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 /** The current position on the board, represented as a FEN string.
  69  * @type {?string}
  70  * @private
  71  */
  72 var fen = null;
  73
  74 /** @typedef {{
  75  *    start_fen: string,
  76  *    uci_pv: Array.<string>,
  77  *    pretty_pv: Array.<string>,
  78  *    line_num: number
  79  * }} DisplayLine
  80  */
  81
  82 /** @type {Array.<DisplayLine>}
  83  * @private
  84  */
  85 var display_lines = [];
  86
  87 /** @type {?DisplayLine} @private */
  88 var current_display_line = null;
  89
  90 /** @type {boolean} @private */
  91 var current_display_line_is_history = false;
  92
  93 /** @type {?number} @private */
  94 var current_display_move = null;
  95
  96 var supports_html5_storage = function() {
  97         try {
  98                 return 'localStorage' in window && window['localStorage'] !== null;
  99         } catch (e) {
 100                 return false;
 101         }
 102 }
 103
 104 // Make the unique token persistent so people refreshing the page won't count twice.
 105 // Of course, you can never fully protect against people deliberately wanting to spam.
 106 var get_unique = function() {
 107         var use_local_storage = supports_html5_storage();
 108         if (use_local_storage && localStorage['unique']) {
 109                 return localStorage['unique'];
 110         }
 111         var unique = Math.random();
 112         if (use_local_storage) {
 113                 localStorage['unique'] = unique;
 114         }
 115         return unique;
 116 }
 117
 118 var request_update = function() {
 119         $.ajax({
 120                 url: "/analysis.pl?ims=" + ims + "&unique=" + unique
 121         }).done(function(data, textstatus, xhr) {
 122                 ims = xhr.getResponseHeader('X-Remoteglot-Last-Modified');
 123                 var num_viewers = xhr.getResponseHeader('X-Remoteglot-Num-Viewers');
 124                 current_analysis_data = data;
 125                 update_board(current_analysis_data, displayed_analysis_data);
 126                 update_num_viewers(num_viewers);
 127
 128                 // Next update.
 129                 setTimeout(function() { request_update(); }, 100);
 130         }).fail(function() {
 131                 // Wait ten seconds, then try again.
 132                 setTimeout(function() { request_update(); }, 10000);
 133         });
 134 }
 135
 136 var clear_arrows = function() {
 137         for (var i = 0; i < arrows.length; ++i) {
 138                 if (arrows[i].svg) {
 139                         arrows[i].svg.parentElement.removeChild(arrows[i].svg);
 140                         delete arrows[i].svg;
 141                 }
 142         }
 143         arrows = [];
 144
 145         occupied_by_arrows = [];
 146         for (var y = 0; y < 8; ++y) {
 147                 occupied_by_arrows.push([false, false, false, false, false, false, false, false]);
 148         }
 149 }
 150
 151 var redraw_arrows = function() {
 152         for (var i = 0; i < arrows.length; ++i) {
 153                 position_arrow(arrows[i]);
 154         }
 155 }
 156
 157 /** @param {!number} x
 158  * @return {!number}
 159  */
 160 var sign = function(x) {
 161         if (x > 0) {
 162                 return 1;
 163         } else if (x < 0) {
 164                 return -1;
 165         } else {
 166                 return 0;
 167         }
 168 }
 169
 170 /** See if drawing this arrow on the board would cause unduly amount of confusion.
 171  * @param {!string} from The square the arrow is from (e.g. e4).
 172  * @param {!string} to The square the arrow is to (e.g. e4).
 173  * @return {boolean}
 174  */
 175 var interfering_arrow = function(from, to) {
 176         var from_col = from.charCodeAt(0) - "a1".charCodeAt(0);
 177         var from_row = from.charCodeAt(1) - "a1".charCodeAt(1);
 178         var to_col   = to.charCodeAt(0) - "a1".charCodeAt(0);
 179         var to_row   = to.charCodeAt(1) - "a1".charCodeAt(1);
 180
 181         occupied_by_arrows[from_row][from_col] = true;
 182
 183         // Knight move: Just check that we haven't been at the destination before.
 184         if ((Math.abs(to_col - from_col) == 2 && Math.abs(to_row - from_row) == 1) ||
 185             (Math.abs(to_col - from_col) == 1 && Math.abs(to_row - from_row) == 2)) {
 186                 return occupied_by_arrows[to_row][to_col];
 187         }
 188
 189         // Sliding piece: Check if anything except the from-square is seen before.
