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, friend, 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: getCookie("expert") === "1" ? true : false,
  20             gameId: "", //used to limit computer moves' time
  21         };
  22     },
  23     render(h) {
  24         const [sizeX,sizeY] = VariantRules.size;
  25         const smallScreen = (screen.width <= 500);
  26         // Precompute hints squares to facilitate rendering
  27         let hintSquares = doubleArray(sizeX, sizeY, false);
  28         this.possibleMoves.forEach(m => { hintSquares[m.end.x][m.end.y] = true; });
  29         // Also precompute in-check squares
  30         let incheckSq = doubleArray(sizeX, sizeY, false);
  31         this.incheck.forEach(sq => { incheckSq[sq[0]][sq[1]] = true; });
  32         let elementArray = [];
  33         let actionArray = [];
  34         actionArray.push(
  35             h('button',
  36             {
  37                 on: { click: this.clickGameSeek },
  38                 attrs: { "aria-label": 'New online game' },
  39                 'class': {
  40                     "tooltip": true,
  41                     "bottom": true, //display below
  42                     "seek": this.seek,
  43                     "playing": this.mode == "human",
  44                     "small": smallScreen,
  45                 },
  46             },
  47             [h('i', { 'class': { "material-icons": true } }, "accessibility")])
  48         );
  49         if (["idle","computer"].includes(this.mode))
  50         {
  51             actionArray.push(
  52                 h('button',
  53                 {
  54                     on: { click: this.clickComputerGame },
  55                     attrs: { "aria-label": 'New game VS computer' },
  56                     'class': {
  57                         "tooltip":true,
  58                         "bottom": true,
  59                         "playing": this.mode == "computer",
  60                         "small": smallScreen,
  61                     },
  62                 },
  63                 [h('i', { 'class': { "material-icons": true } }, "computer")])
  64             );
  65         }
  66         if (["idle","friend"].includes(this.mode))
  67         {
  68             actionArray.push(
  69                 h('button',
  70                 {
  71                     on: { click: this.clickFriendGame },
  72                     attrs: { "aria-label": 'New IRL game' },
  73                     'class': {
  74                         "tooltip":true,
  75                         "bottom": true,
  76                         "playing": this.mode == "friend",
  77                         "small": smallScreen,
  78                     },
  79                 },
  80                 [h('i', { 'class': { "material-icons": true } }, "people")])
  81             );
  82         }
  83         if (!!this.vr)
  84         {
  85             const square00 = document.getElementById("sq-0-0");
  86             const squareWidth = !!square00
  87                 ? parseFloat(window.getComputedStyle(square00).width.slice(0,-2))
  88                 : 0;
  89             const indicWidth = (squareWidth>0 ? squareWidth/2 : 20);
  90             if (this.mode == "human")
  91             {
  92                 let connectedIndic = h(
  93                     'div',
  94                     {
  95                         "class": {
  96                             "topindicator": true,
  97                             "indic-left": true,
  98                             "connected": this.oppConnected,
  99                             "disconnected": !this.oppConnected,
 100                         },
 101                         style: {
 102                             "width": indicWidth + "px",
 103                             "height": indicWidth + "px",
 104                         },
 105                     }
 106                 );
 107                 elementArray.push(connectedIndic);
 108             }
 109             let turnIndic = h(
 110                 'div',
 111                 {
 112                     "class": {
 113                         "topindicator": true,
 114                         "indic-right": true,
 115                         "white-turn": this.vr.turn=="w",
 116                         "black-turn": this.vr.turn=="b",
 117                     },
 118                     style: {
 119                         "width": indicWidth + "px",
 120                         "height": indicWidth + "px",
 121                     },
 122                 }
 123             );
 124             elementArray.push(turnIndic);
 125             let expertSwitch = h(
 126                 'button',
 127                 {
 128                     on: { click: this.toggleExpertMode },
 129                     attrs: { "aria-label": 'Toggle expert mode' },
 130                     'class': {
 131                         "tooltip":true,
 132                         "topindicator": true,
 133                         "indic-right": true,
 134                         "expert-switch": true,
 135                         "expert-mode": this.expert,
 136                         "small": smallScreen,
 137                     },
 138                 },
 139                 [h('i', { 'class': { "material-icons": true } }, "visibility_off")]
 140             );
 141             elementArray.push(expertSwitch);
 142             let choices = h('div',
 143                 {
 144                     attrs: { "id": "choices" },
 145                     'class': { 'row': true },
 146                     style: {
 147                         "display": this.choices.length>0?"block":"none",
 148                         "top": "-" + ((sizeY/2)*squareWidth+squareWidth/2) + "px",
 149                         "width": (this.choices.length * squareWidth) + "px",
 150                         "height": squareWidth + "px",
 151                     },
 152                 },
 153                 this.choices.map( m => { //a "choice" is a move
 154                     return h('div',
 155                         {
 156                             'class': {
 157                                 'board': true,
 158                                 ['board'+sizeY]: true,
 159                             },
 160                             style: {
 161                                 'width': (100/this.choices.length) + "%",
 162                                 'padding-bottom': (100/this.choices.length) + "%",
 163                             },
 164                         },
 165                         [h('img',
 166                             {
 167                                 attrs: { "src": '/images/pieces/' +
 168                                     VariantRules.getPpath(m.appear[0].c+m.appear[0].p) + '.svg' },
 169                                 'class': { 'choice-piece': true },
 170                                 on: { "click": e => { this.play(m); this.choices=[]; } },
 171                             })
 172                         ]
 173                     );
 174                 })
 175             );
 176             // Create board element (+ reserves if needed by variant or mode)
