public/javascripts/components/game.js

   1 // Game logic on a variant page
   2 Vue.component('my-game', {
   3     data: function() {
   4         return {
   5             vr: null, //object to check moves, store them, FEN..
   6             mycolor: "w",
   7             possibleMoves: [], //filled after each valid click/dragstart
   8             choices: [], //promotion pieces, or checkered captures... (as moves)
   9             start: {}, //pixels coordinates + id of starting square (click or drag)
  10             selectedPiece: null, //moving piece (or clicked piece)
  11             conn: null, //socket connection
  12             score: "*", //'*' means 'unfinished'
  13             mode: "idle", //human, friend, computer or idle (when not playing)
  14             oppid: "", //opponent ID in case of HH game
  15             oppConnected: false,
  16             seek: false,
  17             fenStart: "",
  18             incheck: [],
  19             pgnTxt: "",
  20             hints: (getCookie("hints") === "1" ? true : false),
  21             color: getCookie("color", "lichess"), //lichess, chesscom or chesstempo
  22             // sound level: 0 = no sound, 1 = sound only on newgame, 2 = always
  23             sound: getCookie("sound", "2"),
  24         };
  25     },
  26     render(h) {
  27         const [sizeX,sizeY] = VariantRules.size;
  28         const smallScreen = (screen.width <= 420);
  29         // Precompute hints squares to facilitate rendering
  30         let hintSquares = doubleArray(sizeX, sizeY, false);
  31         this.possibleMoves.forEach(m => { hintSquares[m.end.x][m.end.y] = true; });
  32         // Also precompute in-check squares
  33         let incheckSq = doubleArray(sizeX, sizeY, false);
  34         this.incheck.forEach(sq => { incheckSq[sq[0]][sq[1]] = true; });
  35         let elementArray = [];
  36         let actionArray = [];
  37         actionArray.push(
  38             h('button',
  39             {
  40                 on: { click: this.clickGameSeek },
  41                 attrs: { "aria-label": 'New online game' },
  42                 'class': {
  43                     "tooltip": true,
  44                     "bottom": true, //display below
  45                     "seek": this.seek,
  46                     "playing": this.mode == "human",
  47                     "small": smallScreen,
  48                 },
  49             },
  50             [h('i', { 'class': { "material-icons": true } }, "accessibility")])
  51         );
  52         if (["idle","computer"].includes(this.mode))
  53         {
  54             actionArray.push(
  55                 h('button',
  56                 {
  57                     on: { click: this.clickComputerGame },
  58                     attrs: { "aria-label": 'New game VS computer' },
  59                     'class': {
  60                         "tooltip":true,
  61                         "bottom": true,
  62                         "playing": this.mode == "computer",
  63                         "small": smallScreen,
  64                     },
  65                 },
  66                 [h('i', { 'class': { "material-icons": true } }, "computer")])
  67             );
  68         }
  69         if (["idle","friend"].includes(this.mode))
  70         {
  71             actionArray.push(
  72                 h('button',
  73                 {
  74                     on: { click: this.clickFriendGame },
  75                     attrs: { "aria-label": 'New IRL game' },
  76                     'class': {
  77                         "tooltip":true,
  78                         "bottom": true,
  79                         "playing": this.mode == "friend",
  80                         "small": smallScreen,
  81                     },
  82                 },
  83                 [h('i', { 'class': { "material-icons": true } }, "people")])
  84             );
  85         }
  86         if (!!this.vr)
  87         {
  88             const square00 = document.getElementById("sq-0-0");
  89             const squareWidth = !!square00
  90                 ? parseFloat(window.getComputedStyle(square00).width.slice(0,-2))
  91                 : 0;
  92             const settingsBtnElt = document.getElementById("settingsBtn");
  93             const indicWidth = !!settingsBtnElt //-2 for border:
  94                 ? parseFloat(window.getComputedStyle(settingsBtnElt).height.slice(0,-2)) - 2
  95                 : 37; //TODO: always 37?
