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             elementArray.push(gameDiv);
 243             if (!!this.vr.reserve)
 244             {
 245                 const shiftIdx = (this.mycolor=="w" ? 0 : 1);
 246                 let myReservePiecesArray = [];
 247                 for (let i=0; i<VariantRules.RESERVE_PIECES.length; i++)
 248                 {
 249                     myReservePiecesArray.push(h('div',
 250                     {
 251                         'class': {'board':true, ['board'+sizeY]:true},
 252                         attrs: { id: this.getSquareId({x:sizeX+shiftIdx,y:i}) }
 253                     },
 254                     [
 255                         h('img',
 256                         {
 257                             'class': {"piece":true},
 258                             attrs: {
 259                                 "src": "/images/pieces/" +
 260                                     this.vr.getReservePpath(this.mycolor,i) + ".svg",
 261                             }
 262                         }),
 263                         h('sup',
 264                             {style: { "padding-left":"40%"} },
 265                             [ this.vr.reserve[this.mycolor][VariantRules.RESERVE_PIECES[i]] ]
 266                         )
 267                     ]));
 268                 }
 269                 let oppReservePiecesArray = [];
 270                 const oppCol = this.vr.getOppCol(this.mycolor);
 271                 for (let i=0; i<VariantRules.RESERVE_PIECES.length; i++)
 272                 {
 273                     oppReservePiecesArray.push(h('div',
 274                     {
 275                         'class': {'board':true, ['board'+sizeY]:true},
 276                         attrs: { id: this.getSquareId({x:sizeX+(1-shiftIdx),y:i}) }
 277                     },
 278                     [
 279                         h('img',
 280                         {
 281                             'class': {"piece":true},
 282                             attrs: {
 283                                 "src": "/images/pieces/" +
 284                                     this.vr.getReservePpath(oppCol,i) + ".svg",
 285                             }
 286                         }),
 287                         h('sup',
 288                             {style: { "padding-left":"40%"} },
 289                             [ this.vr.reserve[oppCol][VariantRules.RESERVE_PIECES[i]] ]
 290                         )
 291                     ]));
 292                 }
 293                 let reserves = h('div',
 294                     {
 295                         'class':{'game':true},
 296                         style: {"margin-bottom": "20px"},
 297                     },
 298                     [
 299                         h('div',
 300                             {
 301                                 'class': { 'row': true },
 302                                 style: {"margin-bottom": "15px"},
 303                             },
 304                             myReservePiecesArray
 305                         ),
 306                         h('div',
 307                             { 'class': { 'row': true }},
 308                             oppReservePiecesArray
 309                         )
 310                     ]
 311                 );
 312                 elementArray.push(reserves);
 313             }
 314             const eogMessage = this.getEndgameMessage(this.score);
 315             const modalEog = [
 316                 h('input',
 317                     {
 318                         attrs: { "id": "modal-eog", type: "checkbox" },
 319                         "class": { "modal": true },
 320                     }),
 321                 h('div',
 322                     {
 323                         attrs: { "role": "dialog", "aria-labelledby": "dialog-title" },
 324                     },
 325                     [
 326                         h('div',
 327                             {
 328                                 "class": { "card": true, "smallpad": true },
 329                             },
 330                             [
 331                                 h('label',
 332                                     {
 333                                         attrs: { "for": "modal-eog" },
 334                                         "class": { "modal-close": true },
 335                                     }
 336                                 ),
 337                                 h('h3',
 338                                     {
 339                                         "class": { "section": true },
 340                                         domProps: { innerHTML: eogMessage },
 341                                     }
 342                                 )
 343                             ]
 344                         )
 345                     ]
 346                 )
 347             ];
 348             elementArray = elementArray.concat(modalEog);
 349         }
 350         const modalNewgame = [
 351             h('input',
 352                 {
 353                     attrs: { "id": "modal-newgame", type: "checkbox" },
 354                     "class": { "modal": true },
 355                 }),
 356             h('div',
 357                 {
 358                     attrs: { "role": "dialog", "aria-labelledby": "dialog-title" },
 359                 },
 360                 [
 361                     h('div',
 362                         {