 177             let gameDiv = h('div',
 178                 {
 179                     'class': { 'game': true },
 180                 },
 181                 [_.range(sizeX).map(i => {
 182                     let ci = this.mycolor=='w' ? i : sizeX-i-1;
 183                     return h(
 184                         'div',
 185                         {
 186                             'class': {
 187                                 'row': true,
 188                             },
 189                             style: { 'opacity': this.choices.length>0?"0.5":"1" },
 190                         },
 191                         _.range(sizeY).map(j => {
 192                             let cj = this.mycolor=='w' ? j : sizeY-j-1;
 193                             let elems = [];
 194                             if (this.vr.board[ci][cj] != VariantRules.EMPTY)
 195                             {
 196                                 elems.push(
 197                                     h(
 198                                         'img',
 199                                         {
 200                                             'class': {
 201                                                 'piece': true,
 202                                                 'ghost': !!this.selectedPiece
 203                                                     && this.selectedPiece.parentNode.id == "sq-"+ci+"-"+cj,
 204                                             },
 205                                             attrs: {
 206                                                 src: "/images/pieces/" +
 207                                                     VariantRules.getPpath(this.vr.board[ci][cj]) + ".svg",
 208                                             },
 209                                         }
 210                                     )
 211                                 );
 212                             }
 213                             if (!this.expert && hintSquares[ci][cj])
 214                             {
 215                                 elems.push(
 216                                     h(
 217                                         'img',
 218                                         {
 219                                             'class': {
 220                                                 'mark-square': true,
 221                                             },
 222                                             attrs: {
 223                                                 src: "/images/mark.svg",
 224                                             },
 225                                         }
 226                                     )
 227                                 );
 228                             }
 229                             const lm = this.vr.lastMove;
 230                             const showLight = !this.expert &&
 231                                 (this.mode!="idle" || this.cursor==this.vr.moves.length);
 232                             return h(
 233                                 'div',
 234                                 {
 235                                     'class': {
 236                                         'board': true,
 237                                         ['board'+sizeY]: true,
 238                                         'light-square': (i+j)%2==0,
 239                                         'dark-square': (i+j)%2==1,
 240                                         'highlight': showLight && !!lm && _.isMatch(lm.end, {x:ci,y:cj}),
 241                                         'incheck': showLight && incheckSq[ci][cj],
 242                                     },
 243                                     attrs: {
 244                                         id: this.getSquareId({x:ci,y:cj}),
 245                                     },
 246                                 },
 247                                 elems
 248                             );
 249                         })
 250                     );
 251                 }), choices]
 252             );
 253             if (this.mode != "idle")
 254             {
 255                 actionArray.push(
 256                     h('button',
 257                         {
 258                             on: { click: this.resign },
 259                             attrs: { "aria-label": 'Resign' },
 260                             'class': {
 261                                 "tooltip":true,
 262                                 "bottom": true,
 263                                 "small": smallScreen,
 264                             },
 265                         },
 266                         [h('i', { 'class': { "material-icons": true } }, "flag")])
 267                 );
 268             }
 269             else if (this.vr.moves.length > 0)
 270             {
 271                 // A game finished, and another is not started yet: allow navigation
 272                 actionArray = actionArray.concat([
 273                     h('button',
 274                         {
 275                             style: { "margin-left": "30px" },
 276                             on: { click: e => this.undo() },
 277                             attrs: { "aria-label": 'Undo' },
 278                             "class": { "small": smallScreen },
 279                         },
 280                         [h('i', { 'class': { "material-icons": true } }, "fast_rewind")]),
 281                     h('button',
 282                         {
 283                             on: { click: e => this.play() },
 284                             attrs: { "aria-label": 'Play' },
 285                             "class": { "small": smallScreen },
 286                         },
 287                         [h('i', { 'class': { "material-icons": true } }, "fast_forward")]),
 288                     ]
 289                 );
 290             }
 291             if (this.mode == "friend")
 292             {
 293                 actionArray = actionArray.concat(
 294                 [
 295                     h('button',
 296                         {
 297                             style: { "margin-left": "30px" },
 298                             on: { click: this.undoInGame },
 299                             attrs: { "aria-label": 'Undo' },
 300                             "class": { "small": smallScreen },
 301                         },
 302                         [h('i', { 'class': { "material-icons": true } }, "undo")]
 303                     ),
 304                     h('button',
 305                         {
 306                             on: { click: () => { this.mycolor = this.vr.getOppCol(this.mycolor) } },
 307                             attrs: { "aria-label": 'Flip' },
 308                             "class": { "small": smallScreen },
 309                         },
 310                         [h('i', { 'class': { "material-icons": true } }, "cached")]
 311                     ),
 312                 ]);
 313             }
 314             elementArray.push(gameDiv);
 315             if (!!this.vr.reserve)
 316             {
