight = function() {
1816         if (highlighted_move !== null) {
1817                 highlighted_move.classList.remove('highlight'); 
1818         }
1819         if (current_display_line) {
1820                 var display_line_num = find_display_line_matching_num();
1821                 if (display_line_num === null) {
1822                         // Replace the PV with the (complete) line.
1823                         document.getElementById("pvtitle").textContent = "Exploring:";
1824                         current_display_line.start_display_move_num = 0;
1825                         display_lines.push(current_display_line);
1826                         document.getElementById("pv").innerHTML = print_pv(display_lines.length - 1, null);  // FIXME
1827                         display_line_num = display_lines.length - 1;
1828
1829                         // Clear out the PV, so it's not selected by anything later.
1830                         display_lines[1].pv = [];
1831                 }
1832
1833                 highlighted_move = document.getElementById("automove" + display_line_num + "-" + (current_display_move - current_display_line.start_display_move_num));
1834                 if (highlighted_move !== null) {
1835                         highlighted_move.classList.add('highlight');
1836                 }
1837         }
1838 }
1839
1840 /**
1841  * See if the current displayed line is identical to any of the ones
1842  * we have on screen. (It might not be if e.g. the analysis reloaded
1843  * since we started looking.)
1844  *
1845  * @return {?number}
1846  */
1847 var find_display_line_matching_num = function() {
1848         for (var i = 0; i < display_lines.length; ++i) {
1849                 var line = display_lines[i];
1850                 if (line.start_display_move_num > 0) continue;
1851                 if (current_display_line.start_fen !== line.start_fen) continue;
1852                 if (current_display_line.pv.length !== line.pv.length) continue;
1853                 var ok = true;
1854                 for (var j = 0; j < line.pv.length; ++j) {
1855                         if (current_display_line.pv[j] !== line.pv[j]) {
1856                                 ok = false;
1857                                 break;
1858                         }
1859                 }
1860                 if (ok) {
1861                         return i;
1862                 }
1863         }
1864         return null;
1865 }
1866
1867 /** Update the board based on the currently displayed line.
1868  * 
1869  * TODO: This should really be called only whenever something changes,
1870  * instead of all the time.
1871  */
1872 var update_displayed_line = function() {
1873         if (current_display_line === null) {
1874                 document.getElementById("linenav").style.display = 'none';
1875                 document.getElementById("linemsg").style.display = 'revert';
1876                 display_fen = base_fen;
1877                 set_board_position(base_fen);
1878                 update_imbalance(base_fen);
1879                 return;
1880         }
1881
1882         document.getElementById("linenav").style.display = 'revert';
1883         document.getElementById("linemsg").style.display = 'none';
1884
1885         if (current_display_move <= 0) {
1886                 document.getElementById("prevmove").innerHTML = "Previous";
1887         } else {
1888                 document.getElementById("prevmove").innerHTML = "<a href=\"javascript:prev_move();\">Previous</a></span>";
1889         }
1890         if (current_display_move == current_display_line.pv.length - 1) {
1891                 document.getElementById("nextmove").innerHTML = "Next";
1892         } else {
1893                 document.getElementById("nextmove").innerHTML = "<a href=\"javascript:next_move();\">Next</a></span>";
1894         }
1895
1896         var hiddenboard = chess_from(current_display_line.start_fen, current_display_line.pv, current_display_move);
1897         set_board_position(hiddenboard.fen());
1898         if (display_fen !== hiddenboard.fen() && !current_display_line_is_history) {
1899                 // Fire off a hash request, since we're now off the main position
1900                 // and it just changed.
1901                 explore_hash(hiddenboard.fen());
1902         }
1903         display_fen = hiddenboard.fen();
1904         update_imbalance(hiddenboard.fen());
1905 }
1906
1907 var set_board_position = function(new_fen) {
1908         board_is_animating = true;
1909         var old_fen = board.fen();
1910         board.position(new_fen);
1911         if (board.fen() === old_fen) {
1912                 board_is_animating = false;
1913         }
1914 }
1915
1916 /**
1917  * @param {boolean} param_enable_sound
1918  */
1919 var set_sound = function(param_enable_sound) {
1920         enable_sound = param_enable_sound;
1921         if (enable_sound) {
1922                 document.getElementById("soundon").innerHTML = "<strong>On</strong>";
1923                 document.getElementById("soundoff").innerHTML = "<a href=\"javascript:set_sound(false)\">Off</a>";
1924
1925                 // Seemingly at least Firefox prefers MP3 over Opus; tell it otherwise,
1926                 // and also preload the file since the user has selected audio.
