import { and, eq, inArray } from "drizzle-orm";
import type { db } from "../db";
import {
	topArtist as topArtistTable,
	topTrack as topTrackTable,
} from "../db/schema";
import type { Question, QuizRound } from "../party-types";
import {
	buildQuestionWindow,
	getReleaseYearRange,
	isUsableText,
	type PartyAnalytics,
	type PartyQuestionMember,
	pickQuestionCandidate,
	type QuestionCandidate,
	resolveQuestionSong,
} from "./question-utils";

type NumericQuestion = Omit<
	Extract<Question, { type: "numeric" }>,
	"startTimestamp" | "endTimestamp"
>;

type TrackDetails = {
	id: string;
	name: string | null;
	platform_id: string | null;
	album?: { name: string | null; release_date: Date | null } | null;
	artists?: { name: string }[] | null;
};

type BuildNumericQuestionInput = {
	db: typeof db;
	analytics: PartyAnalytics;
	index: number;
	members: PartyQuestionMember[];
	history: QuizRound[];
};

async function getDetailedTopTracks({
	db,
	analytics,
}: BuildNumericQuestionInput): Promise<TrackDetails[]> {
	const tracks: TrackDetails[] = [];
	const seen = new Set<string>();

	for (const topTrack of analytics?.storyClusters?.flatMap(
		(cluster) => cluster.tracks ?? [],
	) ?? []) {
		if (!isUsableText(topTrack.name)) continue;
		const dbTracks = (await db.query.track.findMany({
			where: { name: topTrack.name },
			with: { album: true, artists: true },
		})) as TrackDetails[];
		const topArtists = topTrack.artists?.map((artist) => artist.name) ?? [];
		const track = dbTracks.slice().sort((a, b) => {
			const score = (candidate: typeof a) => {
				const artistNames =
					candidate.artists?.map((artist) => artist.name) ?? [];
				return (
					(candidate.album?.name === topTrack.albumName ? 2 : 0) +
					(topArtists.some((name) => artistNames.includes(name)) ? 2 : 0)
				);
			};
			return score(b) - score(a);
		})[0];
		if (!track || !isUsableText(track.name)) continue;
		const key = track.platform_id ?? track.id;
		if (seen.has(key)) continue;
		seen.add(key);
		tracks.push(track);
	}

	return tracks;
}

async function getAlbumReleaseYear({
	db,
	analytics,
}: BuildNumericQuestionInput): Promise<NumericQuestion | null> {
	const trackName = analytics?.storyClusters?.[0]?.tracks?.[0]?.name;
	const track = trackName
		? await db.query.track.findFirst({
				where: { name: trackName },
				with: { album: true },
			})
		: null;
	const subject = [track?.album?.name, track?.name].find((value) =>
		isUsableText(value),
	);
	if (!subject) return null;
	if (!track?.album?.release_date) return null;
	const song = await resolveQuestionSong(db, analytics, {
		trackName: track?.name ?? trackName ?? undefined,
	});
	const correct = track.album.release_date.getFullYear();
	return {
		type: "numeric",
		text: `What's the release year of ${subject}?`,
		correct,
		range: getReleaseYearRange(correct),
		points: 10,
		song: song ?? undefined,
		questionKey: `numeric:album-year:${subject}`,
		subjectKey: `album:${subject}`,
	};
}

async function getTrackReleaseYear(
	input: BuildNumericQuestionInput,
): Promise<NumericQuestion | null> {
	const tracks = await getDetailedTopTracks(input);
	const track = tracks.find((track) => track.album?.release_date && track.name);
	if (!track?.name || !track.album?.release_date) return null;
	const song = await resolveQuestionSong(input.db, input.analytics, {
		trackName: track.name,
		artistNames: track.artists?.map((artist) => artist.name),
		albumName: track.album?.name ?? undefined,
	});
	const correct = track.album.release_date.getFullYear();
	return {
		type: "numeric",
		text: `What year did "${track.name}" come out?`,
		correct,
		range: getReleaseYearRange(correct),
		points: 10,
		song: song ?? undefined,
		questionKey: `numeric:track-year:${track.name}`,
		subjectKey: `track:${track.name}`,
	};
}

async function getArtistFirstTrackReleaseYear(
	input: BuildNumericQuestionInput,
): Promise<NumericQuestion | null> {
	const tracks = await getDetailedTopTracks(input);
	const tracksByArtist = new Map<string, TrackDetails[]>();

	for (const track of tracks) {
		if (!track.album?.release_date) continue;
		for (const artist of track.artists ?? []) {
			if (!isUsableText(artist.name)) continue;
			const artistTracks = tracksByArtist.get(artist.name) ?? [];
			artistTracks.push(track);
			tracksByArtist.set(artist.name, artistTracks);
		}
	}