 363                             "class": { "card": true, "smallpad": true },
 364                         },
 365                         [
 366                             h('label',
 367                                 {
 368                                     attrs: { "id": "close-newgame", "for": "modal-newgame" },
 369                                     "class": { "modal-close": true },
 370                                 }
 371                             ),
 372                             h('h3',
 373                                 {
 374                                     "class": { "section": true },
 375                                     domProps: { innerHTML: "New game" },
 376                                 }
 377                             ),
 378                             h('p',
 379                                 {
 380                                     "class": { "section": true },
 381                                     domProps: { innerHTML: "Waiting for opponent..." },
 382                                 }
 383                             )
 384                         ]
 385                     )
 386                 ]
 387             )
 388         ];
 389         elementArray = elementArray.concat(modalNewgame);
 390         const actions = h('div',
 391             {
 392                 attrs: { "id": "actions" },
 393                 'class': { 'text-center': true },
 394             },
 395             actionArray
 396         );
 397         elementArray.push(actions);
 398         if (this.score != "*")
 399         {
 400             elementArray.push(
 401                 h('div',
 402                     { attrs: { id: "pgn-div" } },
 403                     [
 404                         h('a',
 405                             {
 406                                 attrs: {
 407                                     id: "download",
 408                                     href: "#",
 409                                 }
 410                             }
 411                         ),
 412                         h('p',
 413                             {
 414                                 attrs: { id: "pgn-game" },
 415                                 on: { click: this.download },
 416                                 domProps: {
 417                                     innerHTML: this.pgnTxt
 418                                 }
 419                             }
 420                         )
 421                     ]
 422                 )
 423             );
 424         }
 425         return h(
 426             'div',
 427             {
 428                 'class': {
 429                     "col-sm-12":true,
 430                     "col-md-8":true,
 431                     "col-md-offset-2":true,
 432                     "col-lg-6":true,
 433                     "col-lg-offset-3":true,
 434                 },
 435                 // NOTE: click = mousedown + mouseup
 436                 on: {
 437                     mousedown: this.mousedown,
 438                     mousemove: this.mousemove,
 439                     mouseup: this.mouseup,
 440 //                  touchstart: this.mousedown, //TODO...
 441 //                  touchmove: this.mousemove,
 442 //                  touchend: this.mouseup,
 443                 },
 444             },
 445             elementArray
 446         );
 447     },
 448     created: function() {
 449         const url = socketUrl;
 450         const continuation = (localStorage.getItem("variant") === variant);
 451         this.myid = continuation
 452             ? localStorage.getItem("myid")
 453             // random enough (TODO: function)
 454             : (Date.now().toString(36) + Math.random().toString(36).substr(2, 7)).toUpperCase();
 455         if (!continuation)
 456         {
 457             // HACK: play a small silent sound to allow "new game" sound later if tab not focused
 458             new Audio("/sounds/silent.mp3").play().then(() => {}).catch(err => {});
 459         }
 460         this.conn = new WebSocket(url + "/?sid=" + this.myid + "&page=" + variant);
 461         const socketOpenListener = () => {
 462             if (continuation)
 463             {
 464                 const fen = localStorage.getItem("fen");
 465                 const mycolor = localStorage.getItem("mycolor");
 466                 const oppid = localStorage.getItem("oppid");
 467                 const moves = JSON.parse(localStorage.getItem("moves"));
 468                 this.newGame("human", fen, mycolor, oppid, moves, true);
 469                 // Send ping to server (answer pong if opponent is connected)
 470                 this.conn.send(JSON.stringify({code:"ping",oppid:this.oppid}));
 471             }
 472             else if (localStorage.getItem("newgame") === variant)
 473             {
 474                 // New game request has been cancelled on disconnect
 475                 this.seek = true;
 476                 this.newGame("human", undefined, undefined, undefined, undefined, "reconnect");
 477             }
 478         };
 479         const socketMessageListener = msg => {
 480             const data = JSON.parse(msg.data);
 481             switch (data.code)
 482             {
 483                 case "newgame": //opponent found
 484                     this.newGame("human", data.fen, data.color, data.oppid); //oppid: opponent socket ID
 485                     break;
 486                 case "newmove": //..he played!
