"use strict"
import {run} from './gameloop.js'
import Camera from './Camera.js'
import EventAdapter from './EventAdapter.js'
import Graphics from './Graphics.js'
import Debug from './Debug.js'
import Communication from './Communication.js'

if (typeof GAME_ID === 'undefined') throw '[ GAME_ID not set ]'
if (typeof WS_ADDRESS === 'undefined') throw '[ WS_ADDRESS not set ]'

if (typeof DEBUG === 'undefined') window.DEBUG = false

function addCanvasToDom(canvas) {
    document.body.append(canvas)
    return canvas
}

function pointDistance(a, b) {
  const diffX = a.x - b.x
  const diffY = a.y - b.y
  return Math.sqrt(diffX * diffX + diffY * diffY)
}

function rectMoved(rect, x, y) {
  return {
    x: rect.x + x,
    y: rect.y + y,
    w: rect.w,
    h: rect.h,
  }
}

const rectCenter = (rect) => {
  return {
    x: rect.x + (rect.w / 2),
    y: rect.y + (rect.h / 2),
  }
}

function rectCenterDistance(a, b) {
  return pointDistance(rectCenter(a), rectCenter(b))
}

function pointInBounds(pt, rect) {
  return pt.x >= rect.x
    && pt.x <= rect.x + rect.w
    && pt.y >= rect.y
    && pt.y <= rect.y + rect.h
}

function getSurroundingTilesByIdx(puzzle, idx) {
  var _X = puzzle.info.coords[idx].x
  var _Y = puzzle.info.coords[idx].y

  return [
    // top
    _Y === 0 ? null : puzzle.tiles[idx - puzzle.info.tiles_x],
    // right
    (_X === puzzle.info.tiles_x - 1) ? null : puzzle.tiles[idx + 1],
    // bottom
    (_Y === puzzle.info.tiles_y - 1) ? null : puzzle.tiles[idx + puzzle.info.tiles_x],
    // left
    _X === 0 ? null : puzzle.tiles[idx - 1]
  ]
}

async function createPuzzleTileBitmaps(img, tiles, info) {
  var tileSize = info.tileSize
  var tileMarginWidth = info.tileMarginWidth
  var tileDrawSize = info.tileDrawSize
  var tileRatio = tileSize / 100.0

  var curvyCoords = [
    0, 0, 40, 15, 37, 5,
    37, 5, 40, 0, 38, -5,
    38, -5, 20, -20, 50, -20,
    50, -20, 80, -20, 62, -5,
    62, -5, 60, 0, 63, 5,
    63, 5, 65, 15, 100, 0
  ];

  const bitmaps = new Array(tiles.length)

  const paths = {}
  function pathForShape(shape) {
    const key = `${shape.top}${shape.right}${shape.left}${shape.bottom}`
    if (paths[key]) {
      return paths[key]
    }