 317                 const shiftIdx = (this.mycolor=="w" ? 0 : 1);
 318                 let myReservePiecesArray = [];
 319                 for (let i=0; i<VariantRules.RESERVE_PIECES.length; i++)
 320                 {
 321                     myReservePiecesArray.push(h('div',
 322                     {
 323                         'class': {'board':true, ['board'+sizeY]:true},
 324                         attrs: { id: this.getSquareId({x:sizeX+shiftIdx,y:i}) }
 325                     },
 326                     [
 327                         h('img',
 328                         {
 329                             'class': {"piece":true},
 330                             attrs: {
 331                                 "src": "/images/pieces/" +
 332                                     this.vr.getReservePpath(this.mycolor,i) + ".svg",
 333                             }
 334                         }),
 335                         h('sup',
 336                             {style: { "padding-left":"40%"} },
 337                             [ this.vr.reserve[this.mycolor][VariantRules.RESERVE_PIECES[i]] ]
 338                         )
 339                     ]));
 340                 }
 341                 let oppReservePiecesArray = [];
 342                 const oppCol = this.vr.getOppCol(this.mycolor);
 343                 for (let i=0; i<VariantRules.RESERVE_PIECES.length; i++)
 344                 {
 345                     oppReservePiecesArray.push(h('div',
 346                     {
 347                         'class': {'board':true, ['board'+sizeY]:true},
 348                         attrs: { id: this.getSquareId({x:sizeX+(1-shiftIdx),y:i}) }
 349                     },
 350                     [
 351                         h('img',
 352                         {
 353                             'class': {"piece":true},
 354                             attrs: {
 355                                 "src": "/images/pieces/" +
 356                                     this.vr.getReservePpath(oppCol,i) + ".svg",
 357                             }
 358                         }),
 359                         h('sup',
 360                             {style: { "padding-left":"40%"} },
 361                             [ this.vr.reserve[oppCol][VariantRules.RESERVE_PIECES[i]] ]
 362                         )
 363                     ]));
 364                 }
 365                 let reserves = h('div',
 366                     {
 367                         'class':{'game':true},
 368                         style: {"margin-bottom": "20px"},
 369                     },
 370                     [
 371                         h('div',
 372                             {
 373                                 'class': { 'row': true },
 374                                 style: {"margin-bottom": "15px"},
 375                             },
 376                             myReservePiecesArray
 377                         ),
 378                         h('div',
 379                             { 'class': { 'row': true }},
 380                             oppReservePiecesArray
 381                         )
 382                     ]
 383                 );
 384                 elementArray.push(reserves);
 385             }
 386             const eogMessage = this.getEndgameMessage(this.score);
 387             const modalEog = [
 388                 h('input',
 389                     {
 390                         attrs: { "id": "modal-eog", type: "checkbox" },
 391                         "class": { "modal": true },
 392                     }),
 393                 h('div',
 394                     {
 395                         attrs: { "role": "dialog", "aria-labelledby": "modal-eog" },
 396                     },
 397                     [
 398                         h('div',
 399                             {
 400                                 "class": { "card": true, "smallpad": true },
 401                             },
 402                             [
 403                                 h('label',
 404                                     {
 405                                         attrs: { "for": "modal-eog" },
 406                                         "class": { "modal-close": true },
 407                                     }
 408                                 ),
 409                                 h('h3',
 410                                     {
 411                                         "class": { "section": true },
 412                                         domProps: { innerHTML: eogMessage },
 413                                     }
 414                                 )
 415                             ]
 416                         )
 417                     ]
 418                 )
 419             ];
 420             elementArray = elementArray.concat(modalEog);
 421         }
 422         const modalNewgame = [
 423             h('input',
 424                 {
 425                     attrs: { "id": "modal-newgame", type: "checkbox" },
 426                     "class": { "modal": true },
 427                 }),
 428             h('div',
 429                 {
 430                     attrs: { "role": "dialog", "aria-labelledby": "modal-newgame" },
 431                 },
 432                 [
 433                     h('div',
 434                         {
 435                             "class": { "card": true, "smallpad": true },
 436                         },
 437                         [
 438                             h('label',
 439                                 {
 440                                     attrs: { "id": "close-newgame", "for": "modal-newgame" },
 441                                     "class": { "modal-close": true },
 442                                 }
 443                             ),
 444                             h('h3',
 445                                 {
 446                                     "class": { "section": true },
 447                                     domProps: { innerHTML: "New game" },
 448                                 }
 449                             ),
 450                             h('p',
 451                                 {
 452                                     "class": { "section": true },
 453                                     domProps: { innerHTML: "Waiting for opponent..." },
 454                                 }
 455                             )
 456                         ]
 457                     )
 458                 ]
 459             )
 460         ];
 461         elementArray = elementArray.concat(modalNewgame);
 462         const modalFenEdit = [
 463             h('input',
 464                 {
 465                     attrs: { "id": "modal-fenedit", type: "checkbox" },
 466                     "class": { "modal": true },
 467                 }),
 468             h('div',
 469                 {
 470                     attrs: { "role": "dialog", "aria-labelledby": "modal-fenedit" },
 471                 },
 472                 [
 473                     h('div',
 474                         {
 475                             "class": { "card": true, "smallpad": true },
 476                         },
