import { SETTING_KEYS, type SettingKey } from "./settingsContract";

/**
 * The canonical settings an in-player subtitle pick stores for a series.
 *
 * Two surfaces have to agree on this list. The player writes these rows when
 * the viewer picks a track (WatchPage), and "Auto" on the item page clears
 * them (useDeleteSubtitlePreference) — profile_series is the first scope in
 * the manifest's resolution order for both keys, so a row this list forgets is
 * a row that outranks every later choice with nothing in the UI able to remove
 * it. Adding a key here wires up both halves at once.
 *
 * playback.show_forced_subtitles is deliberately absent. The player has no
 * forced-subtitle control: the value it holds is the *resolved* one, which for
 * a viewer who never expressed a preference is the contract default. Writing
 * it back would pin that default at the top of the ladder and permanently
 * shadow the profile-scope toggle on the Subtitles settings screen. It stays
 * on the legacy composite row, which is not part of the canonical ladder.
 */
export const SERIES_SUBTITLE_SETTING_KEYS = [
  SETTING_KEYS.PLAYBACK_SUBTITLE_LANGUAGE,
  SETTING_KEYS.PLAYBACK_SUBTITLE_MODE,
] as const satisfies readonly SettingKey[];

export type SeriesSubtitleSettingKey = (typeof SERIES_SUBTITLE_SETTING_KEYS)[number];

/**
 * The values one subtitle pick stores, keyed the way the writer sends them.
 *
 * Returning a full record (rather than letting the caller assemble one) is
 * what keeps the written set and {@link SERIES_SUBTITLE_SETTING_KEYS} from
 * drifting: a key added to the list without a value here fails to type-check.
 */
export function seriesSubtitleSettingValues(selection: {
  /** The chosen track's language, or null when subtitles were turned off. */
  language: string | null;
  mode: string;
}): Record<SeriesSubtitleSettingKey, unknown> {
  return {
    // The contract spells "no preference" as null, where the legacy route
    // spelled it as the empty string.
    [SETTING_KEYS.PLAYBACK_SUBTITLE_LANGUAGE]: selection.language || null,
    [SETTING_KEYS.PLAYBACK_SUBTITLE_MODE]: selection.mode,
  };
}

/** The canonical values path addressing one key at one series. */
export function seriesSubtitleSettingPath(key: SettingKey, seriesId: string): string {
  return `/settings/values/${key}?scope=profile_series&series_id=${encodeURIComponent(seriesId)}`;
}