[vchess.git] / client / src / components / Board.vue

<script>
import { getSquareId, getSquareFromId } from "@/utils/squareId";
import { ArrayFun } from "@/utils/array";
import { store } from "@/store";
export default {
  name: "my-board",
  // Last move cannot be guessed from here, and is required for highlights.
  // vr: object to check moves, print board...
  // userColor is left undefined for an external observer
  props: [
    "vr",
    "lastMove",
    "analyze",
    "score",
    "incheck",
    "orientation",
    "userColor",
    "vname"
  ],
  data: function() {
    return {
      mobileBrowser: ("ontouchstart" in window),
      possibleMoves: [], //filled after each valid click/dragstart
      choices: [], //promotion pieces, or checkered captures... (as moves)
      selectedPiece: null, //moving piece (or clicked piece)
      start: null, //pixels coordinates + id of starting square (click or drag)
      startArrow: null,
      movingArrow: { x: -1, y: -1 },
      arrows: [], //object of {start: x,y / end: x,y}
      circles: {}, //object of squares' ID --> true (TODO: use a set?)
      click: "",
      clickTime: 0,
      settings: store.state.settings
    };
  },
  render(h) {
    if (!this.vr) {
      // Return empty div of class 'game' to avoid error when setting size
      return h("div", {
        class: {
          game: true
        }
      });
    }
    const [sizeX, sizeY] = [V.size.x, V.size.y];
    // Precompute hints squares to facilitate rendering
    let hintSquares = ArrayFun.init(sizeX, sizeY, false);
    this.possibleMoves.forEach(m => {
      hintSquares[m.end.x][m.end.y] = true;
    });
    // Also precompute in-check squares
    let incheckSq = ArrayFun.init(sizeX, sizeY, false);
    this.incheck.forEach(sq => {
      incheckSq[sq[0]][sq[1]] = true;
    });

