Files
gregorlohaus.com/src/app/music/_components/MusicPlayerProvider.tsx
2026-06-16 19:13:32 +02:00

315 lines
8.5 KiB
TypeScript

'use client'
import {
createContext,
useCallback,
useContext,
useEffect,
useMemo,
useRef,
useState,
type ReactNode,
} from "react";
import { trpc } from "~/app/_trpc/Client";
import MusicMiniPlayer from "./MusicMiniPlayer";
export type PlayerTrack = {
id: string;
title: string;
/** Streaming-friendly source actually played. */
src: string;
/** Original high-quality file for the download button. */
downloadUrl: string;
downloadName: string;
};
type MusicPlayerValue = {
tracks: PlayerTrack[];
currentId: string | null;
currentTrack: PlayerTrack | null;
isPlaying: boolean;
shuffle: boolean;
currentTime: number;
duration: number;
/** Play button on a track: start it, or toggle play/pause if already current. */
toggle: (id: string) => void;
/** Global play/pause — acts on the current track (or starts the first one). */
togglePlayCurrent: () => void;
next: () => void;
previous: () => void;
toggleShuffle: () => void;
seek: (seconds: number) => void;
/** Subscribe to playback time updates (for waveform cursors). */
subscribeTime: (cb: (time: number) => void) => () => void;
};
const MusicPlayerContext = createContext<MusicPlayerValue | null>(null);
export function useMusicPlayer() {
const ctx = useContext(MusicPlayerContext);
if (!ctx) throw new Error("useMusicPlayer must be used within a MusicPlayerProvider");
return ctx;
}
export function MusicPlayerProvider({ children }: { children: ReactNode }) {
// The provider owns the playlist so playback survives navigating away from
// the music page. The query is cached, so the music page shares this request.
const { data } = trpc.music.list.useQuery();
const tracks = useMemo<PlayerTrack[]>(
() =>
(data ?? []).map((t) => ({
id: t.id,
title: t.title,
src: t.streamUrl ?? t.fileUrl,
downloadUrl: t.fileUrl,
downloadName: t.fileName,
})),
[data],
);
const [currentId, setCurrentId] = useState<string | null>(null);
const [isPlaying, setIsPlaying] = useState(false);
const [shuffle, setShuffle] = useState(false);
const [currentTime, setCurrentTime] = useState(0);
const [duration, setDuration] = useState(0);
const audioRef = useRef<HTMLAudioElement | null>(null);
const tracksRef = useRef(tracks);
tracksRef.current = tracks;
// Lightweight pub/sub so each waveform can follow playback time without every
// player re-rendering on the audio element's frequent timeupdate.
const timeSubs = useRef<Set<(t: number) => void>>(new Set());
const subscribeTime = useCallback((cb: (t: number) => void) => {
timeSubs.current.add(cb);
return () => {
timeSubs.current.delete(cb);
};
}, []);
const emitTime = useCallback((t: number) => {
timeSubs.current.forEach((cb) => cb(t));
}, []);
const currentTrack = useMemo(
() => tracks.find((t) => t.id === currentId) ?? null,
[tracks, currentId],
);
const toggle = useCallback((id: string) => {
setCurrentId((prev) => {
if (prev === id) {
setIsPlaying((p) => !p);
return prev;
}
setIsPlaying(true);
return id;
});
}, []);
const togglePlayCurrent = useCallback(() => {
setCurrentId((prev) => {
if (prev) {
setIsPlaying((p) => !p);
return prev;
}
const first = tracksRef.current[0]?.id ?? null;
if (first) setIsPlaying(true);
return first;
});
}, []);
const step = useCallback((dir: 1 | -1) => {
const ids = tracksRef.current.map((t) => t.id);
if (ids.length === 0) return;
setCurrentId((prev) => {
let nextId: string;
if (shuffle && dir === 1 && ids.length > 1) {
do {
nextId = ids[Math.floor(Math.random() * ids.length)]!;
} while (nextId === prev);
} else {
const idx = prev ? ids.indexOf(prev) : -1;
nextId = ids[(idx + dir + ids.length) % ids.length]!;
}
setIsPlaying(true);
return nextId;
});
}, [shuffle]);
const next = useCallback(() => step(1), [step]);
const previous = useCallback(() => step(-1), [step]);
const toggleShuffle = useCallback(() => setShuffle((s) => !s), []);
const stepRef = useRef(step);
stepRef.current = step;
const seek = useCallback(
(s: number) => {
if (audioRef.current) audioRef.current.currentTime = s;
setCurrentTime(s);
emitTime(s);
},
[emitTime],
);
// Persistent audio element + listeners, created once on the client.
