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 && !current_display_line_is_history) {
 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>} pretty_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, pretty_pv, move_num, toplay, opt_limit, opt_showlast) {
 432         display_lines.push({
 433                 start_fen: fen,
 434                 pretty_pv: pretty_pv,
 435                 line_number: display_lines.length
 436         });
 437         return print_pv(display_lines.length - 1, pretty_pv, move_num, toplay, opt_limit, opt_showlast);
 438 }
 439
 440 /**
 441  * @param {number} line_num
 442  * @param {Array.<string>} pretty_pv
 443  * @param {number} move_num
 444  * @param {!string} toplay
 445  * @param {number=} opt_limit
 446  * @param {boolean=} opt_showlast
 447  */
 448 var print_pv = function(line_num, pretty_pv, move_num, toplay, opt_limit, opt_showlast) {
 449         var pv = '';
 450         var i = 0;
 451         if (opt_limit && opt_showlast && pretty_pv.length > opt_limit) {
 452                 // Truncate the PV at the beginning (instead of at the end).
 453                 // We assume here that toplay is 'W'. We also assume that if
 454                 // opt_showlast is set, then it is the history, and thus,
 455                 // the UI should be to expand the history.
 456                 pv = '(<a class="move" href="javascript:collapse_history(false)">…</a>) ';
 457                 i = pretty_pv.length - opt_limit;
 458                 if (i % 2 == 1) {
 459                         ++i;
 460                 }
 461                 move_num += i / 2;
 462         } else if (toplay == 'B' && pretty_pv.length > 0) {
 463                 var move = "<a class=\"move\" id=\"automove" + line_num + "-0\" href=\"javascript:show_line(" + line_num + ", " + 0 + ");\">" + pretty_pv[0] + "</a>";
 464                 pv = move_num + '. … ' + move;
 465                 toplay = 'W';
 466                 ++i;
 467                 ++move_num;
 468         }
 469         for ( ; i < pretty_pv.length; ++i) {
 470                 var move = "<a class=\"move\" id=\"automove" + line_num + "-" + i + "\" href=\"javascript:show_line(" + line_num + ", " + i + ");\">" + pretty_pv[i] + "</a>";
 471
 472                 if (toplay == 'W') {
 473                         if (i > opt_limit && !opt_showlast) {
 474                                 return pv + ' (…)';
 475                         }
 476                         if (pv != '') {
 477                                 pv += ' ';
 478                         }
 479                         pv += move_num + '. ' + move;
 480                         ++move_num;
 481                         toplay = 'B';
 482                 } else {
 483                         pv += ' ' + move;
 484                         toplay = 'W';
 485                 }
 486         }
 487         return pv;
 488 }
 489
 490 var update_highlight = function() {
 491         $("#board").find('.square-55d63').removeClass('nonuglyhighlight');
 492         if ((current_display_line === null || current_display_line_is_history) &&
 493             highlight_from !== undefined && highlight_to !== undefined) {
 494                 $("#board").find('.square-' + highlight_from).addClass('nonuglyhighlight');
 495                 $("#board").find('.square-' + highlight_to).addClass('nonuglyhighlight');
 496         }
 497 }
 498
 499 var update_history = function() {
 500         if (display_lines[0] === null || display_lines[0].pretty_pv.length == 0) {
 501                 $("#history").html("No history");
 502         } else if (truncate_display_history) {
 503                 $("#history").html(print_pv(0, display_lines[0].pretty_pv, 1, 'W', 8, true));
 504         } else {
 505                 $("#history").html(
 506                         '(<a class="move" href="javascript:collapse_history(true)">collapse</a>) ' +
 507                         print_pv(0, display_lines[0].pretty_pv, 1, 'W'));
 508         }
 509 }
 510
 511 /**
 512  * @param {!boolean} truncate_history
 513  */
 514 var collapse_history = function(truncate_history) {
 515         truncate_display_history = truncate_history;
 516         update_history();
 517 }
