git.sesse.net Git - remoteglot/blob - www/js/remoteglot.js

   1 (function() {
   2
   3 /** @type {window.ChessBoard} @private */
   4 var board = null;
   5
   6 /**
   7  * The most recent analysis data we have from the server
   8  * (about the most recent position).
   9  *
  10  * @type {?Object}
  11  * @private */
  12 var current_analysis_data = null;
  13
  14 /**
  15  * If we are displaying previous analysis, this is non-null,
  16  * and will override most of current_analysis_data.
  17  *
  18  * @type {?Object}
  19  * @private
  20  */
  21 var displayed_analysis_data = null;
  22
  23 /** @type {Array.<{
  24  *      from_col: number,
  25  *      from_row: number,
  26  *      to_col: number,
  27  *      to_row: number,
  28  *      line_width: number,
  29  *      arrow_size: number,
  30  *      fg_color: string
  31  * }>}
  32  * @private
  33  */
  34 var arrows = [];
  35
  36 /** @type {Array.<Array.<boolean>>} */
  37 var occupied_by_arrows = [];
  38
  39 var refutation_lines = [];
  40
  41 /** @type {!number} @private */
  42 var move_num = 1;
  43
  44 /** @type {!string} @private */
  45 var toplay = 'W';
  46
  47 /** @type {number} @private */
  48 var ims = 0;
  49
  50 /** @type {boolean} @private */
  51 var sort_refutation_lines_by_score = true;
  52
  53 /** @type {boolean} @private */
  54 var truncate_display_history = true;
  55
  56 /** @type {!string|undefined} @private */
  57 var highlight_from = undefined;
  58
  59 /** @type {!string|undefined} @private */
  60 var highlight_to = undefined;
  61
  62 /** @type {?jQuery} @private */
  63 var highlighted_move = null;
  64
  65 /** @type {?number} @private */
  66 var unique = null;
  67
  68 /** @type {boolean} @private */
  69 var enable_sound = false;
  70
  71 /**
  72  * Our best estimate of how many milliseconds we need to add to
  73  * new Date() to get the true UTC time. Calibrated against the
  74  * server clock.
  75  *
  76  * @type {?number}
  77  * @private
  78  */
  79 var client_clock_offset_ms = null;
  80
  81 var clock_timer = null;
  82
  83 /** The current position on the board, represented as a FEN string.
  84  * @type {?string}
  85  * @private
  86  */
  87 var fen = null;
  88
  89 /** @typedef {{
  90  *    start_fen: string,
  91  *    uci_pv: Array.<string>,
  92  *    pretty_pv: Array.<string>,
  93  *    line_num: number
  94  * }} DisplayLine
  95  */
  96
  97 /** @type {Array.<DisplayLine>}
  98  * @private
  99  */
 100 var display_lines = [];
 101
 102 /** @type {?DisplayLine} @private */
 103 var current_display_line = null;
 104
 105 /** @type {boolean} @private */
 106 var current_display_line_is_history = false;
 107
 108 /** @type {?number} @private */
 109 var current_display_move = null;
 110
 111 var supports_html5_storage = function() {
 112         try {
 113                 return 'localStorage' in window && window['localStorage'] !== null;
 114         } catch (e) {
 115                 return false;
 116         }
 117 }
 118
 119 // Make the unique token persistent so people refreshing the page won't count twice.
 120 // Of course, you can never fully protect against people deliberately wanting to spam.
 121 var get_unique = function() {
 122         var use_local_storage = supports_html5_storage();
 123         if (use_local_storage && localStorage['unique']) {
 124                 return localStorage['unique'];
 125         }
 126         var unique = Math.random();
 127         if (use_local_storage) {
 128                 localStorage['unique'] = unique;
 129         }
 130         return unique;
 131 }
 132
 133 var request_update = function() {
 134         $.ajax({
 135                 url: "/analysis.pl?ims=" + ims + "&unique=" + unique
 136         }).done(function(data, textstatus, xhr) {
 137                 sync_server_clock(xhr.getResponseHeader('Date'));
 138                 ims = xhr.getResponseHeader('X-Remoteglot-Last-Modified');
 139                 var num_viewers = xhr.getResponseHeader('X-Remoteglot-Num-Viewers');
 140                 possibly_play_sound(current_analysis_data, data);
 141                 if (Array.isArray(data)) {
 142                         current_analysis_data = JSON_delta.patch(current_analysis_data, data);
 143                 } else {
 144                         current_analysis_data = data;
 145                 }
 146                 update_board(current_analysis_data, displayed_analysis_data);
 147                 update_num_viewers(num_viewers);
 148
 149                 // Next update.
 150                 setTimeout(function() { request_update(); }, 100);
 151         }).fail(function() {
 152                 // Wait ten seconds, then try again.
 153                 setTimeout(function() { request_update(); }, 10000);
 154         });
 155 }
 156
 157 var possibly_play_sound = function(old_data, new_data) {
 158         if (!enable_sound) {
 159                 return;
 160         }
 161         if (old_data === null) {
 162                 return;
 163         }
 164         var ding = document.getElementById('ding');
 165         if (ding && ding.play) {
 166                 if (old_data['position'] && old_data['position']['fen'] &&
 167                     new_data['position'] && new_data['position']['fen'] &&
 168                     (old_data['position']['fen'] !== new_data['position']['fen'] ||
 169                      old_data['position']['move_num'] !== new_data['position']['move_num'])) {
 170                         ding.play();
 171                 }
 172         }
 173 }
 174
 175 /**
 176  * @type {!string} server_date_string
 177  */
 178 var sync_server_clock = function(server_date_string) {
 179         var server_time_ms = new Date(server_date_string).getTime();
 180         var client_time_ms = new Date().getTime();
 181         var estimated_offset_ms = server_time_ms - client_time_ms;
 182
 183         // In order not to let the noise move us too much back and forth
 184         // (the server only has one-second resolution anyway), we only
 185         // change an existing skew if we are at least five seconds off.