    const lm = this.lastMove;
    const showLight = (
      this.settings.highlight &&
      ["all","highlight"].includes(V.ShowMoves)
    );
    const showCheck = (
      this.settings.highlight &&
      ["all","highlight","byrow"].includes(V.ShowMoves)
    );
    const orientation = !V.CanFlip ? "w" : this.orientation;
    // Ensure that squares colors do not change when board is flipped
    const lightSquareMod = (sizeX + sizeY) % 2;
    const showPiece = (x, y) => {
      return (
        this.vr.board[x][y] != V.EMPTY &&
        (!this.vr.enlightened || this.analyze || this.score != "*" ||
          (!!this.userColor && this.vr.enlightened[this.userColor][x][y]))
      );
    };
    const inHighlight = (x, y) => {
      return showLight && !!lm && (
        (lm.end.x == x && lm.end.y == y) ||
        (lm.start.x == x && lm.start.y == y));
    };
    const inShadow = (x, y) => {
      return (
        !this.analyze &&
        this.score == "*" &&
        this.vr.enlightened &&
        (!this.userColor || !this.vr.enlightened[this.userColor][x][y])
      );
    };
    // Create board element (+ reserves if needed by variant)
    let elementArray = [];
    const gameDiv = h(
      "div",
      {
        "class": {
          game: true,
          clearer: true
        }
      },
      [...Array(sizeX).keys()].map(i => {
        const ci = orientation == "w" ? i : sizeX - i - 1;
        return h(
          "div",
          {
            "class": {
              row: true
            },
            style: { opacity: this.choices.length > 0 ? "0.5" : "1" }
          },
          [...Array(sizeY).keys()].map(j => {
            const cj = orientation == "w" ? j : sizeY - j - 1;
            const squareId = "sq-" + ci + "-" + cj;
            let elems = [];
            if (showPiece(ci, cj)) {
              elems.push(
                h("img", {
                  "class": {
                    piece: true,
                    ghost:
                      !!this.selectedPiece &&
                      this.selectedPiece.parentNode.id == squareId
                  },
                  attrs: {
                    src:
                      "/images/pieces/" +
                      this.vr.getPpath(
                        this.vr.board[ci][cj],
                        // Extra args useful for some variants:
                        this.userColor,
                        this.score,
                        this.orientation) +
                      V.IMAGE_EXTENSION
                  }
                })
              );
            }
            if (this.settings.hints && hintSquares[ci][cj]) {
              elems.push(
                h("img", {
                  "class": {
                    "mark-square": true
                  },
                  attrs: {
                    src: "/images/mark.svg"
                  }
                })
              );
            }
            if (!!this.circles[squareId]) {
              elems.push(
                h("img", {
                  "class": {
                    "circle-square": true
                  },
                  attrs: {
                    src: "/images/circle.svg"
                  }
                })
              );
            }
            const lightSquare = (ci + cj) % 2 == lightSquareMod;
            return h(
              "div",
              {
                "class": {
                  board: true,
                  ["board" + sizeY]: true,
                  "light-square": lightSquare,
                  "dark-square": !lightSquare,
                  [this.settings.bcolor]: true,
                  "in-shadow": inShadow(ci, cj),
                  "highlight-light": inHighlight(ci, cj) && lightSquare,
                  "highlight-dark": inHighlight(ci, cj) && !lightSquare,
                  "incheck-light":
                    showCheck && lightSquare && incheckSq[ci][cj],
                  "incheck-dark":
                    showCheck && !lightSquare && incheckSq[ci][cj]
                },
                attrs: {
                  id: getSquareId({ x: ci, y: cj })
                }
              },
              elems
            );
          })
        );
      })
    );
    if (!!this.vr.reserve) {
      const playingColor = this.userColor || "w"; //default for an observer
      const shiftIdx = playingColor == "w" ? 0 : 1;
      let myReservePiecesArray = [];
      for (let i = 0; i < V.RESERVE_PIECES.length; i++) {
        const qty = this.vr.reserve[playingColor][V.RESERVE_PIECES[i]];
        myReservePiecesArray.push(
          h(
            "div",
            {
              "class": { board: true, ["board" + sizeY]: true },
              attrs: { id: getSquareId({ x: sizeX + shiftIdx, y: i }) },
              style: { opacity: qty > 0 ? 1 : 0.35 }
            },
            [
              h("img", {
                "class": { piece: true, reserve: true },
                attrs: {
                  src:
                    "/images/pieces/" +
                    this.vr.getReservePpath(i, playingColor) +
                    ".svg"
                }
              }),
              h("sup", { "class": { "reserve-count": true } }, [ qty ])
            ]
          )
        );
      }
      let oppReservePiecesArray = [];
      const oppCol = V.GetOppCol(playingColor);
      for (let i = 0; i < V.RESERVE_PIECES.length; i++) {
        const qty = this.vr.reserve[oppCol][V.RESERVE_PIECES[i]];
        oppReservePiecesArray.push(
          h(
            "div",
            {
              "class": { board: true, ["board" + sizeY]: true },
              attrs: { id: getSquareId({ x: sizeX + (1 - shiftIdx), y: i }) },
              style: { opacity: qty > 0 ? 1 : 0.35 }
            },
            [
              h("img", {
                "class": { piece: true, reserve: true },
                attrs: {
                  src:
                    "/images/pieces/" +
                    this.vr.getReservePpath(i, oppCol) +
                    ".svg"
                }
              }),
              h("sup", { "class": { "reserve-count": true } }, [ qty ])
            ]
          )
        );
      }
      const myReserveTop = (
        (playingColor == 'w' && orientation == 'b') ||
        (playingColor == 'b' && orientation == 'w')
      );
      // Center reserves, assuming same number of pieces for each side:
      const nbReservePieces = myReservePiecesArray.length;
      const marginLeft = ((100 - nbReservePieces * (100 / sizeY)) / 2) + "%";
      const reserveTop =
        h(
          "div",
          {
            "class": {
              game: true,
              "reserve-div": true
            },
            style: {
              "margin-left": marginLeft
            }
          },
          [
            h(
              "div",
              {
                "class": {
                  row: true,
                  "reserve-row": true
