public/javascripts/components/game.js

   1 Vue.component('my-game', {
   2     data: function() {
   3         return {
   4             vr: null, //object to check moves, store them, FEN..
   5             mycolor: "w",
   6             possibleMoves: [], //filled after each valid click/dragstart
   7             choices: [], //promotion pieces, or checkered captures... (contain possible pieces)
   8             start: {}, //pixels coordinates + id of starting square (click or drag)
   9             selectedPiece: null, //moving piece (or clicked piece)
  10             conn: null, //socket messages
  11             score: "*", //'*' means 'unfinished'
  12             mode: "idle", //human, computer or idle (when not playing)
  13             oppid: "", //opponent ID in case of HH game
  14             oppConnected: false,
  15             seek: false,
  16             fenStart: "",
  17             incheck: [],
  18             pgnTxt: "",
  19             expert: document.cookie.length>0 ? document.cookie.substr(-1)=="1" : false,
  20             gameId: "", //used to limit computer moves' time
  21         };
  22     },
  23     render(h) {
  24         const [sizeX,sizeY] = VariantRules.size;
  25         // Precompute hints squares to facilitate rendering
  26         let hintSquares = doubleArray(sizeX, sizeY, false);
  27         this.possibleMoves.forEach(m => { hintSquares[m.end.x][m.end.y] = true; });
  28         // Also precompute in-check squares
  29         let incheckSq = doubleArray(sizeX, sizeY, false);
  30         this.incheck.forEach(sq => { incheckSq[sq[0]][sq[1]] = true; });
  31         let elementArray = [];
  32         const playingHuman = (this.mode == "human");
  33         const playingComp = (this.mode == "computer");
  34         let actionArray = [
  35             h('button',
  36                 {
  37                     on: { click: this.clickGameSeek },
  38                     attrs: { "aria-label": 'New game VS human' },
  39                     'class': {
  40                         "tooltip": true,
  41                         "bottom": true, //display below
  42                         "seek": this.seek,
  43                         "playing": playingHuman,
  44                     },
  45                 },
  46                 [h('i', { 'class': { "material-icons": true } }, "accessibility")]),
  47             h('button',
  48                 {
  49                     on: { click: this.clickComputerGame },
  50                     attrs: { "aria-label": 'New game VS computer' },
  51                     'class': {
  52                         "tooltip":true,
  53                         "bottom": true,
  54                         "playing": playingComp,
  55                     },
  56                 },
  57                 [h('i', { 'class': { "material-icons": true } }, "computer")])
  58         ];
  59         if (!!this.vr)
  60         {
  61             const square00 = document.getElementById("sq-0-0");
  62             const squareWidth = !!square00
  63                 ? parseFloat(window.getComputedStyle(square00).width.slice(0,-2))
  64                 : 0;
  65             const indicWidth = (squareWidth>0 ? squareWidth/2 : 20);
  66             if (this.mode == "human")
  67             {
  68                 let connectedIndic = h(
  69                     'div',
  70                     {
  71                         "class": {
  72                             "topindicator": true,
  73                             "indic-left": true,
  74                             "connected": this.oppConnected,
  75                             "disconnected": !this.oppConnected,
  76                         },
  77                         style: {
  78                             "width": indicWidth + "px",
  79                             "height": indicWidth + "px",
  80                         },
  81                     }
  82                 );
  83                 elementArray.push(connectedIndic);
  84             }
  85             let turnIndic = h(
  86                 'div',
  87                 {
  88                     "class": {
  89                         "topindicator": true,
  90                         "indic-right": true,
  91                         "white-turn": this.vr.turn=="w",
  92                         "black-turn": this.vr.turn=="b",
  93                     },
  94                     style: {
  95                         "width": indicWidth + "px",
  96                         "height": indicWidth + "px",
  97                     },
  98                 }
  99             );
 100             elementArray.push(turnIndic);
 101             let expertSwitch = h(
 102                 'button',
 103                 {
 104                     on: { click: this.toggleExpertMode },
 105                     attrs: { "aria-label": 'Toggle expert mode' },
 106                     'class': {
 107                         "tooltip":true,
 108                         "topindicator": true,
 109                         "indic-right": true,
 110                         "expert-switch": true,
 111                         "expert-mode": this.expert,
 112                     },
 113                 },
 114                 [h('i', { 'class': { "material-icons": true } }, "remove_red_eye")]
 115             );
 116             elementArray.push(expertSwitch);
 117             let choices = h('div',
 118                 {
 119                     attrs: { "id": "choices" },
 120                     'class': { 'row': true },
 121                     style: {
 122                         "display": this.choices.length>0?"block":"none",
 123                         "top": "-" + ((sizeY/2)*squareWidth+squareWidth/2) + "px",
 124                         "width": (this.choices.length * squareWidth) + "px",
 125                         "height": squareWidth + "px",
 126                     },
 127                 },
 128                 this.choices.map( m => { //a "choice" is a move
 129                     return h('div',
 130                         {
 131                             'class': {
 132                                 'board': true,