 186         if (client_clock_offset_ms === null ||
 187             Math.abs(estimated_offset_ms - client_clock_offset_ms) > 5000) {
 188                 client_clock_offset_ms = estimated_offset_ms;
 189         }
 190 }
 191
 192 var clear_arrows = function() {
 193         for (var i = 0; i < arrows.length; ++i) {
 194                 if (arrows[i].svg) {
 195                         arrows[i].svg.parentElement.removeChild(arrows[i].svg);
 196                         delete arrows[i].svg;
 197                 }
 198         }
 199         arrows = [];
 200
 201         occupied_by_arrows = [];
 202         for (var y = 0; y < 8; ++y) {
 203                 occupied_by_arrows.push([false, false, false, false, false, false, false, false]);
 204         }
 205 }
 206
 207 var redraw_arrows = function() {
 208         for (var i = 0; i < arrows.length; ++i) {
 209                 position_arrow(arrows[i]);
 210         }
 211 }
 212
 213 /** @param {!number} x
 214  * @return {!number}
 215  */
 216 var sign = function(x) {
 217         if (x > 0) {
 218                 return 1;
 219         } else if (x < 0) {
 220                 return -1;
 221         } else {
 222                 return 0;
 223         }
 224 }
 225
 226 /** See if drawing this arrow on the board would cause unduly amount of confusion.
 227  * @param {!string} from The square the arrow is from (e.g. e4).
 228  * @param {!string} to The square the arrow is to (e.g. e4).
 229  * @return {boolean}
 230  */
 231 var interfering_arrow = function(from, to) {
 232         var from_col = from.charCodeAt(0) - "a1".charCodeAt(0);
 233         var from_row = from.charCodeAt(1) - "a1".charCodeAt(1);
 234         var to_col   = to.charCodeAt(0) - "a1".charCodeAt(0);
 235         var to_row   = to.charCodeAt(1) - "a1".charCodeAt(1);
 236
 237         occupied_by_arrows[from_row][from_col] = true;
 238
 239         // Knight move: Just check that we haven't been at the destination before.
 240         if ((Math.abs(to_col - from_col) == 2 && Math.abs(to_row - from_row) == 1) ||
 241             (Math.abs(to_col - from_col) == 1 && Math.abs(to_row - from_row) == 2)) {
 242                 return occupied_by_arrows[to_row][to_col];
 243         }
 244
 245         // Sliding piece: Check if anything except the from-square is seen before.
 246         var dx = sign(to_col - from_col);
 247         var dy = sign(to_row - from_row);
 248         var x = from_col;
 249         var y = from_row;
 250         do {
 251                 x += dx;
 252                 y += dy;
 253                 if (occupied_by_arrows[y][x]) {
 254                         return true;
 255                 }
 256                 occupied_by_arrows[y][x] = true;
 257         } while (x != to_col || y != to_row);
 258
 259         return false;
 260 }
 261
 262 /** Find a point along the coordinate system given by the given line,
 263  * <t> units forward from the start of the line, <u> units to the right of it.
 264  * @param {!number} x1
 265  * @param {!number} x2
 266  * @param {!number} y1
 267  * @param {!number} y2
 268  * @param {!number} t
 269  * @param {!number} u
 270  * @return {!string} The point in "x y" form, suitable for SVG paths.
 271  */
 272 var point_from_start = function(x1, y1, x2, y2, t, u) {
 273         var dx = x2 - x1;
 274         var dy = y2 - y1;
 275
 276         var norm = 1.0 / Math.sqrt(dx * dx + dy * dy);
 277         dx *= norm;
 278         dy *= norm;
 279
 280         var x = x1 + dx * t + dy * u;
 281         var y = y1 + dy * t - dx * u;
 282         return x + " " + y;
 283 }
 284
 285 /** Find a point along the coordinate system given by the given line,
 286  * <t> units forward from the end of the line, <u> units to the right of it.
 287  * @param {!number} x1
 288  * @param {!number} x2
 289  * @param {!number} y1
 290  * @param {!number} y2
 291  * @param {!number} t
 292  * @param {!number} u
 293  * @return {!string} The point in "x y" form, suitable for SVG paths.