                }
              },
              myReserveTop ? myReservePiecesArray : oppReservePiecesArray
            )
          ]
        );
      var reserveBottom =
        h(
          "div",
          {
            "class": {
              game: true,
              "reserve-div": true
            },
            style: {
              "margin-left": marginLeft
            }
          },
          [
            h(
              "div",
              {
                "class": {
                  row: true,
                  "reserve-row": true
                }
              },
              myReserveTop ? oppReservePiecesArray : myReservePiecesArray
            )
          ]
        );
      elementArray.push(reserveTop);
    }
    elementArray.push(gameDiv);
    if (!!this.vr.reserve) elementArray.push(reserveBottom);
    const boardElt = document.querySelector(".game");
    // boardElt might be undefine (at first drawing),
    // but it won't be used in this case.
    const squareWidth = (!!boardElt ? boardElt.offsetWidth / sizeY : 42);
    if (this.choices.length > 0 && !!boardElt) {
      // No choices to show at first drawing
      const offset = [boardElt.offsetTop, boardElt.offsetLeft];
      const maxNbeltsPerRow = Math.min(this.choices.length, sizeY);
      let topOffset = offset[0] + (sizeY / 2) * squareWidth - squareWidth / 2;
      let choicesHeight = squareWidth;
      if (this.choices.length >= sizeY) {
        // A second row is required (Eightpieces variant)
        topOffset -= squareWidth / 2;
        choicesHeight *= 2;
      }
      const choices = h(
        "div",
        {
          attrs: { id: "choices" },
          "class": { row: true },
          style: {
            top: topOffset + "px",
            left:
              offset[1] +
              (squareWidth * Math.max(sizeY - this.choices.length, 0)) / 2 +
              "px",
            width: (maxNbeltsPerRow * squareWidth) + "px",
            height: choicesHeight + "px"
          }
        },
        [ h(
          "div",
          {
            "class": { "full-width": true }
          },
          this.choices.map(m => {
            // A "choice" is a move
            const applyMove = (e) => {
              e.stopPropagation();
              // Force a delay between move is shown and clicked
              // (otherwise a "double-click" bug might occur)
              if (Date.now() - this.clickTime < 200) return;
              this.choices = [];
              this.play(m);
            };
            const onClick =
              this.mobileBrowser
                ? { touchend: applyMove }
                : { mouseup: applyMove };
            return h(
              "div",
              {
                "class": {
                  board: true,
                  ["board" + sizeY]: true
                },
                style: {
                  width: (100 / maxNbeltsPerRow) + "%",
                  "padding-bottom": (100 / maxNbeltsPerRow) + "%"
                }
              },
              [
                h("img", {
                  attrs: {
                    src:
                      "/images/pieces/" +
                      // orientation: extra arg useful for some variants:
                      this.vr.getPPpath(m, this.orientation) +
                      V.IMAGE_EXTENSION
                  },
                  "class": { "choice-piece": true },
                  on: onClick
                })
              ]
            );
          })
        ) ]
      );
      elementArray.unshift(choices);
    }
    if (
      !this.mobileBrowser &&
      (this.arrows.length > 0 || this.movingArrow.x >= 0)
    ) {
      let svgArrows = [];
      const arrowWidth = squareWidth / 4;
      this.arrows.forEach(a => {
        const endPoint = this.adjustEndArrow(a.start, a.end, squareWidth);
        svgArrows.push(
          h(
            "path",
            {
              "class": { "svg-arrow": true },
              attrs: {
                d: (
                  "M" + a.start.x + "," + a.start.y + " " +
                  "L" + endPoint.x + "," + endPoint.y
                ),
                style: "stroke-width:" + arrowWidth + "px"
              }
            }
          )
        );
      });
      if (this.movingArrow.x >= 0) {
        const endPoint =
          this.adjustEndArrow(this.startArrow, this.movingArrow, squareWidth);
        svgArrows.push(
          h(
            "path",
            {
              "class": { "svg-arrow": true },
              attrs: {
                d: (
                  "M" + this.startArrow.x + "," + this.startArrow.y + " " +
                  "L" + endPoint.x + "," + endPoint.y
                ),
                style: "stroke-width:" + arrowWidth + "px"
              }
            }
          )
        );
      }
      // Add SVG element for drawing arrows
      elementArray.push(
        h(
          "svg",
          {
            attrs: {
              id: "arrowCanvas",
              stroke: "none"
            }
          },
          [
            h(
              "defs",
              {},
              [
                h(
                  "marker",
                  {
                    attrs: {
                      id: "arrow",
                      markerWidth: (2 * arrowWidth) + "px",
                      markerHeight: (3 * arrowWidth) + "px",
                      markerUnits: "userSpaceOnUse",
                      refX: "0",
                      refY: (1.5 * arrowWidth) + "px",
                      orient: "auto"
                    }
                  },
                  [
                    h(
                      "path",
                      {
                        "class": { "arrow-head": true },
                        attrs: {
                          d: (
                            "M0,0 L0," + (3 * arrowWidth) + " L" +
                            (2 * arrowWidth) + "," + (1.5 * arrowWidth) + " z"
                          )
                        }
                      }
                    )
                  ]
                )
              ]
            )
          ].concat(svgArrows)
        )
      );
    }
    let onEvents = {};
    // NOTE: click = mousedown + mouseup
    if (this.mobileBrowser) {
      onEvents = {
        on: {
          touchstart: this.mousedown,
          touchmove: this.mousemove,
          touchend: this.mouseup
        }
      };
    } else {
      onEvents = {
        on: {
          mousedown: this.mousedown,
          mousemove: this.mousemove,
          mouseup: this.mouseup,
          contextmenu: this.blockContextMenu
        }
      };
    }
    return h("div", onEvents, elementArray);
  },
  methods: {
    blockContextMenu: function(e) {
      e.preventDefault();
      e.stopPropagation();
      return false;
    },
    cancelResetArrows: function() {
      this.startArrow = null;