1927                 var ding = document.getElementById('ding');
1928                 if (ding && ding.canPlayType && ding.canPlayType('audio/ogg; codecs="opus"') === 'probably') {
1929                         ding.src = 'ding.opus';
1930                         ding.load();
1931                 }
1932         } else {
1933                 document.getElementById("soundon").innerHTML = "<a href=\"javascript:set_sound(true)\">On</a>";
1934                 document.getElementById("soundoff").innerHTML = "<strong>Off</strong>";
1935         }
1936         if (supports_html5_storage()) {
1937                 localStorage['enable_sound'] = enable_sound ? 1 : 0;
1938         }
1939 }
1940 window['set_sound'] = set_sound;
1941
1942 /** Send off a hash probe request to the backend.
1943  * @param {string} fen
1944  */
1945 var explore_hash = function(fen) {
1946         // If we already have a backend response going, abort it.
1947         if (current_hash_xhr) {
1948                 current_hash_xhr.abort();
1949         }
1950         if (current_hash_display_timer) {
1951                 clearTimeout(current_hash_display_timer);
1952                 current_hash_display_timer = null;
1953         }
1954         document.getElementById("refutationlines").replaceChildren();
1955
1956         current_hash_xhr = new AbortController();
1957         const signal = current_analysis_xhr.signal;
1958         fetch(backend_hash_url + "?fen=" + fen, { signal })
1959                 .then((response) => response.json())
1960                 .then((data) => { show_explore_hash_results(data, fen); });
1961 }
1962
1963 /** Process the JSON response from a hash probe request.
1964  * @param {!Object} data
1965  * @param {string} fen
1966  */
1967 var show_explore_hash_results = function(data, fen) {
1968         if (board_is_animating) {
1969                 // Updating while the animation is still going causes
1970                 // the animation to jerk. This is pretty crude, but it will do.
1971                 current_hash_display_timer = setTimeout(function() { show_explore_hash_results(data, fen); }, 100);
1972                 return;
1973         }
1974         current_hash_display_timer = null;
1975         hash_refutation_lines = data['lines'];
1976         update_board();
1977 }
1978
1979 // almost all of this stuff comes from the chessboard.js example page
1980 var onDragStart = function(source, piece, position, orientation) {
1981         var pseudogame = new Chess(display_fen);
1982         if (pseudogame.game_over() === true ||
1983             (pseudogame.turn() === 'w' && piece.search(/^b/) !== -1) ||
1984             (pseudogame.turn() === 'b' && piece.search(/^w/) !== -1)) {
1985                 return false;
1986         }
1987
1988         recommended_move = get_best_move(pseudogame, source, null, pseudogame.turn() === 'b');
1989         if (recommended_move) {
1990                 var squareEl = document.querySelector('#board .square-' + recommended_move.to);
1991                 squareEl.classList.add('highlight1-32417');
1992         }
1993         return true;
1994 }
1995
1996 var mousedownSquare = function(e) {
1997         if (!e.target || !e.target.matches('.square-55d63')) {
1998                 return;
1999         }
2000
2001         reverse_dragging_from = null;
2002         var square = e.target.getAttribute('data-square');
2003
2004         var pseudogame = new Chess(display_fen);
2005         if (pseudogame.game_over() === true) {
2006                 return;
2007         }
2008
2009         // If the square is empty, or has a piece of the side not to move,
2010         // we handle it. If not, normal piece dragging will take it.
2011         var position = board.position();
2012         if (!position.hasOwnProperty(square) ||
2013             (pseudogame.turn() === 'w' && position[square].search(/^b/) !== -1) ||
2014             (pseudogame.turn() === 'b' && position[square].search(/^w/) !== -1)) {
2015                 reverse_dragging_from = square;
2016                 recommended_move = get_best_move(pseudogame, null, square, pseudogame.turn() === 'b');
2017                 if (recommended_move) {
2018                         var squareEl = document.querySelector('#board .square-' + recommended_move.from);
2019                         squareEl.classList.add('highlight1-32417');
2020                         squareEl = document.querySelector('#board .square-' + recommended_move.to);
2021                         squareEl.classList.add('highlight1-32417');
2022                 }
2023         }
2024 }
2025
2026 var mouseupSquare = function(e) {
2027         if (!e.target || !e.target.matches('.square-55d63')) {
2028                 return;
2029         }
2030         if (reverse_dragging_from === null) {
2031                 return;
2032         }
2033         var source = e.target.getAttribute('data-square');
2034         var target = reverse_dragging_from;
2035         reverse_dragging_from = null;
2036         if (onDrop(source, target) !== 'snapback') {
2037                 onSnapEnd(source, target);
2038         }
2039         document.getElementById("board").querySelectorAll('.square-55d63.highlight1-32417').forEach((square) => {
2040                 square.classList.remove('highlight1-32417');
2041         });
2042 }
2043
2044 var get_best_move = function(game, source, target, invert) {
2045         var moves = game.moves({ verbose: true });
2046         if (source !== null) {
2047                 moves = moves.filter(function(move) { return move.from == source; });
2048         }
2049         if (target !== null) {
2050                 moves = moves.filter(function(move) { return move.to == target; });
2051         }
2052         if (moves.length == 0) {
2053                 return null;
2054         }
2055         if (moves.length == 1) {
2056                 return moves[0];
2057         }
2058
2059         // More than one move. Use the display lines (if we have them)
2060         // to disambiguate; otherwise, we have no information.