 294  */
 295 var point_from_end = function(x1, y1, x2, y2, t, u) {
 296         var dx = x2 - x1;
 297         var dy = y2 - y1;
 298
 299         var norm = 1.0 / Math.sqrt(dx * dx + dy * dy);
 300         dx *= norm;
 301         dy *= norm;
 302
 303         var x = x2 + dx * t + dy * u;
 304         var y = y2 + dy * t - dx * u;
 305         return x + " " + y;
 306 }
 307
 308 var position_arrow = function(arrow) {
 309         if (arrow.svg) {
 310                 arrow.svg.parentElement.removeChild(arrow.svg);
 311                 delete arrow.svg;
 312         }
 313         if (current_display_line !== null && !current_display_line_is_history) {
 314                 return;
 315         }
 316
 317         var pos = $(".square-a8").position();
 318
 319         var zoom_factor = $("#board").width() / 400.0;
 320         var line_width = arrow.line_width * zoom_factor;
 321         var arrow_size = arrow.arrow_size * zoom_factor;
 322
 323         var square_width = $(".square-a8").width();
 324         var from_y = (7 - arrow.from_row + 0.5)*square_width;
 325         var to_y = (7 - arrow.to_row + 0.5)*square_width;
 326         var from_x = (arrow.from_col + 0.5)*square_width;
 327         var to_x = (arrow.to_col + 0.5)*square_width;
 328
 329         var SVG_NS = "http://www.w3.org/2000/svg";
 330         var XHTML_NS = "http://www.w3.org/1999/xhtml";
 331         var svg = document.createElementNS(SVG_NS, "svg");
 332         svg.setAttribute("width", /** @type{number} */ ($("#board").width()));
 333         svg.setAttribute("height", /** @type{number} */ ($("#board").height()));
 334         svg.setAttribute("style", "position: absolute");
 335         svg.setAttribute("position", "absolute");
 336         svg.setAttribute("version", "1.1");
 337         svg.setAttribute("class", "c1");
 338         svg.setAttribute("xmlns", XHTML_NS);
 339
 340         var x1 = from_x;
 341         var y1 = from_y;
 342         var x2 = to_x;
 343         var y2 = to_y;
 344
 345         // Draw the line.
 346         var outline = document.createElementNS(SVG_NS, "path");
 347         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));
 348         outline.setAttribute("xmlns", XHTML_NS);
 349         outline.setAttribute("stroke", "#666");
 350         outline.setAttribute("stroke-width", line_width + 2);
 351         outline.setAttribute("fill", "none");
 352         svg.appendChild(outline);
 353
 354         var path = document.createElementNS(SVG_NS, "path");
 355         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));
 356         path.setAttribute("xmlns", XHTML_NS);
 357         path.setAttribute("stroke", arrow.fg_color);
 358         path.setAttribute("stroke-width", line_width);
 359         path.setAttribute("fill", "none");
 360         svg.appendChild(path);
 361
 362         // Then the arrow head.
 363         var head = document.createElementNS(SVG_NS, "path");
 364         head.setAttribute("d",
 365                 "M " +  point_from_end(x1, y1, x2, y2, 0, 0) +
 366                 " L " + point_from_end(x1, y1, x2, y2, -arrow_size, -arrow_size / 2) +
 367                 " L " + point_from_end(x1, y1, x2, y2, -arrow_size * .623, 0.0) +
 368                 " L " + point_from_end(x1, y1, x2, y2, -arrow_size, arrow_size / 2) +
 369                 " L " + point_from_end(x1, y1, x2, y2, 0, 0));
 370         head.setAttribute("xmlns", XHTML_NS);
 371         head.setAttribute("stroke", "#000");
 372         head.setAttribute("stroke-width", "1");
 373         head.setAttribute("fill", arrow.fg_color);
 374         svg.appendChild(head);
 375
 376         $(svg).css({ top: pos.top, left: pos.left });
 377         document.body.appendChild(svg);
 378         arrow.svg = svg;
 379 }
 380
 381 /**
 382  * @param {!string} from_square
 383  * @param {!string} to_square
 384  * @param {!string} fg_color
 385  * @param {number} line_width
 386  * @param {number} arrow_size
 387  */
 388 var create_arrow = function(from_square, to_square, fg_color, line_width, arrow_size) {
 389         var from_col = from_square.charCodeAt(0) - "a1".charCodeAt(0);
 390         var from_row = from_square.charCodeAt(1) - "a1".charCodeAt(1);
 391         var to_col   = to_square.charCodeAt(0) - "a1".charCodeAt(0);
 392         var to_row   = to_square.charCodeAt(1) - "a1".charCodeAt(1);
 393
 394         // Create arrow.
 395         var arrow = {
 396                 from_col: from_col,
 397                 from_row: from_row,
 398                 to_col: to_col,
 399                 to_row: to_row,
 400                 line_width: line_width,
 401                 arrow_size: arrow_size,
 402                 fg_color: fg_color
 403         };
 404
 405         position_arrow(arrow);
 406         arrows.push(arrow);
 407 }
 408
 409 var compare_by_sort_key = function(refutation_lines, a, b) {
 410         var ska = refutation_lines[a]['sort_key'];
 411         var skb = refutation_lines[b]['sort_key'];
 412         if (ska < skb) return -1;
 413         if (ska > skb) return 1;
 414         return 0;
 415 };
 416
 417 var compare_by_score = function(refutation_lines, a, b) {
 418         var sa = parseInt(refutation_lines[b]['score_sort_key'], 10);
 419         var sb = parseInt(refutation_lines[a]['score_sort_key'], 10);
 420         return sa - sb;
 421 }
 422
 423 /**
 424  * Fake multi-PV using the refutation lines. Find all “relevant” moves,
 425  * sorted by quality, descending.
 426  *
 427  * @param {!Object} data
 428  * @param {number} margin The maximum number of centipawns worse than the
 429  *     best move can be and still be included.
 430  * @return {Array.<string>} The UCI representation (e.g. e1g1) of all
 431  *     moves, in score order.
 432  */
 433 var find_nonstupid_moves = function(data, margin) {
 434         // First of all, if there are any moves that are more than 0.5 ahead of
 435         // the primary move, the refutation lines are probably bunk, so just
 436         // kill them all.