 133                                 ['board'+sizeY]: true,
 134                             },
 135                             style: {
 136                                 'width': (100/this.choices.length) + "%",
 137                                 'padding-bottom': (100/this.choices.length) + "%",
 138                             },
 139                         },
 140                         [h('img',
 141                             {
 142                                 attrs: { "src": '/images/pieces/' +
 143                                     VariantRules.getPpath(m.appear[0].c+m.appear[0].p) + '.svg' },
 144                                 'class': { 'choice-piece': true },
 145                                 on: { "click": e => { this.play(m); this.choices=[]; } },
 146                             })
 147                         ]
 148                     );
 149                 })
 150             );
 151             // Create board element (+ reserves if needed by variant or mode)
 152             let gameDiv = h('div',
 153                 {
 154                     'class': { 'game': true },
 155                 },
 156                 [_.range(sizeX).map(i => {
 157                     let ci = this.mycolor=='w' ? i : sizeX-i-1;
 158                     return h(
 159                         'div',
 160                         {
 161                             'class': {
 162                                 'row': true,
 163                             },
 164                             style: { 'opacity': this.choices.length>0?"0.5":"1" },
 165                         },
 166                         _.range(sizeY).map(j => {
 167                             let cj = this.mycolor=='w' ? j : sizeY-j-1;
 168                             let elems = [];
 169                             if (this.vr.board[ci][cj] != VariantRules.EMPTY)
 170                             {
 171                                 elems.push(
 172                                     h(
 173                                         'img',
 174                                         {
 175                                             'class': {
 176                                                 'piece': true,
 177                                                 'ghost': !!this.selectedPiece
 178                                                     && this.selectedPiece.parentNode.id == "sq-"+ci+"-"+cj,
 179                                             },
 180                                             attrs: {
 181                                                 src: "/images/pieces/" +
 182                                                     VariantRules.getPpath(this.vr.board[ci][cj]) + ".svg",
 183                                             },
 184                                         }
 185                                     )
 186                                 );
 187                             }
 188                             if (!this.expert && hintSquares[ci][cj])
 189                             {
 190                                 elems.push(
 191                                     h(
 192                                         'img',
 193                                         {
 194                                             'class': {
 195                                                 'mark-square': true,
 196                                             },
 197                                             attrs: {
 198                                                 src: "/images/mark.svg",
 199                                             },
 200                                         }
 201                                     )
 202                                 );
 203                             }
 204                             const lm = this.vr.lastMove;
 205                             const highlight = !!lm && _.isMatch(lm.end, {x:ci,y:cj});
 206                             return h(
 207                                 'div',
 208                                 {
 209                                     'class': {
 210                                         'board': true,
 211                                         ['board'+sizeY]: true,
 212                                         'light-square': (i+j)%2==0 && (this.expert || !highlight),
 213                                         'dark-square': (i+j)%2==1 && (this.expert || !highlight),
 214                                         'highlight': !this.expert && highlight,
 215                                         'incheck': !this.expert && incheckSq[ci][cj],
 216                                     },
 217                                     attrs: {
 218                                         id: this.getSquareId({x:ci,y:cj}),
 219                                     },
 220                                 },
 221                                 elems
 222                             );
 223                         })
 224                     );
 225                 }), choices]
 226             );
 227             if (this.mode != "idle")
 228             {
 229                 actionArray.push(
 230                     h('button',
 231                         {
 232                             on: { click: this.resign },
 233                             attrs: { "aria-label": 'Resign' },
 234                             'class': {
 235                                 "tooltip":true,
 236                                 "bottom": true,
 237                             },
 238                         },
 239                         [h('i', { 'class': { "material-icons": true } }, "flag")])
 240                 );
 241             }
 242             else if (this.vr.moves.length > 0)
 243             {
 244                 // A game finished, and another is not started yet: allow navigation
 245                 actionArray = actionArray.concat([
 246                     h('button',
 247                         {
 248                             style: { "margin-left": "30px" },
 249                             on: { click: e => this.undo() },
 250                             attrs: { "aria-label": 'Undo' },
 251                             'class': {