useEffect(() => {
const audio = new Audio();
audio.preload = "metadata";
audioRef.current = audio;
const onTime = () => {
setCurrentTime(audio.currentTime);
emitTime(audio.currentTime);
};
const onMeta = () => setDuration(audio.duration || 0);
const onEnded = () => stepRef.current(1);
audio.addEventListener("timeupdate", onTime);
audio.addEventListener("loadedmetadata", onMeta);
audio.addEventListener("ended", onEnded);
return () => {
audio.pause();
audio.removeEventListener("timeupdate", onTime);
audio.removeEventListener("loadedmetadata", onMeta);
audio.removeEventListener("ended", onEnded);
audioRef.current = null;
};
}, [emitTime]);
// Swap the source when the current track changes.
useEffect(() => {
const audio = audioRef.current;
if (!audio) return;
if (!currentTrack) {
audio.removeAttribute("src");
audio.load();
return;
}
if (audio.src !== currentTrack.src) {
audio.src = currentTrack.src;
audio.load();
setCurrentTime(0);
setDuration(0);
}
}, [currentTrack]);
// Reflect the desired play state onto the element.
useEffect(() => {
const audio = audioRef.current;
if (!audio || !currentTrack) return;
if (isPlaying) audio.play().catch(() => {});
else audio.pause();
}, [isPlaying, currentTrack]);
// OS-level media controls (lock screen, notification shade, media keys, etc.)
// via the Media Session API. Wire the transport actions to our state.
useEffect(() => {
if (typeof navigator === "undefined" || !("mediaSession" in navigator)) return;
const ms = navigator.mediaSession;
const handlers: [MediaSessionAction, MediaSessionActionHandler][] = [
["play", () => setIsPlaying(true)],
["pause", () => setIsPlaying(false)],
["previoustrack", () => stepRef.current(-1)],
["nexttrack", () => stepRef.current(1)],
[
"seekto",
(details) => {
if (typeof details.seekTime === "number") seek(details.seekTime);
},
],
[
"seekbackward",
(details) => seek((audioRef.current?.currentTime ?? 0) - (details.seekOffset ?? 10)),
],
[
"seekforward",
(details) => seek((audioRef.current?.currentTime ?? 0) + (details.seekOffset ?? 10)),
],
];
for (const [action, handler] of handlers) {
try {
ms.setActionHandler(action, handler);
} catch {
// Action unsupported by this browser — ignore.
}
}
return () => {
for (const [action] of handlers) {
try {
ms.setActionHandler(action, null);
} catch {
// ignore
}
}
};
}, [seek]);
// Keep the OS-visible metadata in sync with the current track.
useEffect(() => {
if (typeof navigator === "undefined" || !("mediaSession" in navigator)) return;
navigator.mediaSession.metadata = currentTrack
? new MediaMetadata({
title: currentTrack.title,
artist: "Gregor Lohaus",
})
: null;
}, [currentTrack]);
// Reflect play/pause state to the OS so the right button is shown.
useEffect(() => {
if (typeof navigator === "undefined" || !("mediaSession" in navigator)) return;
navigator.mediaSession.playbackState = currentTrack
? isPlaying
? "playing"
: "paused"
: "none";
}, [isPlaying, currentTrack]);
// Keep the scrubber position on the OS controls in sync.
useEffect(() => {
if (typeof navigator === "undefined" || !("mediaSession" in navigator)) return;
if (!("setPositionState" in navigator.mediaSession)) return;
try {
if (duration > 0 && Number.isFinite(duration)) {
navigator.mediaSession.setPositionState({
duration,
position: Math.min(currentTime, duration),
playbackRate: audioRef.current?.playbackRate ?? 1,
});
} else {
navigator.mediaSession.setPositionState();
}
} catch {
// Some browsers throw on invalid state — ignore.
}
}, [currentTime, duration]);
const value = useMemo<MusicPlayerValue>(
() => ({
tracks,
currentId,
currentTrack,
isPlaying,
shuffle,
currentTime,
duration,
toggle,
togglePlayCurrent,
next,
previous,
toggleShuffle,
seek,
subscribeTime,
}),
[
tracks, currentId, currentTrack, isPlaying, shuffle, currentTime, duration,
toggle, togglePlayCurrent, next, previous, toggleShuffle, seek, subscribeTime,
],
);
return (
<MusicPlayerContext.Provider value={value}>
{children}
<MusicMiniPlayer />
</MusicPlayerContext.Provider>
);
}