 190         var dx = sign(to_col - from_col);
 191         var dy = sign(to_row - from_row);
 192         var x = from_col;
 193         var y = from_row;
 194         do {
 195                 x += dx;
 196                 y += dy;
 197                 if (occupied_by_arrows[y][x]) {
 198                         return true;
 199                 }
 200                 occupied_by_arrows[y][x] = true;
 201         } while (x != to_col || y != to_row);
 202
 203         return false;
 204 }
 205
 206 /** Find a point along the coordinate system given by the given line,
 207  * <t> units forward from the start of the line, <u> units to the right of it.
 208  * @param {!number} x1
 209  * @param {!number} x2
 210  * @param {!number} y1
 211  * @param {!number} y2
 212  * @param {!number} t
 213  * @param {!number} u
 214  * @return {!string} The point in "x y" form, suitable for SVG paths.
 215  */
 216 var point_from_start = function(x1, y1, x2, y2, t, u) {
 217         var dx = x2 - x1;
 218         var dy = y2 - y1;
 219
 220         var norm = 1.0 / Math.sqrt(dx * dx + dy * dy);
 221         dx *= norm;
 222         dy *= norm;
 223
 224         var x = x1 + dx * t + dy * u;
 225         var y = y1 + dy * t - dx * u;
 226         return x + " " + y;
 227 }
 228
 229 /** Find a point along the coordinate system given by the given line,
 230  * <t> units forward from the end of the line, <u> units to the right of it.
 231  * @param {!number} x1
 232  * @param {!number} x2
 233  * @param {!number} y1
 234  * @param {!number} y2
 235  * @param {!number} t
 236  * @param {!number} u
 237  * @return {!string} The point in "x y" form, suitable for SVG paths.
 238  */
 239 var point_from_end = function(x1, y1, x2, y2, t, u) {
 240         var dx = x2 - x1;
 241         var dy = y2 - y1;
 242
 243         var norm = 1.0 / Math.sqrt(dx * dx + dy * dy);
 244         dx *= norm;
 245         dy *= norm;
 246
 247         var x = x2 + dx * t + dy * u;
 248         var y = y2 + dy * t - dx * u;
 249         return x + " " + y;
 250 }
 251
 252 var position_arrow = function(arrow) {
 253         if (arrow.svg) {
 254                 arrow.svg.parentElement.removeChild(arrow.svg);
 255                 delete arrow.svg;
 256         }
 257         if (current_display_line !== null) {
 258                 return;
 259         }
 260
 261         var pos = $(".square-a8").position();
 262
 263         var zoom_factor = $("#board").width() / 400.0;
 264         var line_width = arrow.line_width * zoom_factor;
 265         var arrow_size = arrow.arrow_size * zoom_factor;
 266
 267         var square_width = $(".square-a8").width();
 268         var from_y = (7 - arrow.from_row + 0.5)*square_width;
 269         var to_y = (7 - arrow.to_row + 0.5)*square_width;
 270         var from_x = (arrow.from_col + 0.5)*square_width;
 271         var to_x = (arrow.to_col + 0.5)*square_width;
 272
 273         var SVG_NS = "http://www.w3.org/2000/svg";
 274         var XHTML_NS = "http://www.w3.org/1999/xhtml";
 275         var svg = document.createElementNS(SVG_NS, "svg");
 276         svg.setAttribute("width", /** @type{number} */ ($("#board").width()));
 277         svg.setAttribute("height", /** @type{number} */ ($("#board").height()));
 278         svg.setAttribute("style", "position: absolute");
 279         svg.setAttribute("position", "absolute");
 280         svg.setAttribute("version", "1.1");
 281         svg.setAttribute("class", "c1");
 282         svg.setAttribute("xmlns", XHTML_NS);
 283
 284         var x1 = from_x;
 285         var y1 = from_y;
 286         var x2 = to_x;
 287         var y2 = to_y;
 288
 289         // Draw the line.