 477                         [
 478                             h('label',
 479                                 {
 480                                     attrs: { "id": "close-fenedit", "for": "modal-fenedit" },
 481                                     "class": { "modal-close": true },
 482                                 }
 483                             ),
 484                             h('h3',
 485                                 {
 486                                     "class": { "section": true },
 487                                     domProps: { innerHTML: "Position + flags (FEN):" },
 488                                 }
 489                             ),
 490                             h('input',
 491                                 {
 492                                     attrs: {
 493                                         "id": "input-fen",
 494                                         type: "text",
 495                                         value: VariantRules.GenRandInitFen(),
 496                                     },
 497                                 }
 498                             ),
 499                             h('button',
 500                                 {
 501                                     on: { click:
 502                                         () => {
 503                                             const fen = document.getElementById("input-fen").value;
 504                                             document.getElementById("modal-fenedit").checked = false;
 505                                             this.newGame("friend", fen);
 506                                         }
 507                                     },
 508                                     domProps: { innerHTML: "Ok" },
 509                                 }
 510                             ),
 511                             h('button',
 512                                 {
 513                                     on: { click:
 514                                         () => {
 515                                             document.getElementById("input-fen").value =
 516                                                 VariantRules.GenRandInitFen();
 517                                         }
 518                                     },
 519                                     domProps: { innerHTML: "Random" },
 520                                 }
 521                             ),
 522                         ]
 523                     )
 524                 ]
 525             )
 526         ];
 527         elementArray = elementArray.concat(modalFenEdit);
 528         const actions = h('div',
 529             {
 530                 attrs: { "id": "actions" },
 531                 'class': { 'text-center': true },
 532             },
 533             actionArray
 534         );
 535         elementArray.push(actions);
 536         if (this.score != "*")
 537         {
 538             elementArray.push(
 539                 h('div',
 540                     { attrs: { id: "pgn-div" } },
 541                     [
 542                         h('a',
 543                             {
 544                                 attrs: {
 545                                     id: "download",
 546                                     href: "#",
 547                                 }
 548                             }
 549                         ),
 550                         h('p',
 551                             {
 552                                 attrs: { id: "pgn-game" },
 553                                 on: { click: this.download },
 554                                 domProps: { innerHTML: this.pgnTxt }
 555                             }
 556                         )
 557                     ]
 558                 )
 559             );
 560         }
 561         else if (this.mode != "idle")
 562         {
 563             // Show current FEN
 564             elementArray.push(
 565                 h('div',
 566                     { attrs: { id: "fen-div" } },
 567                     [
 568                         h('p',
 569                             {
 570                                 attrs: { id: "fen-string" },
 571                                 domProps: { innerHTML: this.vr.getFen() }
 572                             }
 573                         )
 574                     ]
 575                 )
 576             );
 577         }
 578         return h(
 579             'div',
 580             {
 581                 'class': {
 582                     "col-sm-12":true,
 583                     "col-md-8":true,
 584                     "col-md-offset-2":true,
 585                     "col-lg-6":true,
 586                     "col-lg-offset-3":true,
 587                 },
 588                 // NOTE: click = mousedown + mouseup
 589                 on: {
 590                     mousedown: this.mousedown,
 591                     mousemove: this.mousemove,
 592                     mouseup: this.mouseup,
 593                     touchstart: this.mousedown,
 594                     touchmove: this.mousemove,
 595                     touchend: this.mouseup,
 596                 },
 597             },
 598             elementArray
 599         );
 600     },
 601     created: function() {
 602         const url = socketUrl;
 603         const continuation = (localStorage.getItem("variant") === variant);
 604         this.myid = continuation ? localStorage.getItem("myid") : getRandString();
 605         if (!continuation)
 606         {
 607             // HACK: play a small silent sound to allow "new game" sound later if tab not focused
 608             new Audio("/sounds/silent.mp3").play().then(() => {}).catch(err => {});
 609         }
 610         this.conn = new WebSocket(url + "/?sid=" + this.myid + "&page=" + variant);
 611         const socketOpenListener = () => {
 612             if (continuation)
 613             {
 614                 const fen = localStorage.getItem("fen");
 615                 const mycolor = localStorage.getItem("mycolor");
 616                 const oppid = localStorage.getItem("oppid");
 617                 const moves = JSON.parse(localStorage.getItem("moves"));
 618                 this.newGame("human", fen, mycolor, oppid, moves, true);
 619                 // Send ping to server (answer pong if opponent is connected)
 620                 this.conn.send(JSON.stringify({code:"ping",oppid:this.oppid}));
 621             }
 622             else if (localStorage.getItem("newgame") === variant)
 623             {
 624                 // New game request has been cancelled on disconnect
 625                 this.newGame("human", undefined, undefined, undefined, undefined, "reconnect");
 626             }
 627         };
 628         const socketMessageListener = msg => {
 629             const data = JSON.parse(msg.data);
 630             switch (data.code)
 631             {
 632                 case "newgame": //opponent found
 633                     this.newGame("human", data.fen, data.color, data.oppid); //oppid: opponent socket ID
 634                     break;
 635                 case "newmove": //..he played!
