conway.coffee

class Grid
  constructor: (@heightInCells, @widthInCells, @cellSize, canvas) ->
    @canvas = canvas
    @canvas.width = @widthInCells * @cellSize
    @canvas.height = @heightInCells * @cellSize
    @ctx = @canvas.getContext("2d")
    @cells = @initializeCells()

  initializeCells: ->
    rows = (((new Cell(x,y,'dead',@)) for x in [0..(@widthInCells-1)]) for y in [0..(@heightInCells-1)])

  seed: ->
    x = (Math.floor(Math.random() * @widthInCells))
    y = (Math.floor(Math.random() * @heightInCells))
    cell = @cells[y][x]
    cell.revive() if cell.state != 'alive'

  drawCells: ->
    (cell.draw() for cell in row for row in @cells)

  step: ->
    @ctx.clearRect(0, 0, @canvas.width, @canvas.height)
    cell.applyRules() for cell in row for row in @cells
    @drawCells()


class Cell
  constructor: (@x, @y, @state='dead', @grid) ->

  revive: ->
    @state = 'alive'

  isAlive: =>
    @state == 'alive'

  draw: ->
    if @isAlive()
      @grid.ctx.fillRect(@x*@grid.cellSize, @y*@grid.cellSize, @grid.cellSize, @grid.cellSize)

  applyRules: ->
    neighbors = {}
    neighbors['n'] = @grid.cells[@y-1][@x] if @y > 0
    neighbors['s'] = @grid.cells[@y+1][@x] if @y < @grid.heightInCells - 1
    neighbors['e'] = @grid.cells[@y][@x+1] if @x < @grid.widthInCells - 1
    neighbors['w'] = @grid.cells[@y][@x-1] if @x > 0
    neighbors['ne'] = @grid.cells[@y-1][@x+1] if @y > 0 && @x < @grid.widthInCells - 1
    neighbors['nw'] = @grid.cells[@y-1][@x-1] if @y > 0 && @x < 0
    neighbors['se'] = @grid.cells[@y+1][@x+1] if @x < @grid.widthInCells - 1 && @y < @grid.heightInCells - 1
    neighbors['sw'] = @grid.cells[@y+1][@x-1] if @y < @grid.heightInCells - 1 && @x > 0
    livingNeighbors = (cell for cell in neighbors when cell.isAlive())
    if @isAlive()
      if livingNeighbors <= 1 || livingNeighbors >= 4
        @state = 'dead'
      if livingNeighbors is 2 || livingNeighbors is 3
        @revive()
    else
      if livingNeighbors.length is 3
        @revive()


$ ->
  canvas = (document.getElementById "gol")
  grid = new Grid(30, 30, 5, canvas)
  ctx = grid.ctx
  grid.seed() for x in [0..100]
  grid.drawCells()
  grid.cells[1][1].applyRules()
  # setInterval((-> grid.step()), 1000)