 437         var best_score = undefined;
 438         var pv_score = undefined;
 439         for (var move in data['refutation_lines']) {
 440                 var score = parseInt(data['refutation_lines'][move]['score_sort_key'], 10);
 441                 if (move == data['pv_uci'][0]) {
 442                         pv_score = score;
 443                 }
 444                 if (best_score === undefined || score > best_score) {
 445                         best_score = score;
 446                 }
 447                 if (!(data['refutation_lines'][move]['depth'] >= 8)) {
 448                         return [];
 449                 }
 450         }
 451
 452         if (best_score - pv_score > 50) {
 453                 return [];
 454         }
 455
 456         // Now find all moves that are within “margin” of the best score.
 457         // The PV move will always be first.
 458         var moves = [];
 459         for (var move in data['refutation_lines']) {
 460                 var score = parseInt(data['refutation_lines'][move]['score_sort_key'], 10);
 461                 if (move != data['pv_uci'][0] && best_score - score <= margin) {
 462                         moves.push(move);
 463                 }
 464         }
 465         moves = moves.sort(function(a, b) { return compare_by_score(data['refutation_lines'], a, b) });
 466         moves.unshift(data['pv_uci'][0]);
 467
 468         return moves;
 469 }
 470
 471 /**
 472  * @param {number} x
 473  * @return {!string}
 474  */
 475 var thousands = function(x) {
 476         return String(x).split('').reverse().join('').replace(/(\d{3}\B)/g, '$1,').split('').reverse().join('');
 477 }
 478
 479 /**
 480  * @param {!string} fen
 481  * @param {Array.<string>} pretty_pv
 482  * @param {number} move_num
 483  * @param {!string} toplay
 484  * @param {number=} opt_limit
 485  * @param {boolean=} opt_showlast
 486  */
 487 var add_pv = function(fen, pretty_pv, move_num, toplay, opt_limit, opt_showlast) {
 488         display_lines.push({
 489                 start_fen: fen,
 490                 pretty_pv: pretty_pv,
 491                 line_number: display_lines.length
 492         });
 493         return print_pv(display_lines.length - 1, pretty_pv, move_num, toplay, opt_limit, opt_showlast);
 494 }
 495
 496 /**
 497  * @param {number} line_num
 498  * @param {Array.<string>} pretty_pv
 499  * @param {number} move_num
 500  * @param {!string} toplay
 501  * @param {number=} opt_limit
 502  * @param {boolean=} opt_showlast
 503  */
 504 var print_pv = function(line_num, pretty_pv, move_num, toplay, opt_limit, opt_showlast) {
 505         var pv = '';
 506         var i = 0;
 507         if (opt_limit && opt_showlast && pretty_pv.length > opt_limit) {
 508                 // Truncate the PV at the beginning (instead of at the end).
 509                 // We assume here that toplay is 'W'. We also assume that if
 510                 // opt_showlast is set, then it is the history, and thus,
 511                 // the UI should be to expand the history.
 512                 pv = '(<a class="move" href="javascript:collapse_history(false)">…</a>) ';
 513                 i = pretty_pv.length - opt_limit;
 514                 if (i % 2 == 1) {
 515                         ++i;
 516                 }
 517                 move_num += i / 2;
 518         } else if (toplay == 'B' && pretty_pv.length > 0) {
 519                 var move = "<a class=\"move\" id=\"automove" + line_num + "-0\" href=\"javascript:show_line(" + line_num + ", " + 0 + ");\">" + pretty_pv[0] + "</a>";
 520                 pv = move_num + '. … ' + move;
 521                 toplay = 'W';
 522                 ++i;
 523                 ++move_num;
 524         }
 525         for ( ; i < pretty_pv.length; ++i) {
 526                 var move = "<a class=\"move\" id=\"automove" + line_num + "-" + i + "\" href=\"javascript:show_line(" + line_num + ", " + i + ");\">" + pretty_pv[i] + "</a>";
 527
 528                 if (toplay == 'W') {
 529                         if (i > opt_limit && !opt_showlast) {
 530                                 return pv + ' (…)';
 531                         }
 532                         if (pv != '') {
 533                                 pv += ' ';
 534                         }
 535                         pv += move_num + '. ' + move;
 536                         ++move_num;
 537                         toplay = 'B';
 538                 } else {
 539                         pv += ' ' + move;
 540                         toplay = 'W';
 541                 }
 542         }
 543         return pv;
 544 }
 545
 546 var update_highlight = function() {
 547         $("#board").find('.square-55d63').removeClass('nonuglyhighlight');
 548         if ((current_display_line === null || current_display_line_is_history) &&
 549             highlight_from !== undefined && highlight_to !== undefined) {
 550                 $("#board").find('.square-' + highlight_from).addClass('nonuglyhighlight');
 551                 $("#board").find('.square-' + highlight_to).addClass('nonuglyhighlight');
 552         }
 553 }
 554
 555 var update_history = function() {
 556         if (display_lines[0] === null || display_lines[0].pretty_pv.length == 0) {
 557                 $("#history").html("No history");
 558         } else if (truncate_display_history) {
 559                 $("#history").html(print_pv(0, display_lines[0].pretty_pv, 1, 'W', 8, true));
 560         } else {
 561                 $("#history").html(
 562                         '(<a class="move" href="javascript:collapse_history(true)">collapse</a>) ' +
 563                         print_pv(0, display_lines[0].pretty_pv, 1, 'W'));
 564         }
 565 }
 566
 567 /**
 568  * @param {!boolean} truncate_history
 569  */
 570 var collapse_history = function(truncate_history) {
 571         truncate_display_history = truncate_history;
 572         update_history();
 573 }
 574 window['collapse_history'] = collapse_history;
 575
 576 var update_refutation_lines = function() {
 577         if (fen === null) {
 578                 return;