 252                                 "tooltip":true,
 253                                 "bottom": true,
 254                             },
 255                         },
 256                         [h('i', { 'class': { "material-icons": true } }, "fast_rewind")]),
 257                     h('button',
 258                         {
 259                             on: { click: e => this.play() },
 260                             attrs: { "aria-label": 'Play' },
 261                             'class': {
 262                                 "tooltip":true,
 263                                 "bottom": true,
 264                             },
 265                         },
 266                         [h('i', { 'class': { "material-icons": true } }, "fast_forward")]),
 267                     ]
 268                 );
 269             }
 270             elementArray.push(gameDiv);
 271             if (!!this.vr.reserve)
 272             {
 273                 const shiftIdx = (this.mycolor=="w" ? 0 : 1);
 274                 let myReservePiecesArray = [];
 275                 for (let i=0; i<VariantRules.RESERVE_PIECES.length; i++)
 276                 {
 277                     myReservePiecesArray.push(h('div',
 278                     {
 279                         'class': {'board':true, ['board'+sizeY]:true},
 280                         attrs: { id: this.getSquareId({x:sizeX+shiftIdx,y:i}) }
 281                     },
 282                     [
 283                         h('img',
 284                         {
 285                             'class': {"piece":true},
 286                             attrs: {
 287                                 "src": "/images/pieces/" +
 288                                     this.vr.getReservePpath(this.mycolor,i) + ".svg",
 289                             }
 290                         }),
 291                         h('sup',
 292                             {style: { "padding-left":"40%"} },
 293                             [ this.vr.reserve[this.mycolor][VariantRules.RESERVE_PIECES[i]] ]
 294                         )
 295                     ]));
 296                 }
 297                 let oppReservePiecesArray = [];
 298                 const oppCol = this.vr.getOppCol(this.mycolor);
 299                 for (let i=0; i<VariantRules.RESERVE_PIECES.length; i++)
 300                 {
 301                     oppReservePiecesArray.push(h('div',
 302                     {
 303                         'class': {'board':true, ['board'+sizeY]:true},
 304                         attrs: { id: this.getSquareId({x:sizeX+(1-shiftIdx),y:i}) }
 305                     },
 306                     [
 307                         h('img',
 308                         {
 309                             'class': {"piece":true},
 310                             attrs: {
 311                                 "src": "/images/pieces/" +
 312                                     this.vr.getReservePpath(oppCol,i) + ".svg",
 313                             }
 314                         }),
 315                         h('sup',
 316                             {style: { "padding-left":"40%"} },
 317                             [ this.vr.reserve[oppCol][VariantRules.RESERVE_PIECES[i]] ]
 318                         )
 319                     ]));
 320                 }
 321                 let reserves = h('div',
 322                     {
 323                         'class':{'game':true},
 324                         style: {"margin-bottom": "20px"},
 325                     },
 326                     [
 327                         h('div',
 328                             {
 329                                 'class': { 'row': true },
 330                                 style: {"margin-bottom": "15px"},
 331                             },
 332                             myReservePiecesArray
 333                         ),
 334                         h('div',
 335                             { 'class': { 'row': true }},
 336                             oppReservePiecesArray
 337                         )
 338                     ]
 339                 );
 340                 elementArray.push(reserves);
 341             }
 342             const eogMessage = this.getEndgameMessage(this.score);
 343             const modalEog = [
 344                 h('input',
 345                     {
 346                         attrs: { "id": "modal-eog", type: "checkbox" },
 347                         "class": { "modal": true },
 348                     }),
 349                 h('div',
 350                     {
 351                         attrs: { "role": "dialog", "aria-labelledby": "dialog-title" },
 352                     },
 353                     [
 354                         h('div',
 355                             {
 356                                 "class": { "card": true, "smallpad": true },
 357                             },
 358                             [
 359                                 h('label',
 360                                     {
 361                                         attrs: { "for": "modal-eog" },
 362                                         "class": { "modal-close": true },
 363                                     }
 364                                 ),
 365                                 h('h3',
 366                                     {
 367                                         "class": { "section": true },
 368                                         domProps: { innerHTML: eogMessage },
 369                                     }
 370                                 )
 371                             ]
 372                         )
 373                     ]
 374                 )
 375             ];
 376             elementArray = elementArray.concat(modalEog);
 377         }
 378         const modalNewgame = [
 379             h('input',
 380                 {
 381                     attrs: { "id": "modal-newgame", type: "checkbox" },
 382                     "class": { "modal": true },
 383                 }),
 384             h('div',
 385                 {
 386                     attrs: { "role": "dialog", "aria-labelledby": "dialog-title" },