    const path = new Path2D()
    const topLeftEdge = { x: tileMarginWidth, y: tileMarginWidth }
    path.moveTo(topLeftEdge.x, topLeftEdge.y)
    for (let i = 0; i < curvyCoords.length / 6; i++) {
      const p1 = pointAdd(topLeftEdge, { x: curvyCoords[i * 6 + 0] * tileRatio, y: shape.top * curvyCoords[i * 6 + 1] * tileRatio })
      const p2 = pointAdd(topLeftEdge, { x: curvyCoords[i * 6 + 2] * tileRatio, y: shape.top * curvyCoords[i * 6 + 3] * tileRatio })
      const p3 = pointAdd(topLeftEdge, { x: curvyCoords[i * 6 + 4] * tileRatio, y: shape.top * curvyCoords[i * 6 + 5] * tileRatio })
      path.bezierCurveTo(p1.x, p1.y, p2.x, p2.y, p3.x, p3.y);
    }
    const topRightEdge = pointAdd(topLeftEdge, { x: tileSize, y: 0 })
    for (let i = 0; i < curvyCoords.length / 6; i++) {
      const p1 = pointAdd(topRightEdge, { x: -shape.right * curvyCoords[i * 6 + 1] * tileRatio, y: curvyCoords[i * 6 + 0] * tileRatio })
      const p2 = pointAdd(topRightEdge, { x: -shape.right * curvyCoords[i * 6 + 3] * tileRatio, y: curvyCoords[i * 6 + 2] * tileRatio })
      const p3 = pointAdd(topRightEdge, { x: -shape.right * curvyCoords[i * 6 + 5] * tileRatio, y: curvyCoords[i * 6 + 4] * tileRatio })
      path.bezierCurveTo(p1.x, p1.y, p2.x, p2.y, p3.x, p3.y);
    }
    const bottomRightEdge = pointAdd(topRightEdge, { x: 0, y: tileSize })
    for (let i = 0; i < curvyCoords.length / 6; i++) {
      let p1 = pointSub(bottomRightEdge, { x: curvyCoords[i * 6 + 0] * tileRatio, y: shape.bottom * curvyCoords[i * 6 + 1] * tileRatio })
      let p2 = pointSub(bottomRightEdge, { x: curvyCoords[i * 6 + 2] * tileRatio, y: shape.bottom * curvyCoords[i * 6 + 3] * tileRatio })
      let p3 = pointSub(bottomRightEdge, { x: curvyCoords[i * 6 + 4] * tileRatio, y: shape.bottom * curvyCoords[i * 6 + 5] * tileRatio })
      path.bezierCurveTo(p1.x, p1.y, p2.x, p2.y, p3.x, p3.y);
    }
    const bottomLeftEdge = pointSub(bottomRightEdge, { x: tileSize, y: 0 })
    for (let i = 0; i < curvyCoords.length / 6; i++) {
      let p1 = pointSub(bottomLeftEdge, { x: -shape.left * curvyCoords[i * 6 + 1] * tileRatio, y: curvyCoords[i * 6 + 0] * tileRatio })
      let p2 = pointSub(bottomLeftEdge, { x: -shape.left * curvyCoords[i * 6 + 3] * tileRatio, y: curvyCoords[i * 6 + 2] * tileRatio })
      let p3 = pointSub(bottomLeftEdge, { x: -shape.left * curvyCoords[i * 6 + 5] * tileRatio, y: curvyCoords[i * 6 + 4] * tileRatio })
      path.bezierCurveTo(p1.x, p1.y, p2.x, p2.y, p3.x, p3.y);
    }
    paths[key] = path
    return path
  }

  for (let tile of tiles) {
    const srcRect = srcRectByIdx(info, tile.idx)
    const path = pathForShape(info.shapes[tile.idx])

    const c = Graphics.createCanvas(tileDrawSize, tileDrawSize)
    const ctx = c.getContext('2d')
    // -----------------------------------------------------------
    // -----------------------------------------------------------
    ctx.lineWidth = 2
    ctx.stroke(path)
    // -----------------------------------------------------------
    // -----------------------------------------------------------
    ctx.save();
    ctx.clip(path)
    ctx.drawImage(
      img,
      srcRect.x - tileMarginWidth,
      srcRect.y - tileMarginWidth,
      tileDrawSize,
      tileDrawSize,
      0,
      0,
      tileDrawSize,
      tileDrawSize,
    )
    ctx.stroke(path)
    ctx.restore();

    bitmaps[tile.idx] = await createImageBitmap(c)
  }

  return bitmaps
}

function srcRectByIdx(puzzleInfo, idx) {
  let c = puzzleInfo.coords[idx]
  let cx = c.x * puzzleInfo.tileSize
  let cy = c.y * puzzleInfo.tileSize
  return {
    x: cx,
    y: cy,
    w: puzzleInfo.tileSize,
    h: puzzleInfo.tileSize,
  }
}

const pointSub = (a, b) => ({ x: a.x - b.x, y: a.y - b.y })

const pointAdd = (a, b) => ({x: a.x + b.x, y: a.y + b.y})

