import { ConfiguredInstance, DBOS } from "@dbos-inc/dbos-sdk";
import type {
	Artist,
	PlayHistory,
	SavedAlbum,
	SavedTrack,
	Track,
} from "@spotify/web-api-ts-sdk";
import { SpotifyApi } from "@spotify/web-api-ts-sdk";
import { eq } from "drizzle-orm";
import { auth, SPOTIFY_CLIENT_ID } from "../auth";
import { db } from "../db";
import {
	followedArtist,
	savedAlbum,
	savedTrack,
	topArtist,
	topTrack,
} from "../db/schema";
import {
	upsertFollowedArtists,
	upsertPlaybackHistory,
	upsertSavedAlbums,
	upsertSavedTracks,
	upsertTopArtists,
	upsertTopTracks,
} from "../db/spotify";

const timelines = ["short_term", "medium_term", "long_term"] as const;
type Timeline = (typeof timelines)[number];

type SyncPayload = {
	topArtistsByTimeline: Record<Timeline, Artist[]>;
	topTracksByTimeline: Record<Timeline, Track[]>;
	followedArtists: Artist[];
	savedAlbums: SavedAlbum[];
	savedTracks: SavedTrack[];
	recentlyPlayed: PlayHistory[];
};

export class SpotifySyncWorkflow extends ConfiguredInstance {
	@DBOS.workflow()
	async syncUser(userId: string) {
		console.log("Sync start");
		const data = await this.fetchSpotifyData(userId);
		console.log("Sync data fetched");
		await this.persistSpotifyData(userId, data);
		console.log("Synced");
		return { ok: true };
	}

	private async fetchSpotifyData(userId: string): Promise<SyncPayload> {
		const topArtistsByTimeline = await this.fetchTopArtists(userId);
		const topTracksByTimeline = await this.fetchTopTracks(userId);
		const followedArtists = await this.fetchFollowedArtists(userId);
		const savedAlbums = await this.fetchSavedAlbums(userId);
		const savedTracks = await this.fetchSavedTracks(userId);
		const recentlyPlayed = await this.fetchRecentlyPlayed(userId);
		return {
			topArtistsByTimeline,
			topTracksByTimeline,
			followedArtists,
			savedAlbums,
			savedTracks,
			recentlyPlayed,
		};
	}

	private async persistSpotifyData(userId: string, data: SyncPayload) {
		await this.persistTopArtists(userId, data.topArtistsByTimeline);
		await this.persistTopTracks(userId, data.topTracksByTimeline);
		await this.persistFollowedArtists(userId, data.followedArtists);
		await this.persistSavedAlbums(userId, data.savedAlbums);
		await this.persistSavedTracks(userId, data.savedTracks);
		await this.persistPlaybackHistory(userId, data.recentlyPlayed);
	}

	@DBOS.step()
	private async persistTopArtists(
		userId: string,
		topArtistsByTimeline: Record<Timeline, Artist[]>,
	) {
		await db.transaction(async (tx) => {
			await tx.delete(topArtist).where(eq(topArtist.userId, userId));
			for (const timeline of timelines) {
				await upsertTopArtists(
					userId,
					timeline,
					topArtistsByTimeline[timeline],
					tx,
				);
			}
		});
	}

	@DBOS.step()
	private async persistTopTracks(
		userId: string,
		topTracksByTimeline: Record<Timeline, Track[]>,
	) {
		await db.transaction(async (tx) => {
			await tx.delete(topTrack).where(eq(topTrack.userId, userId));
			for (const timeline of timelines) {
				await upsertTopTracks(
					userId,
					timeline,
					topTracksByTimeline[timeline],
					tx,
				);
			}
		});
	}

	@DBOS.step()
	private async persistFollowedArtists(userId: string, artists: Artist[]) {
		await db.transaction(async (tx) => {
			await tx.delete(followedArtist).where(eq(followedArtist.userId, userId));
			await upsertFollowedArtists(userId, artists, tx);
		});
	}

