import { ColorNameMap } from './color_map';
import { reHSLa, reHex, reRGBa } from './constants';
import { hue2rgb, hexify } from './util';

/**
 * RGB format
 */
export type TRGBColorSource = [red: number, green: number, blue: number];

/**
 * RGBA format
 */
export type TRGBAColorSource = [
  red: number,
  green: number,
  blue: number,
  alpha: number
];

export type TColorArg = string | TRGBColorSource | TRGBAColorSource | Color;

/**
 * @class Color common color operations
 * @tutorial {@link http://fabricjs.com/fabric-intro-part-2/#colors colors}
 */
export class Color {
  private declare _source: TRGBAColorSource;

  /**
   *
   * @param {string} [color] optional in hex or rgb(a) or hsl format or from known color list
   */
  constructor(color?: TColorArg) {
    if (!color) {
      // we default to black as canvas does
      this.setSource([0, 0, 0, 1]);
    } else if (color instanceof Color) {
      this.setSource([...color._source]);
    } else if (Array.isArray(color)) {
      const [r, g, b, a = 1] = color;
      this.setSource([r, g, b, a]);
    } else {
      this.setSource(this._tryParsingColor(color));
    }
  }

  /**
   * @private
   * @param {string} [color] Color value to parse
   * @returns {TRGBAColorSource}
   */
  protected _tryParsingColor(color: string) {
    if (color in ColorNameMap) {
      color = ColorNameMap[color as keyof typeof ColorNameMap];
    }
    return color === 'transparent'
      ? ([255, 255, 255, 0] as TRGBAColorSource)
      : Color.sourceFromHex(color) ||
          Color.sourceFromRgb(color) ||
          Color.sourceFromHsl(color) ||
          // color is not recognized
          // we default to black as canvas does
          ([0, 0, 0, 1] as TRGBAColorSource);
  }

  /**
   * Adapted from {@link https://gist.github.com/mjackson/5311256 https://gist.github.com/mjackson}
   * @private
   * @param {Number} r Red color value
   * @param {Number} g Green color value
   * @param {Number} b Blue color value
   * @return {TRGBColorSource} Hsl color
   */
  _rgbToHsl(r: number, g: number, b: number): TRGBColorSource {
    r /= 255;
    g /= 255;
    b /= 255;
    const maxValue = Math.max(r, g, b),
      minValue = Math.min(r, g, b);

    let h!: number, s: number;
    const l = (maxValue + minValue) / 2;

    if (maxValue === minValue) {
      h = s = 0; // achromatic
    } else {
      const d = maxValue - minValue;
      s = l > 0.5 ? d / (2 - maxValue - minValue) : d / (maxValue + minValue);
      switch (maxValue) {
        case r:
          h = (g - b) / d + (g < b ? 6 : 0);
          break;
        case g:
          h = (b - r) / d + 2;
          break;
        case b:
          h = (r - g) / d + 4;
          break;
      }
      h /= 6;
    }

    return [Math.round(h * 360), Math.round(s * 100), Math.round(l * 100)];
  }

  /**
   * Returns source of this color (where source is an array representation; ex: [200, 200, 100, 1])
   * @return {TRGBAColorSource}
   */
  getSource() {
    return this._source;
  }

  /**
   * Sets source of this color (where source is an array representation; ex: [200, 200, 100, 1])
   * @param {TRGBAColorSource} source
   */
  setSource(source: TRGBAColorSource) {
    this._source = source;
  }

  /**
   * Returns color representation in RGB format
   * @return {String} ex: rgb(0-255,0-255,0-255)
   */
  toRgb() {
    const source = this.getSource();
    return `rgb(${source[0]},${source[1]},${source[2]})`;
  }

  /**
   * Returns color representation in RGBA format
   * @return {String} ex: rgba(0-255,0-255,0-255,0-1)
   */
  toRgba() {
    const source = this.getSource();
    return `rgba(${source[0]},${source[1]},${source[2]},${source[3]})`;
  }