	const artistEntry = Array.from(tracksByArtist.entries()).find(
		([, artistTracks]) => artistTracks.length >= 2,
	);
	if (!artistEntry) return null;
	const [artistName, artistTracks] = artistEntry;
	const firstTrack = artistTracks
		.slice()
		.sort(
			(a, b) =>
				Number(a.album?.release_date ?? 0) - Number(b.album?.release_date ?? 0),
		)[0];
	if (!firstTrack?.album?.release_date) return null;
	const song = await resolveQuestionSong(input.db, input.analytics, {
		trackName: firstTrack.name ?? undefined,
		artistNames: [artistName],
		albumName: firstTrack.album?.name ?? undefined,
	});
	const correct = firstTrack.album.release_date.getFullYear();
	return {
		type: "numeric",
		text: `What year did ${artistName}'s first party track come out?`,
		correct,
		range: getReleaseYearRange(correct),
		points: 10,
		song: song ?? undefined,
		questionKey: `numeric:artist-first-track-year:${artistName}`,
		subjectKey: `artist:${artistName}`,
	};
}

async function countTopTrackListeners({
	db,
	analytics,
	members,
}: BuildNumericQuestionInput): Promise<NumericQuestion | null> {
	const trackName = analytics?.storyClusters?.[0]?.tracks?.[0]?.name;
	if (!trackName || members.length === 0) return null;
	const dbTrack = await db.query.track.findFirst({
		where: { name: trackName },
	});
	if (!dbTrack) return null;
	const song = await resolveQuestionSong(db, analytics, { trackName });
	const memberIds = members.map((m) => m.userId);
	const entries = await db
		.select({ userId: topTrackTable.userId })
		.from(topTrackTable)
		.where(
			and(
				eq(topTrackTable.trackId, dbTrack.id),
				inArray(topTrackTable.userId, memberIds),
			),
		);
	const correct = new Set(entries.map((e) => e.userId)).size;
	if (correct <= 0) return null;
	return {
		type: "numeric",
		text: `For how many players in the party is "${trackName}" a top track?`,
		correct,
		range: { min: 0, max: members.length },
		points: 10,
		song: song ?? undefined,
		questionKey: `numeric:top-track-count:${trackName}`,
		subjectKey: `track:${trackName}`,
	};
}

async function countFavouriteArtistListeners({
	db,
	analytics,
	members,
}: BuildNumericQuestionInput): Promise<NumericQuestion | null> {
	const artistName = analytics?.storyClusters?.[0]?.artists?.[0]?.name;
	if (!artistName || members.length === 0) return null;
	const dbArtist = await db.query.artist.findFirst({
		where: { name: artistName },
	});
	if (!dbArtist) return null;
	const song = await resolveQuestionSong(db, analytics, {
		artistNames: [artistName],
	});
	const memberIds = members.map((m) => m.userId);
	const entries = await db
		.select({ userId: topArtistTable.userId })
		.from(topArtistTable)
		.where(
			and(
				eq(topArtistTable.artistId, dbArtist.id),
				inArray(topArtistTable.userId, memberIds),
			),
		);
	const correct = new Set(entries.map((e) => e.userId)).size;
	if (correct <= 0) return null;
	return {
		type: "numeric",
		text: `How many players in the party have "${artistName}" as a favourite artist?`,
		correct,
		range: { min: 0, max: members.length },
		points: 10,
		song: song ?? undefined,
		questionKey: `numeric:artist-count:${artistName}`,
		subjectKey: `artist:${artistName}`,
	};
}

export async function buildNumericQuestion(
	input: BuildNumericQuestionInput,
): Promise<Question | null> {
	const questions: Array<QuestionCandidate<NumericQuestion>> = [];

	const albumYearQ = await getAlbumReleaseYear(input);
	if (albumYearQ) {
		questions.push({
			key: albumYearQ.questionKey ?? `numeric:album-year:${albumYearQ.text}`,
			subjectKey: albumYearQ.subjectKey,
			question: albumYearQ,
		});
	}

	const trackYearQ = await getTrackReleaseYear(input);
	if (trackYearQ) {
		questions.push({
			key: trackYearQ.questionKey ?? `numeric:track-year:${trackYearQ.text}`,
			subjectKey: trackYearQ.subjectKey,
			question: trackYearQ,
		});
	}

	const artistFirstTrackYearQ = await getArtistFirstTrackReleaseYear(input);
	if (artistFirstTrackYearQ) {
		questions.push({
			key:
				artistFirstTrackYearQ.questionKey ??
				`numeric:artist-first-track-year:${artistFirstTrackYearQ.text}`,
			subjectKey: artistFirstTrackYearQ.subjectKey,
			question: artistFirstTrackYearQ,
		});
	}

	const topTrackQ = await countTopTrackListeners(input);
	if (topTrackQ) {
		questions.push({
			key: topTrackQ.questionKey ?? `numeric:top-track-count:${topTrackQ.text}`,
			subjectKey: topTrackQ.subjectKey,
			question: topTrackQ,
		});
	}

	const artistQ = await countFavouriteArtistListeners(input);
	if (artistQ) {
		questions.push({
			key: artistQ.questionKey ?? `numeric:artist-count:${artistQ.text}`,
			subjectKey: artistQ.subjectKey,
			question: artistQ,
		});
	}

	const question = pickQuestionCandidate(questions, input.history, input.index);
	if (!question) return null;
	return buildQuestionWindow(question);
}