  96             if (this.mode == "human")
  97             {
  98                 let connectedIndic = h(
  99                     'div',
 100                     {
 101                         "class": {
 102                             "topindicator": true,
 103                             "indic-left": true,
 104                             "connected": this.oppConnected,
 105                             "disconnected": !this.oppConnected,
 106                         },
 107                         style: {
 108                             "width": indicWidth + "px",
 109                             "height": indicWidth + "px",
 110                         },
 111                     }
 112                 );
 113                 elementArray.push(connectedIndic);
 114             }
 115             let turnIndic = h(
 116                 'div',
 117                 {
 118                     "class": {
 119                         "topindicator": true,
 120                         "indic-right": true,
 121                         "white-turn": this.vr.turn=="w",
 122                         "black-turn": this.vr.turn=="b",
 123                     },
 124                     style: {
 125                         "width": indicWidth + "px",
 126                         "height": indicWidth + "px",
 127                     },
 128                 }
 129             );
 130             elementArray.push(turnIndic);
 131             let settingsBtn = h(
 132                 'button',
 133                 {
 134                     on: { click: this.showSettings },
 135                     attrs: {
 136                         "aria-label": 'Settings',
 137                         "id": "settingsBtn",
 138                     },
 139                     'class': {
 140                         "tooltip": true,
 141                         "topindicator": true,
 142                         "indic-right": true,
 143                         "settings-btn": true,
 144                     },
 145                 },
 146                 [h('i', { 'class': { "material-icons": true } }, "settings")]
 147             );
 148             elementArray.push(settingsBtn);
 149             let choices = h('div',
 150                 {
 151                     attrs: { "id": "choices" },
 152                     'class': { 'row': true },
 153                     style: {
 154                         "display": this.choices.length>0?"block":"none",
 155                         "top": "-" + ((sizeY/2)*squareWidth+squareWidth/2) + "px",
 156                         "width": (this.choices.length * squareWidth) + "px",
 157                         "height": squareWidth + "px",
 158                     },
 159                 },
 160                 this.choices.map( m => { //a "choice" is a move
 161                     return h('div',
 162                         {
 163                             'class': {
 164                                 'board': true,
 165                                 ['board'+sizeY]: true,
 166                             },
 167                             style: {
 168                                 'width': (100/this.choices.length) + "%",
 169                                 'padding-bottom': (100/this.choices.length) + "%",
 170                             },
 171                         },
 172                         [h('img',
 173                             {
 174                                 attrs: { "src": '/images/pieces/' +
 175                                     VariantRules.getPpath(m.appear[0].c+m.appear[0].p) + '.svg' },
 176                                 'class': { 'choice-piece': true },
 177                                 on: { "click": e => { this.play(m); this.choices=[]; } },
 178                             })
 179                         ]
 180                     );
 181                 })
 182             );
 183             // Create board element (+ reserves if needed by variant or mode)
 184             let gameDiv = h('div',
 185                 {
 186                     'class': { 'game': true },
 187                 },
 188                 [_.range(sizeX).map(i => {
 189                     let ci = this.mycolor=='w' ? i : sizeX-i-1;
 190                     return h(
 191                         'div',
 192                         {
 193                             'class': {
 194                                 'row': true,
 195                             },
 196                             style: { 'opacity': this.choices.length>0?"0.5":"1" },
 197                         },
 198                         _.range(sizeY).map(j => {
 199                             let cj = this.mycolor=='w' ? j : sizeY-j-1;
 200                             let elems = [];
 201                             if (this.vr.board[ci][cj] != VariantRules.EMPTY)
 202                             {
 203                                 elems.push(
 204                                     h(
 205                                         'img',
 206                                         {
 207                                             'class': {
 208                                                 'piece': true,
 209                                                 'ghost': !!this.selectedPiece
 210                                                     && this.selectedPiece.parentNode.id == "sq-"+ci+"-"+cj,
 211                                             },
 212                                             attrs: {
 213                                                 src: "/images/pieces/" +
 214                                                     VariantRules.getPpath(this.vr.board[ci][cj]) + ".svg",
 215                                             },
 216                                         }
 217                                     )
 218                                 );
 219                             }
 220                             if (this.hints && hintSquares[ci][cj])
 221                             {
 222                                 elems.push(
 223                                     h(
 224                                         'img',
 225                                         {
 226                                             'class': {
 227                                                 'mark-square': true,
 228                                             },
 229                                             attrs: {
 230                                                 src: "/images/mark.svg",
 231                                             },
 232                                         }
 233                                     )
 234                                 );
 235                             }
 236                             const lm = this.vr.lastMove;
 237                             const showLight = this.hints &&
 238                                 (this.mode!="idle" || this.cursor==this.vr.moves.length);
 239                             return h(
 240                                 'div',
 241                                 {
 242                                     'class': {
 243                                         'board': true,
 244                                         ['board'+sizeY]: true,
 245                                         'light-square': (i+j)%2==0,
 246                                         'dark-square': (i+j)%2==1,
 247                                         [this.color]: true,
 248                                         'highlight': showLight && !!lm && _.isMatch(lm.end, {x:ci,y:cj}),
 249                                         'incheck': showLight && incheckSq[ci][cj],
 250                                     },
 251                                     attrs: {
 252                                         id: this.getSquareId({x:ci,y:cj}),
 253                                     },
 254                                 },
 255                                 elems
 256                             );
 257                         })
 258                     );
 259                 }), choices]
 260             );
 261             if (this.mode != "idle")
 262             {