2061         var move_hash = {};
2062         for (var i = 0; i < moves.length; ++i) {
2063                 move_hash[moves[i].san] = moves[i];
2064         }
2065
2066         // See if we're already exploring some line.
2067         if (current_display_line &&
2068             current_display_move < current_display_line.pv.length - 1) {
2069                 var first_move = current_display_line.pv[current_display_move + 1];
2070                 if (move_hash[first_move]) {
2071                         return move_hash[first_move];
2072                 }
2073         }
2074
2075         // History and PV take priority over the display lines.
2076         for (var i = 0; i < 2; ++i) {
2077                 var line = display_lines[i];
2078                 var first_move = line.pv[line.start_display_move_num];
2079                 if (move_hash[first_move]) {
2080                         return move_hash[first_move];
2081                 }
2082         }
2083
2084         var best_move = null;
2085         var best_move_score = null;
2086
2087         for (var move in refutation_lines) {
2088                 var line = refutation_lines[move];
2089                 if (!line['score']) {
2090                         continue;
2091                 }
2092                 var first_move = line['pv'][0];
2093                 if (move_hash[first_move]) {
2094                         var score = compute_score_sort_key(line['score'], line['depth'], invert);
2095                         if (best_move_score === null || score > best_move_score) {
2096                                 best_move = move_hash[first_move];
2097                                 best_move_score = score;
2098                         }
2099                 }
2100         }
2101         return best_move;
2102 }
2103
2104 var onDrop = function(source, target) {
2105         if (source === target) {
2106                 if (recommended_move === null) {
2107                         return 'snapback';
2108                 } else {
2109                         // Accept the move. It will be changed in onSnapEnd.
2110                         return;
2111                 }
2112         } else {
2113                 // Suggestion not asked for.
2114                 recommended_move = null;
2115         }
2116
2117         // see if the move is legal
2118         var pseudogame = new Chess(display_fen);
2119         var move = pseudogame.move({
2120                 from: source,
2121                 to: target,
2122                 promotion: 'q' // NOTE: always promote to a queen for example simplicity
2123         });
2124
2125         // illegal move
2126         if (move === null) return 'snapback';
2127 }
2128
2129 var onSnapEnd = function(source, target) {
2130         if (source === target && recommended_move !== null) {
2131                 source = recommended_move.from;
2132                 target = recommended_move.to;
2133         }
2134         recommended_move = null;
2135         var pseudogame = new Chess(display_fen);
2136         var move = pseudogame.move({
2137                 from: source,
2138                 to: target,
2139                 promotion: 'q' // NOTE: always promote to a queen for example simplicity
2140         });
2141
2142         if (current_display_line &&
2143             current_display_move < current_display_line.pv.length - 1 &&
2144             current_display_line.pv[current_display_move + 1] === move.san) {
2145                 next_move();
2146                 return;
2147         }
2148
2149         // Walk down the displayed lines until we find one that starts with
2150         // this move, then select that. Note that this gives us a good priority
2151         // order (history first, then PV, then multi-PV lines).
2152         for (var i = 0; i < display_lines.length; ++i) {
2153                 if (i == 1 && current_display_line) {
2154                         // Do not choose PV if not on it.
2155                         continue;
2156                 }
2157                 var line = display_lines[i];
2158                 if (line.pv[line.start_display_move_num] === move.san) {
2159                         show_line(i, 0);
2160                         return;
2161                 }
2162         }
2163
2164         // Shouldn't really be here if we have hash probes, but there's really
2165         // nothing we can do.
2166 }
2167 // End of dragging-related code.