 387                 },
 388                 [
 389                     h('div',
 390                         {
 391                             "class": { "card": true, "smallpad": true },
 392                         },
 393                         [
 394                             h('label',
 395                                 {
 396                                     attrs: { "id": "close-newgame", "for": "modal-newgame" },
 397                                     "class": { "modal-close": true },
 398                                 }
 399                             ),
 400                             h('h3',
 401                                 {
 402                                     "class": { "section": true },
 403                                     domProps: { innerHTML: "New game" },
 404                                 }
 405                             ),
 406                             h('p',
 407                                 {
 408                                     "class": { "section": true },
 409                                     domProps: { innerHTML: "Waiting for opponent..." },
 410                                 }
 411                             )
 412                         ]
 413                     )
 414                 ]
 415             )
 416         ];
 417         elementArray = elementArray.concat(modalNewgame);
 418         const actions = h('div',
 419             {
 420                 attrs: { "id": "actions" },
 421                 'class': { 'text-center': true },
 422             },
 423             actionArray
 424         );
 425         elementArray.push(actions);
 426         if (this.score != "*")
 427         {
 428             elementArray.push(
 429                 h('div',
 430                     { attrs: { id: "pgn-div" } },
 431                     [
 432                         h('a',
 433                             {
 434                                 attrs: {
 435                                     id: "download",
 436                                     href: "#",
 437                                 }
 438                             }
 439                         ),
 440                         h('p',
 441                             {
 442                                 attrs: { id: "pgn-game" },
 443                                 on: { click: this.download },
 444                                 domProps: { innerHTML: this.pgnTxt }
 445                             }
 446                         )
 447                     ]
 448                 )
 449             );
 450         }
 451         else if (this.mode != "idle")
 452         {
 453             // Show current FEN (at least for debug)
 454             elementArray.push(
 455                 h('div',
 456                     { attrs: { id: "fen-div" } },
 457                     [
 458                         h('p',
 459                             {
 460                                 attrs: { id: "fen-string" },
 461                                 domProps: { innerHTML: this.vr.getBaseFen() }
 462                             }
 463                         )
 464                     ]
 465                 )
 466             );
 467         }
 468         return h(
 469             'div',
 470             {
 471                 'class': {
 472                     "col-sm-12":true,
 473                     "col-md-8":true,
 474                     "col-md-offset-2":true,
 475                     "col-lg-6":true,
 476                     "col-lg-offset-3":true,
 477                 },
 478                 // NOTE: click = mousedown + mouseup
 479                 on: {
 480                     mousedown: this.mousedown,
 481                     mousemove: this.mousemove,
 482                     mouseup: this.mouseup,
 483                     touchstart: this.mousedown,
 484                     touchmove: this.mousemove,
 485                     touchend: this.mouseup,
 486                 },
 487             },
 488             elementArray
 489         );
 490     },
 491     created: function() {
 492         const url = socketUrl;
 493         const continuation = (localStorage.getItem("variant") === variant);
 494         this.myid = continuation
 495             ? localStorage.getItem("myid")
 496             // random enough (TODO: function)
 497             : (Date.now().toString(36) + Math.random().toString(36).substr(2, 7)).toUpperCase();
 498         if (!continuation)
 499         {
 500             // HACK: play a small silent sound to allow "new game" sound later if tab not focused
 501             new Audio("/sounds/silent.mp3").play().then(() => {}).catch(err => {});
 502         }
 503         this.conn = new WebSocket(url + "/?sid=" + this.myid + "&page=" + variant);
 504         const socketOpenListener = () => {
 505             if (continuation)
 506             {
 507                 const fen = localStorage.getItem("fen");
 508                 const mycolor = localStorage.getItem("mycolor");
 509                 const oppid = localStorage.getItem("oppid");
 510                 const moves = JSON.parse(localStorage.getItem("moves"));
 511                 this.newGame("human", fen, mycolor, oppid, moves, true);
 512                 // Send ping to server (answer pong if opponent is connected)
 513                 this.conn.send(JSON.stringify({code:"ping",oppid:this.oppid}));
 514             }
 515             else if (localStorage.getItem("newgame") === variant)
 516             {
 517                 // New game request has been cancelled on disconnect
 518                 this.seek = true;
 519                 this.newGame("human", undefined, undefined, undefined, undefined, "reconnect");
 520             }
 521         };
 522         const socketMessageListener = msg => {
 523             const data = JSON.parse(msg.data);
 524             switch (data.code)
 525             {
 526                 case "newgame": //opponent found
 527                     this.newGame("human", data.fen, data.color, data.oppid); //oppid: opponent socket ID
 528                     break;
 529                 case "newmove": //..he played!