  /**
   * Returns color representation in HSL format
   * @return {String} ex: hsl(0-360,0%-100%,0%-100%)
   */
  toHsl() {
    const source = this.getSource(),
      hsl = this._rgbToHsl(source[0], source[1], source[2]);

    return `hsl(${hsl[0]},${hsl[1]}%,${hsl[2]}%)`;
  }

  /**
   * Returns color representation in HSLA format
   * @return {String} ex: hsla(0-360,0%-100%,0%-100%,0-1)
   */
  toHsla() {
    const source = this.getSource(),
      hsl = this._rgbToHsl(source[0], source[1], source[2]);

    return `hsla(${hsl[0]},${hsl[1]}%,${hsl[2]}%,${source[3]})`;
  }

  /**
   * Returns color representation in HEX format
   * @return {String} ex: FF5555
   */
  toHex() {
    const [r, g, b] = this.getSource();
    return `${hexify(r)}${hexify(g)}${hexify(b)}`;
  }

  /**
   * Returns color representation in HEXA format
   * @return {String} ex: FF5555CC
   */
  toHexa() {
    const source = this.getSource();
    return `${this.toHex()}${hexify(Math.round(source[3] * 255))}`;
  }

  /**
   * Gets value of alpha channel for this color
   * @return {Number} 0-1
   */
  getAlpha() {
    return this.getSource()[3];
  }

  /**
   * Sets value of alpha channel for this color
   * @param {Number} alpha Alpha value 0-1
   * @return {Color} thisArg
   */
  setAlpha(alpha: number) {
    const source = this.getSource();
    source[3] = alpha;
    this.setSource(source);
    return this;
  }

  /**
   * Transforms color to its grayscale representation
   * @return {Color} thisArg
   */
  toGrayscale() {
    const source = this.getSource(),
      average = parseInt(
        (source[0] * 0.3 + source[1] * 0.59 + source[2] * 0.11).toFixed(0),
        10
      ),
      currentAlpha = source[3];
    this.setSource([average, average, average, currentAlpha]);
    return this;
  }

  /**
   * Transforms color to its black and white representation
   * @param {Number} threshold
   * @return {Color} thisArg
   */
  toBlackWhite(threshold: number) {
    const source = this.getSource(),
      currentAlpha = source[3];
    let average = Math.round(
      source[0] * 0.3 + source[1] * 0.59 + source[2] * 0.11
    );

    average = average < (threshold || 127) ? 0 : 255;
    this.setSource([average, average, average, currentAlpha]);
    return this;
  }

  /**
   * Overlays color with another color
   * @param {String|Color} otherColor
   * @return {Color} thisArg
   */
  overlayWith(otherColor: string | Color) {
    if (!(otherColor instanceof Color)) {
      otherColor = new Color(otherColor);
    }

    const [r, g, b, alpha] = this.getSource(),
      otherAlpha = 0.5,
      otherSource = otherColor.getSource(),
      [R, G, B] = [r, g, b].map((value, index) =>
        Math.round(value * (1 - otherAlpha) + otherSource[index] * otherAlpha)
      );

    this.setSource([R, G, B, alpha]);
    return this;
  }

  /**
   * Returns new color object, when given a color in RGB format
   * @memberOf Color
   * @param {String} color Color value ex: rgb(0-255,0-255,0-255)
   * @return {Color}
   */
  static fromRgb(color: string): Color {
    return Color.fromRgba(color);
  }

  /**
   * Returns new color object, when given a color in RGBA format
   * @static
   * @function
   * @memberOf Color
   * @param {String} color
   * @return {Color}
   */
  static fromRgba(color: string): Color {
    return new Color(Color.sourceFromRgb(color));
  }