// Returns the index of the puzzle tile with the highest z index
// that is not finished yet and that matches the position
const unfinishedTileByPos = (puzzle, pos) => {
  let maxZ = -1
  let tileIdx = -1
  for (let idx = 0; idx < puzzle.tiles.length; idx++) {
    const tile = puzzle.tiles[idx]
    if (tile.owner === -1) {
      continue
    }

    const collisionRect = {
      x: tile.pos.x,
      y: tile.pos.y,
      w: puzzle.info.tileSize,
      h: puzzle.info.tileSize,
    }
    if (pointInBounds(pos, collisionRect)) {
      if (maxZ === -1 || tile.z > maxZ) {
        maxZ = tile.z
        tileIdx = idx
      }
    }
  }
  return tileIdx
}

class DirtyRect {
  constructor() {
    this.reset()
  }
  get () {
    return this.x0 === null ? null : [
      {x0: this.x0, x1: this.x1, y0: this.y0, y1: this.y1}
    ]
  }
  add (pos, offset) {
    const x0 = pos.x - offset
    const x1 = pos.x + offset
    const y0 = pos.y - offset
    const y1 = pos.y + offset
    this.x0 = this.x0 === null ? x0 : Math.min(this.x0, x0)
    this.x1 = this.x1 === null ? x1 : Math.max(this.x1, x1)
    this.y0 = this.y0 === null ? y0 : Math.min(this.y0, y0)
    this.y1 = this.y1 === null ? y1 : Math.max(this.y1, y1)
  }
  reset () {
    this.x0 = null
    this.x1 = null
    this.y0 = null
    this.y1 = null
  }
}

async function loadPuzzleBitmaps(puzzle) {
  // load bitmap, to determine the original size of the image
  const bmp = await Graphics.loadImageToBitmap(puzzle.info.imageUrl)

  // creation of tile bitmaps
  // then create the final puzzle bitmap
  // NOTE: this can decrease OR increase in size!
  const bmpResized = await Graphics.resizeBitmap(bmp, puzzle.info.width, puzzle.info.height)
  return await createPuzzleTileBitmaps(bmpResized, puzzle.tiles, puzzle.info)
}

function uniqId() {
  return Date.now().toString(36) + Math.random().toString(36).substring(2)
}

function initme() {
  // return uniqId()
  let ID = localStorage.getItem("ID")
  if (!ID) {
    ID = uniqId()
    localStorage.setItem("ID", ID)
  }
  return ID
}

async function main () {
  let gameId = GAME_ID
  let me = initme()

  let cursorGrab = await Graphics.loadImageToBitmap('/grab.png')
  let cursorHand = await Graphics.loadImageToBitmap('/hand.png')

  const game = await Communication.connect(gameId, me)

  const bitmaps = await loadPuzzleBitmaps(game.puzzle)
  const puzzle = game.puzzle
  const players = game.players

  // information for next render cycle
  let rectPlayer = new DirtyRect()
  let rerenderPlayer = true
  let rectTable = new DirtyRect()
  let rerenderTable = true
  let rerender = true

  const changePlayer = (change) => {
    for (let k of Object.keys(change)) {
      players[me][k] = change[k]
    }
    Communication.addChange({type: 'change_player', player: players[me]})
  }
  const changeData = (change) => {
    for (let k of Object.keys(change)) {
      puzzle.data[k] = change[k]
    }
    Communication.addChange({type: 'change_data', data: puzzle.data})
  }
  const changeTile = (t, change) => {
    for (let k of Object.keys(change)) {
      t[k] = change[k]
    }
    Communication.addChange({type: 'change_tile', tile: t})
  }

  // Create a dom and attach adapters to it so we can work with it
  const canvas = addCanvasToDom(Graphics.createCanvas())
  const ctx = canvas.getContext('2d')
  const evts = new EventAdapter(canvas)

  // initialize some view data
  // this global data will change according to input events
  const viewport = new Camera(canvas)