 263                 actionArray.push(
 264                     h('button',
 265                         {
 266                             on: { click: this.resign },
 267                             attrs: { "aria-label": 'Resign' },
 268                             'class': {
 269                                 "tooltip":true,
 270                                 "bottom": true,
 271                                 "small": smallScreen,
 272                             },
 273                         },
 274                         [h('i', { 'class': { "material-icons": true } }, "flag")])
 275                 );
 276             }
 277             else if (this.vr.moves.length > 0)
 278             {
 279                 // A game finished, and another is not started yet: allow navigation
 280                 actionArray = actionArray.concat([
 281                     h('button',
 282                         {
 283                             on: { click: e => this.undo() },
 284                             attrs: { "aria-label": 'Undo' },
 285                             "class": {
 286                                 "small": smallScreen,
 287                                 "marginleft": true,
 288                             },
 289                         },
 290                         [h('i', { 'class': { "material-icons": true } }, "fast_rewind")]),
 291                     h('button',
 292                         {
 293                             on: { click: e => this.play() },
 294                             attrs: { "aria-label": 'Play' },
 295                             "class": { "small": smallScreen },
 296                         },
 297                         [h('i', { 'class': { "material-icons": true } }, "fast_forward")]),
 298                     ]
 299                 );
 300             }
 301             if (this.mode == "friend")
 302             {
 303                 actionArray = actionArray.concat(
 304                 [
 305                     h('button',
 306                         {
 307                             on: { click: this.undoInGame },
 308                             attrs: { "aria-label": 'Undo' },
 309                             "class": {
 310                                 "small": smallScreen,
 311                                 "marginleft": true,
 312                             },
 313                         },
 314                         [h('i', { 'class': { "material-icons": true } }, "undo")]
 315                     ),
 316                     h('button',
 317                         {
 318                             on: { click: () => { this.mycolor = this.vr.getOppCol(this.mycolor) } },
 319                             attrs: { "aria-label": 'Flip' },
 320                             "class": { "small": smallScreen },
 321                         },
 322                         [h('i', { 'class': { "material-icons": true } }, "cached")]
 323                     ),
 324                 ]);
 325             }
 326             elementArray.push(gameDiv);
 327             if (!!this.vr.reserve)
 328             {
 329                 const shiftIdx = (this.mycolor=="w" ? 0 : 1);
 330                 let myReservePiecesArray = [];
 331                 for (let i=0; i<VariantRules.RESERVE_PIECES.length; i++)
 332                 {
 333                     myReservePiecesArray.push(h('div',
 334                     {
 335                         'class': {'board':true, ['board'+sizeY]:true},
 336                         attrs: { id: this.getSquareId({x:sizeX+shiftIdx,y:i}) }
 337                     },
 338                     [
 339                         h('img',
 340                         {
 341                             'class': {"piece":true},
 342                             attrs: {
 343                                 "src": "/images/pieces/" +
 344                                     this.vr.getReservePpath(this.mycolor,i) + ".svg",
 345                             }
 346                         }),
 347                         h('sup',
 348                             {"class": { "reserve-count": true } },
 349                             [ this.vr.reserve[this.mycolor][VariantRules.RESERVE_PIECES[i]] ]
 350                         )
 351                     ]));
 352                 }
 353                 let oppReservePiecesArray = [];
 354                 const oppCol = this.vr.getOppCol(this.mycolor);
 355                 for (let i=0; i<VariantRules.RESERVE_PIECES.length; i++)
 356                 {
 357                     oppReservePiecesArray.push(h('div',
 358                     {
 359                         'class': {'board':true, ['board'+sizeY]:true},
 360                         attrs: { id: this.getSquareId({x:sizeX+(1-shiftIdx),y:i}) }
 361                     },
 362                     [
 363                         h('img',
 364                         {
 365                             'class': {"piece":true},
 366                             attrs: {
 367                                 "src": "/images/pieces/" +
 368                                     this.vr.getReservePpath(oppCol,i) + ".svg",
 369                             }
 370                         }),
 371                         h('sup',
 372                             {"class": { "reserve-count": true } },
 373                             [ this.vr.reserve[oppCol][VariantRules.RESERVE_PIECES[i]] ]
 374                         )
 375                     ]));
 376                 }
 377                 let reserves = h('div',
 378                     {
 379                         'class':{
 380                             'game': true,
 381                             "reserve-div": true,
 382                         },
 383                     },
 384                     [
 385                         h('div',
 386                             {
 387                                 'class': {
 388                                     'row': true,
 389                                     "reserve-row-1": true,
 390                                 },
 391                             },
 392                             myReservePiecesArray
 393                         ),
 394                         h('div',
 395                             { 'class': { 'row': true }},
 396                             oppReservePiecesArray
 397                         )
 398                     ]
 399                 );
 400                 elementArray.push(reserves);
 401             }
 402             const eogMessage = this.getEndgameMessage(this.score);
 403             const modalEog = [
 404                 h('input',
 405                     {
 406                         attrs: { "id": "modal-eog", type: "checkbox" },
 407                         "class": { "modal": true },
 408                     }),
 409                 h('div',
 410                     {
 411                         attrs: { "role": "dialog", "aria-labelledby": "modal-eog" },
 412                     },
 413                     [
 414                         h('div',
 415                             {
 416                                 "class": { "card": true, "smallpad": true },
 417                             },
 418                             [
 419                                 h('label',
 420                                     {
 421                                         attrs: { "for": "modal-eog" },
 422                                         "class": { "modal-close": true },
 423                                     }
 424                                 ),
 425                                 h('h3',
 426                                     {
 427                                         "class": { "section": true },
 428                                         domProps: { innerHTML: eogMessage },
 429                                     }
 430                                 )
 431                             ]
 432                         )
 433                     ]
 434                 )
 435             ];
 436             elementArray = elementArray.concat(modalEog);
 437         }
 438         // TODO: next 3 modals in (pug) view directly?!
