import {useEffect, useRef} from 'react';
import type {VideoConfig} from 'remotion';
import {usePlayer} from './use-player.js';

export type BrowserMediaControlsBehavior =
	| {
			mode: 'do-nothing';
	  }
	| {
			mode: 'prevent-media-session';
	  }
	| {
			mode: 'register-media-session';
	  };

export const useBrowserMediaSession = ({
	browserMediaControlsBehavior,
	videoConfig,
	playbackRate,
}: {
	browserMediaControlsBehavior: BrowserMediaControlsBehavior;
	videoConfig: VideoConfig | null;
	playbackRate: number;
}) => {
	const {playing, pause, play, emitter, getCurrentFrame, seek} = usePlayer();
	const hasEverPlayed = useRef(false);

	useEffect(() => {
		if (playing) {
			hasEverPlayed.current = true;
		}
	}, [playing]);

	useEffect(() => {
		if (!navigator.mediaSession) {
			return;
		}

		if (browserMediaControlsBehavior.mode === 'do-nothing') {
			return;
		}

		if (playing) {
			navigator.mediaSession.playbackState = 'playing';
		} else if (hasEverPlayed.current) {
			navigator.mediaSession.playbackState = 'paused';
		}
	}, [browserMediaControlsBehavior.mode, playing]);

	useEffect(() => {
		if (!navigator.mediaSession) {
			return;
		}

		if (browserMediaControlsBehavior.mode === 'do-nothing') {
			return;
		}

		const onTimeUpdate = () => {
			if (!videoConfig) {
				return;
			}

			if (navigator.mediaSession) {
				navigator.mediaSession.setPositionState({
					duration: videoConfig.durationInFrames / videoConfig.fps,
					playbackRate,
					position: getCurrentFrame() / videoConfig.fps,
				});
			}
		};

		emitter.addEventListener('timeupdate', onTimeUpdate);

		return () => {
			emitter.removeEventListener('timeupdate', onTimeUpdate);
		};
	}, [
		browserMediaControlsBehavior.mode,
		emitter,
		getCurrentFrame,
		playbackRate,
		videoConfig,
	]);

	useEffect(() => {
		if (!navigator.mediaSession) {
			return;
		}

		if (browserMediaControlsBehavior.mode === 'do-nothing') {
			return;
		}

		navigator.mediaSession.setActionHandler('play', () => {
			if (browserMediaControlsBehavior.mode === 'register-media-session') {
				play();
			}
		});
		navigator.mediaSession.setActionHandler('pause', () => {
			if (browserMediaControlsBehavior.mode === 'register-media-session') {
				pause();
			}
		});
		navigator.mediaSession.setActionHandler('seekto', (event) => {
			if (
				browserMediaControlsBehavior.mode === 'register-media-session' &&
				event.seekTime !== undefined &&
				videoConfig
			) {
				seek(Math.round(event.seekTime * videoConfig.fps));
			}
		});

		navigator.mediaSession.setActionHandler('seekbackward', () => {
			if (
				browserMediaControlsBehavior.mode === 'register-media-session' &&
				videoConfig
			) {
				seek(
					Math.max(0, Math.round((getCurrentFrame() - 10) * videoConfig.fps)),
				);
			}
		});

		navigator.mediaSession.setActionHandler('seekforward', () => {
			if (
				browserMediaControlsBehavior.mode === 'register-media-session' &&
				videoConfig
			) {
				seek(
					Math.max(
						videoConfig.durationInFrames - 1,
						Math.round((getCurrentFrame() + 10) * videoConfig.fps),
					),
				);
			}
		});

		navigator.mediaSession.setActionHandler('previoustrack', () => {
			if (browserMediaControlsBehavior.mode === 'register-media-session') {
				seek(0);
			}
		});

		return () => {
			navigator.mediaSession.metadata = null;
			navigator.mediaSession.setActionHandler('play', null);
			navigator.mediaSession.setActionHandler('pause', null);
			navigator.mediaSession.setActionHandler('seekto', null);
			navigator.mediaSession.setActionHandler('seekbackward', null);
			navigator.mediaSession.setActionHandler('seekforward', null);
			navigator.mediaSession.setActionHandler('previoustrack', null);
		};
	}, [
		browserMediaControlsBehavior.mode,
		getCurrentFrame,
		pause,
		play,
		seek,
		videoConfig,
	]);
};