 518 window['collapse_history'] = collapse_history;
 519
 520 var update_refutation_lines = function() {
 521         if (fen === null) {
 522                 return;
 523         }
 524         if (display_lines.length > 2) {
 525                 display_lines = [ display_lines[0], display_lines[1] ];
 526         }
 527
 528         var tbl = $("#refutationlines");
 529         tbl.empty();
 530
 531         var moves = [];
 532         for (var move in refutation_lines) {
 533                 moves.push(move);
 534         }
 535         var compare = sort_refutation_lines_by_score ? compare_by_score : compare_by_sort_key;
 536         moves = moves.sort(function(a, b) { return compare(refutation_lines, a, b) });
 537         for (var i = 0; i < moves.length; ++i) {
 538                 var line = refutation_lines[moves[i]];
 539
 540                 var tr = document.createElement("tr");
 541
 542                 var move_td = document.createElement("td");
 543                 tr.appendChild(move_td);
 544                 $(move_td).addClass("move");
 545                 if (line['pv_pretty'].length == 0) {
 546                         $(move_td).text(line['pretty_move']);
 547                 } else {
 548                         var move = "<a class=\"move\" href=\"javascript:show_line(" + display_lines.length + ", " + 0 + ");\">" + line['pretty_move'] + "</a>";
 549                         $(move_td).html(move);
 550                 }
 551
 552                 var score_td = document.createElement("td");
 553                 tr.appendChild(score_td);
 554                 $(score_td).addClass("score");
 555                 $(score_td).text(line['pretty_score']);
 556
 557                 var depth_td = document.createElement("td");
 558                 tr.appendChild(depth_td);
 559                 $(depth_td).addClass("depth");
 560                 $(depth_td).text("d" + line['depth']);
 561
 562                 var pv_td = document.createElement("td");
 563                 tr.appendChild(pv_td);
 564                 $(pv_td).addClass("pv");
 565                 $(pv_td).html(add_pv(fen, line['pv_pretty'], move_num, toplay, 10));
 566
 567                 tbl.append(tr);
 568         }
 569
 570         // Make one of the links clickable and the other nonclickable.
 571         if (sort_refutation_lines_by_score) {
 572                 $("#sortbyscore0").html("<a href=\"javascript:resort_refutation_lines(false)\">Move</a>");
 573                 $("#sortbyscore1").html("<strong>Score</strong>");
 574         } else {
 575                 $("#sortbyscore0").html("<strong>Move</strong>");
 576                 $("#sortbyscore1").html("<a href=\"javascript:resort_refutation_lines(true)\">Score</a>");
 577         }
 578 }
 579
 580 /**
 581  * @param {Object} data
 582  * @param {?Object} display_data
 583  */
 584 var update_board = function(current_data, display_data) {
 585         var data = display_data || current_data;
 586
 587         display_lines = [];
 588
 589         // Print the history. This is pretty much the only thing that's
 590         // unconditionally taken from current_data (we're not interested in
 591         // historic history).
 592         if (current_data['position']['pretty_history']) {
 593                 add_pv('start', current_data['position']['pretty_history'], 1, 'W', 8, true);
 594         } else {
 595                 display_lines.push(null);
 596         }
 597         update_history();
 598
 599         // The headline. Names are always fetched from current_data;
 600         // the rest can depend a bit.
 601         var headline;
 602         if (current_data &&
 603             current_data['position']['player_w'] && current_data['position']['player_b']) {
 604                 headline = current_data['position']['player_w'] + '–' +
 605                         current_data['position']['player_b'] + ', analysis';
 606         } else {
 607                 headline = 'Analysis';
 608         }
 609
 610         var last_move;
 611         if (display_data) {
 612                 // Displaying some non-current position, pick out the last move
 613                 // from the history. This will work even if the fetch failed.