 290         var outline = document.createElementNS(SVG_NS, "path");
 291         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));
 292         outline.setAttribute("xmlns", XHTML_NS);
 293         outline.setAttribute("stroke", "#666");
 294         outline.setAttribute("stroke-width", line_width + 2);
 295         outline.setAttribute("fill", "none");
 296         svg.appendChild(outline);
 297
 298         var path = document.createElementNS(SVG_NS, "path");
 299         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));
 300         path.setAttribute("xmlns", XHTML_NS);
 301         path.setAttribute("stroke", arrow.fg_color);
 302         path.setAttribute("stroke-width", line_width);
 303         path.setAttribute("fill", "none");
 304         svg.appendChild(path);
 305
 306         // Then the arrow head.
 307         var head = document.createElementNS(SVG_NS, "path");
 308         head.setAttribute("d",
 309                 "M " +  point_from_end(x1, y1, x2, y2, 0, 0) +
 310                 " L " + point_from_end(x1, y1, x2, y2, -arrow_size, -arrow_size / 2) +
 311                 " L " + point_from_end(x1, y1, x2, y2, -arrow_size * .623, 0.0) +
 312                 " L " + point_from_end(x1, y1, x2, y2, -arrow_size, arrow_size / 2) +
 313                 " L " + point_from_end(x1, y1, x2, y2, 0, 0));
 314         head.setAttribute("xmlns", XHTML_NS);
 315         head.setAttribute("stroke", "#000");
 316         head.setAttribute("stroke-width", "1");
 317         head.setAttribute("fill", arrow.fg_color);
 318         svg.appendChild(head);
 319
 320         $(svg).css({ top: pos.top, left: pos.left });
 321         document.body.appendChild(svg);
 322         arrow.svg = svg;
 323 }
 324
 325 /**
 326  * @param {!string} from_square
 327  * @param {!string} to_square
 328  * @param {!string} fg_color
 329  * @param {number} line_width
 330  * @param {number} arrow_size
 331  */
 332 var create_arrow = function(from_square, to_square, fg_color, line_width, arrow_size) {
 333         var from_col = from_square.charCodeAt(0) - "a1".charCodeAt(0);
 334         var from_row = from_square.charCodeAt(1) - "a1".charCodeAt(1);
 335         var to_col   = to_square.charCodeAt(0) - "a1".charCodeAt(0);
 336         var to_row   = to_square.charCodeAt(1) - "a1".charCodeAt(1);
 337
 338         // Create arrow.
 339         var arrow = {
 340                 from_col: from_col,
 341                 from_row: from_row,
 342                 to_col: to_col,
 343                 to_row: to_row,
 344                 line_width: line_width,
 345                 arrow_size: arrow_size,
 346                 fg_color: fg_color
 347         };
 348
 349         position_arrow(arrow);
 350         arrows.push(arrow);
 351 }
 352
 353 var compare_by_sort_key = function(refutation_lines, a, b) {
 354         var ska = refutation_lines[a]['sort_key'];
 355         var skb = refutation_lines[b]['sort_key'];
 356         if (ska < skb) return -1;
 357         if (ska > skb) return 1;
 358         return 0;
 359 };
 360
 361 var compare_by_score = function(refutation_lines, a, b) {
 362         var sa = parseInt(refutation_lines[b]['score_sort_key'], 10);
 363         var sb = parseInt(refutation_lines[a]['score_sort_key'], 10);
 364         return sa - sb;
 365 }
 366
 367 /**
 368  * Fake multi-PV using the refutation lines. Find all “relevant” moves,
 369  * sorted by quality, descending.
 370  *
 371  * @param {!Object} data
 372  * @param {number} margin The maximum number of centipawns worse than the
 373  *     best move can be and still be included.
 374  * @return {Array.<string>} The UCI representation (e.g. e1g1) of all
 375  *     moves, in score order.
 376  */
 377 var find_nonstupid_moves = function(data, margin) {
 378         // First of all, if there are any moves that are more than 0.5 ahead of
 379         // the primary move, the refutation lines are probably bunk, so just
 380         // kill them all.
 381         var best_score = undefined;
 382         var pv_score = undefined;
 383         for (var move in data['refutation_lines']) {
 384                 var score = parseInt(data['refutation_lines'][move]['score_sort_key'], 10);
 385                 if (move == data['pv_uci'][0]) {
 386                         pv_score = score;
 387                 }
 388                 if (best_score === undefined || score > best_score) {
 389                         best_score = score;
 390                 }
 391                 if (!(data['refutation_lines'][move]['depth'] >= 8)) {
 392                         return [];
 393                 }
 394         }
 395
 396         if (best_score - pv_score > 50) {
 397                 return [];
 398         }
 399
 400         // Now find all moves that are within “margin” of the best score.