 636                     this.play(data.move, "animate");
 637                     break;
 638                 case "pong": //received if we sent a ping (game still alive on our side)
 639                     this.oppConnected = true;
 640                     const L = this.vr.moves.length;
 641                     // Send our "last state" informations to opponent
 642                     this.conn.send(JSON.stringify({
 643                         code:"lastate",
 644                         oppid:this.oppid,
 645                         lastMove:L>0?this.vr.moves[L-1]:undefined,
 646                         movesCount:L,
 647                     }));
 648                     break;
 649                 case "lastate": //got opponent infos about last move (we might have resigned)
 650                     if (this.mode!="human" || this.oppid!=data.oppid)
 651                     {
 652                         // OK, we resigned
 653                         this.conn.send(JSON.stringify({
 654                             code:"lastate",
 655                             oppid:this.oppid,
 656                             lastMove:undefined,
 657                             movesCount:-1,
 658                         }));
 659                     }
 660                     else if (data.movesCount < 0)
 661                     {
 662                         // OK, he resigned
 663                         this.endGame(this.mycolor=="w"?"1-0":"0-1");
 664                     }
 665                     else if (data.movesCount < this.vr.moves.length)
 666                     {
 667                         // We must tell last move to opponent
 668                         const L = this.vr.moves.length;
 669                         this.conn.send(JSON.stringify({
 670                             code:"lastate",
 671                             oppid:this.oppid,
 672                             lastMove:this.vr.moves[L-1],
 673                             movesCount:L,
 674                         }));
 675                     }
 676                     else if (data.movesCount > this.vr.moves.length) //just got last move from him
 677                         this.play(data.lastMove, "animate");
 678                     break;
 679                 case "resign": //..you won!
 680                     this.endGame(this.mycolor=="w"?"1-0":"0-1");
 681                     break;
 682                 // TODO: also use (dis)connect info to count online players?
 683                 case "connect":
 684                 case "disconnect":
 685                     if (this.mode == "human" && this.oppid == data.id)
 686                         this.oppConnected = (data.code == "connect");
 687                     break;
 688             }
 689         };
 690         const socketCloseListener = () => {
 691             this.conn = new WebSocket(url + "/?sid=" + this.myid + "&page=" + variant);
 692             this.conn.addEventListener('open', socketOpenListener);
 693             this.conn.addEventListener('message', socketMessageListener);
 694             this.conn.addEventListener('close', socketCloseListener);
 695         };
 696         this.conn.onopen = socketOpenListener;
 697         this.conn.onmessage = socketMessageListener;
 698         this.conn.onclose = socketCloseListener;
 699         // Listen to keyboard left/right to navigate in game
 700         document.onkeydown = event => {
 701             if (this.mode == "idle" && !!this.vr && this.vr.moves.length > 0
 702                 && [37,39].includes(event.keyCode))
 703             {
 704                 event.preventDefault();
 705                 if (event.keyCode == 37) //Back
 706                     this.undo();
 707                 else //Forward (39)
 708                     this.play();
 709             }
 710         };
 711     },
 712     methods: {
 713         download: function() {
 714             let content = document.getElementById("pgn-game").innerHTML;
 715             content = content.replace(/<br>/g, "\n");
 716             // Prepare and trigger download link
 717             let downloadAnchor = document.getElementById("download");
 718             downloadAnchor.setAttribute("download", "game.pgn");
 719             downloadAnchor.href = "data:text/plain;charset=utf-8," + encodeURIComponent(content);
 720             downloadAnchor.click();
 721         },
 722         endGame: function(score) {
 723             this.score = score;
 724             let modalBox = document.getElementById("modal-eog");
 725             modalBox.checked = true;
 726             // Variants may have special PGN structure (so next function isn't defined here)
 727             this.pgnTxt = this.vr.getPGN(this.mycolor, this.score, this.fenStart, this.mode);
 728             setTimeout(() => { modalBox.checked = false; }, 2000);
 729             if (this.mode == "human")
 730                 this.clearStorage();
 731             this.mode = "idle";
 732             this.cursor = this.vr.moves.length; //to navigate in finished game
 733             this.oppid = "";
 734         },
 735         getEndgameMessage: function(score) {
 736             let eogMessage = "Unfinished";
 737             switch (this.score)
 738             {
 739                 case "1-0":
 740                     eogMessage = "White win";
 741                     break;
 742                 case "0-1":
 743                     eogMessage = "Black win";
 744                     break;
 745                 case "1/2":
 746                     eogMessage = "Draw";
 747                     break;
 748             }
 749             return eogMessage;
 750         },
 751         setStorage: function() {
 752             localStorage.setItem("myid", this.myid);
 753             localStorage.setItem("variant", variant);
 754             localStorage.setItem("mycolor", this.mycolor);
 755             localStorage.setItem("oppid", this.oppid);
 756             localStorage.setItem("fenStart", this.fenStart);
 757             localStorage.setItem("moves", JSON.stringify(this.vr.moves));
 758             localStorage.setItem("fen", this.vr.getFen());
 759         },
 760         updateStorage: function() {
 761             localStorage.setItem("moves", JSON.stringify(this.vr.moves));
 762             localStorage.setItem("fen", this.vr.getFen());
 763         },
 764         clearStorage: function() {
 765             delete localStorage["variant"];
 766             delete localStorage["myid"];
 767             delete localStorage["mycolor"];
 768             delete localStorage["oppid"];
 769             delete localStorage["fenStart"];
 770             delete localStorage["fen"];
 771             delete localStorage["moves"];
 772         },
 773         // HACK because mini-css tooltips are persistent after click...