 439         const modalNewgame = [
 440             h('input',
 441                 {
 442                     attrs: { "id": "modal-newgame", type: "checkbox" },
 443                     "class": { "modal": true },
 444                 }),
 445             h('div',
 446                 {
 447                     attrs: { "role": "dialog", "aria-labelledby": "modal-newgame" },
 448                 },
 449                 [
 450                     h('div',
 451                         {
 452                             "class": { "card": true, "smallpad": true },
 453                         },
 454                         [
 455                             h('label',
 456                                 {
 457                                     attrs: { "id": "close-newgame", "for": "modal-newgame" },
 458                                     "class": { "modal-close": true },
 459                                 }
 460                             ),
 461                             h('h3',
 462                                 {
 463                                     "class": { "section": true },
 464                                     domProps: { innerHTML: "New game" },
 465                                 }
 466                             ),
 467                             h('p',
 468                                 {
 469                                     "class": { "section": true },
 470                                     domProps: { innerHTML: "Waiting for opponent..." },
 471                                 }
 472                             )
 473                         ]
 474                     )
 475                 ]
 476             )
 477         ];
 478         elementArray = elementArray.concat(modalNewgame);
 479         const modalFenEdit = [
 480             h('input',
 481                 {
 482                     attrs: { "id": "modal-fenedit", type: "checkbox" },
 483                     "class": { "modal": true },
 484                 }),
 485             h('div',
 486                 {
 487                     attrs: { "role": "dialog", "aria-labelledby": "modal-fenedit" },
 488                 },
 489                 [
 490                     h('div',
 491                         {
 492                             "class": { "card": true, "smallpad": true },
 493                         },
 494                         [
 495                             h('label',
 496                                 {
 497                                     attrs: { "id": "close-fenedit", "for": "modal-fenedit" },
 498                                     "class": { "modal-close": true },
 499                                 }
 500                             ),
 501                             h('h3',
 502                                 {
 503                                     "class": { "section": true },
 504                                     domProps: { innerHTML: "Position + flags (FEN):" },
 505                                 }
 506                             ),
 507                             h('input',
 508                                 {
 509                                     attrs: {
 510                                         "id": "input-fen",
 511                                         type: "text",
 512                                         value: VariantRules.GenRandInitFen(),
 513                                     },
 514                                 }
 515                             ),
 516                             h('button',
 517                                 {
 518                                     on: { click:
 519                                         () => {
 520                                             const fen = document.getElementById("input-fen").value;
 521                                             document.getElementById("modal-fenedit").checked = false;
 522                                             this.newGame("friend", fen);
 523                                         }
 524                                     },
 525                                     domProps: { innerHTML: "Ok" },
 526                                 }
 527                             ),
 528                             h('button',
 529                                 {
 530                                     on: { click:
 531                                         () => {
 532                                             document.getElementById("input-fen").value =
 533                                                 VariantRules.GenRandInitFen();
 534                                         }
 535                                     },
 536                                     domProps: { innerHTML: "Random" },
 537                                 }
 538                             ),
 539                         ]
 540                     )
 541                 ]
 542             )
 543         ];
 544         elementArray = elementArray.concat(modalFenEdit);
 545         const modalSettings = [
 546             h('input',
 547                 {
 548                     attrs: { "id": "modal-settings", type: "checkbox" },
 549                     "class": { "modal": true },
 550                 }),
 551             h('div',
 552                 {
 553                     attrs: { "role": "dialog", "aria-labelledby": "modal-settings" },
 554                 },
 555                 [
 556                     h('div',
 557                         {
 558                             "class": { "card": true, "smallpad": true },
 559                         },
 560                         [
 561                             h('label',
 562                                 {
 563                                     attrs: { "id": "close-settings", "for": "modal-settings" },
 564                                     "class": { "modal-close": true },
 565                                 }
 566                             ),
 567                             h('h3',
 568                                 {
 569                                     "class": { "section": true },
 570                                     domProps: { innerHTML: "Preferences" },
 571                                 }
 572                             ),
 573                             // https://minicss.org/docs#forms-and-input
 574                             h('input',
 575                                 {
 576                                     attrs: {
 577                                         "id": "setHints",
 578                                         type: "checkbox",
 579                                         checked: this.hints,
 580                                     },
 581                                 }
 582                             ),
 583                             h('label',
 584                                 {
 585                                     attrs: {
 586                                         for: "setHints",
 587                                     },
 588                                     domProps: { innerHTML: "Show hints?" },
 589                                 },
 590                             ),
 591                             h('p', { domProps: { innerHTML: "TODO: board(color)" } }),
 592                             h('p', { domProps: { innerHTML: "TODO: sound(level)" } }),
 593                         ]
 594                     )
 595                 ]
 596             )
 597         ];
 598         elementArray = elementArray.concat(modalSettings);
 599         const actions = h('div',
 600             {
 601                 attrs: { "id": "actions" },
 602                 'class': { 'text-center': true },
 603             },
 604             actionArray
 605         );
 606         elementArray.push(actions);
 607         if (this.score != "*")
 608         {
 609             elementArray.push(
 610                 h('div',
 611                     { attrs: { id: "pgn-div" } },
 612                     [
 613                         h('a',
 614                             {
 615                                 attrs: {
 616                                     id: "download",
 617                                     href: "#",
 618                                 }
 619                             }
 620                         ),
 621                         h('p',
 622                             {
 623                                 attrs: { id: "pgn-game" },
 624                                 on: { click: this.download },
 625                                 domProps: { innerHTML: this.pgnTxt }
 626                             }
 627                         )
 628                     ]
 629                 )
 630             );
 631         }
 632         else if (this.mode != "idle")
 633         {
 634             // Show current FEN
 635             elementArray.push(
 636                 h('div',
 637                     { attrs: { id: "fen-div" } },
 638                     [
 639                         h('p',
 640                             {
 641                                 attrs: { id: "fen-string" },
 642                                 domProps: { innerHTML: this.vr.getFen() }
 643                             }
 644                         )
 645                     ]
 646                 )
 647             );
 648         }
 649         return h(
 650             'div',
 651             {
 652                 'class': {
 653                     "col-sm-12":true,
 654                     "col-md-8":true,
 655                     "col-md-offset-2":true,
 656                     "col-lg-6":true,
 657                     "col-lg-offset-3":true,
 658                 },
 659                 // NOTE: click = mousedown + mouseup
 660                 on: {
 661                     mousedown: this.mousedown,
 662                     mousemove: this.mousemove,
 663                     mouseup: this.mouseup,
 664                     touchstart: this.mousedown,
 665                     touchmove: this.mousemove,
 666                     touchend: this.mouseup,
 667                 },
 668             },
 669             elementArray
 670         );
 671     },
 672     created: function() {
 673         const url = socketUrl;
 674         const continuation = (localStorage.getItem("variant") === variant);
 675         this.myid = continuation ? localStorage.getItem("myid") : getRandString();
 676         if (!continuation)
 677         {
 678             // HACK: play a small silent sound to allow "new game" sound later
 679             // if tab not focused (TODO: does it really work ?!)
