import { AttachmentId, PieceId, RepertoireId, Sha256 } from "common";
import api, { NotFound, Role, Unauthorized } from "common/the_api";
import { DateTime, Effect, HashSet, Number, Option, pipe } from "effect";
import { sql } from "kysely";
import * as crypto from "node:crypto";
import * as uuid from "uuid";
import { implement } from "./api.ts";
import * as Authentication from "./services/Authentication.ts";
import * as Database from "./services/Database.ts";

const READ_ACCESS = HashSet.make(Role.Admin, Role.Editor, Role.Viewer);
const WRITE_ACCESS = HashSet.make(Role.Admin, Role.Editor);
const ADMIN_ACCESS = HashSet.make(Role.Admin);

const requireAuthenticated = pipe(
	Authentication.Authentication,
	Effect.flatMap(({ me }) => me),
);

const requireOneOf = (roles: HashSet.HashSet<Role>) => pipe(
	Authentication.Authentication,
	Effect.flatMap(({ me }) => me),
	Effect.flatMap((user) => pipe(
		HashSet.intersection(user.roles, roles),
		HashSet.size,
		Number.greaterThan(0),
	)
		? Effect.succeed(user)
		: Effect.fail(Unauthorized.make())
	),
);

export const handle = implement(api, {

	// --- Authentication ---

	me: () => pipe(
		Authentication.Authentication,
		Effect.flatMap(({ me }) => me),
	),
	logout: () => pipe(
		Authentication.Authentication,
		Effect.flatMap(({ logout }) => logout),
	),

	// --- User CRUD ---

	getUser: (userId) => Effect.gen(function* () {
		yield* requireAuthenticated;

		const user = yield* pipe(
			Authentication.getUser(userId),
			Effect.catchTag("NoSuchElementException", () => Effect.fail(NotFound.make())),
		);

		return user;
	}),
	queryUsers: ({ displayName, role, offset, limit }) => Effect.gen(function* () {
		yield* requireAuthenticated;
		const db = yield* Database.Database;

		let query = db
			.selectFrom("User")
			.leftJoin("UserRole", "User.userId", "UserRole.userId")
			.select("User.userId")
			.groupBy("User.userId")
			.orderBy("displayName")
			.offset(offset)
			.limit(limit);

		query = Option.match(displayName, {
			onNone: () => query,
			onSome: (displayName) => query.where("User.displayName", "like", "%" + displayName + "%"),
		});

		query = Option.match(role, {
			onNone: () => query,
			onSome: (role) => query.where("UserRole.role", "=", role),
		});

		const res = yield* query.$call(Database.execute);
		return res.map(({ userId }) => userId);
	}),
	updateUser: ({ userId, ...user }) => Effect.gen(function* () {
		yield* requireOneOf(ADMIN_ACCESS);
		const db = yield* Database.Database;

		const res = yield* pipe(
			Authentication.getUser(userId),
			Effect.mapError(() => NotFound.make()),
		);

		yield* db
			.deleteFrom("UserRole")
			.where("userId", "=", userId)
			.$call(Database.execute);

		const roles = yield* pipe(
			user.roles,
			Effect.forEach((role) => db
				.insertInto("UserRole")
				.values({ userId, role })
				.returning("role")
				.$call(Database.executeTakeFirstOrDie)
				.pipe(Effect.map(({ role }) => role)),
			),
		);

		return {
			userId: res.userId,
			displayName: res.displayName,
			avatarUrl: res.avatarUrl,
			roles: HashSet.fromIterable(roles),
		};
	}),
	deleteUser: (userId) => Effect.gen(function* () {
		yield* requireOneOf(ADMIN_ACCESS);
		const db = yield* Database.Database;

		yield* db
			.deleteFrom("User")
			.where("userId", "=", userId)
			.returning("userId")
			.$call(Database.executeTakeFirst)
			.pipe(Effect.mapError(() => NotFound.make()));
	}),