 614                 last_move = format_move_with_number(
 615                         current_display_line.pretty_pv[current_display_move],
 616                         Math.floor((current_display_move + 1) / 2) + 1,
 617                         (current_display_move % 2 == 1));
 618                 headline += ' after ' + last_move;
 619         } else if (data['position']['last_move'] !== 'none') {
 620                 last_move = format_move_with_number(
 621                         data['position']['last_move'],
 622                         data['position']['move_num'],
 623                         data['position']['toplay'] == 'W');
 624                 headline += ' after ' + last_move;
 625         } else {
 626                 last_move = null;
 627         }
 628         $("#headline").text(headline);
 629
 630         // The <title> contains a very brief headline.
 631         var title_elems = [];
 632         if (data['short_score'] !== undefined && data['short_score'] !== null) {
 633                 title_elems.push(data['short_score']);
 634         }
 635         if (last_move !== null) {
 636                 title_elems.push(last_move);
 637         }
 638
 639         if (title_elems.length != 0) {
 640                 document.title = '(' + title_elems.join(', ') + ') analysis.sesse.net';
 641         } else {
 642                 document.title = 'analysis.sesse.net';
 643         }
 644
 645         if (data['failed']) {
 646                 $("#score").text("No analysis for this move");
 647                 $("#pv").empty();
 648                 $("#searchstats").html("&nbsp;");
 649                 $("#refutationlines").empty();
 650                 refutation_lines = [];
 651                 update_refutation_lines();
 652                 clear_arrows();
 653                 return;
 654         }
 655
 656         // The engine id.
 657         if (data['id'] && data['id']['name'] !== null) {
 658                 $("#engineid").text(data['id']['name']);
 659         }
 660
 661         // The score.
 662         if (data['score'] !== null) {
 663                 $("#score").text(data['score']);
 664         }
 665
 666         // The search stats.
 667         if (data['tablebase'] == 1) {
 668                 $("#searchstats").text("Tablebase result");
 669         } else if (data['nodes'] && data['nps'] && data['depth']) {
 670                 var stats = thousands(data['nodes']) + ' nodes, ' + thousands(data['nps']) + ' nodes/sec, depth ' + data['depth'] + ' ply';
 671                 if (data['seldepth']) {
 672                         stats += ' (' + data['seldepth'] + ' selective)';
 673                 }
 674                 if (data['tbhits'] && data['tbhits'] > 0) {
 675                         if (data['tbhits'] == 1) {
 676                                 stats += ', one Syzygy hit';
 677                         } else {
 678                                 stats += ', ' + thousands(data['tbhits']) + ' Syzygy hits';
 679                         }
 680                 }
 681
 682                 $("#searchstats").text(stats);
 683         } else {
 684                 $("#searchstats").text("");
 685         }
 686
 687         // Update the board itself.
 688         fen = data['position']['fen'];
 689         update_displayed_line();
 690
 691         if (data['position']['last_move_uci']) {
 692                 highlight_from = data['position']['last_move_uci'].substr(0, 2);
 693                 highlight_to = data['position']['last_move_uci'].substr(2, 2);
 694         } else {
 695                 highlight_from = highlight_to = undefined;
 696         }
 697         update_highlight();
 698
 699         // Print the PV.
 700         $("#pv").html(add_pv(data['position']['fen'], data['pv_pretty'], data['position']['move_num'], data['position']['toplay']));
 701
 702         // Update the PV arrow.
 703         clear_arrows();
 704         if (data['pv_uci'].length >= 1) {
 705                 // draw a continuation arrow as long as it's the same piece
 706                 for (var i = 0; i < data['pv_uci'].length; i += 2) {
 707                         var from = data['pv_uci'][i].substr(0, 2);
 708                         var to = data['pv_uci'][i].substr(2,4);
 709                         if ((i >= 2 && from != data['pv_uci'][i - 2].substr(2, 2)) ||
 710                              interfering_arrow(from, to)) {
 711                                 break;
 712                         }
 713                         create_arrow(from, to, '#f66', 6, 20);
 714                 }
 715
 716                 var alt_moves = find_nonstupid_moves(data, 30);
 717                 for (var i = 1; i < alt_moves.length && i < 3; ++i) {
 718                         create_arrow(alt_moves[i].substr(0, 2),
 719                                      alt_moves[i].substr(2, 2), '#f66', 1, 10);
 720                 }
 721         }
 722
 723         // See if all semi-reasonable moves have only one possible response.
