color.coffee

class Color
  @regex: /(?:#([0-9a-f]{3,6})|rgba?\(([^)]+)\))/i

  @fromHex: (hex) ->
    if hex[0] is '#'
      hex = hex.substring(1, 7)

    if hex.length is 3
      hex = hex.charAt(0) + hex.charAt(0) +
            hex.charAt(1) + hex.charAt(1) +
            hex.charAt(2) + hex.charAt(2)

    r = parseInt(hex.substring(0,2), 16)
    g = parseInt(hex.substring(2,4), 16)
    b = parseInt(hex.substring(4,6), 16)

    new this(r, g, b)

  @fromString: (str) ->
    match = str.match(@regex)
    return null unless match

    if hex = match[1]
      @fromHex(hex)

    else if rgba = match[2]
      [r, g, b, a] = rgba.split(/\s*,\s*/)
      new this(r, g, b, a)

  constructor: (r, g, b, a = 1) ->
    @r = parseInt(r, 10) if r?
    @g = parseInt(g, 10) if g?
    @b = parseInt(b, 10) if b?
    @a = parseFloat(a)