 487                     this.play(data.move, "animate");
 488                     break;
 489                 case "pong": //received if we sent a ping (game still alive on our side)
 490                     this.oppConnected = true;
 491                     const L = this.vr.moves.length;
 492                     // Send our "last state" informations to opponent
 493                     this.conn.send(JSON.stringify({
 494                         code:"lastate",
 495                         oppid:this.oppid,
 496                         lastMove:L>0?this.vr.moves[L-1]:undefined,
 497                         movesCount:L,
 498                     }));
 499                     break;
 500                 case "lastate": //got opponent infos about last move (we might have resigned)
 501                     if (this.mode!="human" || this.oppid!=data.oppid)
 502                     {
 503                         // OK, we resigned
 504                         this.conn.send(JSON.stringify({
 505                             code:"lastate",
 506                             oppid:this.oppid,
 507                             lastMove:undefined,
 508                             movesCount:-1,
 509                         }));
 510                     }
 511                     else if (data.movesCount < 0)
 512                     {
 513                         // OK, he resigned
 514                         this.endGame(this.mycolor=="w"?"1-0":"0-1");
 515                     }
 516                     else if (data.movesCount < this.vr.moves.length)
 517                     {
 518                         // We must tell last move to opponent
 519                         const L = this.vr.moves.length;
 520                         this.conn.send(JSON.stringify({
 521                             code:"lastate",
 522                             oppid:this.oppid,
 523                             lastMove:this.vr.moves[L-1],
 524                             movesCount:L,
 525                         }));
 526                     }
 527                     else if (data.movesCount > this.vr.moves.length) //just got last move from him
 528                         this.play(data.lastMove, "animate");
 529                     break;
 530                 case "resign": //..you won!
 531                     this.endGame(this.mycolor=="w"?"1-0":"0-1");
 532                     break;
 533                 // TODO: also use (dis)connect info to count online players?
 534                 case "connect":
 535                 case "disconnect":
 536                     if (this.mode == "human" && this.oppid == data.id)
 537                         this.oppConnected = (data.code == "connect");
 538                     break;
 539             }
 540         };
 541         const socketCloseListener = () => {
 542             this.conn = new WebSocket(url + "/?sid=" + this.myid + "&page=" + variant);
 543             this.conn.addEventListener('open', socketOpenListener);
 544             this.conn.addEventListener('message', socketMessageListener);
 545             this.conn.addEventListener('close', socketCloseListener);
 546         };
 547         this.conn.onopen = socketOpenListener;
 548         this.conn.onmessage = socketMessageListener;
 549         this.conn.onclose = socketCloseListener;
 550     },
 551     methods: {
 552         download: function() {
 553             let content = document.getElementById("pgn-game").innerHTML;
 554             content = content.replace(/<br>/g, "\n");
 555             // Prepare and trigger download link
 556             let downloadAnchor = document.getElementById("download");
 557             downloadAnchor.setAttribute("download", "game.pgn");
 558             downloadAnchor.href = "data:text/plain;charset=utf-8," + encodeURIComponent(content);
 559             downloadAnchor.click();
 560         },
 561         endGame: function(score) {
 562             this.score = score;
 563             let modalBox = document.getElementById("modal-eog");
 564             modalBox.checked = true;
 565             // Variants may have special PGN structure (so next function isn't defined here)
 566             this.pgnTxt = this.vr.getPGN(this.mycolor, this.score, this.fenStart, this.mode);
 567             setTimeout(() => { modalBox.checked = false; }, 2000);
 568             if (this.mode == "human")
 569                 this.clearStorage();
 570             this.mode = "idle";
 571             this.oppid = "";
 572         },
 573         getEndgameMessage: function(score) {
 574             let eogMessage = "Unfinished";
 575             switch (this.score)
 576             {
 577                 case "1-0":
 578                     eogMessage = "White win";