      this.arrows = [];
      this.circles = {};
    },
    adjustEndArrow: function(start, end, squareWidth) {
      // Simple heuristic for now, just remove 1/3 square.
      // TODO: should depend on the orientation.
      const delta = [end.x - start.x, end.y - start.y];
      const dist = Math.sqrt(delta[0] * delta[0] + delta[1] * delta[1]);
      const fracSqWidth = squareWidth / 3;
      return {
        x: end.x - delta[0] * fracSqWidth / dist,
        y: end.y - delta[1] * fracSqWidth / dist
      };
    },
    mousedown: function(e) {
      e.preventDefault();
      if (!this.mobileBrowser && e.which != 3)
        // Cancel current drawing and circles, if any
        this.cancelResetArrows();
      if (this.mobileBrowser || e.which == 1) {
        // Mouse left button
        if (!this.start) {
          // NOTE: classList[0] is enough: 'piece' is the first assigned class
          const withPiece = (e.target.classList[0] == "piece");
          // Emit the click event which could be used by some variants
          this.$emit(
            "click-square",
            getSquareFromId(withPiece ? e.target.parentNode.id : e.target.id)
          );
          // Start square must contain a piece.
          if (!withPiece) return;
          let parent = e.target.parentNode; //surrounding square
          // Show possible moves if current player allowed to play
          const startSquare = getSquareFromId(parent.id);
          this.possibleMoves = [];
          const color = this.analyze ? this.vr.turn : this.userColor;
          if (this.vr.canIplay(color, startSquare))
            this.possibleMoves = this.vr.getPossibleMovesFrom(startSquare);
          // For potential drag'n drop, remember start coordinates
          // (to center the piece on mouse cursor)
          const rect = parent.getBoundingClientRect();
          this.start = {
            x: rect.x + rect.width / 2,
            y: rect.y + rect.width / 2,
            id: parent.id
          };
          // Add the moving piece to the board, just after current image
          this.selectedPiece = e.target.cloneNode();
          Object.assign(
            this.selectedPiece.style,
            {
              position: "absolute",
              top: 0,
              display: "inline-block",
              zIndex: 3000
            }
          );
          parent.insertBefore(this.selectedPiece, e.target.nextSibling);
        } else {
          this.processMoveAttempt(e);
        }
      } else if (e.which == 3) {
        // Mouse right button
        let elem = e.target;
        // Next loop because of potential marks
        while (elem.tagName == "IMG") elem = elem.parentNode;
        // To center the arrow in square:
        const rect = elem.getBoundingClientRect();
        this.startArrow = {
          x: rect.x + rect.width / 2,
          y: rect.y + rect.width / 2,
          id: elem.id
        };
      }
    },
    mousemove: function(e) {
      if (!this.selectedPiece && !this.startArrow) return;
      e.preventDefault();
      if (!!this.selectedPiece) {
        // There is an active element: move it around
        const [offsetX, offsetY] =
          this.mobileBrowser
            ? [e.changedTouches[0].pageX, e.changedTouches[0].pageY]
            : [e.clientX, e.clientY];
        Object.assign(
          this.selectedPiece.style,
          {
            left: offsetX - this.start.x + "px",
            top: offsetY - this.start.y + "px"
          }
        );
      }
      else {
        let elem = e.target;
        // Next loop because of potential marks
        while (elem.tagName == "IMG") elem = elem.parentNode;
        // To center the arrow in square:
        if (elem.id != this.startArrow.id) {
          const rect = elem.getBoundingClientRect();
          this.movingArrow = {
            x: rect.x + rect.width / 2,
            y: rect.y + rect.width / 2
          };
        }
      }
    },
    mouseup: function(e) {
      e.preventDefault();
      if (this.mobileBrowser || e.which == 1) {
        if (!this.selectedPiece) return;
        // Drag'n drop. Selected piece is no longer needed:
        this.selectedPiece.parentNode.removeChild(this.selectedPiece);
        delete this.selectedPiece;
        this.selectedPiece = null;
        this.processMoveAttempt(e);
      } else if (e.which == 3) {
        // Mouse right button
        this.movingArrow = { x: -1, y: -1 };
        this.processArrowAttempt(e);
      }
    },
    processMoveAttempt: function(e) {
      // Obtain the move from start and end squares
      const [offsetX, offsetY] =
        this.mobileBrowser
          ? [e.changedTouches[0].pageX, e.changedTouches[0].pageY]
          : [e.clientX, e.clientY];
      let landing = document.elementFromPoint(offsetX, offsetY);
      // Next condition: classList.contains(piece) fails because of marks
      while (landing.tagName == "IMG") landing = landing.parentNode;
      if (this.start.id == landing.id) {
        if (this.click == landing.id) {
          // Second click on same square: cancel current move
          this.possibleMoves = [];
          this.start = null;
          this.click = "";
        } else this.click = landing.id;
        return;
      }
      this.start = null;
      // OK: process move attempt, landing is a square node
      let endSquare = getSquareFromId(landing.id);
      let moves = this.findMatchingMoves(endSquare);
      this.possibleMoves = [];
      if (moves.length > 1) {
        this.clickTime = Date.now();
        this.choices = moves;
      } else if (moves.length == 1) this.play(moves[0]);
      // else: forbidden move attempt
    },
    processArrowAttempt: function(e) {
      // Obtain the arrow from start and end squares
      const [offsetX, offsetY] = [e.clientX, e.clientY];
      let landing = document.elementFromPoint(offsetX, offsetY);
      // Next condition: classList.contains(piece) fails because of marks
      while (landing.tagName == "IMG") landing = landing.parentNode;
      if (this.startArrow.id == landing.id)
        // Draw (or erase) a circle
        this.$set(this.circles, landing.id, !this.circles[landing.id]);
      else {
        // OK: add arrow, landing is a new square
        const rect = landing.getBoundingClientRect();
        this.arrows.push({
          start: {
            x: this.startArrow.x,
            y: this.startArrow.y
          },
          end: {
            x: rect.x + rect.width / 2,
            y: rect.y + rect.width / 2
          }
        });
      }
      this.startArrow = null;
    },
    findMatchingMoves: function(endSquare) {
      // Run through moves list and return the matching set (if promotions...)
      return (
        this.possibleMoves.filter(m => {
          return (endSquare[0] == m.end.x && endSquare[1] == m.end.y);
        })
      );
    },
    play: function(move) {
      this.$emit("play-move", move);
    }
  }
};
</script>