	// --- Piece CRUD ---

	createPiece: (piece) => Effect.gen(function* () {
		const { userId } = yield* requireOneOf(WRITE_ACCESS);
		const db = yield* Database.Database;

		const res = yield* db
			.insertInto("Piece")
			.values({
				pieceId: PieceId.make(uuid.v7()),
				name: piece.name,
				composer: Option.getOrNull(piece.composer),
				lyricist: Option.getOrNull(piece.lyricist),
				arranger: Option.getOrNull(piece.arranger),
				createdBy: userId,
				createdAt: sql`datetime()`,
			})
			.returningAll()
			.$call(Database.executeTakeFirstOrDie);

		return {
			pieceId: res.pieceId,
			name: res.name,
			composer: Option.fromNullable(res.composer),
			lyricist: Option.fromNullable(res.lyricist),
			arranger: Option.fromNullable(res.arranger),
			attachments: [],
			createdBy: Option.fromNullable(res.createdBy),
			createdAt: DateTime.unsafeMake(res.createdAt),
			modifiedBy: Option.fromNullable(res.modifiedBy),
			modifiedAt: pipe(
				res.modifiedAt,
				Option.fromNullable,
				Option.map(DateTime.unsafeMake),
			),
		};
	}),
	getPiece: (pieceId) => Effect.gen(function* () {
		yield* requireOneOf(READ_ACCESS);
		const db = yield* Database.Database;

		const piece = yield* db
			.selectFrom("Piece")
			.selectAll()
			.where("pieceId", "=", pieceId)
			.$call(Database.executeTakeFirst)
			.pipe(Effect.mapError(() => NotFound.make()));

		const attachments = yield* db
			.selectFrom("Attachment")
			.selectAll()
			.where("pieceId", "=", pieceId)
			.$call(Database.execute);

		return {
			pieceId: piece.pieceId,
			name: piece.name,
			composer: Option.fromNullable(piece.composer),
			lyricist: Option.fromNullable(piece.lyricist),
			arranger: Option.fromNullable(piece.arranger),
			attachments: attachments.map(({
				createdBy,
				createdAt,
				modifiedBy,
				modifiedAt,
				...rest
			}) => ({
				createdBy: Option.fromNullable(createdBy),
				createdAt: DateTime.unsafeMake(createdAt),
				modifiedBy: Option.fromNullable(modifiedBy),
				modifiedAt: pipe(
					modifiedAt,
					Option.fromNullable,
					Option.map(DateTime.unsafeMake),
				),
				...rest,
			})),
			createdBy: Option.fromNullable(piece.createdBy),
			createdAt: DateTime.unsafeMake(piece.createdAt),
			modifiedBy: Option.fromNullable(piece.modifiedBy),
			modifiedAt: pipe(
				piece.modifiedAt,
				Option.fromNullable,
				Option.map(DateTime.unsafeMake),
			),
		};
	}),
	queryPieces: ({ name, author, offset, limit }) => Effect.gen(function* () {
		yield* requireOneOf(READ_ACCESS);
		const db = yield* Database.Database;

		let query = db
			.selectFrom("Piece")
			.select("pieceId")
			.orderBy("name")
			.orderBy("composer")
			.orderBy("arranger")
			.offset(offset)
			.limit(limit);

		query = Option.match(name, {
			onNone: () => query,
			onSome: (name) => query.where("name", "like", "%" + name + "%"),
		});

		query = Option.match(author, {
			onNone: () => query,
			onSome: (author) => query.where((eb) => eb.or([
				eb("composer", "like", "%" + author + "%"),
				eb("arranger", "like", "%" + author + "%"),
				eb("lyricist", "like", "%" + author + "%"),
			]))
		});

		const res = yield* query.$call(Database.execute);
		return res.map(({ pieceId }) => pieceId);
	}),
	updatePiece: ({ pieceId, ...piece }) => Effect.gen(function* () {
		const { userId } = yield* requireOneOf(WRITE_ACCESS);
		const db = yield* Database.Database;

		const res = yield* db
			.updateTable("Piece")
			.set({
				name: piece.name,
				composer: Option.getOrUndefined(piece.composer),
				lyricist: Option.getOrUndefined(piece.lyricist),
				arranger: Option.getOrUndefined(piece.arranger),
				modifiedBy: userId,
				modifiedAt: sql`datetime()`,
			})
			.where("pieceId", "=", pieceId)
			.returningAll()
			.$call(Database.executeTakeFirst)
			.pipe(Effect.mapError(() => NotFound.make()));

		const attachments = yield* db
			.selectFrom("Attachment")
			.selectAll()
			.where("pieceId", "=", pieceId)
			.$call(Database.execute);