 401         // The PV move will always be first.
 402         var moves = [];
 403         for (var move in data['refutation_lines']) {
 404                 var score = parseInt(data['refutation_lines'][move]['score_sort_key'], 10);
 405                 if (move != data['pv_uci'][0] && best_score - score <= margin) {
 406                         moves.push(move);
 407                 }
 408         }
 409         moves = moves.sort(function(a, b) { return compare_by_score(data['refutation_lines'], a, b) });
 410         moves.unshift(data['pv_uci'][0]);
 411
 412         return moves;
 413 }
 414
 415 /**
 416  * @param {number} x
 417  * @return {!string}
 418  */
 419 var thousands = function(x) {
 420         return String(x).split('').reverse().join('').replace(/(\d{3}\B)/g, '$1,').split('').reverse().join('');
 421 }
 422
 423 /**
 424  * @param {!string} fen
 425  * @param {Array.<string>} uci_pv
 426  * @param {number} move_num
 427  * @param {!string} toplay
 428  * @param {number=} opt_limit
 429  * @param {boolean=} opt_showlast
 430  */
 431 var add_pv = function(fen, uci_pv, move_num, toplay, opt_limit, opt_showlast) {
 432         var hiddenboard = new Chess();
 433         hiddenboard.load(fen);
 434         for (var i = 0; i < uci_pv.length; ++i) {
 435                 hiddenboard.move(ucimove_to_chessjs_move(uci_pv[i]));
 436         }
 437         var pretty_pv = hiddenboard.history();
 438
 439         display_lines.push({
 440                 start_fen: fen,
 441                 uci_pv: uci_pv,
 442                 pretty_pv: pretty_pv,
 443                 line_number: display_lines.length
 444         });
 445         return print_pv(display_lines.length - 1, pretty_pv, move_num, toplay, opt_limit, opt_showlast);
 446 }
 447
 448 /**
 449  * @param {number} line_num
 450  * @param {Array.<string>} pretty_pv
 451  * @param {number} move_num
 452  * @param {!string} toplay
 453  * @param {number=} opt_limit
 454  * @param {boolean=} opt_showlast
 455  */
 456 var print_pv = function(line_num, pretty_pv, move_num, toplay, opt_limit, opt_showlast) {
 457         var pv = '';
 458         var i = 0;
 459         if (opt_limit && opt_showlast && pretty_pv.length > opt_limit) {
 460                 // Truncate the PV at the beginning (instead of at the end).
 461                 // We assume here that toplay is 'W'. We also assume that if
 462                 // opt_showlast is set, then it is the history, and thus,
 463                 // the UI should be to expand the history.
 464                 pv = '(<a class="move" href="javascript:collapse_history(false)">…</a>) ';
 465                 i = pretty_pv.length - opt_limit;
 466                 if (i % 2 == 1) {
 467                         ++i;
 468                 }
 469                 move_num += i / 2;
 470         } else if (toplay == 'B' && pretty_pv.length > 0) {
 471                 var move = "<a class=\"move\" id=\"automove" + line_num + "-0\" href=\"javascript:show_line(" + line_num + ", " + 0 + ");\">" + pretty_pv[0] + "</a>";
 472                 pv = move_num + '. … ' + move;
 473                 toplay = 'W';
 474                 ++i;
 475                 ++move_num;
 476         }
 477         for ( ; i < pretty_pv.length; ++i) {
 478                 var move = "<a class=\"move\" id=\"automove" + line_num + "-" + i + "\" href=\"javascript:show_line(" + line_num + ", " + i + ");\">" + pretty_pv[i] + "</a>";
 479
 480                 if (toplay == 'W') {
 481                         if (i > opt_limit && !opt_showlast) {
 482                                 return pv + ' (…)';
 483                         }
 484                         if (pv != '') {
 485                                 pv += ' ';
 486                         }
 487                         pv += move_num + '. ' + move;
 488                         ++move_num;
 489                         toplay = 'B';
 490                 } else {
 491                         pv += ' ' + move;
 492                         toplay = 'W';
 493                 }
 494         }
 495         return pv;
 496 }
 497
 498 var update_highlight = function() {
 499         $("#board").find('.square-55d63').removeClass('nonuglyhighlight');
 500         if (current_display_line === null && highlight_from !== undefined && highlight_to !== undefined) {
 501                 $("#board").find('.square-' + highlight_from).addClass('nonuglyhighlight');