 774         getRidOfTooltip: function(elt) {
 775             elt.style.visibility = "hidden";
 776             setTimeout(() => { elt.style.visibility="visible"; }, 100);
 777         },
 778         clickGameSeek: function(e) {
 779             this.getRidOfTooltip(e.currentTarget);
 780             if (this.mode == "human")
 781                 return; //no newgame while playing
 782             if (this.seek)
 783             {
 784                 this.conn.send(JSON.stringify({code:"cancelnewgame"}));
 785                 delete localStorage["newgame"]; //cancel game seek
 786                 this.seek = false;
 787             }
 788             else
 789                 this.newGame("human");
 790         },
 791         clickComputerGame: function(e) {
 792             this.getRidOfTooltip(e.currentTarget);
 793             if (this.mode == "human")
 794                 return; //no newgame while playing
 795             this.newGame("computer");
 796         },
 797         clickFriendGame: function(e) {
 798             this.getRidOfTooltip(e.currentTarget);
 799             document.getElementById("modal-fenedit").checked = true;
 800         },
 801         toggleExpertMode: function(e) {
 802             this.getRidOfTooltip(e.currentTarget);
 803             this.expert = !this.expert;
 804             setCookie("expert", this.expert ? "1" : "0");
 805         },
 806         resign: function(e) {
 807             this.getRidOfTooltip(e.currentTarget);
 808             if (this.mode == "human" && this.oppConnected)
 809             {
 810                 try {
 811                     this.conn.send(JSON.stringify({code: "resign", oppid: this.oppid}));
 812                 } catch (INVALID_STATE_ERR) {
 813                     return; //socket is not ready (and not yet reconnected)
 814                 }
 815             }
 816             this.endGame(this.mycolor=="w"?"0-1":"1-0");
 817         },
 818         newGame: function(mode, fenInit, color, oppId, moves, continuation) {
 819             const fen = fenInit || VariantRules.GenRandInitFen();
 820             console.log(fen); //DEBUG
 821             if (mode=="human" && !oppId)
 822             {
 823                 const storageVariant = localStorage.getItem("variant");
 824                 if (!!storageVariant && storageVariant !== variant)
 825                 {
 826                     alert("Finish your " + storageVariant + " game first!");
 827                     return;
 828                 }
 829                 // Send game request and wait..
 830                 localStorage["newgame"] = variant;
 831                 this.seek = true;
 832                 this.clearStorage(); //in case of
 833                 try {
 834                     this.conn.send(JSON.stringify({code:"newgame", fen:fen}));
 835                 } catch (INVALID_STATE_ERR) {
 836                     return; //nothing achieved
 837                 }
 838                 if (continuation !== "reconnect") //TODO: bad HACK...
 839                 {
 840                     let modalBox = document.getElementById("modal-newgame");
 841                     modalBox.checked = true;
 842                     setTimeout(() => { modalBox.checked = false; }, 2000);
 843                 }
 844                 return;
 845             }
 846             this.gameId = getRandString();
 847             this.vr = new VariantRules(fen, moves || []);
 848             this.score = "*";
 849             this.pgnTxt = ""; //redundant with this.score = "*", but cleaner
 850             this.mode = mode;
 851             this.incheck = []; //in case of
 852             this.fenStart = (continuation ? localStorage.getItem("fenStart") : fen);
 853             if (mode=="human")
 854             {
 855                 // Opponent found!
