/**
 * A class to parse color values
 * @author Stoyan Stefanov <sstoo@gmail.com>
 * @link   http://www.phpied.com/rgb-color-parser-in-javascript/
 * @license Use it if you like it
 * MODIFICATIONS by Peter Cottle :D
 */
function Color(color_string)
{
    // if it's an object, just clone and return
    if (typeof color_string === 'object') {
      this.r = color_string.r; this.g = color_string.g;
      this.a = color_string.a; this.b = color_string.b;
      this.ok = true;
      return;
    }

    // strip any leading #
    if (color_string.charAt(0) == '#') { // remove # if any
        color_string = color_string.substr(1,6);
    }

    color_string = color_string.replace(/ /g,'');
    color_string = color_string.toLowerCase();

   // array of color definition objects
    var color_defs = [
        {
            re: /^rgb\((\d{1,3}),\s*(\d{1,3}),\s*(\d{1,3})\)$/,
            example: ['rgb(123, 234, 45)', 'rgb(255,234,245)'],
            process: function (bits){
                return [
                    parseInt(bits[1]),
                    parseInt(bits[2]),
                    parseInt(bits[3])
                ];
            }
        },
        {
            re: /^(\w{2})(\w{2})(\w{2})$/,
            example: ['#00ff00', '336699'],
            process: function (bits){
                return [
                    parseInt(bits[1], 16),
                    parseInt(bits[2], 16),
                    parseInt(bits[3], 16)
                ];
            }
        },
        {
            re: /^(\w{1})(\w{1})(\w{1})$/,
            example: ['#fb0', 'f0f'],
            process: function (bits){
                return [
                    parseInt(bits[1] + bits[1], 16),
                    parseInt(bits[2] + bits[2], 16),
                    parseInt(bits[3] + bits[3], 16)
                ];
            }
        },
        {
            re: /^rgba\((\d{1,3}),\s*(\d{1,3}),\s*(\d{1,3}),\s*([0-9.]+)\)*$/,
            example: ['rgba(123, 234, 45, 0.2)', 'rgba(255,234,245,1)'],
            process: function (bits){
                return [
                    parseInt(bits[1]),
                    parseInt(bits[2]),
                    parseInt(bits[3]),
                    parseFloat(bits[4])
                ];
            }
        },
        {
            re: /^rgba\((\d{1,3})%,\s*(\d{1,3})%,\s*(\d{1,3})%,\s*([0-9.]+)\)*$/,
            example: ['rgba(100%, 97%, 45%, 0.2)', 'rgba(1%,4%,245%,1)'],
            process: function (bits){
                var parseRound = function(bit) {
                  return Math.round((parseInt(bit) / 100) * 256);
                };
                return [
                    parseRound(bits[1]),
                    parseRound(bits[2]),
                    parseRound(bits[3]),
                    parseFloat(bits[4])
                ];
            }
        }
    ];

    var found = false;
    // search through the definitions to find a match
    for (var i = 0; i < color_defs.length; i++) {
        var re = color_defs[i].re;
        var processor = color_defs[i].process;
        var bits = re.exec(color_string);
        if (bits) {
            channels = processor(bits);
            this.r = channels[0];
            this.g = channels[1];
            this.b = channels[2];
            this.a = channels[3] || 1;
            found = true;
            break;
        }
    }
    if (!found) {
      throw new Error('Could not parse the color_string ' + JSON.stringify(color_string));
    }

    // validate/cleanup values
    this.r = (this.r < 0 || isNaN(this.r)) ? 0 : ((this.r > 255) ? 255 : this.r);
    this.g = (this.g < 0 || isNaN(this.g)) ? 0 : ((this.g > 255) ? 255 : this.g);
    this.b = (this.b < 0 || isNaN(this.b)) ? 0 : ((this.b > 255) ? 255 : this.b);
    this.a = (this.a < 0 || isNaN(this.a)) ? 1 : ((this.a > 1) ? 1 : this.a);

    // some getters
    this.toRGB = function () {
        return 'rgb(' + this.r + ', ' + this.g + ', ' + this.b + ')';
    }
    this.toRGBA = function() {
        return 'rgba(' + this.r + ', ' + this.g + ', ' + this.b + ', ' + this.a + ')';
    }

    this.toHex = function () {
        var r = this.r.toString(16);
        var g = this.g.toString(16);
        var b = this.b.toString(16);
        if (r.length == 1) r = '0' + r;
        if (g.length == 1) g = '0' + g;
        if (b.length == 1) b = '0' + b;
        return '#' + r + g + b;
    }
}