<style lang="sass" scoped>
// NOTE: no variants with reserve of size != 8
.game.reserve-div
  margin-bottom: 18px
.reserve-count
  padding-left: 40%
.reserve-row
  margin-bottom: 15px

.full-width
  width: 100%

.game
  user-select: none
  width: 100%
  margin: 0
  .board
    cursor: pointer

#choices
  user-select: none
  margin: 0
  position: absolute
  z-index: 300
  overflow-y: inherit
  background-color: rgba(0,0,0,0)
  img
    cursor: pointer
    background-color: #e6ee9c
    &:hover
      background-color: skyblue
    &.choice-piece
      width: 100%
      height: auto
      display: block

img.ghost
  position: absolute
  opacity: 0.5
  top: 0

#arrowCanvas
  pointer-events: none
  position: absolute
  top: 0
  left: 0
  width: 100%
  height: 100%

.svg-arrow
  opacity: 0.65
  stroke: #5f0e78
  fill: none
  marker-end: url(#arrow)

.arrow-head
  fill: #5f0e78

.incheck-light
  background-color: rgba(204, 51, 0, 0.7) !important
.incheck-dark
  background-color: rgba(204, 51, 0, 0.9) !important

.light-square.lichess
  background-color: #f0d9b5;
.dark-square.lichess
  background-color: #b58863;

.light-square.chesscom
  background-color: #e5e5ca;
.dark-square.chesscom
  background-color: #6f8f57;

.light-square.chesstempo
  background-color: #dfdfdf;
.dark-square.chesstempo
  background-color: #7287b6;

// TODO: no predefined highlight colors, but layers. How?

.light-square.lichess.highlight-light
  background-color: #cdd26a
.dark-square.lichess.highlight-dark
  background-color: #aaa23a

.light-square.chesscom.highlight-light
  background-color: #f7f783
.dark-square.chesscom.highlight-dark
  background-color: #bacb44

.light-square.chesstempo.highlight-light
  background-color: #9f9fff
.dark-square.chesstempo.highlight-dark
  background-color: #557fff

</style>