 579                     break;
 580                 case "0-1":
 581                     eogMessage = "Black win";
 582                     break;
 583                 case "1/2":
 584                     eogMessage = "Draw";
 585                     break;
 586             }
 587             return eogMessage;
 588         },
 589         toggleExpertMode: function() {
 590             this.expert = !this.expert;
 591             document.cookie = "expert=" + (this.expert ? "1" : "0");
 592         },
 593         resign: function() {
 594             if (this.mode == "human" && this.oppConnected)
 595             {
 596                 try {
 597                     this.conn.send(JSON.stringify({code: "resign", oppid: this.oppid}));
 598                 } catch (INVALID_STATE_ERR) {
 599                     return; //socket is not ready (and not yet reconnected)
 600                 }
 601             }
 602             this.endGame(this.mycolor=="w"?"0-1":"1-0");
 603         },
 604         setStorage: function() {
 605             localStorage.setItem("myid", this.myid);
 606             localStorage.setItem("variant", variant);
 607             localStorage.setItem("mycolor", this.mycolor);
 608             localStorage.setItem("oppid", this.oppid);
 609             localStorage.setItem("fenStart", this.fenStart);
 610             localStorage.setItem("moves", JSON.stringify(this.vr.moves));
 611             localStorage.setItem("fen", this.vr.getFen());
 612         },
 613         updateStorage: function() {
 614             localStorage.setItem("moves", JSON.stringify(this.vr.moves));
 615             localStorage.setItem("fen", this.vr.getFen());
 616         },
 617         clearStorage: function() {
 618             delete localStorage["variant"];
 619             delete localStorage["myid"];
 620             delete localStorage["mycolor"];
 621             delete localStorage["oppid"];
 622             delete localStorage["fenStart"];
 623             delete localStorage["fen"];
 624             delete localStorage["moves"];
 625         },
 626         clickGameSeek: function() {
 627             if (this.mode == "human")
 628                 return; //no newgame while playing
 629             if (this.seek)
 630             {
 631                 delete localStorage["newgame"]; //cancel game seek
 632                 this.seek = false;
 633             }
 634             else
 635                 this.newGame("human");
 636         },
 637         clickComputerGame: function() {
 638             if (this.mode == "human")
 639                 return; //no newgame while playing
 640             this.newGame("computer");
 641         },
 642         newGame: function(mode, fenInit, color, oppId, moves, continuation) {
 643             const fen = fenInit || VariantRules.GenRandInitFen();
 644             console.log(fen); //DEBUG
 645             this.score = "*";
 646             if (mode=="human" && !oppId)
 647             {
 648                 const storageVariant = localStorage.getItem("variant");
 649                 if (!!storageVariant && storageVariant !== variant)
 650                 {
 651                     alert("Finish your " + storageVariant + " game first!");
 652                     return;
 653                 }
 654                 // Send game request and wait..
 655                 localStorage["newgame"] = variant;
 656                 this.seek = true;
 657                 this.clearStorage(); //in case of
 658                 try {
 659                     this.conn.send(JSON.stringify({code:"newgame", fen:fen}));
 660                 } catch (INVALID_STATE_ERR) {
 661                     return; //nothing achieved
 662                 }
 663                 if (continuation !== "reconnect") //TODO: bad HACK...
 664                 {
 665                     let modalBox = document.getElementById("modal-newgame");
 666                     modalBox.checked = true;
 667                     setTimeout(() => { modalBox.checked = false; }, 2000);
 668                 }
 669                 return;
 670             }
 671             // random enough (TODO: function)
 672             this.gameId = (Date.now().toString(36) + Math.random().toString(36).substr(2, 7)).toUpperCase();
 673             this.vr = new VariantRules(fen, moves || []);
 674             this.pgnTxt = ""; //redundant with this.score = "*", but cleaner
 675             this.mode = mode;
 676             this.incheck = []; //in case of
 677             this.fenStart = continuation
 678                 ? localStorage.getItem("fenStart")
 679                 : fen.split(" ")[0]; //Only the position matters
 680             if (mode=="human")
 681             {
 682                 // Opponent found!