 502                 $("#board").find('.square-' + highlight_to).addClass('nonuglyhighlight');
 503         }
 504 }
 505
 506 var update_history = function() {
 507         if (display_lines[0] === null || display_lines[0].pretty_pv.length == 0) {
 508                 $("#history").html("No history");
 509         } else if (truncate_display_history) {
 510                 $("#history").html(print_pv(0, display_lines[0].pretty_pv, 1, 'W', 8, true));
 511         } else {
 512                 $("#history").html(
 513                         '(<a class="move" href="javascript:collapse_history(true)">collapse</a>) ' +
 514                         print_pv(0, display_lines[0].pretty_pv, 1, 'W'));
 515         }
 516 }
 517
 518 /**
 519  * @param {!boolean} truncate_history
 520  */
 521 var collapse_history = function(truncate_history) {
 522         truncate_display_history = truncate_history;
 523         update_history();
 524 }
 525 window['collapse_history'] = collapse_history;
 526
 527 var update_refutation_lines = function() {
 528         if (fen === null) {
 529                 return;
 530         }
 531         if (display_lines.length > 2) {
 532                 display_lines = [ display_lines[0], display_lines[1] ];
 533         }
 534
 535         var tbl = $("#refutationlines");
 536         tbl.empty();
 537
 538         var moves = [];
 539         for (var move in refutation_lines) {
 540                 moves.push(move);
 541         }
 542         var compare = sort_refutation_lines_by_score ? compare_by_score : compare_by_sort_key;
 543         moves = moves.sort(function(a, b) { return compare(refutation_lines, a, b) });
 544         for (var i = 0; i < moves.length; ++i) {
 545                 var line = refutation_lines[moves[i]];
 546
 547                 var tr = document.createElement("tr");
 548
 549                 var move_td = document.createElement("td");
 550                 tr.appendChild(move_td);
 551                 $(move_td).addClass("move");
 552                 if (line['pv_uci'].length == 0) {
 553                         $(move_td).text(line['pretty_move']);
 554                 } else {
 555                         var move = "<a class=\"move\" href=\"javascript:show_line(" + display_lines.length + ", " + 0 + ");\">" + line['pretty_move'] + "</a>";
 556                         $(move_td).html(move);
 557                 }
 558
 559                 var score_td = document.createElement("td");
 560                 tr.appendChild(score_td);
 561                 $(score_td).addClass("score");
 562                 $(score_td).text(line['pretty_score']);
 563
 564                 var depth_td = document.createElement("td");
 565                 tr.appendChild(depth_td);
 566                 $(depth_td).addClass("depth");
 567                 $(depth_td).text("d" + line['depth']);
 568
 569                 var pv_td = document.createElement("td");
 570                 tr.appendChild(pv_td);
 571                 $(pv_td).addClass("pv");
 572                 $(pv_td).html(add_pv(fen, line['pv_uci'], move_num, toplay, 10));
 573
 574                 tbl.append(tr);
 575         }
 576
 577         // Make one of the links clickable and the other nonclickable.
 578         if (sort_refutation_lines_by_score) {
 579                 $("#sortbyscore0").html("<a href=\"javascript:resort_refutation_lines(false)\">Move</a>");
 580                 $("#sortbyscore1").html("<strong>Score</strong>");
 581         } else {
 582                 $("#sortbyscore0").html("<strong>Move</strong>");
 583                 $("#sortbyscore1").html("<a href=\"javascript:resort_refutation_lines(true)\">Score</a>");
 584         }
 585 }
 586
 587 /**
 588  * @param {Object} data
 589  * @param {?Object} display_data
 590  */
 591 var update_board = function(current_data, display_data) {
 592         var data = display_data || current_data;
 593
 594         display_lines = [];
 595
 596         // Print the history. This is pretty much the only thing that's
 597         // unconditionally taken from current_data (we're not interested in
 598         // historic history).
 599         if (current_data['position']['history']) {
 600                 add_pv('start', current_data['position']['history'], 1, 'W', 8, true);
 601         } else {
 602                 display_lines.push(null);
 603         }
 604         update_history();
 605
 606         // The headline. Names are always fetched from current_data;
 607         // the rest can depend a bit.
