export type Color = ColorData;
export type AcceptedModel = 'rgb'|'hwb'|'hsl'|'hsv'|'cmyk';

/** Type for `ColorSettable.toHex()` method. */
export type HexMode = 'full'|'short'|'name';
/** Type for `ColorSettable.toRgb()` method. */
export type RgbMode = 'default'|'percent';

/** A data object that includes color data. */
export interface ColorData {
  model: AcceptedModel;
  values: number[];
  alpha?: number;
}

/** An argument for `ColorModifiable.random()` method. */
export interface RandomArguments {
  /** The hue value from 0 to 360. Also you can give this as range. e.g. [0, 180] */
  hue?: number|[number, number];
  /** The whiteness value from 0 to 100. Also you can give this as range. e.g. [0, 50] */
  white?: number|[number, number];
  /** The blackness value from 0 to 100. Also you can give this as range. e.g. [0, 50] */
  black?: number|[number, number];
}

/** It can set or get color data. and also can change color to another model. */
export interface ColorSettable {
  color?: Color;

  setColor: (color: Color) => this;
  getColor: () => Color;
  getColorAs: (model: AcceptedModel) => Color;
  getModel: () => AcceptedModel|undefined;
  changeModel: (model: AcceptedModel) => this;
  getAlpha: () => number;
  setAlpha: (alpha: number) => this;
  convert: (color: Color, model: AcceptedModel) => Color;
}

/**
 * It can represent color to multiple notations.
 * accepted color models: 'rgb'|'hwb'|'hsl'|'hsv'|'cmyk' + 'hex'
 */
export interface ColorRepresentable {
  color?: Color;

  toString(model?: AcceptedModel|'hex', ...args: any[]): string;
  toHex(mode?: HexMode): string;
  toRgb(mode?: RgbMode): string;
  toHwb(): string;
  toHsl(): string;
  toHsv(): string;
  toCmyk(): string;
}

/**
 * It can access color state. such as brightness, luminance..
 * @see https://www.w3.org/TR/AERT/#color-contrast
 * @see https://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef
 */
export interface ColorStateAccessible {
  color?: Color;

  readonly brightness: number;
  readonly isLight: boolean;
  readonly isDark: boolean;
  readonly luminance: number;

  contrastRatioWith(color: ColorStateAccessible): number;
  isContrastEnough(color: ColorStateAccessible): boolean;
}

/**
 * It can manipulate color values.
 */
export interface ColorModifiable<T extends ColorSettable> {
  color?: Color;

  lighten(amount: number): this;
  darken(amount: number): this;
  saturate(amount: number): this;
  desaturate(amount: number): this;
  grayscale(): this;
  whiten(amount: number): this;
  blacken(amount: number): this;
  rotate(degree: number): this;
  mix(color: T, percent?: number): T;
  complement(): this;
  invert(percent?: number): this;
}