 683                 if (!continuation)
 684                 {
 685                     // Not playing sound on game continuation:
 686                     new Audio("/sounds/newgame.mp3").play().then(() => {}).catch(err => {});
 687                     document.getElementById("modal-newgame").checked = false;
 688                 }
 689                 this.oppid = oppId;
 690                 this.oppConnected = true;
 691                 this.mycolor = color;
 692                 this.seek = false;
 693                 if (!!moves && moves.length > 0) //imply continuation
 694                 {
 695                     const lastMove = moves[moves.length-1];
 696                     this.vr.undo(lastMove);
 697                     this.incheck = this.vr.getCheckSquares(lastMove);
 698                     this.vr.play(lastMove, "ingame");
 699                 }
 700                 delete localStorage["newgame"];
 701                 this.setStorage(); //in case of interruptions
 702             }
 703             else //against computer
 704             {
 705                 this.mycolor = Math.random() < 0.5 ? 'w' : 'b';
 706                 if (this.mycolor == 'b')
 707                     setTimeout(this.playComputerMove, 500);
 708             }
 709         },
 710         playComputerMove: function() {
 711             const timeStart = Date.now();
 712             const nbMoves = this.vr.moves.length; //using played moves to know if search finished
 713             const gameId = this.gameId; //to know if game was reset before timer end
 714             setTimeout(
 715                 () => {
 716                     if (gameId != this.gameId)
 717                         return; //game stopped
 718                     const L = this.vr.moves.length;
 719                     if (nbMoves == L || !this.vr.moves[L-1].notation) //move search didn't finish
 720                         this.vr.shouldReturn = true;
 721                 }, 5000);
 722             const compMove = this.vr.getComputerMove();
 723             // (first move) HACK: avoid selecting elements before they appear on page:
 724             const delay = Math.max(500-(Date.now()-timeStart), 0);
 725             setTimeout(() => this.play(compMove, "animate"), delay);
 726         },
 727         // Get the identifier of a HTML table cell from its numeric coordinates o.x,o.y.
 728         getSquareId: function(o) {
 729             // NOTE: a separator is required to allow any size of board
 730             return  "sq-" + o.x + "-" + o.y;
 731         },
 732         // Inverse function
 733         getSquareFromId: function(id) {
 734             let idParts = id.split('-');
 735             return [parseInt(idParts[1]), parseInt(idParts[2])];
 736         },
 737         mousedown: function(e) {
 738             e = e || window.event;
 739             let ingame = false;
 740             let elem = e.target;
 741             while (!ingame && elem !== null)
 742             {
 743                 if (elem.classList.contains("game"))
 744                 {
 745                     ingame = true;
 746                     break;
 747                 }
 748                 elem = elem.parentElement;
 749             }
 750             if (!ingame) //let default behavior (click on button...)
 751                 return;
 752             e.preventDefault(); //disable native drag & drop
 753             if (!this.selectedPiece && e.target.classList.contains("piece"))
 754             {
 755                 // Next few lines to center the piece on mouse cursor
 756                 let rect = e.target.parentNode.getBoundingClientRect();
 757                 this.start = {
 758                     x: rect.x + rect.width/2,
 759                     y: rect.y + rect.width/2,
 760                     id: e.target.parentNode.id
 761                 };
 762                 this.selectedPiece = e.target.cloneNode();
 763                 this.selectedPiece.style.position = "absolute";
 764                 this.selectedPiece.style.top = 0;
 765                 this.selectedPiece.style.display = "inline-block";
 766                 this.selectedPiece.style.zIndex = 3000;
 767                 let startSquare = this.getSquareFromId(e.target.parentNode.id);
 768                 this.possibleMoves = this.mode!="idle" && this.vr.canIplay(this.mycolor,startSquare)
 769                     ? this.vr.getPossibleMovesFrom(startSquare)
 770                     : [];
 771                 // Next line add moving piece just after current image (required for Crazyhouse reserve)
 772                 e.target.parentNode.insertBefore(this.selectedPiece, e.target.nextSibling);
 773             }
 774         },
 775         mousemove: function(e) {
 776             if (!this.selectedPiece)
 777                 return;
 778             e = e || window.event;