 579         }
 580         if (display_lines.length > 2) {
 581                 display_lines = [ display_lines[0], display_lines[1] ];
 582         }
 583
 584         var tbl = $("#refutationlines");
 585         tbl.empty();
 586
 587         var moves = [];
 588         for (var move in refutation_lines) {
 589                 moves.push(move);
 590         }
 591         var compare = sort_refutation_lines_by_score ? compare_by_score : compare_by_sort_key;
 592         moves = moves.sort(function(a, b) { return compare(refutation_lines, a, b) });
 593         for (var i = 0; i < moves.length; ++i) {
 594                 var line = refutation_lines[moves[i]];
 595
 596                 var tr = document.createElement("tr");
 597
 598                 var move_td = document.createElement("td");
 599                 tr.appendChild(move_td);
 600                 $(move_td).addClass("move");
 601                 if (line['pv_pretty'].length == 0) {
 602                         $(move_td).text(line['pretty_move']);
 603                 } else {
 604                         var move = "<a class=\"move\" href=\"javascript:show_line(" + display_lines.length + ", " + 0 + ");\">" + line['pretty_move'] + "</a>";
 605                         $(move_td).html(move);
 606                 }
 607
 608                 var score_td = document.createElement("td");
 609                 tr.appendChild(score_td);
 610                 $(score_td).addClass("score");
 611                 $(score_td).text(line['pretty_score']);
 612
 613                 var depth_td = document.createElement("td");
 614                 tr.appendChild(depth_td);
 615                 $(depth_td).addClass("depth");
 616                 $(depth_td).text("d" + line['depth']);
 617
 618                 var pv_td = document.createElement("td");
 619                 tr.appendChild(pv_td);
 620                 $(pv_td).addClass("pv");
 621                 $(pv_td).html(add_pv(fen, line['pv_pretty'], move_num, toplay, 10));
 622
 623                 tbl.append(tr);
 624         }
 625
 626         // Make one of the links clickable and the other nonclickable.
 627         if (sort_refutation_lines_by_score) {
 628                 $("#sortbyscore0").html("<a href=\"javascript:resort_refutation_lines(false)\">Move</a>");
 629                 $("#sortbyscore1").html("<strong>Score</strong>");
 630         } else {
 631                 $("#sortbyscore0").html("<strong>Move</strong>");
 632                 $("#sortbyscore1").html("<a href=\"javascript:resort_refutation_lines(true)\">Score</a>");
 633         }
 634 }
 635
 636 /**
 637  * @param {Object} data
 638  * @param {?Object} display_data
 639  */
 640 var update_board = function(current_data, display_data) {
 641         var data = display_data || current_data;
 642
 643         display_lines = [];
 644
 645         // Print the history. This is pretty much the only thing that's
 646         // unconditionally taken from current_data (we're not interested in
 647         // historic history).
 648         if (current_data['position']['pretty_history']) {
 649                 add_pv('start', current_data['position']['pretty_history'], 1, 'W', 8, true);
 650         } else {
 651                 display_lines.push(null);
 652         }
 653         update_history();
 654
 655         // The headline. Names are always fetched from current_data;
 656         // the rest can depend a bit.
 657         var headline;
 658         if (current_data &&
 659             current_data['position']['player_w'] && current_data['position']['player_b']) {
 660                 headline = current_data['position']['player_w'] + '–' +
 661                         current_data['position']['player_b'] + ', analysis';
 662         } else {
 663                 headline = 'Analysis';
 664         }
 665
 666         var last_move;
 667         if (display_data) {
 668                 // Displaying some non-current position, pick out the last move
 669                 // from the history. This will work even if the fetch failed.
 670                 last_move = format_move_with_number(
 671                         current_display_line.pretty_pv[current_display_move],
 672                         Math.floor((current_display_move + 1) / 2) + 1,
 673                         (current_display_move % 2 == 1));
 674                 headline += ' after ' + last_move;
 675         } else if (data['position']['last_move'] !== 'none') {
 676                 last_move = format_move_with_number(
 677                         data['position']['last_move'],
 678                         data['position']['move_num'],
 679                         data['position']['toplay'] == 'W');
 680                 headline += ' after ' + last_move;
 681         } else {
 682                 last_move = null;
 683         }
 684         $("#headline").text(headline);
 685
 686         // The <title> contains a very brief headline.
 687         var title_elems = [];
 688         if (data['short_score'] !== undefined && data['short_score'] !== null) {
 689                 title_elems.push(data['short_score'].replace(/^ /, ""));
 690         }
 691         if (last_move !== null) {
 692                 title_elems.push(last_move);
 693         }
 694
 695         if (title_elems.length != 0) {
 696                 document.title = '(' + title_elems.join(', ') + ') analysis.sesse.net';
 697         } else {
 698                 document.title = 'analysis.sesse.net';
 699         }
 700
 701         // The last move (shown by highlighting the from and to squares).
 702         if (data['position'] && data['position']['last_move_uci']) {
 703                 highlight_from = data['position']['last_move_uci'].substr(0, 2);
 704                 highlight_to = data['position']['last_move_uci'].substr(2, 2);
 705         } else if (current_display_line_is_history && current_display_move >= 0) {
 706                 // We don't have historic analysis for this position, but we
 707                 // can reconstruct what the last move was by just replaying
 708                 // from the start.