  /**
   * Returns array representation (ex: [100, 100, 200, 1]) of a color that's in RGB or RGBA format
   * @memberOf Color
   * @param {String} color Color value ex: rgb(0-255,0-255,0-255), rgb(0%-100%,0%-100%,0%-100%)
   * @return {TRGBAColorSource | undefined} source
   */
  static sourceFromRgb(color: string): TRGBAColorSource | undefined {
    const match = color.match(reRGBa);
    if (match) {
      const r =
          (parseInt(match[1], 10) / (/%$/.test(match[1]) ? 100 : 1)) *
          (/%$/.test(match[1]) ? 255 : 1),
        g =
          (parseInt(match[2], 10) / (/%$/.test(match[2]) ? 100 : 1)) *
          (/%$/.test(match[2]) ? 255 : 1),
        b =
          (parseInt(match[3], 10) / (/%$/.test(match[3]) ? 100 : 1)) *
          (/%$/.test(match[3]) ? 255 : 1);

      return [r, g, b, match[4] ? parseFloat(match[4]) : 1];
    }
  }

  /**
   * Returns new color object, when given a color in HSL format
   * @param {String} color Color value ex: hsl(0-260,0%-100%,0%-100%)
   * @memberOf Color
   * @return {Color}
   */
  static fromHsl(color: string): Color {
    return Color.fromHsla(color);
  }

  /**
   * Returns new color object, when given a color in HSLA format
   * @static
   * @function
   * @memberOf Color
   * @param {String} color
   * @return {Color}
   */
  static fromHsla(color: string): Color {
    return new Color(Color.sourceFromHsl(color));
  }

  /**
   * Returns array representation (ex: [100, 100, 200, 1]) of a color that's in HSL or HSLA format.
   * Adapted from <a href="https://rawgithub.com/mjijackson/mjijackson.github.com/master/2008/02/rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript.html">https://github.com/mjijackson</a>
   * @memberOf Color
   * @param {String} color Color value ex: hsl(0-360,0%-100%,0%-100%) or hsla(0-360,0%-100%,0%-100%, 0-1)
   * @return {TRGBAColorSource | undefined} source
   * @see http://http://www.w3.org/TR/css3-color/#hsl-color
   */
  static sourceFromHsl(color: string): TRGBAColorSource | undefined {
    const match = color.match(reHSLa);
    if (!match) {
      return;
    }

    const h = (((parseFloat(match[1]) % 360) + 360) % 360) / 360,
      s = parseFloat(match[2]) / (/%$/.test(match[2]) ? 100 : 1),
      l = parseFloat(match[3]) / (/%$/.test(match[3]) ? 100 : 1);
    let r: number, g: number, b: number;

    if (s === 0) {
      r = g = b = l;
    } else {
      const q = l <= 0.5 ? l * (s + 1) : l + s - l * s,
        p = l * 2 - q;

      r = hue2rgb(p, q, h + 1 / 3);
      g = hue2rgb(p, q, h);
      b = hue2rgb(p, q, h - 1 / 3);
    }

    return [
      Math.round(r * 255),
      Math.round(g * 255),
      Math.round(b * 255),
      match[4] ? parseFloat(match[4]) : 1,
    ];
  }

  /**
   * Returns new color object, when given a color in HEX format
   * @static
   * @memberOf Color
   * @param {String} color Color value ex: FF5555
   * @return {Color}
   */
  static fromHex(color: string): Color {
    return new Color(Color.sourceFromHex(color));
  }

  /**
   * Returns array representation (ex: [100, 100, 200, 1]) of a color that's in HEX format
   * @static
   * @memberOf Color
   * @param {String} color ex: FF5555 or FF5544CC (RGBa)
   * @return {TRGBAColorSource | undefined} source
   */
  static sourceFromHex(color: string): TRGBAColorSource | undefined {
    if (color.match(reHex)) {
      const value = color.slice(color.indexOf('#') + 1),
        isShortNotation = value.length === 3 || value.length === 4,
        isRGBa = value.length === 8 || value.length === 4,
        r = isShortNotation
          ? value.charAt(0) + value.charAt(0)
          : value.substring(0, 2),
        g = isShortNotation
          ? value.charAt(1) + value.charAt(1)
          : value.substring(2, 4),
        b = isShortNotation
          ? value.charAt(2) + value.charAt(2)
          : value.substring(4, 6),
        a = isRGBa
          ? isShortNotation
            ? value.charAt(3) + value.charAt(3)
            : value.substring(6, 8)
          : 'FF';

      return [
        parseInt(r, 16),
        parseInt(g, 16),
        parseInt(b, 16),
        parseFloat((parseInt(a, 16) / 255).toFixed(2)),
      ];
    }
  }
}