  Communication.onChanges((changes) => {
    for (let change of changes) {
      switch (change.type) {
        case 'change_player': {
          if (players[change.player.id]) {
            rectPlayer.add(viewport.worldToViewport(players[change.player.id]), cursorGrab.width)
          }

          players[change.player.id] = change.player

          rectPlayer.add(viewport.worldToViewport(players[change.player.id]), cursorGrab.width)
        } break;

        case 'change_tile': {
          rectTable.add(puzzle.tiles[change.tile.idx].pos, puzzle.info.tileDrawSize)

          puzzle.tiles[change.tile.idx] = change.tile

          rectTable.add(puzzle.tiles[change.tile.idx].pos, puzzle.info.tileDrawSize)
        } break;
        case 'change_data': {
          puzzle.data = change.data
        } break;
      }
    }
  })

  // Information about what tile is the player currently grabbing
  let grabbingTileIdx = -1

  // The actual place for the puzzle. The tiles may
  // not be moved around infinitely, just on the (invisible)
  // puzzle table. however, the camera may move away from the table
  const puzzleTableColor = '#222'
  const puzzleTable = await Graphics.createBitmap(
    puzzle.info.table.width,
    puzzle.info.table.height,
    puzzleTableColor
  )

  // In the middle of the table, there is a board. this is to
  // tell the player where to place the final puzzle
  const boardColor = '#505050'
  const board = await Graphics.createBitmap(
    puzzle.info.width,
    puzzle.info.height,
    boardColor
  )
  const boardPos = {
    x: (puzzleTable.width - board.width) / 2,
    y: (puzzleTable.height - board.height) / 2
  } // relative to table.


  // Some helper functions for working with the grabbing and snapping
  // ---------------------------------------------------------------

  // get all grouped tiles for a tile
  function getGroupedTiles(tile) {
    let grouped = []
    if (tile.group) {
      for (let other of puzzle.tiles) {
        if (other.group === tile.group) {
          grouped.push(other)
        }
      }
    } else {
      grouped.push(tile)
    }
    return grouped
  }

  // put both tiles (and their grouped tiles) in the same group
  const groupTiles = (tile, other) => {
    let targetGroup
    let searchGroups = []
    if (tile.group) {
      searchGroups.push(tile.group)
    }
    if (other.group) {
      searchGroups.push(other.group)
    }
    if (tile.group) {
      targetGroup = tile.group
    } else if (other.group) {
      targetGroup = other.group
    } else {
      changeData({ maxGroup: puzzle.data.maxGroup + 1 })
      targetGroup = puzzle.data.maxGroup
    }

    changeTile(tile, { group: targetGroup })
    changeTile(other, { group: targetGroup })

    if (searchGroups.length > 0) {
      for (let tmp of puzzle.tiles) {
        if (searchGroups.includes(tmp.group)) {
          changeTile(tmp, { group: targetGroup })
        }
      }
    }
  }

  // determine if two tiles are grouped together
  const areGrouped = (t1, t2) => {
    return t1.group && t1.group === t2.group
  }

  // get the center position of a tile
  const tileCenterPos = (tile) => {

    return rectCenter(tileRectByTile(tile))
  }

  // get the would-be visible bounding rect if a tile was
  // in given position
  const tileRectByPos = (pos) => {
    return {
      x: pos.x,
      y: pos.y,
      w: puzzle.info.tileSize,
      h: puzzle.info.tileSize,
    }
  }

  // get the current visible bounding rect for a tile
  const tileRectByTile = (tile) => {
    return tileRectByPos(tile.pos)
  }

  const tilesSortedByZIndex = () => {
    const sorted = puzzle.tiles.slice()
    return sorted.sort((t1, t2) => t1.z - t2.z)
  }

  const setGroupedZIndex = (tile, zIndex) => {
    for (let t of getGroupedTiles(tile)) {
      changeTile(t, { z: zIndex })
    }
  }

  const setGroupedOwner = (tile, owner) => {
    for (let t of getGroupedTiles(tile)) {
      // may only change own tiles or untaken tiles
      if (t.owner === me || t.owner === 0) {
        changeTile(t, { owner: owner })
      }
    }
  }

  const moveGroupedTilesDiff = (tile, diffX, diffY) => {
    for (let t of getGroupedTiles(tile)) {
      changeTile(t, { pos: pointAdd(t.pos, { x: diffX, y: diffY }) })