 724         if (data['pv_uci'].length >= 2) {
 725                 var nonstupid_moves = find_nonstupid_moves(data, 300);
 726                 var response = data['pv_uci'][1];
 727                 for (var i = 0; i < nonstupid_moves.length; ++i) {
 728                         if (nonstupid_moves[i] == data['pv_uci'][0]) {
 729                                 // ignore the PV move for refutation lines.
 730                                 continue;
 731                         }
 732                         if (!data['refutation_lines'] ||
 733                             !data['refutation_lines'][nonstupid_moves[i]] ||
 734                             !data['refutation_lines'][nonstupid_moves[i]]['pv_uci'] ||
 735                             data['refutation_lines'][nonstupid_moves[i]]['pv_uci'].length < 1) {
 736                                 // Incomplete PV, abort.
 737                                 response = undefined;
 738                                 break;
 739                         }
 740                         var this_response = data['refutation_lines'][nonstupid_moves[i]]['pv_uci'][1];
 741                         if (response !== this_response) {
 742                                 // Different response depending on lines, abort.
 743                                 response = undefined;
 744                                 break;
 745                         }
 746                 }
 747
 748                 if (nonstupid_moves.length > 0 && response !== undefined) {
 749                         create_arrow(response.substr(0, 2),
 750                                      response.substr(2, 2), '#66f', 6, 20);
 751                 }
 752         }
 753
 754         // Update the refutation lines.
 755         fen = data['position']['fen'];
 756         move_num = data['position']['move_num'];
 757         toplay = data['position']['toplay'];
 758         refutation_lines = data['refutation_lines'];
 759         update_refutation_lines();
 760 }
 761
 762 /**
 763  * @param {number} num_viewers
 764  */
 765 var update_num_viewers = function(num_viewers) {
 766         if (num_viewers === null) {
 767                 $("#numviewers").text("");
 768         } else if (num_viewers == 1) {
 769                 $("#numviewers").text("You are the only current viewer");
 770         } else {
 771                 $("#numviewers").text(num_viewers + " current viewers");
 772         }
 773 }
 774
 775 /**
 776  * @param {string} move
 777  * @param {Number} move_num
 778  * @param {boolean} white_to_play
 779  */
 780 var format_move_with_number = function(move, move_num, white_to_play) {
 781         var ret;
 782         if (white_to_play) {
 783                 ret = (move_num - 1) + '… ';
 784         } else {
 785                 ret = move_num + '. ';
 786         }
 787         ret += move;
 788         return ret;
 789 }
 790
 791 /**
 792  * @param {boolean} sort_by_score
 793  */
 794 var resort_refutation_lines = function(sort_by_score) {
 795         sort_refutation_lines_by_score = sort_by_score;
 796         update_refutation_lines();
 797 }
 798 window['resort_refutation_lines'] = resort_refutation_lines;
 799
 800 /**
 801  * @param {boolean} truncate_history
 802  */
 803 var set_truncate_history = function(truncate_history) {
 804         truncate_display_history = truncate_history;
 805         update_refutation_lines();
 806 }
 807 window['set_truncate_history'] = set_truncate_history;
 808
 809 /**
 810  * @param {number} line_num
 811  * @param {number} move_num
 812  */
 813 var show_line = function(line_num, move_num) {
 814         if (line_num == -1) {
 815                 current_display_line = null;
 816                 current_display_move = null;
 817                 if (displayed_analysis_data) {
 818                         // TODO: Support exiting to history position if we are in an
 819                         // analysis line of a history position.