 608         var headline;
 609         if (current_data &&
 610             current_data['position']['player_w'] && current_data['position']['player_b']) {
 611                 headline = current_data['position']['player_w'] + '–' +
 612                         current_data['position']['player_b'] + ', analysis';
 613         } else {
 614                 headline = 'Analysis';
 615         }
 616
 617         var last_move;
 618         if (display_data) {
 619                 // Displaying some non-current position, pick out the last move
 620                 // from the history. This will work even if the fetch failed.
 621                 last_move = format_move_with_number(
 622                         current_display_line.pretty_pv[current_display_move],
 623                         Math.floor((current_display_move + 1) / 2) + 1,
 624                         (current_display_move % 2 == 1));
 625                 headline += ' after ' + last_move;
 626         } else if (data['position']['last_move'] !== 'none') {
 627                 last_move = format_move_with_number(
 628                         data['position']['last_move'],
 629                         data['position']['move_num'],
 630                         data['position']['toplay'] == 'W');
 631                 headline += ' after ' + last_move;
 632         } else {
 633                 last_move = null;
 634         }
 635         $("#headline").text(headline);
 636
 637         // The <title> contains a very brief headline.
 638         var title_elems = [];
 639         if (data['short_score'] !== undefined && data['short_score'] !== null) {
 640                 title_elems.push(data['short_score']);
 641         }
 642         if (last_move !== null) {
 643                 title_elems.push(last_move);
 644         }
 645
 646         if (title_elems.length != 0) {
 647                 document.title = '(' + title_elems.join(', ') + ') analysis.sesse.net';
 648         } else {
 649                 document.title = 'analysis.sesse.net';
 650         }
 651
 652         if (data['failed']) {
 653                 $("#score").text("No analysis for this move");
 654                 $("#pv").empty();
 655                 $("#searchstats").html("&nbsp;");
 656                 $("#refutationlines").empty();
 657                 refutation_lines = [];
 658                 update_refutation_lines();
 659                 return;
 660         }
 661
 662         // The engine id.
 663         if (data['id'] && data['id']['name'] !== null) {
 664                 $("#engineid").text(data['id']['name']);
 665         }
 666
 667         // The score.
 668         if (data['score'] !== null) {
 669                 $("#score").text(data['score']);
 670         }
 671
 672         // The search stats.
 673         if (data['tablebase'] == 1) {
 674                 $("#searchstats").text("Tablebase result");
 675         } else if (data['nodes'] && data['nps'] && data['depth']) {
 676                 var stats = thousands(data['nodes']) + ' nodes, ' + thousands(data['nps']) + ' nodes/sec, depth ' + data['depth'] + ' ply';
 677                 if (data['seldepth']) {
 678                         stats += ' (' + data['seldepth'] + ' selective)';
 679                 }
 680                 if (data['tbhits'] && data['tbhits'] > 0) {
 681                         if (data['tbhits'] == 1) {
 682                                 stats += ', one Syzygy hit';
 683                         } else {
 684                                 stats += ', ' + thousands(data['tbhits']) + ' Syzygy hits';
 685                         }
 686                 }
 687
 688                 $("#searchstats").text(stats);
 689         } else {
 690                 $("#searchstats").text("");
 691         }
 692
 693         // Update the board itself.
 694         fen = data['position']['fen'];
 695         update_displayed_line();
 696
 697         if (data['position']['last_move_uci']) {
 698                 highlight_from = data['position']['last_move_uci'].substr(0, 2);
 699                 highlight_to = data['position']['last_move_uci'].substr(2, 2);
 700         } else {
 701                 highlight_from = highlight_to = undefined;
 702         }
 703         update_highlight();
 704
 705         // Print the PV.
 706         $("#pv").html(add_pv(data['position']['fen'], data['pv_uci'], data['position']['move_num'], data['position']['toplay']));
 707
 708         // Update the PV arrow.
