export const COLORS: string[] = [
  '#C10020',
  '#007D34',
  '#803E75',
  '#FF6800',
  '#B32851',
  '#7F180D',
  '#232C16',
  '#A6BDD7',
  '#CEA262',
  '#817066',
  '#FF8E00',
  '#F6768E',
  '#00538A',
  '#FF7A5C',
  '#53377A',
  '#FFB300',
  '#F4C800',
  '#93AA00',
  '#593315',
  '#F13A13',
];

function percentToHex(p: number): string {
  const percent = Math.max(0, Math.min(100, p));
  const intValue = Math.round((percent / 100) * 255);
  const hexValue = intValue.toString(16);
  return percent === 100 ? '' : hexValue.padStart(2, '0');
}

export function adjustAlpha(color: string, factor: number): string {
  return color + percentToHex(factor);
}

interface Options {
  isRandom?: boolean;
  usedColors?: string[];
  opacity?: number;
}

export function generateColor(options: Options) {
  const { isRandom = false, usedColors = [], opacity = 100 } = options;

  if (opacity > 100 || opacity < 0) {
    throw new Error(`Opacity value must be within the range of 0 to 100`);
  }

  const resetColors = COLORS.filter((c) => !usedColors.includes(c));
  if (resetColors.length > 0 && !isRandom) {
    return resetColors[0] + percentToHex(opacity);
  } else {
    const lum = -0.25;
    let hex =
      `#${Math.random().toString(16).slice(2, 8).toUpperCase()}`.replaceAll(
        /[^\da-f]/gi,
        '',
      );
    if (hex.length < 6) {
      hex = hex[0] + hex[0] + hex[1] + hex[1] + hex[2] + hex[2];
    }
    let rgb = '#';
    let c: number | string;
    for (let i = 0; i < 3; i++) {
      c = Number.parseInt(hex.slice(i * 2, i * 2 + 2), 16);
      c = Math.round(Math.min(Math.max(0, c + c * lum), 255)).toString(16);
      rgb += `00${c}`.slice(c.length);
    }

    return rgb + percentToHex(opacity);
  }
}