 709                 var hiddenboard = new Chess();
 710                 for (var i = 0; i <= current_display_move; ++i) {
 711                         hiddenboard.move(current_display_line.pretty_pv[i]);
 712                 }
 713                 var moves = hiddenboard.history({ verbose: true });
 714                 var last_move = moves.pop();
 715                 highlight_from = last_move.from;
 716                 highlight_to = last_move.to;
 717         } else {
 718                 highlight_from = highlight_to = undefined;
 719         }
 720         update_highlight();
 721
 722         if (data['failed']) {
 723                 $("#score").text("No analysis for this move");
 724                 $("#pv").empty();
 725                 $("#searchstats").html("&nbsp;");
 726                 $("#refutationlines").empty();
 727                 $("#whiteclock").empty();
 728                 $("#blackclock").empty();
 729                 refutation_lines = [];
 730                 update_refutation_lines();
 731                 clear_arrows();
 732                 update_displayed_line();
 733                 return;
 734         }
 735
 736         update_clock();
 737
 738         // The engine id.
 739         if (data['id'] && data['id']['name'] !== null) {
 740                 $("#engineid").text(data['id']['name']);
 741         }
 742
 743         // The score.
 744         if (data['score'] !== null) {
 745                 $("#score").text(data['score']);
 746         }
 747
 748         // The search stats.
 749         if (data['tablebase'] == 1) {
 750                 $("#searchstats").text("Tablebase result");
 751         } else if (data['nodes'] && data['nps'] && data['depth']) {
 752                 var stats = thousands(data['nodes']) + ' nodes, ' + thousands(data['nps']) + ' nodes/sec, depth ' + data['depth'] + ' ply';
 753                 if (data['seldepth']) {
 754                         stats += ' (' + data['seldepth'] + ' selective)';
 755                 }
 756                 if (data['tbhits'] && data['tbhits'] > 0) {
 757                         if (data['tbhits'] == 1) {
 758                                 stats += ', one Syzygy hit';
 759                         } else {
 760                                 stats += ', ' + thousands(data['tbhits']) + ' Syzygy hits';
 761                         }
 762                 }
 763
 764                 $("#searchstats").text(stats);
 765         } else {
 766                 $("#searchstats").text("");
 767         }
 768
 769         // Update the board itself.
 770         fen = data['position']['fen'];
 771         update_displayed_line();
 772
 773         // Print the PV.
 774         $("#pv").html(add_pv(data['position']['fen'], data['pv_pretty'], data['position']['move_num'], data['position']['toplay']));
 775
 776         // Update the PV arrow.
 777         clear_arrows();
 778         if (data['pv_uci'].length >= 1) {
 779                 // draw a continuation arrow as long as it's the same piece
 780                 for (var i = 0; i < data['pv_uci'].length; i += 2) {
 781                         var from = data['pv_uci'][i].substr(0, 2);
 782                         var to = data['pv_uci'][i].substr(2,4);
 783                         if ((i >= 2 && from != data['pv_uci'][i - 2].substr(2, 2)) ||
 784                              interfering_arrow(from, to)) {
 785                                 break;
 786                         }
 787                         create_arrow(from, to, '#f66', 6, 20);
 788                 }
 789
 790                 var alt_moves = find_nonstupid_moves(data, 30);
 791                 for (var i = 1; i < alt_moves.length && i < 3; ++i) {
 792                         create_arrow(alt_moves[i].substr(0, 2),
 793                                      alt_moves[i].substr(2, 2), '#f66', 1, 10);
 794                 }
 795         }
 796
 797         // See if all semi-reasonable moves have only one possible response.
 798         if (data['pv_uci'].length >= 2) {
 799                 var nonstupid_moves = find_nonstupid_moves(data, 300);
 800                 var response = data['pv_uci'][1];
 801                 for (var i = 0; i < nonstupid_moves.length; ++i) {
 802                         if (nonstupid_moves[i] == data['pv_uci'][0]) {
 803                                 // ignore the PV move for refutation lines.
 804                                 continue;
 805                         }
 806                         if (!data['refutation_lines'] ||
 807                             !data['refutation_lines'][nonstupid_moves[i]] ||
 808                             !data['refutation_lines'][nonstupid_moves[i]]['pv_uci'] ||
 809                             data['refutation_lines'][nonstupid_moves[i]]['pv_uci'].length < 1) {
 810                                 // Incomplete PV, abort.
 811                                 response = undefined;
 812                                 break;
 813                         }
 814                         var this_response = data['refutation_lines'][nonstupid_moves[i]]['pv_uci'][1];
 815                         if (response !== this_response) {
 816                                 // Different response depending on lines, abort.
 817                                 response = undefined;
 818                                 break;
 819                         }
 820                 }
 821
 822                 if (nonstupid_moves.length > 0 && response !== undefined) {
 823                         create_arrow(response.substr(0, 2),
 824                                      response.substr(2, 2), '#66f', 6, 20);
 825                 }
 826         }
 827
 828         // Update the refutation lines.
