const AVATAR_BACKGROUNDS = [
  "#B9DED4",
  "#C6D8F0",
  "#D7C9ED",
  "#EEC8D4",
  "#EBCDB6",
  "#E4DBAB",
  "#CADDAD",
  "#ADDCDD",
  "#BCD0E6",
  "#DCC8DA",
  "#D9D4BF",
  "#C3DCCD",
] as const;

/** Colores estables al normalizar mayúsculas, espacios y acentos del nombre. */
export function getInitialsAvatarAppearance(name: string) {
  const displayName = name.normalize("NFC").trim().replace(/\s+/gu, " ");
  const words = displayName.match(/[\p{L}\p{N}]+/gu) ?? [];
  const firstWord = words[0] ?? "";
  const initials =
    words.length === 1 &&
    firstWord === firstWord.toUpperCase() &&
    firstWord !== firstWord.toLowerCase() &&
    Array.from(firstWord).length <= 3
      ? firstWord
      : words
          .slice(0, 2)
          .map((word) => Array.from(word)[0] ?? "")
          .join("")
          .toUpperCase();
  const colorKey = displayName.normalize("NFKD").replace(/\p{M}/gu, "").toLowerCase();
  let hash = 0;
  for (const character of colorKey) {
    hash = (Math.imul(hash, 31) + (character.codePointAt(0) ?? 0)) >>> 0;
  }
  return {
    initials: initials || "?",
    background: AVATAR_BACKGROUNDS[hash % AVATAR_BACKGROUNDS.length] ?? AVATAR_BACKGROUNDS[0],
    foreground: "#223C4B",
  };
}