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