/*
 * The colors we support generating an Avatar background color from a "seed" for.
 * Changing this array will change the assignment between seeds.
 * Do not change this array.
 */
const avatarColors = [
  'var(--color-bright-blue)',
  'var(--color-bright-yellow)',
  'var(--color-bright-pink)',
  'var(--color-bright-orange)',
] as const;

/*
 * Takes in a "seed" string and spits out an index for the color we should use.
 * This implementation has been synced across all three clients so that we consistently
 * generate branded avatar colors when rendering a list of Avatars.
 * Do not change this implementation.
 */
const hashSeed = (seed: string): number => {
  const base = 31;
  const modulo = avatarColors.length;

  let hashValue = 0;
  let basePow = 1;

  for (let i = 0; i < seed.length; i += 1) {
    hashValue = (hashValue + seed.charCodeAt(i) * basePow) % modulo;
    basePow = (basePow * base) % modulo;
  }

  return hashValue;
};

export const getBrandColorFromSeed = (seed: string): (typeof avatarColors)[number] => {
  return avatarColors[hashSeed(seed)];
};