refactor(playback): share series navigation state

libs/ui/playback/src/lib/embedded-mpv-player/embedded-mpv-player.component.ts

@@ -9,6 +9,7 @@ import {
     effect,
     inject,
     input,
+    output,
     signal,
     untracked,
     viewChild,
@@ -76,9 +77,9 @@ export class EmbeddedMpvPlayerComponent implements OnDestroy {
         currentTime: number;
         duration: number;
     }>();
-    @Output() playbackEnded = new EventEmitter<void>();
-    @Output() previousEpisodeRequested = new EventEmitter<void>();
-    @Output() nextEpisodeRequested = new EventEmitter<void>();
+    readonly playbackEnded = output<void>();
+    readonly previousEpisodeRequested = output<void>();
+    readonly nextEpisodeRequested = output<void>();
 
     private readonly overlayVisibility = inject(
         EmbeddedMpvOverlayVisibilityService

libs/ui/playback/src/lib/portal-inline-player/series-playback-navigation.ts

@@ -20,6 +20,22 @@ export interface SeriesPlaybackEpisodeState<TEpisode> {
     next: TEpisode | null;
 }
 
+export interface SeriesPlaybackEpisodeLike {
+    id: string | number;
+    season?: string | number;
+    episode_num?: string | number;
+    title?: string;
+}
+
+export interface ResolveSeriesPlaybackEpisodeStateOptions<
+    TEpisode extends SeriesPlaybackEpisodeLike,
+> {
+    episodesBySeason: Record<string, readonly TEpisode[]> | null | undefined;
+    currentEpisodeId: string | number | null | undefined;
+    fallbackSeasonNumber?: number;
+    fallbackEpisodeNumber?: number;
+}
+
 export function formatSeriesEpisodeLabel(
     seasonNumber: number,
     episodeNumber: number
@@ -27,6 +43,89 @@ export function formatSeriesEpisodeLabel(
     return `S${padSeriesNumber(seasonNumber)}E${padSeriesNumber(episodeNumber)}`;
 }
 
+export function resolveSeriesPlaybackEpisodeState<
+    TEpisode extends SeriesPlaybackEpisodeLike,
+>({
+    episodesBySeason,
+    currentEpisodeId,
+    fallbackSeasonNumber,
+    fallbackEpisodeNumber,
+}: ResolveSeriesPlaybackEpisodeStateOptions<TEpisode>): SeriesPlaybackEpisodeState<TEpisode> | null {
+    if (
+        !episodesBySeason ||
+        currentEpisodeId === null ||
+        currentEpisodeId === undefined
+    ) {
+        return null;
+    }
+
+    for (const [seasonKey, episodes] of Object.entries(episodesBySeason)) {
+        const episodeIndex = episodes.findIndex(
+            (episode) => Number(episode.id) === Number(currentEpisodeId)
+        );
+        if (episodeIndex < 0) {
+            continue;
+        }
+
+        const episode = episodes[episodeIndex];
+        const seasonNumber =
+            Number(episode.season) ||
+            Number(seasonKey) ||
+            fallbackSeasonNumber ||
+            0;
+        const episodeNumber =
+            Number(episode.episode_num) ||
+            fallbackEpisodeNumber ||
+            episodeIndex + 1;
+
+        return {
+            seasonKey,
+            seasonNumber,
+            episodeNumber,
+            episode,
+            previous: episodes[episodeIndex - 1] ?? null,
+            next: episodes[episodeIndex + 1] ?? null,
+        };
+    }
+
+    return null;
+}
+
+export function getSeriesEpisodeMetadata<
+    TEpisode extends SeriesPlaybackEpisodeLike,
+>(
+    state: SeriesPlaybackEpisodeState<TEpisode> | null
+): SeriesEpisodeMetadata | null {
+    if (!state) {
+        return null;
+    }
+
+    return {
+        label: formatSeriesEpisodeLabel(
+            state.seasonNumber,
+            state.episodeNumber
+        ),
+        seasonNumber: state.seasonNumber,
+        episodeNumber: state.episodeNumber,
+        title: state.episode.title,
+    };
+}
+
+export function getSeriesPlaybackNavigation(
+    state: SeriesPlaybackEpisodeState<unknown> | null,
+    autoplayEnabled = true
+): SeriesPlaybackNavigation | null {
+    if (!state) {
+        return null;
+    }
+
+    return {
+        canPrevious: Boolean(state.previous),
+        canNext: Boolean(state.next),
+        autoplayEnabled,
+    };
+}
+
 function padSeriesNumber(value: number): string {
     const normalized = Number.isFinite(value) && value > 0 ? value : 0;
     return String(normalized).padStart(2, '0');