2168
2169 var fmt_cp = function(v) {
2170         if (v === 0) {
2171                 return "0.00";
2172         } else if (v > 0) {
2173                 return "+" + (v / 100).toFixed(2);
2174         } else {
2175                 v = -v;
2176                 return "-" + (v / 100).toFixed(2);
2177         }
2178 }
2179
2180 var format_short_score = function(score) {
2181         if (!score) {
2182                 return "???";
2183         }
2184         if (score[0] === 'T' || score[0] === 't') {
2185                 var ret = "TB\u00a0";
2186                 if (score[2]) {  // Is a bound.
2187                         ret = score[2] + "\u00a0TB\u00a0";
2188                 }
2189                 if (score[0] === 'T') {
2190                         return ret + Math.ceil(score[1] / 2);
2191                 } else {
2192                         return ret + "-" + Math.ceil(score[1] / 2);
2193                 }
2194         } else if (score[0] === 'M' || score[0] === 'm') {
2195                 var sign = (score[0] === 'm') ? '-' : '';
2196                 if (score[2]) {  // Is a bound.
2197                         return score[2] + "\u00a0M " + sign + score[1];
2198                 } else {
2199                         return "M " + sign + score[1];
2200                 }
2201         } else if (score[0] === 'd') {
2202                 return "TB =0";
2203         } else if (score[0] === 'cp') {
2204                 if (score[2]) {  // Is a bound.
2205                         return score[2] + "\u00a0" + fmt_cp(score[1]);
2206                 } else {
2207                         return fmt_cp(score[1]);
2208                 }
2209         }
2210         return null;
2211 }
2212
2213 var format_long_score = function(score) {
2214         if (!score) {
2215                 return "???";
2216         }
2217         if (score[0] === 'T') {
2218                 if (score[1] == 0) {
2219                         return "Won for white (tablebase)";
2220                 } else {
2221                         return "White wins in " + Math.ceil(score[1] / 2);
2222                 }
2223         } else if (score[0] === 't') {
2224                 if (score[1] == -1) {
2225                         return "Won for black (tablebase)";
2226                 } else {
2227                         return "Black wins in " + Math.ceil(score[1] / 2);
2228                 }
2229         } else if (score[0] === 'M') {
2230                 if (score[1] == 0) {
2231                         return "White wins by checkmate";
2232                 } else {
2233                         return "White mates in " + score[1];
2234                 }
2235         } else if (score[0] === 'm') {
2236                 if (score[1] == 0) {
2237                         return "Black wins by checkmate";
2238                 } else {
2239                         return "Black mates in " + score[1];
2240                 }
2241         } else if (score[0] === 'd') {
2242                 return "Theoretical draw";
2243         } else if (score[0] === 'cp') {
2244                 return "Score: " + format_short_score(score);
2245         }
2246         return null;
2247 }
2248
2249 var compute_plot_score = function(score) {
2250         if (score[0] === 'M' || score[0] === 'T') {
2251                 return 500;
2252         } else if (score[0] === 'm' || score[0] === 't') {
2253                 return -500;
2254         } else if (score[0] === 'd') {
2255                 return 0;
2256         } else if (score[0] === 'cp') {
2257                 if (score[1] > 500) {
2258                         return 500;
2259                 } else if (score[1] < -500) {
2260                         return -500;
2261                 } else {
2262                         return score[1];
2263                 }
2264         }
2265         return null;
2266 }
2267
2268 /**
2269  * @param score The score digest tuple.
2270  * @param {?number} depth Depth the move has been computed to, or null.
2271  * @param {boolean} invert Whether black is to play.
2272  * @param {boolean=} depth_secondary_key
2273  * @return {number}
2274  */
2275 var compute_score_sort_key = function(score, depth, invert, depth_secondary_key) {
2276         var s;
2277         if (!score) {
2278                 return -10000000;
2279         }
2280         if (score[0] === 'T') {
2281                 // White reaches TB win.
2282                 s = 89999 - score[1];
2283         } else if (score[0] === 't') {
2284                 // Black reaches TB win.
2285                 s = -(89999 - score[1]);
2286         } else if (score[0] === 'M') {
2287                 // White mates.
2288                 s = 99999 - score[1];
2289         } else if (score[0] === 'm') {
2290                 // Black mates.
2291                 s = -(99999 - score[1]);
2292         } else if (score[0] === 'd') {
2293                 s = 0;
2294         } else if (score[0] === 'cp') {
2295                 s = score[1];
2296         }
2297         if (s) {
2298                 if (invert) s = -s;
2299                 if (depth_secondary_key) {
2300                         return s * 200 + (depth || 0);
2301                 } else {
2302                         return s;
2303                 }
2304         } else {
2305                 return null;
2306         }
2307 }
2308
2309 /**
2310  * @param {Object} game
2311  */
2312 var switch_backend = function(game) {
2313         // Stop looking at historic data.