      // TODO: instead there could be a function to
      //       get min/max x/y of a group
      rectTable.add(tileCenterPos(t), puzzle.info.tileDrawSize)
    }
  }
  const moveGroupedTiles = (tile, dst) => {
    let diff = pointSub(tile.pos, dst)
    moveGroupedTilesDiff(tile, -diff.x, -diff.y)
  }
  const finishGroupedTiles = (tile) => {
    for (let t of getGroupedTiles(tile)) {
      changeTile(t, { owner: -1, z: 1 })
    }
  }
  // ---------------------------------------------------------------







  let _last_mouse = null
  let _last_mouse_down = null
  const onUpdate = () => {
    let last_x = null
    let last_y = null

    if (_last_mouse_down !== null) {
      last_x = _last_mouse_down.x
      last_y = _last_mouse_down.y
    }
    for (let mouse of evts.consumeAll()) {
      const tp = viewport.viewportToWorld(mouse)
      if (mouse.type === 'move') {
        changePlayer({ x: tp.x, y: tp.y })
        if (_last_mouse) {
          rectPlayer.add(_last_mouse, cursorGrab.width)
        }
        rectPlayer.add(mouse, cursorGrab.width)

        if (_last_mouse_down !== null) {
          _last_mouse_down = mouse

          if (last_x === null || last_y === null) {
            last_x = mouse.x
            last_y = mouse.y
          }

          if (grabbingTileIdx >= 0) {
            const tp_last = viewport.viewportToWorld({ x: last_x, y: last_y })
            const diffX = tp.x - tp_last.x
            const diffY = tp.y - tp_last.y

            const t = puzzle.tiles[grabbingTileIdx]
            moveGroupedTilesDiff(t, diffX, diffY)

            // todo: dont +- tileDrawSize, we can work with less?
            rectTable.add(tp, puzzle.info.tileDrawSize)
            rectTable.add(tp_last, puzzle.info.tileDrawSize)
          } else {
            // move the cam
            const diffX = Math.round(mouse.x - last_x)
            const diffY = Math.round(mouse.y - last_y)
            viewport.move(diffX, diffY)
            rerender = true
          }
        }
      } else if (mouse.type === 'down') {
        changePlayer({ down: true })
        rectPlayer.add(mouse, cursorGrab.width)

        _last_mouse_down = mouse
        if (last_x === null || last_y === null) {
          last_x = mouse.x
          last_y = mouse.y
        }

        grabbingTileIdx = unfinishedTileByPos(puzzle, tp)
        console.log(grabbingTileIdx)
        if (grabbingTileIdx >= 0) {
          changeData({ maxZ: puzzle.data.maxZ + 1 })
          setGroupedZIndex(puzzle.tiles[grabbingTileIdx], puzzle.data.maxZ)
          setGroupedOwner(puzzle.tiles[grabbingTileIdx], me)
        }

      } else if (mouse.type === 'up') {
        changePlayer({ down: false })
        if (_last_mouse) {
          rectPlayer.add(_last_mouse, cursorGrab.width)
        }
        rectPlayer.add(mouse, cursorGrab.width)

        _last_mouse_down = null
        last_x = null
        last_y === null

        if (grabbingTileIdx >= 0) {
          // Check if the tile was dropped at the correct
          // location