 530                     this.play(data.move, "animate");
 531                     break;
 532                 case "pong": //received if we sent a ping (game still alive on our side)
 533                     this.oppConnected = true;
 534                     const L = this.vr.moves.length;
 535                     // Send our "last state" informations to opponent
 536                     this.conn.send(JSON.stringify({
 537                         code:"lastate",
 538                         oppid:this.oppid,
 539                         lastMove:L>0?this.vr.moves[L-1]:undefined,
 540                         movesCount:L,
 541                     }));
 542                     break;
 543                 case "lastate": //got opponent infos about last move (we might have resigned)
 544                     if (this.mode!="human" || this.oppid!=data.oppid)
 545                     {
 546                         // OK, we resigned
 547                         this.conn.send(JSON.stringify({
 548                             code:"lastate",
 549                             oppid:this.oppid,
 550                             lastMove:undefined,
 551                             movesCount:-1,
 552                         }));
 553                     }
 554                     else if (data.movesCount < 0)
 555                     {
 556                         // OK, he resigned
 557                         this.endGame(this.mycolor=="w"?"1-0":"0-1");
 558                     }
 559                     else if (data.movesCount < this.vr.moves.length)
 560                     {
 561                         // We must tell last move to opponent
 562                         const L = this.vr.moves.length;
 563                         this.conn.send(JSON.stringify({
 564                             code:"lastate",
 565                             oppid:this.oppid,
 566                             lastMove:this.vr.moves[L-1],
 567                             movesCount:L,
 568                         }));
 569                     }
 570                     else if (data.movesCount > this.vr.moves.length) //just got last move from him
 571                         this.play(data.lastMove, "animate");
 572                     break;
 573                 case "resign": //..you won!
 574                     this.endGame(this.mycolor=="w"?"1-0":"0-1");
 575                     break;
 576                 // TODO: also use (dis)connect info to count online players?
 577                 case "connect":
 578                 case "disconnect":
 579                     if (this.mode == "human" && this.oppid == data.id)
 580                         this.oppConnected = (data.code == "connect");
 581                     break;
 582             }
 583         };
 584         const socketCloseListener = () => {
 585             this.conn = new WebSocket(url + "/?sid=" + this.myid + "&page=" + variant);
 586             this.conn.addEventListener('open', socketOpenListener);
 587             this.conn.addEventListener('message', socketMessageListener);
 588             this.conn.addEventListener('close', socketCloseListener);
 589         };
 590         this.conn.onopen = socketOpenListener;
 591         this.conn.onmessage = socketMessageListener;
 592         this.conn.onclose = socketCloseListener;
 593         // Listen to keyboard left/right to navigate in game
 594         document.onkeydown = event => {
 595             if (this.mode == "idle" && this.vr.moves.length > 0
 596                 && [37,39].includes(event.keyCode))
 597             {
 598                 event.preventDefault();
 599                 if (event.keyCode == 37) //Back
 600                     this.undo();
 601                 else //Forward (39)
 602                     this.play();
 603             }
 604         };
 605     },
 606     methods: {
 607         download: function() {
 608             let content = document.getElementById("pgn-game").innerHTML;
 609             content = content.replace(/<br>/g, "\n");
 610             // Prepare and trigger download link
 611             let downloadAnchor = document.getElementById("download");
 612             downloadAnchor.setAttribute("download", "game.pgn");
 613             downloadAnchor.href = "data:text/plain;charset=utf-8," + encodeURIComponent(content);
 614             downloadAnchor.click();
 615         },
 616         endGame: function(score) {
 617             this.score = score;
 618             let modalBox = document.getElementById("modal-eog");
 619             modalBox.checked = true;
 620             // Variants may have special PGN structure (so next function isn't defined here)
 621             this.pgnTxt = this.vr.getPGN(this.mycolor, this.score, this.fenStart, this.mode);
 622             setTimeout(() => { modalBox.checked = false; }, 2000);
 623             if (this.mode == "human")
 624                 this.clearStorage();
 625             this.mode = "idle";
 626             this.cursor = this.vr.moves.length; //to navigate in finished game