 680             new Audio("/sounds/silent.mp3").play().then(() => {}).catch(err => {});
 681         }
 682         this.conn = new WebSocket(url + "/?sid=" + this.myid + "&page=" + variant);
 683         const socketOpenListener = () => {
 684             if (continuation)
 685             {
 686                 const fen = localStorage.getItem("fen");
 687                 const mycolor = localStorage.getItem("mycolor");
 688                 const oppid = localStorage.getItem("oppid");
 689                 const moves = JSON.parse(localStorage.getItem("moves"));
 690                 this.newGame("human", fen, mycolor, oppid, moves, true);
 691                 // Send ping to server (answer pong if opponent is connected)
 692                 this.conn.send(JSON.stringify({code:"ping",oppid:this.oppid}));
 693             }
 694             else if (localStorage.getItem("newgame") === variant)
 695             {
 696                 // New game request has been cancelled on disconnect
 697                 this.newGame("human", undefined, undefined, undefined, undefined, "reconnect");
 698             }
 699         };
 700         const socketMessageListener = msg => {
 701             const data = JSON.parse(msg.data);
 702             switch (data.code)
 703             {
 704                 case "newgame": //opponent found
 705                     // oppid: opponent socket ID
 706                     this.newGame("human", data.fen, data.color, data.oppid);
 707                     break;
 708                 case "newmove": //..he played!
 709                     this.play(data.move, "animate");
 710                     break;
 711                 case "pong": //received if we sent a ping (game still alive on our side)
 712                     this.oppConnected = true;
 713                     const L = this.vr.moves.length;
 714                     // Send our "last state" informations to opponent
 715                     this.conn.send(JSON.stringify({
 716                         code:"lastate",
 717                         oppid:this.oppid,
 718                         lastMove:L>0?this.vr.moves[L-1]:undefined,
 719                         movesCount:L,
 720                     }));
 721                     break;
 722                 case "lastate": //got opponent infos about last move (we might have resigned)
 723                     if (this.mode!="human" || this.oppid!=data.oppid)
 724                     {
 725                         // OK, we resigned
 726                         this.conn.send(JSON.stringify({
 727                             code:"lastate",
 728                             oppid:this.oppid,
 729                             lastMove:undefined,
 730                             movesCount:-1,
 731                         }));
 732                     }
 733                     else if (data.movesCount < 0)
 734                     {
 735                         // OK, he resigned
 736                         this.endGame(this.mycolor=="w"?"1-0":"0-1");
 737                     }
 738                     else if (data.movesCount < this.vr.moves.length)
 739                     {
 740                         // We must tell last move to opponent
 741                         const L = this.vr.moves.length;
 742                         this.conn.send(JSON.stringify({
 743                             code:"lastate",
 744                             oppid:this.oppid,
 745                             lastMove:this.vr.moves[L-1],
 746                             movesCount:L,
 747                         }));
 748                     }
 749                     else if (data.movesCount > this.vr.moves.length) //just got last move from him
 750                         this.play(data.lastMove, "animate");
 751                     break;
 752                 case "resign": //..you won!
 753                     this.endGame(this.mycolor=="w"?"1-0":"0-1");
 754                     break;
 755                 // TODO: also use (dis)connect info to count online players?