 856                 if (!continuation)
 857                 {
 858                     // Not playing sound on game continuation:
 859                     new Audio("/sounds/newgame.mp3").play().then(() => {}).catch(err => {});
 860                     document.getElementById("modal-newgame").checked = false;
 861                 }
 862                 this.oppid = oppId;
 863                 this.oppConnected = true;
 864                 this.mycolor = color;
 865                 this.seek = false;
 866                 if (!!moves && moves.length > 0) //imply continuation
 867                 {
 868                     const lastMove = moves[moves.length-1];
 869                     this.vr.undo(lastMove);
 870                     this.incheck = this.vr.getCheckSquares(lastMove);
 871                     this.vr.play(lastMove, "ingame");
 872                 }
 873                 delete localStorage["newgame"];
 874                 this.setStorage(); //in case of interruptions
 875             }
 876             else if (mode == "computer")
 877             {
 878                 this.mycolor = Math.random() < 0.5 ? 'w' : 'b';
 879                 if (this.mycolor == 'b')
 880                     setTimeout(this.playComputerMove, 500);
 881             }
 882             //else: against a (IRL) friend: nothing more to do
 883         },
 884         playComputerMove: function() {
 885             const timeStart = Date.now();
 886             const nbMoves = this.vr.moves.length; //using played moves to know if search finished
 887             const gameId = this.gameId; //to know if game was reset before timer end
 888             setTimeout(
 889                 () => {
 890                     if (gameId != this.gameId)
 891                         return; //game stopped
 892                     const L = this.vr.moves.length;
 893                     if (nbMoves == L || !this.vr.moves[L-1].notation) //move search didn't finish
 894                         this.vr.shouldReturn = true;
 895                 }, 5000);
 896             const compMove = this.vr.getComputerMove();
 897             // (first move) HACK: avoid selecting elements before they appear on page:
 898             const delay = Math.max(500-(Date.now()-timeStart), 0);
 899             setTimeout(() => this.play(compMove, "animate"), delay);
 900         },
 901         // Get the identifier of a HTML table cell from its numeric coordinates o.x,o.y.
 902         getSquareId: function(o) {
 903             // NOTE: a separator is required to allow any size of board
 904             return  "sq-" + o.x + "-" + o.y;
 905         },
 906         // Inverse function
 907         getSquareFromId: function(id) {
 908             let idParts = id.split('-');
 909             return [parseInt(idParts[1]), parseInt(idParts[2])];
 910         },
 911         mousedown: function(e) {
 912             e = e || window.event;
 913             let ingame = false;
 914             let elem = e.target;
 915             while (!ingame && elem !== null)
 916             {
 917                 if (elem.classList.contains("game"))
 918                 {
 919                     ingame = true;
 920                     break;
 921                 }
 922                 elem = elem.parentElement;
 923             }
 924             if (!ingame) //let default behavior (click on button...)
 925                 return;
 926             e.preventDefault(); //disable native drag & drop
 927             if (!this.selectedPiece && e.target.classList.contains("piece"))
 928             {
 929                 // Next few lines to center the piece on mouse cursor
 930                 let rect = e.target.parentNode.getBoundingClientRect();
 931                 this.start = {
 932                     x: rect.x + rect.width/2,
 933                     y: rect.y + rect.width/2,
 934                     id: e.target.parentNode.id
 935                 };
 936                 this.selectedPiece = e.target.cloneNode();
 937                 this.selectedPiece.style.position = "absolute";
 938                 this.selectedPiece.style.top = 0;
 939                 this.selectedPiece.style.display = "inline-block";
 940                 this.selectedPiece.style.zIndex = 3000;
 941                 let startSquare = this.getSquareFromId(e.target.parentNode.id);
 942                 const iCanPlay = this.mode!="idle"
 943                     && (this.mode=="friend" || this.vr.canIplay(this.mycolor,startSquare));
 944                 this.possibleMoves = iCanPlay ? this.vr.getPossibleMovesFrom(startSquare) : [];
 945                 // Next line add moving piece just after current image (required for Crazyhouse reserve)
 946                 e.target.parentNode.insertBefore(this.selectedPiece, e.target.nextSibling);
 947             }
 948         },
 949         mousemove: function(e) {
 950             if (!this.selectedPiece)
 951                 return;
 952             e = e || window.event;
 953             // If there is an active element, move it around
 954             if (!!this.selectedPiece)
 955             {
 956                 const [offsetX,offsetY] = !!e.clientX
 957                     ? [e.clientX,e.clientY] //desktop browser
 958                     : [e.changedTouches[0].pageX, e.changedTouches[0].pageY]; //smartphone
 959                 this.selectedPiece.style.left = (offsetX-this.start.x) + "px";
 960                 this.selectedPiece.style.top = (offsetY-this.start.y) + "px";
 961             }
 962         },
 963         mouseup: function(e) {
 964             if (!this.selectedPiece)
 965                 return;
 966             e = e || window.event;
 967             // Read drop target (or parentElement, parentNode... if type == "img")
 968             this.selectedPiece.style.zIndex = -3000; //HACK to find square from final coordinates
 969             const [offsetX,offsetY] = !!e.clientX
 970                 ? [e.clientX,e.clientY]
 971                 : [e.changedTouches[0].pageX, e.changedTouches[0].pageY];
 972             let landing = document.elementFromPoint(offsetX, offsetY);
 973             this.selectedPiece.style.zIndex = 3000;
 974             while (landing.tagName == "IMG") //classList.contains(piece) fails because of mark/highlight
 975                 landing = landing.parentNode;
 976             if (this.start.id == landing.id) //a click: selectedPiece and possibleMoves already filled
 977                 return;
 978             // OK: process move attempt
 979             let endSquare = this.getSquareFromId(landing.id);
 980             let moves = this.findMatchingMoves(endSquare);
 981             this.possibleMoves = [];
 982             if (moves.length > 1)
 983                 this.choices = moves;
 984             else if (moves.length==1)
 985                 this.play(moves[0]);
 986             // Else: impossible move
 987             this.selectedPiece.parentNode.removeChild(this.selectedPiece);
 988             delete this.selectedPiece;
 989             this.selectedPiece = null;
 990         },
 991         findMatchingMoves: function(endSquare) {
 992             // Run through moves list and return the matching set (if promotions...)