 627             this.oppid = "";
 628         },
 629         getEndgameMessage: function(score) {
 630             let eogMessage = "Unfinished";
 631             switch (this.score)
 632             {
 633                 case "1-0":
 634                     eogMessage = "White win";
 635                     break;
 636                 case "0-1":
 637                     eogMessage = "Black win";
 638                     break;
 639                 case "1/2":
 640                     eogMessage = "Draw";
 641                     break;
 642             }
 643             return eogMessage;
 644         },
 645         toggleExpertMode: function() {
 646             this.expert = !this.expert;
 647             document.cookie = "expert=" + (this.expert ? "1" : "0");
 648         },
 649         resign: function() {
 650             if (this.mode == "human" && this.oppConnected)
 651             {
 652                 try {
 653                     this.conn.send(JSON.stringify({code: "resign", oppid: this.oppid}));
 654                 } catch (INVALID_STATE_ERR) {
 655                     return; //socket is not ready (and not yet reconnected)
 656                 }
 657             }
 658             this.endGame(this.mycolor=="w"?"0-1":"1-0");
 659         },
 660         setStorage: function() {
 661             localStorage.setItem("myid", this.myid);
 662             localStorage.setItem("variant", variant);
 663             localStorage.setItem("mycolor", this.mycolor);
 664             localStorage.setItem("oppid", this.oppid);
 665             localStorage.setItem("fenStart", this.fenStart);
 666             localStorage.setItem("moves", JSON.stringify(this.vr.moves));
 667             localStorage.setItem("fen", this.vr.getFen());
 668         },
 669         updateStorage: function() {
 670             localStorage.setItem("moves", JSON.stringify(this.vr.moves));
 671             localStorage.setItem("fen", this.vr.getFen());
 672         },
 673         clearStorage: function() {
 674             delete localStorage["variant"];
 675             delete localStorage["myid"];
 676             delete localStorage["mycolor"];
 677             delete localStorage["oppid"];
 678             delete localStorage["fenStart"];
 679             delete localStorage["fen"];
 680             delete localStorage["moves"];
 681         },
 682         clickGameSeek: function() {
 683             if (this.mode == "human")
 684                 return; //no newgame while playing
 685             if (this.seek)
 686             {
 687                 delete localStorage["newgame"]; //cancel game seek
 688                 this.seek = false;
 689             }
 690             else
 691                 this.newGame("human");
 692         },
 693         clickComputerGame: function() {
 694             if (this.mode == "human")
 695                 return; //no newgame while playing
 696             this.newGame("computer");
 697         },
 698         newGame: function(mode, fenInit, color, oppId, moves, continuation) {
 699             const fen = fenInit || VariantRules.GenRandInitFen();
 700             console.log(fen); //DEBUG
 701             this.score = "*";
 702             if (mode=="human" && !oppId)
 703             {
 704                 const storageVariant = localStorage.getItem("variant");
 705                 if (!!storageVariant && storageVariant !== variant)
 706                 {
 707                     alert("Finish your " + storageVariant + " game first!");
 708                     return;
 709                 }
 710                 // Send game request and wait..
 711                 localStorage["newgame"] = variant;
 712                 this.seek = true;
 713                 this.clearStorage(); //in case of
 714                 try {
 715                     this.conn.send(JSON.stringify({code:"newgame", fen:fen}));
 716                 } catch (INVALID_STATE_ERR) {
 717                     return; //nothing achieved
 718                 }
 719                 if (continuation !== "reconnect") //TODO: bad HACK...
 720                 {
 721                     let modalBox = document.getElementById("modal-newgame");
 722                     modalBox.checked = true;
 723                     setTimeout(() => { modalBox.checked = false; }, 2000);
 724                 }
 725                 return;
 726             }
 727             // random enough (TODO: function)
 728             this.gameId = (Date.now().toString(36) + Math.random().toString(36).substr(2, 7)).toUpperCase();
 729             this.vr = new VariantRules(fen, moves || []);
 730             this.pgnTxt = ""; //redundant with this.score = "*", but cleaner
 731             this.mode = mode;
 732             this.incheck = []; //in case of
 733             this.fenStart = continuation
 734                 ? localStorage.getItem("fenStart")
 735                 : fen.split(" ")[0]; //Only the position matters
 736             if (mode=="human")
 737             {
 738                 // Opponent found!