 756                 case "connect":
 757                 case "disconnect":
 758                     if (this.mode == "human" && this.oppid == data.id)
 759                         this.oppConnected = (data.code == "connect");
 760                     break;
 761             }
 762         };
 763         const socketCloseListener = () => {
 764             this.conn = new WebSocket(url + "/?sid=" + this.myid + "&page=" + variant);
 765             this.conn.addEventListener('open', socketOpenListener);
 766             this.conn.addEventListener('message', socketMessageListener);
 767             this.conn.addEventListener('close', socketCloseListener);
 768         };
 769         this.conn.onopen = socketOpenListener;
 770         this.conn.onmessage = socketMessageListener;
 771         this.conn.onclose = socketCloseListener;
 772         // Listen to keyboard left/right to navigate in game
 773         document.onkeydown = event => {
 774             if (this.mode == "idle" && !!this.vr && this.vr.moves.length > 0
 775                 && [37,39].includes(event.keyCode))
 776             {
 777                 event.preventDefault();
 778                 if (event.keyCode == 37) //Back
 779                     this.undo();
 780                 else //Forward (39)
 781                     this.play();
 782             }
 783         };
 784     },
 785     methods: {
 786         download: function() {
 787             let content = document.getElementById("pgn-game").innerHTML;
 788             content = content.replace(/<br>/g, "\n");
 789             // Prepare and trigger download link
 790             let downloadAnchor = document.getElementById("download");
 791             downloadAnchor.setAttribute("download", "game.pgn");
 792             downloadAnchor.href = "data:text/plain;charset=utf-8," +
 793                 encodeURIComponent(content);
 794             downloadAnchor.click();
 795         },
 796         endGame: function(score) {
 797             this.score = score;
 798             let modalBox = document.getElementById("modal-eog");
 799             modalBox.checked = true;
 800             // Variants may have special PGN structure (so next function isn't defined here)
 801             this.pgnTxt = this.vr.getPGN(this.mycolor, this.score, this.fenStart, this.mode);
 802             setTimeout(() => { modalBox.checked = false; }, 2000);
 803             if (this.mode == "human")
 804                 this.clearStorage();
 805             this.mode = "idle";
 806             this.cursor = this.vr.moves.length; //to navigate in finished game
 807             this.oppid = "";
 808         },
 809         getEndgameMessage: function(score) {
 810             let eogMessage = "Unfinished";
 811             switch (this.score)
 812             {
 813                 case "1-0":
 814                     eogMessage = "White win";
 815                     break;
 816                 case "0-1":
 817                     eogMessage = "Black win";
 818                     break;
 819                 case "1/2":
 820                     eogMessage = "Draw";
 821                     break;
 822             }
 823             return eogMessage;
 824         },
 825         setStorage: function() {
 826             localStorage.setItem("myid", this.myid);
 827             localStorage.setItem("variant", variant);
 828             localStorage.setItem("mycolor", this.mycolor);
 829             localStorage.setItem("oppid", this.oppid);
 830             localStorage.setItem("fenStart", this.fenStart);
 831             localStorage.setItem("moves", JSON.stringify(this.vr.moves));
 832             localStorage.setItem("fen", this.vr.getFen());
 833         },
 834         updateStorage: function() {
 835             localStorage.setItem("moves", JSON.stringify(this.vr.moves));
 836             localStorage.setItem("fen", this.vr.getFen());
 837         },
 838         clearStorage: function() {
 839             delete localStorage["variant"];
 840             delete localStorage["myid"];
 841             delete localStorage["mycolor"];
 842             delete localStorage["oppid"];
 843             delete localStorage["fenStart"];
 844             delete localStorage["fen"];
 845             delete localStorage["moves"];
 846         },
 847         // HACK because mini-css tooltips are persistent after click...
 848         getRidOfTooltip: function(elt) {
 849             elt.style.visibility = "hidden";
 850             setTimeout(() => { elt.style.visibility="visible"; }, 100);
 851         },
 852         showSettings: function(e) {
 853             this.getRidOfTooltip(e.currentTarget);
 854             document.getElementById("modal-settings").checked = true;
 855         },
 856         toggleHints: function() {
 857             this.hints = !this.hints;
 858             setCookie("hints", this.hints ? "1" : "0");
 859         },
 860         clickGameSeek: function(e) {
 861             this.getRidOfTooltip(e.currentTarget);
 862             if (this.mode == "human")
 863                 return; //no newgame while playing
 864             if (this.seek)
 865             {
 866                 this.conn.send(JSON.stringify({code:"cancelnewgame"}));
 867                 delete localStorage["newgame"]; //cancel game seek
 868                 this.seek = false;
 869             }
 870             else
 871                 this.newGame("human");
 872         },
 873         clickComputerGame: function(e) {
 874             this.getRidOfTooltip(e.currentTarget);
 875             if (this.mode == "human")
 876                 return; //no newgame while playing
 877             this.newGame("computer");
 878         },
 879         clickFriendGame: function(e) {
 880             this.getRidOfTooltip(e.currentTarget);
 881             document.getElementById("modal-fenedit").checked = true;
 882         },
 883         resign: function(e) {
 884             this.getRidOfTooltip(e.currentTarget);
 885             if (this.mode == "human" && this.oppConnected)
 886             {
 887                 try {
 888                     this.conn.send(JSON.stringify({code: "resign", oppid: this.oppid}));
 889                 } catch (INVALID_STATE_ERR) {
 890                     return; //socket is not ready (and not yet reconnected)
 891                 }
 892             }
 893             this.endGame(this.mycolor=="w"?"0-1":"1-0");
 894         },
 895         newGame: function(mode, fenInit, color, oppId, moves, continuation) {
 896             const fen = fenInit || VariantRules.GenRandInitFen();
 897             console.log(fen); //DEBUG
 898             if (mode=="human" && !oppId)
 899             {
 900                 const storageVariant = localStorage.getItem("variant");
 901                 if (!!storageVariant && storageVariant !== variant)
 902                 {
 903                     alert("Finish your " + storageVariant + " game first!");
 904                     return;
 905                 }
 906                 // Send game request and wait..