	@DBOS.step()
	private async persistSavedAlbums(userId: string, albums: SavedAlbum[]) {
		await db.transaction(async (tx) => {
			await tx.delete(savedAlbum).where(eq(savedAlbum.userId, userId));
			await upsertSavedAlbums(userId, albums, tx);
		});
	}

	@DBOS.step()
	private async persistSavedTracks(userId: string, tracks: SavedTrack[]) {
		await db.transaction(async (tx) => {
			await tx.delete(savedTrack).where(eq(savedTrack.userId, userId));
			await upsertSavedTracks(userId, tracks, tx);
		});
	}

	@DBOS.step()
	private async persistPlaybackHistory(userId: string, items: PlayHistory[]) {
		await db.transaction(async (tx) => {
			await upsertPlaybackHistory(userId, items, tx);
		});
	}

	@DBOS.step()
	private async fetchTopArtists(
		userId: string,
	): Promise<Record<Timeline, Artist[]>> {
		const sdk = await this.createSdk(userId);
		const topArtistsByTimeline = {} as Record<Timeline, Artist[]>;
		for (const timeline of timelines) {
			const topArtists = await sdk.currentUser.topItems(
				"artists",
				timeline,
				50,
			);
			topArtistsByTimeline[timeline] = topArtists.items;
		}
		return topArtistsByTimeline;
	}

	@DBOS.step()
	private async fetchTopTracks(
		userId: string,
	): Promise<Record<Timeline, Track[]>> {
		const sdk = await this.createSdk(userId);
		const topTracksByTimeline = {} as Record<Timeline, Track[]>;
		for (const timeline of timelines) {
			const topTracks = await sdk.currentUser.topItems("tracks", timeline, 50);
			topTracksByTimeline[timeline] = topTracks.items;
		}
		return topTracksByTimeline;
	}

	@DBOS.step()
	private async fetchFollowedArtists(userId: string): Promise<Artist[]> {
		const sdk = await this.createSdk(userId);
		const followed: Artist[] = [];
		let after: string | undefined;
		while (true) {
			const page = await sdk.currentUser.followedArtists(after, 50);
			const artists = page.artists;
			followed.push(...artists.items);
			if (!artists.next || artists.items.length === 0) break;
			const lastArtist = artists.items.at(-1);
			after = lastArtist?.id;
		}
		return followed;
	}

	@DBOS.step()
	private async fetchSavedAlbums(userId: string): Promise<SavedAlbum[]> {
		const sdk = await this.createSdk(userId);
		const saved: SavedAlbum[] = [];
		let offset = 0;
		while (true) {
			const page = await sdk.currentUser.albums.savedAlbums(50, offset);
			saved.push(...page.items);
			offset += page.items.length;
			if (!page.next || offset >= page.total) break;
		}
		return saved;
	}

	@DBOS.step()
	private async fetchSavedTracks(userId: string): Promise<SavedTrack[]> {
		const sdk = await this.createSdk(userId);
		const saved: SavedTrack[] = [];
		let offset = 0;
		while (true) {
			const page = await sdk.currentUser.tracks.savedTracks(50, offset);
			saved.push(...page.items);
			offset += page.items.length;
			if (!page.next || offset >= page.total) break;
		}
		return saved;
	}

	@DBOS.step()
	private async fetchRecentlyPlayed(userId: string): Promise<PlayHistory[]> {
		const sdk = await this.createSdk(userId);
		const recentlyPlayed = await sdk.player.getRecentlyPlayedTracks(50);
		return recentlyPlayed.items;
	}

	private async createSdk(userId: string) {
		const accessToken = await auth.api.getAccessToken({
			body: {
				userId,
				providerId: "spotify",
			},
		});
		return SpotifyApi.withAccessToken(SPOTIFY_CLIENT_ID, {
			access_token: accessToken.accessToken,
			expires_in: accessToken.accessTokenExpiresAt
				? Date.now() - Number(accessToken.accessTokenExpiresAt)
				: 0,
			expires: accessToken.accessTokenExpiresAt
				? Number(accessToken.accessTokenExpiresAt)
				: 0,
			refresh_token: "",
			token_type: "",
		});
	}
}

export const spotifySyncWorkflow = new SpotifySyncWorkflow("spotify-sync");