 739                 if (!continuation)
 740                 {
 741                     // Not playing sound on game continuation:
 742                     new Audio("/sounds/newgame.mp3").play().then(() => {}).catch(err => {});
 743                     document.getElementById("modal-newgame").checked = false;
 744                 }
 745                 this.oppid = oppId;
 746                 this.oppConnected = true;
 747                 this.mycolor = color;
 748                 this.seek = false;
 749                 if (!!moves && moves.length > 0) //imply continuation
 750                 {
 751                     const lastMove = moves[moves.length-1];
 752                     this.vr.undo(lastMove);
 753                     this.incheck = this.vr.getCheckSquares(lastMove);
 754                     this.vr.play(lastMove, "ingame");
 755                 }
 756                 delete localStorage["newgame"];
 757                 this.setStorage(); //in case of interruptions
 758             }
 759             else //against computer
 760             {
 761                 this.mycolor = Math.random() < 0.5 ? 'w' : 'b';
 762                 if (this.mycolor == 'b')
 763                     setTimeout(this.playComputerMove, 500);
 764             }
 765         },
 766         playComputerMove: function() {
 767             const timeStart = Date.now();
 768             const nbMoves = this.vr.moves.length; //using played moves to know if search finished
 769             const gameId = this.gameId; //to know if game was reset before timer end
 770             setTimeout(
 771                 () => {
 772                     if (gameId != this.gameId)
 773                         return; //game stopped
 774                     const L = this.vr.moves.length;
 775                     if (nbMoves == L || !this.vr.moves[L-1].notation) //move search didn't finish
 776                         this.vr.shouldReturn = true;
 777                 }, 5000);
 778             const compMove = this.vr.getComputerMove();
 779             // (first move) HACK: avoid selecting elements before they appear on page:
 780             const delay = Math.max(500-(Date.now()-timeStart), 0);
 781             setTimeout(() => this.play(compMove, "animate"), delay);
 782         },
 783         // Get the identifier of a HTML table cell from its numeric coordinates o.x,o.y.
 784         getSquareId: function(o) {
 785             // NOTE: a separator is required to allow any size of board
 786             return  "sq-" + o.x + "-" + o.y;
 787         },
 788         // Inverse function
 789         getSquareFromId: function(id) {
 790             let idParts = id.split('-');
 791             return [parseInt(idParts[1]), parseInt(idParts[2])];
 792         },
 793         mousedown: function(e) {
 794             e = e || window.event;
 795             let ingame = false;
 796             let elem = e.target;
 797             while (!ingame && elem !== null)
 798             {
 799                 if (elem.classList.contains("game"))
 800                 {
 801                     ingame = true;
 802                     break;
 803                 }
 804                 elem = elem.parentElement;
 805             }
 806             if (!ingame) //let default behavior (click on button...)
 807                 return;
 808             e.preventDefault(); //disable native drag & drop
 809             if (!this.selectedPiece && e.target.classList.contains("piece"))
 810             {
 811                 // Next few lines to center the piece on mouse cursor
 812                 let rect = e.target.parentNode.getBoundingClientRect();
 813                 this.start = {
 814                     x: rect.x + rect.width/2,
 815                     y: rect.y + rect.width/2,
 816                     id: e.target.parentNode.id
 817                 };
 818                 this.selectedPiece = e.target.cloneNode();
 819                 this.selectedPiece.style.position = "absolute";
 820                 this.selectedPiece.style.top = 0;
 821                 this.selectedPiece.style.display = "inline-block";
 822                 this.selectedPiece.style.zIndex = 3000;
 823                 let startSquare = this.getSquareFromId(e.target.parentNode.id);
 824                 this.possibleMoves = this.mode!="idle" && this.vr.canIplay(this.mycolor,startSquare)
 825                     ? this.vr.getPossibleMovesFrom(startSquare)
 826                     : [];
 827                 // Next line add moving piece just after current image (required for Crazyhouse reserve)
 828                 e.target.parentNode.insertBefore(this.selectedPiece, e.target.nextSibling);
 829             }
 830         },
 831         mousemove: function(e) {
 832             if (!this.selectedPiece)
 833                 return;
 834             e = e || window.event;
 835             // If there is an active element, move it around
 836             if (!!this.selectedPiece)
 837             {
 838                 const [offsetX,offsetY] = !!e.clientX
 839                     ? [e.clientX,e.clientY] //desktop browser
 840                     : [e.changedTouches[0].pageX, e.changedTouches[0].pageY]; //smartphone
 841                 this.selectedPiece.style.left = (offsetX-this.start.x) + "px";
 842                 this.selectedPiece.style.top = (offsetY-this.start.y) + "px";
 843             }
 844         },
 845         mouseup: function(e) {
 846             if (!this.selectedPiece)
 847                 return;
 848             e = e || window.event;
 849             // Read drop target (or parentElement, parentNode... if type == "img")
 850             this.selectedPiece.style.zIndex = -3000; //HACK to find square from final coordinates
 851             const [offsetX,offsetY] = !!e.clientX
 852                 ? [e.clientX,e.clientY]
 853                 : [e.changedTouches[0].pageX, e.changedTouches[0].pageY];
 854             let landing = document.elementFromPoint(offsetX, offsetY);
 855             this.selectedPiece.style.zIndex = 3000;
 856             while (landing.tagName == "IMG") //classList.contains(piece) fails because of mark/highlight
 857                 landing = landing.parentNode;
 858             if (this.start.id == landing.id) //a click: selectedPiece and possibleMoves already filled
 859                 return;
 860             // OK: process move attempt
 861             let endSquare = this.getSquareFromId(landing.id);
 862             let moves = this.findMatchingMoves(endSquare);
 863             this.possibleMoves = [];
 864             if (moves.length > 1)
 865                 this.choices = moves;
 866             else if (moves.length==1)
 867                 this.play(moves[0]);
 868             // Else: impossible move
 869             this.selectedPiece.parentNode.removeChild(this.selectedPiece);
 870             delete this.selectedPiece;
 871             this.selectedPiece = null;
 872         },
 873         findMatchingMoves: function(endSquare) {
 874             // Run through moves list and return the matching set (if promotions...)