 907                 localStorage["newgame"] = variant;
 908                 this.seek = true;
 909                 this.clearStorage(); //in case of
 910                 try {
 911                     this.conn.send(JSON.stringify({code:"newgame", fen:fen}));
 912                 } catch (INVALID_STATE_ERR) {
 913                     return; //nothing achieved
 914                 }
 915                 if (continuation !== "reconnect") //TODO: bad HACK...
 916                 {
 917                     let modalBox = document.getElementById("modal-newgame");
 918                     modalBox.checked = true;
 919                     setTimeout(() => { modalBox.checked = false; }, 2000);
 920                 }
 921                 return;
 922             }
 923             this.vr = new VariantRules(fen, moves || []);
 924             this.score = "*";
 925             this.pgnTxt = ""; //redundant with this.score = "*", but cleaner
 926             this.mode = mode;
 927             this.incheck = []; //in case of
 928             this.fenStart = (continuation ? localStorage.getItem("fenStart") : fen);
 929             if (mode=="human")
 930             {
 931                 // Opponent found!
 932                 if (!continuation)
 933                 {
 934                     // Not playing sound on game continuation:
 935                     new Audio("/sounds/newgame.mp3").play().then(() => {}).catch(err => {});
 936                     document.getElementById("modal-newgame").checked = false;
 937                 }
 938                 this.oppid = oppId;
 939                 this.oppConnected = true;
 940                 this.mycolor = color;
 941                 this.seek = false;
 942                 if (!!moves && moves.length > 0) //imply continuation
 943                 {
 944                     const lastMove = moves[moves.length-1];
 945                     this.vr.undo(lastMove);
 946                     this.incheck = this.vr.getCheckSquares(lastMove);
 947                     this.vr.play(lastMove, "ingame");
 948                 }
 949                 delete localStorage["newgame"];
 950                 this.setStorage(); //in case of interruptions
 951             }
 952             else if (mode == "computer")
 953             {
 954                 this.mycolor = Math.random() < 0.5 ? 'w' : 'b';
 955                 if (this.mycolor == 'b')
 956                     setTimeout(this.playComputerMove, 500);
 957             }
 958             //else: against a (IRL) friend: nothing more to do
 959         },
 960         playComputerMove: function() {
 961             const timeStart = Date.now();
 962             const compMove = this.vr.getComputerMove();
 963             // (first move) HACK: avoid selecting elements before they appear on page:
 964             const delay = Math.max(500-(Date.now()-timeStart), 0);
 965             setTimeout(() => this.play(compMove, "animate"), delay);
 966         },
 967         // Get the identifier of a HTML table cell from its numeric coordinates o.x,o.y.
 968         getSquareId: function(o) {
 969             // NOTE: a separator is required to allow any size of board
 970             return  "sq-" + o.x + "-" + o.y;
 971         },
 972         // Inverse function
 973         getSquareFromId: function(id) {
 974             let idParts = id.split('-');
 975             return [parseInt(idParts[1]), parseInt(idParts[2])];
 976         },
 977         mousedown: function(e) {
 978             e = e || window.event;
 979             let ingame = false;
 980             let elem = e.target;
 981             while (!ingame && elem !== null)
 982             {
 983                 if (elem.classList.contains("game"))
 984                 {
 985                     ingame = true;
 986                     break;
 987                 }
 988                 elem = elem.parentElement;
 989             }
 990             if (!ingame) //let default behavior (click on button...)
 991                 return;
 992             e.preventDefault(); //disable native drag & drop
 993             if (!this.selectedPiece && e.target.classList.contains("piece"))
 994             {
 995                 // Next few lines to center the piece on mouse cursor
 996                 let rect = e.target.parentNode.getBoundingClientRect();
 997                 this.start = {
 998                     x: rect.x + rect.width/2,
 999                     y: rect.y + rect.width/2,
1000                     id: e.target.parentNode.id
1001                 };
1002                 this.selectedPiece = e.target.cloneNode();
1003                 this.selectedPiece.style.position = "absolute";
1004                 this.selectedPiece.style.top = 0;
1005                 this.selectedPiece.style.display = "inline-block";
1006                 this.selectedPiece.style.zIndex = 3000;
1007                 let startSquare = this.getSquareFromId(e.target.parentNode.id);
1008                 const iCanPlay = this.mode!="idle"
1009                     && (this.mode=="friend" || this.vr.canIplay(this.mycolor,startSquare));
1010                 this.possibleMoves = iCanPlay ? this.vr.getPossibleMovesFrom(startSquare) : [];
1011                 // Next line add moving piece just after current image
1012                 // (required for Crazyhouse reserve)
1013                 e.target.parentNode.insertBefore(this.selectedPiece, e.target.nextSibling);
1014             }
1015         },
1016         mousemove: function(e) {
1017             if (!this.selectedPiece)
1018                 return;
1019             e = e || window.event;
1020             // If there is an active element, move it around
1021             if (!!this.selectedPiece)
1022             {
1023                 const [offsetX,offsetY] = !!e.clientX
1024                     ? [e.clientX,e.clientY] //desktop browser
1025                     : [e.changedTouches[0].pageX, e.changedTouches[0].pageY]; //smartphone
1026                 this.selectedPiece.style.left = (offsetX-this.start.x) + "px";
1027                 this.selectedPiece.style.top = (offsetY-this.start.y) + "px";
1028             }
1029         },
1030         mouseup: function(e) {
1031             if (!this.selectedPiece)
1032                 return;
1033             e = e || window.event;
1034             // Read drop target (or parentElement, parentNode... if type == "img")
1035             this.selectedPiece.style.zIndex = -3000; //HACK to find square from final coords
1036             const [offsetX,offsetY] = !!e.clientX
1037                 ? [e.clientX,e.clientY]
1038                 : [e.changedTouches[0].pageX, e.changedTouches[0].pageY];
1039             let landing = document.elementFromPoint(offsetX, offsetY);
1040             this.selectedPiece.style.zIndex = 3000;
1041             // Next condition: classList.contains(piece) fails because of marks
1042             while (landing.tagName == "IMG")
1043                 landing = landing.parentNode;
1044             if (this.start.id == landing.id)
1045             {
1046                 // A click: selectedPiece and possibleMoves are already filled
1047                 return;
1048             }
1049             // OK: process move attempt
1050             let endSquare = this.getSquareFromId(landing.id);
1051             let moves = this.findMatchingMoves(endSquare);
1052             this.possibleMoves = [];
1053             if (moves.length > 1)
1054                 this.choices = moves;
1055             else if (moves.length==1)
1056                 this.play(moves[0]);
1057             // Else: impossible move
1058             this.selectedPiece.parentNode.removeChild(this.selectedPiece);
1059             delete this.selectedPiece;
1060             this.selectedPiece = null;
1061         },
1062         findMatchingMoves: function(endSquare) {
1063             // Run through moves list and return the matching set (if promotions...)