 829         fen = data['position']['fen'];
 830         move_num = data['position']['move_num'];
 831         toplay = data['position']['toplay'];
 832         refutation_lines = data['refutation_lines'];
 833         update_refutation_lines();
 834 }
 835
 836 /**
 837  * @param {number} num_viewers
 838  */
 839 var update_num_viewers = function(num_viewers) {
 840         if (num_viewers === null) {
 841                 $("#numviewers").text("");
 842         } else if (num_viewers == 1) {
 843                 $("#numviewers").text("You are the only current viewer");
 844         } else {
 845                 $("#numviewers").text(num_viewers + " current viewers");
 846         }
 847 }
 848
 849 var update_clock = function() {
 850         clearTimeout(clock_timer);
 851
 852         var data = displayed_analysis_data || current_analysis_data;
 853         if (data['position']) {
 854                 var result = data['position']['result'];
 855                 if (result === '1-0') {
 856                         $("#whiteclock").text("1");
 857                         $("#blackclock").text("0");
 858                         $("#whiteclock").removeClass("running-clock");
 859                         $("#blackclock").removeClass("running-clock");
 860                         return;
 861                 }
 862                 if (result === '1/2-1/2') {
 863                         $("#whiteclock").text("1/2");
 864                         $("#blackclock").text("1/2");
 865                         $("#whiteclock").removeClass("running-clock");
 866                         $("#blackclock").removeClass("running-clock");
 867                         return;
 868                 }
 869                 if (result === '0-1') {
 870                         $("#whiteclock").text("0");
 871                         $("#blackclock").text("1");
 872                         $("#whiteclock").removeClass("running-clock");
 873                         $("#blackclock").removeClass("running-clock");
 874                         return;
 875                 }
 876         }
 877
 878         var white_clock = "";
 879         var black_clock = "";
 880
 881         // Static clocks.
 882         if (data['position'] &&
 883             data['position']['white_clock'] &&
 884             data['position']['black_clock']) {
 885                 white_clock = data['position']['white_clock'].replace(/:[0-5][0-9]$/, "");
 886                 black_clock = data['position']['black_clock'].replace(/:[0-5][0-9]$/, "");
 887         }
 888
 889         // Dynamic clock (only one, obviously).
 890         var color;
 891         if (data['position']['white_clock_target']) {
 892                 color = "white";
 893                 $("#whiteclock").addClass("running-clock");
 894                 $("#blackclock").removeClass("running-clock");
 895         } else if (data['position']['black_clock_target']) {
 896                 color = "black";
 897                 $("#whiteclock").removeClass("running-clock");
 898                 $("#blackclock").addClass("running-clock");
 899         } else {
 900                 $("#whiteclock").removeClass("running-clock");
 901                 $("#blackclock").removeClass("running-clock");
 902         }
 903         if (color) {
 904                 var now = new Date().getTime() + client_clock_offset_ms;
 905                 var remaining_ms = data['position'][color + '_clock_target'] * 1000 - now;
 906                 if (color === "white") {
 907                         white_clock = format_clock(remaining_ms);
 908                 } else {
 909                         black_clock = format_clock(remaining_ms);
 910                 }
 911
 912                 // See when the clock will change next, and update right after that.
 913                 var next_update_ms = remaining_ms % 60000 + 100;
 914                 clock_timer = setTimeout(update_clock, next_update_ms);
 915         }
 916
 917         $("#whiteclock").text(white_clock);
 918         $("#blackclock").text(black_clock);
 919 }
 920
 921 /**
 922  * @param {Number} remaining_ms
 923  */
 924 var format_clock = function(remaining_ms) {
 925         if (remaining_ms <= 0) {
 926                 return "00:00";
 927         }
 928
 929         var remaining = Math.floor(remaining_ms / 1000);
 930         var seconds = remaining % 60;
 931         remaining = (remaining - seconds) / 60;
 932         var minutes = remaining % 60;
 933         remaining = (remaining - minutes) / 60;
 934         var hours = remaining;
 935         return format_2d(hours) + ":" + format_2d(minutes);
 936 }
 937
 938 /**
 939  * @param {Number} x
 940  */
 941 var format_2d = function(x) {
 942         if (x >= 10) {
 943                 return x;
 944         } else {
 945                 return "0" + x;
 946         }
 947 }
 948
 949 /**
 950  * @param {string} move
 951  * @param {Number} move_num
 952  * @param {boolean} white_to_play
 953  */
 954 var format_move_with_number = function(move, move_num, white_to_play) {
 955         var ret;
 956         if (white_to_play) {
 957                 ret = (move_num - 1) + '… ';
 958         } else {
 959                 ret = move_num + '. ';
 960         }
 961         ret += move;
 962         return ret;
 963 }
 964
 965 /**
 966  * @param {boolean} sort_by_score
 967  */
 968 var resort_refutation_lines = function(sort_by_score) {
 969         sort_refutation_lines_by_score = sort_by_score;
 970         if (supports_html5_storage()) {
 971                 localStorage['sort_refutation_lines_by_score'] = sort_by_score ? 1 : 0;
 972         }
 973         update_refutation_lines();
 974 }
 975 window['resort_refutation_lines'] = resort_refutation_lines;
 976
 977 /**
 978  * @param {boolean} truncate_history
 979  */
 980 var set_truncate_history = function(truncate_history) {
 981         truncate_display_history = truncate_history;
 982         update_refutation_lines();
 983 }
 984 window['set_truncate_history'] = set_truncate_history;
 985
 986 /**
 987  * @param {number} line_num
 988  * @param {number} move_num
 989  */
 990 var show_line = function(line_num, move_num) {
 991         if (line_num == -1) {
 992                 current_display_line = null;
 993                 current_display_move = null;
 994                 if (displayed_analysis_data) {
 995                         // TODO: Support exiting to history position if we are in an
 996                         // analysis line of a history position.