 875             let moves = [];
 876             this.possibleMoves.forEach(function(m) {
 877                 if (endSquare[0] == m.end.x && endSquare[1] == m.end.y)
 878                     moves.push(m);
 879             });
 880             return moves;
 881         },
 882         animateMove: function(move) {
 883             let startSquare = document.getElementById(this.getSquareId(move.start));
 884             let endSquare = document.getElementById(this.getSquareId(move.end));
 885             let rectStart = startSquare.getBoundingClientRect();
 886             let rectEnd = endSquare.getBoundingClientRect();
 887             let translation = {x:rectEnd.x-rectStart.x, y:rectEnd.y-rectStart.y};
 888             let movingPiece =
 889                 document.querySelector("#" + this.getSquareId(move.start) + " > img.piece");
 890             // HACK for animation (with positive translate, image slides "under background"...)
 891             // Possible improvement: just alter squares on the piece's way...
 892             squares = document.getElementsByClassName("board");
 893             for (let i=0; i<squares.length; i++)
 894             {
 895                 let square = squares.item(i);
 896                 if (square.id != this.getSquareId(move.start))
 897                     square.style.zIndex = "-1";
 898             }
 899             movingPiece.style.transform = "translate(" + translation.x + "px," + translation.y + "px)";
 900             movingPiece.style.transitionDuration = "0.2s";
 901             movingPiece.style.zIndex = "3000";
 902             setTimeout( () => {
 903                 for (let i=0; i<squares.length; i++)
 904                     squares.item(i).style.zIndex = "auto";
 905                 movingPiece.style = {}; //required e.g. for 0-0 with KR swap
 906                 this.play(move);
 907             }, 200);
 908         },
 909         play: function(move, programmatic) {
 910             if (!move)
 911             {
 912                 // Navigate after game is over
 913                 if (this.cursor >= this.vr.moves.length)
 914                     return; //already at the end
 915                 move = this.vr.moves[this.cursor++];
 916             }
 917             if (!!programmatic) //computer or human opponent
 918             {
 919                 this.animateMove(move);
 920                 return;
 921             }
 922             this.incheck = this.vr.getCheckSquares(move); //is opponent in check?
 923             // Not programmatic, or animation is over
 924             if (this.mode == "human" && this.vr.turn == this.mycolor)
 925                 this.conn.send(JSON.stringify({code:"newmove", move:move, oppid:this.oppid}));
 926             new Audio("/sounds/chessmove1.mp3").play().then(() => {}).catch(err => {});
 927             if (this.mode != "idle")
 928                 this.vr.play(move, "ingame");
 929             else
 930                 VariantRules.PlayOnBoard(this.vr.board, move);
 931             if (this.mode == "human")
 932                 this.updateStorage(); //after our moves and opponent moves
 933             if (this.mode != "idle")
 934             {
 935                 const eog = this.vr.checkGameOver();
 936                 if (eog != "*")
 937                     this.endGame(eog);
 938             }
 939             if (this.mode == "computer" && this.vr.turn != this.mycolor)
 940                 setTimeout(this.playComputerMove, 500);
 941         },
 942         undo: function() {
 943             // Navigate after game is over
 944             if (this.cursor == 0)
 945                 return; //already at the beginning
 946             const move = this.vr.moves[--this.cursor];
 947             VariantRules.UndoOnBoard(this.vr.board, move);
 948             this.$forceUpdate(); //TODO: ?!
 949         }
 950     },
 951 })