 709         clear_arrows();
 710         if (data['pv_uci'].length >= 1) {
 711                 // draw a continuation arrow as long as it's the same piece
 712                 for (var i = 0; i < data['pv_uci'].length; i += 2) {
 713                         var from = data['pv_uci'][i].substr(0, 2);
 714                         var to = data['pv_uci'][i].substr(2,4);
 715                         if ((i >= 2 && from != data['pv_uci'][i - 2].substr(2, 2)) ||
 716                              interfering_arrow(from, to)) {
 717                                 break;
 718                         }
 719                         create_arrow(from, to, '#f66', 6, 20);
 720                 }
 721
 722                 var alt_moves = find_nonstupid_moves(data, 30);
 723                 for (var i = 1; i < alt_moves.length && i < 3; ++i) {
 724                         create_arrow(alt_moves[i].substr(0, 2),
 725                                      alt_moves[i].substr(2, 2), '#f66', 1, 10);
 726                 }
 727         }
 728
 729         // See if all semi-reasonable moves have only one possible response.
 730         if (data['pv_uci'].length >= 2) {
 731                 var nonstupid_moves = find_nonstupid_moves(data, 300);
 732                 var response = data['pv_uci'][1];
 733                 for (var i = 0; i < nonstupid_moves.length; ++i) {
 734                         if (nonstupid_moves[i] == data['pv_uci'][0]) {
 735                                 // ignore the PV move for refutation lines.
 736                                 continue;
 737                         }
 738                         if (!data['refutation_lines'] ||
 739                             !data['refutation_lines'][nonstupid_moves[i]] ||
 740                             !data['refutation_lines'][nonstupid_moves[i]]['pv_uci'] ||
 741                             data['refutation_lines'][nonstupid_moves[i]]['pv_uci'].length < 1) {
 742                                 // Incomplete PV, abort.
 743                                 response = undefined;
 744                                 break;
 745                         }
 746                         var this_response = data['refutation_lines'][nonstupid_moves[i]]['pv_uci'][1];
 747                         if (response !== this_response) {
 748                                 // Different response depending on lines, abort.
 749                                 response = undefined;
 750                                 break;
 751                         }
 752                 }
 753
 754                 if (nonstupid_moves.length > 0 && response !== undefined) {
 755                         create_arrow(response.substr(0, 2),
 756                                      response.substr(2, 2), '#66f', 6, 20);
 757                 }
 758         }
 759
 760         // Update the refutation lines.
 761         fen = data['position']['fen'];
 762         move_num = data['position']['move_num'];
 763         toplay = data['position']['toplay'];
 764         refutation_lines = data['refutation_lines'];
 765         update_refutation_lines();
 766 }
 767
 768 /**
 769  * @param {number} num_viewers
 770  */
 771 var update_num_viewers = function(num_viewers) {
 772         if (num_viewers === null) {
 773                 $("#numviewers").text("");
 774         } else if (num_viewers == 1) {
 775                 $("#numviewers").text("You are the only current viewer");
 776         } else {
 777                 $("#numviewers").text(num_viewers + " current viewers");
 778         }
 779 }
 780
 781 /**
 782  * @param {string} move
 783  * @param {Number} move_num
 784  * @param {boolean} white_to_play
 785  */
 786 var format_move_with_number = function(move, move_num, white_to_play) {
 787         var ret;
 788         if (white_to_play) {
 789                 ret = (move_num - 1) + '… ';
 790         } else {
 791                 ret = move_num + '. ';
 792         }
 793         ret += move;
 794         return ret;
 795 }
 796
 797 /**
 798  * @param {boolean} sort_by_score
 799  */
 800 var resort_refutation_lines = function(sort_by_score) {
 801         sort_refutation_lines_by_score = sort_by_score;
 802         update_refutation_lines();
 803 }
 804 window['resort_refutation_lines'] = resort_refutation_lines;
 805
 806 /**
 807  * @param {boolean} truncate_history
 808  */
 809 var set_truncate_history = function(truncate_history) {
 810         truncate_display_history = truncate_history;
 811         update_refutation_lines();
 812 }
 813 window['set_truncate_history'] = set_truncate_history;
 814
 815 /**
 816  * @param {number} line_num
 817  * @param {number} move_num
 818  */
 819 var show_line = function(line_num, move_num) {
 820         if (line_num == -1) {
 821                 current_display_line = null;
 822                 current_display_move = null;
 823                 if (displayed_analysis_data) {
 824                         // TODO: Support exiting to history position if we are in an
 825                         // analysis line of a history position.