1064             let moves = [];
1065             this.possibleMoves.forEach(function(m) {
1066                 if (endSquare[0] == m.end.x && endSquare[1] == m.end.y)
1067                     moves.push(m);
1068             });
1069             return moves;
1070         },
1071         animateMove: function(move) {
1072             let startSquare = document.getElementById(this.getSquareId(move.start));
1073             let endSquare = document.getElementById(this.getSquareId(move.end));
1074             let rectStart = startSquare.getBoundingClientRect();
1075             let rectEnd = endSquare.getBoundingClientRect();
1076             let translation = {x:rectEnd.x-rectStart.x, y:rectEnd.y-rectStart.y};
1077             let movingPiece =
1078                 document.querySelector("#" + this.getSquareId(move.start) + " > img.piece");
1079             // HACK for animation (with positive translate, image slides "under background")
1080             // Possible improvement: just alter squares on the piece's way...
1081             squares = document.getElementsByClassName("board");
1082             for (let i=0; i<squares.length; i++)
1083             {
1084                 let square = squares.item(i);
1085                 if (square.id != this.getSquareId(move.start))
1086                     square.style.zIndex = "-1";
1087             }
1088             movingPiece.style.transform = "translate(" + translation.x + "px," +
1089                 translation.y + "px)";
1090             movingPiece.style.transitionDuration = "0.2s";
1091             movingPiece.style.zIndex = "3000";
1092             setTimeout( () => {
1093                 for (let i=0; i<squares.length; i++)
1094                     squares.item(i).style.zIndex = "auto";
1095                 movingPiece.style = {}; //required e.g. for 0-0 with KR swap
1096                 this.play(move);
1097             }, 200);
1098         },
1099         play: function(move, programmatic) {
1100             if (!move)
1101             {
1102                 // Navigate after game is over
1103                 if (this.cursor >= this.vr.moves.length)
1104                     return; //already at the end
1105                 move = this.vr.moves[this.cursor++];
1106             }
1107             if (!!programmatic) //computer or human opponent
1108             {
1109                 this.animateMove(move);
1110                 return;
1111             }
1112             // Not programmatic, or animation is over
1113             if (this.mode == "human" && this.vr.turn == this.mycolor)
1114                 this.conn.send(JSON.stringify({code:"newmove", move:move, oppid:this.oppid}));
1115             new Audio("/sounds/chessmove1.mp3").play().then(() => {}).catch(err => {});
1116             if (this.mode != "idle")
1117             {
1118                 this.incheck = this.vr.getCheckSquares(move); //is opponent in check?
1119                 this.vr.play(move, "ingame");
1120             }
1121             else
1122             {
1123                 VariantRules.PlayOnBoard(this.vr.board, move);
1124                 this.$forceUpdate(); //TODO: ?!
1125             }
1126             if (this.mode == "human")
1127                 this.updateStorage(); //after our moves and opponent moves
1128             if (this.mode != "idle")
1129             {
1130                 const eog = this.vr.checkGameOver();
1131                 if (eog != "*")
1132                     this.endGame(eog);
1133             }
1134             if (this.mode == "computer" && this.vr.turn != this.mycolor)
1135                 setTimeout(this.playComputerMove, 500);
1136         },
1137         undo: function() {
1138             // Navigate after game is over
1139             if (this.cursor == 0)
1140                 return; //already at the beginning
1141             if (this.cursor == this.vr.moves.length)
1142                 this.incheck = []; //in case of...
1143             const move = this.vr.moves[--this.cursor];
1144             VariantRules.UndoOnBoard(this.vr.board, move);
1145             this.$forceUpdate(); //TODO: ?!
1146         },
1147         undoInGame: function() {
1148             const lm = this.vr.lastMove;
1149             if (!!lm)
1150                 this.vr.undo(lm);
1151         },
1152     },
1153 })