 997                         displayed_analysis_data = null;
 998                         update_board(current_analysis_data, displayed_analysis_data);
 999                 }
1000         } else {
1001                 current_display_line = display_lines[line_num];
1002                 current_display_move = move_num;
1003         }
1004         current_display_line_is_history = (line_num == 0);
1005
1006         update_historic_analysis();
1007         update_displayed_line();
1008         update_highlight();
1009         redraw_arrows();
1010 }
1011 window['show_line'] = show_line;
1012
1013 var prev_move = function() {
1014         if (current_display_move > -1) {
1015                 --current_display_move;
1016         }
1017         update_historic_analysis();
1018         update_displayed_line();
1019 }
1020 window['prev_move'] = prev_move;
1021
1022 var next_move = function() {
1023         if (current_display_line && current_display_move < current_display_line.pretty_pv.length - 1) {
1024                 ++current_display_move;
1025         }
1026         update_historic_analysis();
1027         update_displayed_line();
1028 }
1029 window['next_move'] = next_move;
1030
1031 var update_historic_analysis = function() {
1032         if (!current_display_line_is_history) {
1033                 return;
1034         }
1035         if (current_display_move == current_display_line.pretty_pv.length - 1) {
1036                 displayed_analysis_data = null;
1037                 update_board(current_analysis_data, displayed_analysis_data);
1038         }
1039
1040         // Fetch old analysis for this line if it exists.
1041         var hiddenboard = new Chess();
1042         for (var i = 0; i <= current_display_move; ++i) {
1043                 hiddenboard.move(current_display_line.pretty_pv[i]);
1044         }
1045         var filename = "/history/move" + (current_display_move + 1) + "-" +
1046                 hiddenboard.fen().replace(/ /g, '_').replace(/\//g, '-') + ".json";
1047
1048         $.ajax({
1049                 url: filename
1050         }).done(function(data, textstatus, xhr) {
1051                 displayed_analysis_data = data;
1052                 update_board(current_analysis_data, displayed_analysis_data);
1053         }).fail(function() {
1054                 displayed_analysis_data = {'failed': true};
1055                 update_board(current_analysis_data, displayed_analysis_data);
1056         });
1057 }
1058
1059 var update_displayed_line = function() {
1060         if (highlighted_move !== null) {
1061                 highlighted_move.removeClass('highlight');
1062         }
1063         if (current_display_line === null) {
1064                 $("#linenav").hide();
1065                 $("#linemsg").show();
1066                 board.position(fen);
1067                 return;
1068         }
1069
1070         $("#linenav").show();
1071         $("#linemsg").hide();
1072
1073         if (current_display_move <= 0) {
1074                 $("#prevmove").html("Previous");
1075         } else {
1076                 $("#prevmove").html("<a href=\"javascript:prev_move();\">Previous</a></span>");
1077         }
1078         if (current_display_move == current_display_line.pretty_pv.length - 1) {
1079                 $("#nextmove").html("Next");
1080         } else {
1081                 $("#nextmove").html("<a href=\"javascript:next_move();\">Next</a></span>");
1082         }
1083
1084         var hiddenboard = new Chess();
1085         hiddenboard.load(current_display_line.start_fen);
1086         for (var i = 0; i <= current_display_move; ++i) {
1087                 hiddenboard.move(current_display_line.pretty_pv[i]);
1088         }
1089
1090         highlighted_move = $("#automove" + current_display_line.line_number + "-" + current_display_move);
1091         highlighted_move.addClass('highlight');
1092
1093         board.position(hiddenboard.fen());
1094 }
1095
1096 /**
1097  * @param {boolean} param_enable_sound
1098  */
1099 var set_sound = function(param_enable_sound) {
1100         enable_sound = param_enable_sound;
1101         if (enable_sound) {
1102                 $("#soundon").html("<strong>On</strong>");
1103                 $("#soundoff").html("<a href=\"javascript:set_sound(false)\">Off</a>");
1104
1105                 // Seemingly at least Firefox prefers MP3 over Opus; tell it otherwise,
1106                 // and also preload the file since the user has selected audio.
1107                 var ding = document.getElementById('ding');
1108                 if (ding && ding.canPlayType && ding.canPlayType('audio/ogg; codecs="opus"') === 'probably') {
1109                         ding.src = 'ding.opus';
1110                         ding.load();
1111                 }
1112         } else {
1113                 $("#soundon").html("<a href=\"javascript:set_sound(true)\">On</a>");
1114                 $("#soundoff").html("<strong>Off</strong>");
1115         }
1116         if (supports_html5_storage()) {
1117                 localStorage['enable_sound'] = enable_sound ? 1 : 0;
1118         }
1119 }
1120 window['set_sound'] = set_sound;
1121
1122 var init = function() {
1123         unique = get_unique();
1124
1125         // Load settings from HTML5 local storage if available.
1126         if (supports_html5_storage() && localStorage['enable_sound']) {
1127                 set_sound(parseInt(localStorage['enable_sound']));
1128         } else {
1129                 set_sound(false);
1130         }
1131         if (supports_html5_storage() && localStorage['sort_refutation_lines_by_score']) {
1132                 sort_refutation_lines_by_score = parseInt(localStorage['sort_refutation_lines_by_score']);
1133         } else {
1134                 sort_refutation_lines_by_score = true;
1135         }
1136
1137         // Create board.
1138         board = new window.ChessBoard('board', 'start');
1139
1140         request_update();
1141         $(window).resize(function() {
1142                 board.resize();
1143                 update_highlight();
1144                 redraw_arrows();
1145         });
1146         $(window).keyup(function(event) {
1147                 if (event.which == 39) {
1148                         next_move();
1149                 } else if (event.which == 37) {
1150                         prev_move();
1151                 }
1152         });
1153 };
1154 $(document).ready(init);
1155
1156 })();