 826                         displayed_analysis_data = null;
 827                         update_board(current_analysis_data, displayed_analysis_data);
 828                 }
 829         } else {
 830                 current_display_line = display_lines[line_num];
 831                 current_display_move = move_num;
 832         }
 833         current_display_line_is_history = (line_num == 0);
 834
 835         update_historic_analysis();
 836         update_displayed_line();
 837         update_highlight();
 838         redraw_arrows();
 839 }
 840 window['show_line'] = show_line;
 841
 842 var prev_move = function() {
 843         if (current_display_move > -1) {
 844                 --current_display_move;
 845         }
 846         update_historic_analysis();
 847         update_displayed_line();
 848 }
 849 window['prev_move'] = prev_move;
 850
 851 var next_move = function() {
 852         if (current_display_line && current_display_move < current_display_line.pretty_pv.length - 1) {
 853                 ++current_display_move;
 854         }
 855         update_historic_analysis();
 856         update_displayed_line();
 857 }
 858 window['next_move'] = next_move;
 859
 860 var update_historic_analysis = function() {
 861         if (!current_display_line_is_history) {
 862                 return;
 863         }
 864         if (current_display_move == current_display_line.pretty_pv.length - 1) {
 865                 displayed_analysis_data = null;
 866                 update_board(current_analysis_data, displayed_analysis_data);
 867         }
 868
 869         // Fetch old analysis for this line if it exists.
 870         var hiddenboard = new Chess();
 871         for (var i = 0; i <= current_display_move; ++i) {
 872                 hiddenboard.move(ucimove_to_chessjs_move(current_display_line.uci_pv[i]));
 873         }
 874         var filename = "/history/move" + (current_display_move + 1) + "-" +
 875                 hiddenboard.fen().replace(/ /g, '_').replace(/\//g, '-') + ".json";
 876
 877         $.ajax({
 878                 url: filename
 879         }).done(function(data, textstatus, xhr) {
 880                 displayed_analysis_data = data;
 881                 update_board(current_analysis_data, displayed_analysis_data);
 882         }).fail(function() {
 883                 displayed_analysis_data = {'failed': true};
 884                 update_board(current_analysis_data, displayed_analysis_data);
 885         });
 886 }
 887
 888 var update_displayed_line = function() {
 889         if (highlighted_move !== null) {
 890                 highlighted_move.removeClass('highlight');
 891         }
 892         if (current_display_line === null) {
 893                 $("#linenav").hide();
 894                 $("#linemsg").show();
 895                 board.position(fen);
 896                 return;
 897         }
 898
 899         $("#linenav").show();
 900         $("#linemsg").hide();
 901
 902         if (current_display_move <= 0) {
 903                 $("#prevmove").html("Previous");
 904         } else {
 905                 $("#prevmove").html("<a href=\"javascript:prev_move();\">Previous</a></span>");
 906         }
 907         if (current_display_move == current_display_line.uci_pv.length - 1) {
 908                 $("#nextmove").html("Next");
 909         } else {
 910                 $("#nextmove").html("<a href=\"javascript:next_move();\">Next</a></span>");
 911         }
 912
 913         var hiddenboard = new Chess();
 914         hiddenboard.load(current_display_line.start_fen);
 915         for (var i = 0; i <= current_display_move; ++i) {
 916                 hiddenboard.move(ucimove_to_chessjs_move(current_display_line.uci_pv[i]));
 917         }
 918
 919         highlighted_move = $("#automove" + current_display_line.line_number + "-" + current_display_move);
 920         highlighted_move.addClass('highlight');
 921
 922         board.position(hiddenboard.fen());
 923 }
 924
 925 var ucimove_to_chessjs_move = function(move) {
 926         var source = move.substr(0, 2);
 927         var target = move.substr(2, 2);
 928         var promo = move.substr(4, 1);
 929
 930         if (promo === '') {
 931                 return { from: source, to: target };
 932         } else {
 933                 return { from: source, to: target, promotion: promo };
 934         }
 935 }
 936
 937 var init = function() {
 938         unique = get_unique();
 939
 940         // Create board.
 941         board = new window.ChessBoard('board', 'start');
 942
 943         request_update();
 944         $(window).resize(function() {
 945                 board.resize();
 946                 update_highlight();
 947                 redraw_arrows();
 948         });
 949         $(window).keyup(function(event) {
 950                 if (event.which == 39) {
 951                         next_move();
 952                 } else if (event.which == 37) {
 953                         prev_move();
 954                 }
 955         });
 956 };
 957 $(document).ready(init);
 958
 959 })();