import type { SubsonicArtist } from '../../api/subsonicTypes';

export const ALL_SENTINEL = 'ALL';
export const ALPHABET = [ALL_SENTINEL, '#', ...'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split('')];

/** Virtual row height guesses — letter heading vs dense rows vs last row in section (group gap). */
export const ARTIST_LIST_LETTER_ROW_EST = 48;
export const ARTIST_LIST_ROW_EST = 64;
export const ARTIST_LIST_LAST_IN_LETTER_EST = 88;

export type ArtistListFlatRow =
  | { kind: 'letter'; letter: string }
  | { kind: 'artist'; artist: SubsonicArtist; isLastInLetter: boolean };

// Catppuccin accent colors — one is picked deterministically from the artist name
const CTP_COLORS = [
  'var(--ctp-rosewater)', 'var(--ctp-flamingo)', 'var(--ctp-pink)',    'var(--ctp-mauve)',
  'var(--ctp-red)',       'var(--ctp-maroon)',    'var(--ctp-peach)',   'var(--ctp-yellow)',
  'var(--ctp-green)',     'var(--ctp-teal)',      'var(--ctp-sky)',     'var(--ctp-sapphire)',
  'var(--ctp-blue)',      'var(--ctp-lavender)',
];

export function nameColor(name: string): string {
  let h = 0;
  for (let i = 0; i < name.length; i++) h = (h * 31 + name.charCodeAt(i)) >>> 0;
  return CTP_COLORS[h % CTP_COLORS.length];
}

export function nameInitial(name: string): string {
  // \p{L} matches any Unicode letter — covers cyrillic, arabic, CJK, etc.
  const letter = name.match(/\p{L}/u)?.[0];
  if (letter) return letter.toUpperCase();
  const alnum = name.match(/[0-9]/)?.[0];
  return alnum ?? '?';
}