          let tile = puzzle.tiles[grabbingTileIdx]
          setGroupedOwner(tile, 0)
          let pt = pointSub(tile.pos, boardPos)
          let dst = tileRectByPos(pt)
          let srcRect = srcRectByIdx(puzzle.info, grabbingTileIdx)
          if (rectCenterDistance(srcRect, dst) < puzzle.info.snapDistance) {
            // Snap the tile to the final destination
            moveGroupedTiles(tile, {
              x: srcRect.x + boardPos.x,
              y: srcRect.y + boardPos.y,
            })
            finishGroupedTiles(tile)
            rectTable.add(tp, puzzle.info.tileDrawSize)
          } else {
            // Snap to other tiles
            const check = (t, off, other) => {
              if (!other || (other.owner === -1) || areGrouped(t, other)) {
                return false
              }
              const trec_ = tileRectByTile(t)
              const otrec = rectMoved(
                tileRectByTile(other),
                off[0] * puzzle.info.tileSize,
                off[1] * puzzle.info.tileSize
              )
              if (rectCenterDistance(trec_, otrec) < puzzle.info.snapDistance) {
                moveGroupedTiles(t, { x: otrec.x, y: otrec.y })
                groupTiles(t, other)
                setGroupedZIndex(t, t.z)
                rectTable.add(tileCenterPos(t), puzzle.info.tileDrawSize)
                return true
              }
              return false
            }

            for (let t of getGroupedTiles(tile)) {
              let others = getSurroundingTilesByIdx(puzzle, t.idx)
              if (
                check(t, [0, 1], others[0]) // top
                || check(t, [-1, 0], others[1]) // right
                || check(t, [0, -1], others[2]) // bottom
                || check(t, [1, 0], others[3]) // left
              ) {
                break
              }
            }
          }
        }
        grabbingTileIdx = -1
      } else if (mouse.type === 'wheel') {
        if (
          mouse.deltaY < 0 && viewport.zoomIn()
          || mouse.deltaY > 0 && viewport.zoomOut()
        ) {
          rerender = true
          changePlayer({ x: tp.x, y: tp.y })
          if (_last_mouse) {
            rectPlayer.add(_last_mouse, cursorGrab.width)
          }
          rectPlayer.add(mouse, cursorGrab.width)
        }
      }
      // console.log(mouse)
      _last_mouse = mouse
    }
    if (rectTable.get()) {
      rerenderTable = true
    }
    if (rectPlayer.get()) {
      rerenderPlayer = true
    }

    Communication.sendChanges()
  }

  const onRender = () => {
    if (!rerenderTable && !rerenderPlayer && !rerender) {
      return
    }

    let pos
    let dim

    if (DEBUG) Debug.checkpoint_start(0)

    ctx.fillStyle = puzzleTableColor
    ctx.fillRect(0, 0, canvas.width, canvas.height)
    if (DEBUG) Debug.checkpoint('clear done')

    // DRAW BOARD
    // ---------------------------------------------------------------
    pos = viewport.worldToViewport(boardPos)
    dim = viewport.worldDimToViewport({w: board.width, h: board.height})
    ctx.drawImage(board,
      0, 0, board.width, board.height,
      pos.x, pos.y, dim.w, dim.h
    )
    if (DEBUG) Debug.checkpoint('board done')

    // DRAW TILES
    // ---------------------------------------------------------------
    for (let tile of tilesSortedByZIndex()) {
      let bmp = bitmaps[tile.idx]
      pos = viewport.worldToViewport({
        x: puzzle.info.tileDrawOffset + tile.pos.x,
        y: puzzle.info.tileDrawOffset + tile.pos.y,
      })
      dim = viewport.worldDimToViewport({
        w: puzzle.info.tileDrawSize,
        h: puzzle.info.tileDrawSize,
      })
      ctx.drawImage(bmp,
        0, 0, bmp.width, bmp.height,
        pos.x, pos.y, dim.w, dim.h
      )
    }
    if (DEBUG) Debug.checkpoint('tiles done')

    // DRAW PLAYERS
    // ---------------------------------------------------------------
    for (let id of Object.keys(players)) {
      const p = players[id]
      const cursor = p.down ? cursorGrab : cursorHand
      const pos = viewport.worldToViewport(p)
      ctx.drawImage(cursor, pos.x, pos.y)
    }
    //
    if (DEBUG) Debug.checkpoint('players done')


    if (DEBUG) Debug.checkpoint('all done')

    rerenderTable = false
    rerenderPlayer = false
    rerender = false
    rectTable.reset()
    rectPlayer.reset()
  }

  run({
    update: onUpdate,
    render: onRender,
  })
}

main()