 993             let moves = [];
 994             this.possibleMoves.forEach(function(m) {
 995                 if (endSquare[0] == m.end.x && endSquare[1] == m.end.y)
 996                     moves.push(m);
 997             });
 998             return moves;
 999         },
1000         animateMove: function(move) {
1001             let startSquare = document.getElementById(this.getSquareId(move.start));
1002             let endSquare = document.getElementById(this.getSquareId(move.end));
1003             let rectStart = startSquare.getBoundingClientRect();
1004             let rectEnd = endSquare.getBoundingClientRect();
1005             let translation = {x:rectEnd.x-rectStart.x, y:rectEnd.y-rectStart.y};
1006             let movingPiece =
1007                 document.querySelector("#" + this.getSquareId(move.start) + " > img.piece");
1008             // HACK for animation (with positive translate, image slides "under background"...)
1009             // Possible improvement: just alter squares on the piece's way...
1010             squares = document.getElementsByClassName("board");
1011             for (let i=0; i<squares.length; i++)
1012             {
1013                 let square = squares.item(i);
1014                 if (square.id != this.getSquareId(move.start))
1015                     square.style.zIndex = "-1";
1016             }
1017             movingPiece.style.transform = "translate(" + translation.x + "px," + translation.y + "px)";
1018             movingPiece.style.transitionDuration = "0.2s";
1019             movingPiece.style.zIndex = "3000";
1020             setTimeout( () => {
1021                 for (let i=0; i<squares.length; i++)
1022                     squares.item(i).style.zIndex = "auto";
1023                 movingPiece.style = {}; //required e.g. for 0-0 with KR swap
1024                 this.play(move);
1025             }, 200);
1026         },
1027         play: function(move, programmatic) {
1028             if (!move)
1029             {
1030                 // Navigate after game is over
1031                 if (this.cursor >= this.vr.moves.length)
1032                     return; //already at the end
1033                 move = this.vr.moves[this.cursor++];
1034             }
1035             if (!!programmatic) //computer or human opponent
1036             {
1037                 this.animateMove(move);
1038                 return;
1039             }
1040             // Not programmatic, or animation is over
1041             if (this.mode == "human" && this.vr.turn == this.mycolor)
1042                 this.conn.send(JSON.stringify({code:"newmove", move:move, oppid:this.oppid}));
1043             new Audio("/sounds/chessmove1.mp3").play().then(() => {}).catch(err => {});
1044             if (this.mode != "idle")
1045             {
1046                 this.incheck = this.vr.getCheckSquares(move); //is opponent in check?
1047                 this.vr.play(move, "ingame");
1048             }
1049             else
1050             {
1051                 VariantRules.PlayOnBoard(this.vr.board, move);
1052                 this.$forceUpdate(); //TODO: ?!
1053             }
1054             if (this.mode == "human")
1055                 this.updateStorage(); //after our moves and opponent moves
1056             if (this.mode != "idle")
1057             {
1058                 const eog = this.vr.checkGameOver();
1059                 if (eog != "*")
1060                     this.endGame(eog);
1061             }
1062             if (this.mode == "computer" && this.vr.turn != this.mycolor)
1063                 setTimeout(this.playComputerMove, 500);
1064         },
1065         undo: function() {
1066             // Navigate after game is over
1067             if (this.cursor == 0)
1068                 return; //already at the beginning
1069             if (this.cursor == this.vr.moves.length)
1070                 this.incheck = []; //in case of...
1071             const move = this.vr.moves[--this.cursor];
1072             VariantRules.UndoOnBoard(this.vr.board, move);
1073             this.$forceUpdate(); //TODO: ?!
1074         },
1075         undoInGame: function() {
1076             const lm = this.vr.lastMove;
1077             if (!!lm)
1078                 this.vr.undo(lm);
1079         },
1080     },
1081 })