2314         current_display_line = null;
2315         current_display_move = null;
2316         displayed_analysis_data = null;
2317         if (current_historic_xhr) {
2318                 current_historic_xhr.abort();
2319         }
2320
2321         // If we already have a backend response going, abort it.
2322         if (current_analysis_xhr) {
2323                 current_analysis_xhr.abort();
2324         }
2325         if (current_hash_xhr) {
2326                 current_hash_xhr.abort();
2327         }
2328
2329         // Otherwise, we should have a timer going to start a new one.
2330         // Kill that, too.
2331         if (current_analysis_request_timer) {
2332                 clearTimeout(current_analysis_request_timer);
2333                 current_analysis_request_timer = null;
2334         }
2335         if (current_hash_display_timer) {
2336                 clearTimeout(current_hash_display_timer);
2337                 current_hash_display_timer = null;
2338         }
2339
2340         // Request an immediate fetch with the new backend.
2341         backend_url = game['url'];
2342         backend_hash_url = game['hashurl'];
2343         window.location.hash = '#' + game['id'];
2344         current_analysis_data = null;
2345         ims = 0;
2346         request_update();
2347 }
2348 window['switch_backend'] = switch_backend;
2349
2350 window['flip'] = function() { board.flip(); redraw_arrows(); };
2351 window['set_delay_ms'] = function(ms) { delay_ms = ms; console.log('Delay is now ' + ms + ' ms.'); };
2352
2353 // Mostly from Wikipedia's chess set as of October 2022, but some pieces are from
2354 // the 2013 version, as I like those better (and it matches the 2014 PNGs; nobody
2355 // really likes change, do they?). That is wK, bK, bQ. wQ is also slightly different,
2356 // but not enough to notice.
2357 const svg_pieces = {
2358        'wK': 'data:image/svg+xml;base64,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',
2359         'wQ': 'data:image/svg+xml;base64,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',
2360         'wR': 'data:image/svg+xml;base64,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',
2361         'wB': 'data:image/svg+xml;base64,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',
2362         'wN': 'data:image/svg+xml;base64,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',
2363         'wP': 'data:image/svg+xml;base64,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',
2364        'bK': 'data:image/svg+xml;base64,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',
2365         'bQ': 'data:image/svg+xml;base64,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',
2366         'bR': 'data:image/svg+xml;base64,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',
2367         'bB': 'data:image/svg+xml;base64,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',
2368         'bN': 'data:image/svg+xml;base64,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',
2369         'bP': 'data:image/svg+xml;base64,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',
2370 };
2371
2372 var svg_piece_theme = function(piece) {
2373         return svg_pieces[piece];
2374 }
2375
2376 var init = function() {
2377         unique = get_unique();
2378
2379         // Load settings from HTML5 local storage if available.
2380         if (supports_html5_storage() && localStorage['enable_sound']) {
2381                 set_sound(parseInt(localStorage['enable_sound']));
2382         } else {
2383                 set_sound(false);
2384         }
2385
2386         // Create board.
2387         board = new window.ChessBoard('board', {
2388                 onMoveEnd: function() { board_is_animating = false; },
2389
2390                 draggable: true,
2391                 pieceTheme: svg_piece_theme,
2392                 onDragStart: onDragStart,
2393                 onDrop: onDrop,
2394                 onSnapEnd: onSnapEnd
2395         });
2396         document.getElementById("board").addEventListener('mousedown', mousedownSquare);
2397         document.getElementById("board").addEventListener('mouseup', mouseupSquare);
2398
2399         request_update();
2400         window.addEventListener('resize', function() {
2401                 board.resize();
2402                 update_sparkline(displayed_analysis_data || current_analysis_data);
2403                 update_board_highlight();
2404                 redraw_arrows();
2405         });
2406         window.addEventListener('keyup', function(event) {
2407                 if (event.which == 39) {  // Left arrow.
2408                         next_move();
2409                 } else if (event.which == 37) {  // Right arrow.
2410                         prev_move();
2411                 } else if (event.which >= 49 && event.which <= 57) {  // 1-9.
2412                         var num = event.which - 49;
2413                         if (current_games && current_games.length >= num) {
2414                                 switch_backend(current_games[num]);
2415                         }
2416                 } else if (event.which == 78) {  // N.
2417                         next_game();
2418                 }
2419         });
2420         window.addEventListener('hashchange', possibly_switch_game_from_hash, false);
2421         possibly_switch_game_from_hash();
2422 };
2423 document.addEventListener('DOMContentLoaded', init);
2424
2425 })();