import { createSelector, type Accessor, type Setter, createSignal, type ResourceActions, createEffect } from "solid-js";
import "./Playlist.css";
import { getItemName, type PlayerState, type PlaylistItem, type AppOptions } from "../types";
import { formatTime, toast } from "../utils";
import { ClearSVG, DownloadSVG, DragSVG, LinkSVG, SaveSVG, SyncSVG } from "./SVG";
import { savePlaylist, isFileCached, download, downloadStatusMap } from "../offline";
import { DraggableList } from "./DraggableList";
import type { FileListing } from "music-server-shared/types";

interface PlaylistProps {
	currentDir: Accessor<string>;
	playlist: Accessor<PlaylistItem[]>;
	setPlaylist: Setter<PlaylistItem[]>;
	playerState: Accessor<PlayerState>;
	setPlayerState: Setter<PlayerState>;
	playTrack: (item: PlaylistItem) => void;
	audioElement: HTMLAudioElement;
	options: Accessor<AppOptions>;
	fetchFiles: ResourceActions<FileListing>;
}

export default function Playlist(props: PlaylistProps) {
	function removeFromPlaylist(id: string) {
		const currentTrack = props.playerState().currentTrack;
		const newPlaylist = props.playlist().filter((i) => i.id !== id);
		if (currentTrack && currentTrack.id === id) {
			const idx = props.playlist().findIndex((i) => i.id === id);
			if (newPlaylist.length > 0) {
				props.playTrack(idx < newPlaylist.length ? newPlaylist[idx] : newPlaylist[0]);
			}
		}
		props.setPlaylist(newPlaylist);
	}

	async function playlistDownload(download: boolean) {
		try {
			const playlist = props.playlist();
			const filePaths = playlist.map((item) => item.path);
			const response = await fetch("/prepare-playlist", { body: JSON.stringify(filePaths), method: "POST" });
			if (!response.ok) throw new Error(`Generating playlist id not successful: ${await response.text()}`);
			const id = await response.text();
			if (download) {
				toast("Started playlist download", "info");
				const a = document.createElement("a");
				a.href = `/download-playlist/${id}`;
				document.body.appendChild(a);
				a.click();
				document.body.removeChild(a);
			} else {
				toast("Copied playlist link to clipboard", "info");
				const urlPath = location.href.split(/\?|#/)[0];
				navigator.clipboard.writeText(`${urlPath}${urlPath.endsWith("/") ? "" : "/"}download-playlist/${id}`);
			}
		} catch (e) {
			toast("Playlist items download failed", "error", e);
		}
	}

	const [syncing, setSyncing] = createSignal(false);
	async function syncPlaylist() {
		if (syncing()) return;
		setSyncing(true);
		const progressToast = toast("Syncing files in playlist...", "progress");
		try {
			const itemsToSync: PlaylistItem[] = [];
			for (const item of props.playlist()) {
				if (!(await isFileCached(item.path, downloadStatusMap[item.path]))) itemsToSync.push(item);
			}
			const syncPromises = itemsToSync.map((item) => {
				const basePath = item.path.split("/").slice(0, -1).join("/");
				const fileName = item.path.split("/").toReversed()[0];
				return download(fileName, item, basePath, props.currentDir, props.options(), props.fetchFiles);
			});
			await Promise.allSettled(syncPromises);
			progressToast.hideToast();
			toast("Playlist sync completed", "success");
		} catch (e) {
			progressToast.hideToast();
			toast("Playlist sync failed", "error", e);
		} finally {
			setSyncing(false);
		}
	}

	let dialogElement!: HTMLDialogElement;
	let playlistNameInput!: HTMLInputElement;
	let allowOverwriteCheckbox!: HTMLInputElement;

	async function save() {
		try {
			if (!playlistNameInput.reportValidity()) return;
			await savePlaylist({ name: playlistNameInput.value, items: props.playlist() }, allowOverwriteCheckbox.checked);
			closeDialog();
		} catch (e) {
			if (e instanceof Error && e.name === "ConstraintError") {
				toast("Playlist with this name already exists", "error");
			} else {
				toast("Saving playlist failed", "error", e);
			}
		}
	}

	function closeDialog() {
		dialogElement.close();
		playlistNameInput.value = "";
		allowOverwriteCheckbox.checked = false;
	}

	const [syncedCount, setSyncedCount] = createSignal(0);
	createEffect(async () => {
		const playlist = props.playlist();
		let count = 0;
		const promises = [];
		for (const item of playlist) {
			promises.push(
				isFileCached(item.path, downloadStatusMap[item.path]).then((res) => {
					if (res) count++;
				}),
			);
		}
		await Promise.all(promises);
		setSyncedCount(count);
	});
	return (
		<div class="playlist-container">
			<dialog class="save-dialog" ref={dialogElement}>
				<div>
					<input ref={playlistNameInput} required type="text" placeholder="Playlist name" />
					<div class="save-buttons">
						<label for="overwrite-checkbox">allow overwrite</label>
						<input ref={allowOverwriteCheckbox} id="overwrite-checkbox" type="checkbox" />
						<button onClick={save}>Save</button>
						<button onClick={closeDialog}>Cancel</button>
					</div>
				</div>
			</dialog>

			<div class="playlist-header">
				<span>
					Playlist ({props.playlist().length} tracks, {syncedCount()} synced)
				</span>
				<div class="spacer" />
				<button title="Save playlist" onClick={() => dialogElement.showModal()}>
					<SaveSVG />
				</button>
				<button title="Sync all unsynced files in playlist" onClick={syncPlaylist} disabled={syncing()}>
					<SyncSVG />
				</button>
				<button
					title="Copies and 1-hour valid link for the same action as the download button"
					onClick={() => playlistDownload(false)}
				>
					<LinkSVG />
				</button>
				<button
					title="Download all files in the playlist in their original format as a .tar file, or without archive if it contains just a single item"
					onClick={() => playlistDownload(true)}
				>
					<DownloadSVG />
				</button>
				<button title="Clear Playlist" onClick={() => props.setPlaylist([])}>
					<ClearSVG />
				</button>
			</div>

			<DraggableList<PlaylistItem> items={props.playlist} setItems={props.setPlaylist} id="playlist">
				{(item, _, { dragHandlers, isDragging, dropPosition }) => {
					const isActive = createSelector(
						() => props.playerState().currentTrack?.id,
						(itemId, currentId) => currentId === itemId,
					);
					return (
						<div
							classList={{
								"playlist-item": true,
								"draggable-item": true,
								active: isActive(item.id),
								"drop-target-top-border": dropPosition() === "before",
								"drop-target-bottom-border": dropPosition() === "after",
							}}
							style={{ opacity: isDragging() ? 0.5 : 1 }}
							onClick={() => props.playTrack(item)}
						>
							<div class="playlist-drag-btn" {...dragHandlers}>
								<DragSVG />
							</div>
							<span>{getItemName(item)}</span>
							<div class="spacer" />
							{formatTime(item.metadata.duration)}
							<button
								title={`Remove ${getItemName(item)}`}
								onClick={(e) => {
									e.stopPropagation();
									removeFromPlaylist(item.id);
								}}
							>
								<ClearSVG />
							</button>
						</div>
					);
				}}
			</DraggableList>
		</div>
	);
}