 779             // If there is an active element, move it around
 780             if (!!this.selectedPiece)
 781             {
 782                 this.selectedPiece.style.left = (e.clientX-this.start.x) + "px";
 783                 this.selectedPiece.style.top = (e.clientY-this.start.y) + "px";
 784             }
 785         },
 786         mouseup: function(e) {
 787             if (!this.selectedPiece)
 788                 return;
 789             e = e || window.event;
 790             // Read drop target (or parentElement, parentNode... if type == "img")
 791             this.selectedPiece.style.zIndex = -3000; //HACK to find square from final coordinates
 792             let landing = document.elementFromPoint(e.clientX, e.clientY);
 793             this.selectedPiece.style.zIndex = 3000;
 794             while (landing.tagName == "IMG") //classList.contains(piece) fails because of mark/highlight
 795                 landing = landing.parentNode;
 796             if (this.start.id == landing.id) //a click: selectedPiece and possibleMoves already filled
 797                 return;
 798             // OK: process move attempt
 799             let endSquare = this.getSquareFromId(landing.id);
 800             let moves = this.findMatchingMoves(endSquare);
 801             this.possibleMoves = [];
 802             if (moves.length > 1)
 803                 this.choices = moves;
 804             else if (moves.length==1)
 805                 this.play(moves[0]);
 806             // Else: impossible move
 807             this.selectedPiece.parentNode.removeChild(this.selectedPiece);
 808             delete this.selectedPiece;
 809             this.selectedPiece = null;
 810         },
 811         findMatchingMoves: function(endSquare) {
 812             // Run through moves list and return the matching set (if promotions...)
 813             let moves = [];
 814             this.possibleMoves.forEach(function(m) {
 815                 if (endSquare[0] == m.end.x && endSquare[1] == m.end.y)
 816                     moves.push(m);
 817             });
 818             return moves;
 819         },
 820         animateMove: function(move) {
 821             let startSquare = document.getElementById(this.getSquareId(move.start));
 822             let endSquare = document.getElementById(this.getSquareId(move.end));
 823             let rectStart = startSquare.getBoundingClientRect();
 824             let rectEnd = endSquare.getBoundingClientRect();
 825             let translation = {x:rectEnd.x-rectStart.x, y:rectEnd.y-rectStart.y};
 826             let movingPiece =
 827                 document.querySelector("#" + this.getSquareId(move.start) + " > img.piece");
 828             // HACK for animation (with positive translate, image slides "under background"...)
 829             // Possible improvement: just alter squares on the piece's way...
 830             squares = document.getElementsByClassName("board");
 831             for (let i=0; i<squares.length; i++)
 832             {
 833                 let square = squares.item(i);
 834                 if (square.id != this.getSquareId(move.start))
 835                     square.style.zIndex = "-1";
 836             }
 837             movingPiece.style.transform = "translate(" + translation.x + "px," + translation.y + "px)";
 838             movingPiece.style.transitionDuration = "0.2s";
 839             movingPiece.style.zIndex = "3000";
 840             setTimeout( () => {
 841                 for (let i=0; i<squares.length; i++)
 842                     squares.item(i).style.zIndex = "auto";
 843                 movingPiece.style = {}; //required e.g. for 0-0 with KR swap
 844                 this.play(move);
 845             }, 200);
 846         },
 847         play: function(move, programmatic) {
 848             if (!!programmatic) //computer or human opponent
 849             {
 850                 this.animateMove(move);
 851                 return;
 852             }
 853             this.incheck = this.vr.getCheckSquares(move); //is opponent in check?
 854             // Not programmatic, or animation is over
 855             if (this.mode == "human" && this.vr.turn == this.mycolor)
 856                 this.conn.send(JSON.stringify({code:"newmove", move:move, oppid:this.oppid}));
 857             new Audio("/sounds/chessmove1.mp3").play().then(() => {}).catch(err => {});
 858             this.vr.play(move, "ingame");
 859             if (this.mode == "human")
 860                 this.updateStorage(); //after our moves and opponent moves
 861             const eog = this.vr.checkGameOver();
 862             if (eog != "*")
 863                 this.endGame(eog);
 864             else if (this.mode == "computer" && this.vr.turn != this.mycolor)
 865                 setTimeout(this.playComputerMove, 500);
 866         },
 867     },
 868 })