 820                         displayed_analysis_data = null;
 821                         update_board(current_analysis_data, displayed_analysis_data);
 822                 }
 823         } else {
 824                 current_display_line = display_lines[line_num];
 825                 current_display_move = move_num;
 826         }
 827         current_display_line_is_history = (line_num == 0);
 828
 829         update_historic_analysis();
 830         update_displayed_line();
 831         update_highlight();
 832         redraw_arrows();
 833 }
 834 window['show_line'] = show_line;
 835
 836 var prev_move = function() {
 837         if (current_display_move > -1) {
 838                 --current_display_move;
 839         }
 840         update_historic_analysis();
 841         update_displayed_line();
 842 }
 843 window['prev_move'] = prev_move;
 844
 845 var next_move = function() {
 846         if (current_display_line && current_display_move < current_display_line.pretty_pv.length - 1) {
 847                 ++current_display_move;
 848         }
 849         update_historic_analysis();
 850         update_displayed_line();
 851 }
 852 window['next_move'] = next_move;
 853
 854 var update_historic_analysis = function() {
 855         if (!current_display_line_is_history) {
 856                 return;
 857         }
 858         if (current_display_move == current_display_line.pretty_pv.length - 1) {
 859                 displayed_analysis_data = null;
 860                 update_board(current_analysis_data, displayed_analysis_data);
 861         }
 862
 863         // Fetch old analysis for this line if it exists.
 864         var hiddenboard = new Chess();
 865         for (var i = 0; i <= current_display_move; ++i) {
 866                 hiddenboard.move(current_display_line.pretty_pv[i]);
 867         }
 868         var filename = "/history/move" + (current_display_move + 1) + "-" +
 869                 hiddenboard.fen().replace(/ /g, '_').replace(/\//g, '-') + ".json";
 870
 871         $.ajax({
 872                 url: filename
 873         }).done(function(data, textstatus, xhr) {
 874                 displayed_analysis_data = data;
 875                 update_board(current_analysis_data, displayed_analysis_data);
 876         }).fail(function() {
 877                 displayed_analysis_data = {'failed': true};
 878                 update_board(current_analysis_data, displayed_analysis_data);
 879         });
 880 }
 881
 882 var update_displayed_line = function() {
 883         if (highlighted_move !== null) {
 884                 highlighted_move.removeClass('highlight');
 885         }
 886         if (current_display_line === null) {
 887                 $("#linenav").hide();
 888                 $("#linemsg").show();
 889                 board.position(fen);
 890                 return;
 891         }
 892
 893         $("#linenav").show();
 894         $("#linemsg").hide();
 895
 896         if (current_display_move <= 0) {
 897                 $("#prevmove").html("Previous");
 898         } else {
 899                 $("#prevmove").html("<a href=\"javascript:prev_move();\">Previous</a></span>");
 900         }
 901         if (current_display_move == current_display_line.pretty_pv.length - 1) {
 902                 $("#nextmove").html("Next");
 903         } else {
 904                 $("#nextmove").html("<a href=\"javascript:next_move();\">Next</a></span>");
 905         }
 906
 907         var hiddenboard = new Chess();
 908         hiddenboard.load(current_display_line.start_fen);
 909         for (var i = 0; i <= current_display_move; ++i) {
 910                 hiddenboard.move(current_display_line.pretty_pv[i]);
 911         }
 912
 913         highlighted_move = $("#automove" + current_display_line.line_number + "-" + current_display_move);
 914         highlighted_move.addClass('highlight');
 915
 916         board.position(hiddenboard.fen());
 917 }
 918
 919 var init = function() {
 920         unique = get_unique();
 921
 922         // Create board.
 923         board = new window.ChessBoard('board', 'start');
 924
 925         request_update();
 926         $(window).resize(function() {
 927                 board.resize();
 928                 update_highlight();
 929                 redraw_arrows();
 930         });
 931         $(window).keyup(function(event) {
 932                 if (event.which == 39) {
 933                         next_move();
 934                 } else if (event.which == 37) {
 935                         prev_move();
 936                 }
 937         });
 938 };
 939 $(document).ready(init);
 940
 941 })();