		return {
			pieceId: res.pieceId,
			name: res.name,
			composer: Option.fromNullable(res.composer),
			lyricist: Option.fromNullable(res.lyricist),
			arranger: Option.fromNullable(res.arranger),
			attachments: attachments.map(({
				createdBy,
				createdAt,
				modifiedBy,
				modifiedAt,
				...rest
			}) => ({
				createdBy: Option.fromNullable(createdBy),
				createdAt: DateTime.unsafeMake(createdAt),
				modifiedBy: Option.fromNullable(modifiedBy),
				modifiedAt: pipe(
					modifiedAt,
					Option.fromNullable,
					Option.map(DateTime.unsafeMake),
				),
				...rest,
			})),
			createdBy: Option.fromNullable(res.createdBy),
			createdAt: DateTime.unsafeMake(res.createdAt),
			modifiedBy: Option.fromNullable(res.modifiedBy),
			modifiedAt: pipe(
				res.modifiedAt,
				Option.fromNullable,
				Option.map(DateTime.unsafeMake),
			),
		};
	}),
	deletePiece: (pieceId) => Effect.gen(function* () {
		yield* requireOneOf(WRITE_ACCESS);
		const db = yield* Database.Database;

		yield* db
			.deleteFrom("Piece")
			.where("pieceId", "=", pieceId)
			.returning("pieceId")
			.$call(Database.executeTakeFirst)
			.pipe(Effect.mapError(() => NotFound.make()));
	}),

	// --- Attachment CRUD ---

	createAttachment: (attachment) => Effect.gen(function* () {
		const { userId } = yield* requireOneOf(WRITE_ACCESS);
		const db = yield* Database.Database;

		let sha256: Sha256;
		if ("sha256" in attachment) {
			sha256 = attachment.sha256;

			yield* db
				.selectFrom("File")
				.select("sha256")
				.where("sha256", "=", sha256)
				.$call(Database.executeTakeFirst)
				.pipe(Effect.mapError(() => NotFound.make()));
		} else {
			const buffer = crypto.hash("sha256", attachment.data, { outputEncoding: "buffer" }) as Buffer<ArrayBuffer>;
			sha256 = Sha256.make(buffer);

			yield* db
				.insertInto("File")
				.values({ sha256, data: attachment.data })
				.onConflict((cb) => cb.column("sha256").doNothing())
				.$call(Database.execute);
		}

		const res = yield* db
			.insertInto("Attachment")
			.values({
				attachmentId: AttachmentId.make(uuid.v7()),
				pieceId: attachment.pieceId,
				filename: attachment.filename,
				mediaType: attachment.mediaType,
				sha256,
				createdBy: userId,
				createdAt: sql`datetime()`,
			})
			.returningAll()
			.$call(Database.executeTakeFirstOrDie);

		return {
			attachmentId: res.attachmentId,
			pieceId: res.pieceId,
			filename: res.filename,
			sha256: res.sha256,
			mediaType: res.mediaType,
			createdBy: Option.fromNullable(res.createdBy),
			createdAt: DateTime.unsafeMake(res.createdAt),
			modifiedBy: Option.fromNullable(res.modifiedBy),
			modifiedAt: pipe(
				res.modifiedAt,
				Option.fromNullable,
				Option.map(DateTime.unsafeMake),
			),
		};
	}),
	getAttachment: (attachmentId) => Effect.gen(function* () {
		yield* requireOneOf(READ_ACCESS);
		const db = yield* Database.Database;

		const res = yield* db
			.selectFrom("File")
			.innerJoin("Attachment", "File.sha256", "Attachment.sha256")
			.select(["Attachment.filename", "Attachment.mediaType", "File.data"])
			.where("Attachment.attachmentId", "=", attachmentId)
			.$call(Database.executeTakeFirst)
			.pipe(Effect.mapError(() => NotFound.make()));

		return res;
	}),
	updateAttachment: ({ attachmentId, ...attachment }) => Effect.gen(function* () {
		const { userId } = yield* requireOneOf(WRITE_ACCESS);
		const db = yield* Database.Database;

		const res = yield* db
			.updateTable("Attachment")
			.set({
				...attachment,
				modifiedBy: userId,
				modifiedAt: sql`datetime()`,
			})
			.returningAll()
			.$call(Database.executeTakeFirst)
			.pipe(Effect.mapError(() => NotFound.make()));

		return {
			attachmentId: res.attachmentId,
			pieceId: res.pieceId,
			filename: res.filename,
			sha256: res.sha256,
			mediaType: res.mediaType,
			createdBy: Option.fromNullable(res.createdBy),
			createdAt: DateTime.unsafeMake(res.createdAt),
			modifiedBy: Option.fromNullable(res.modifiedBy),
			modifiedAt: pipe(
				res.modifiedAt,
				Option.fromNullable,
				Option.map(DateTime.unsafeMake),
			),
		};
	}),
	deleteAttachment: (attachmentId) => Effect.gen(function* () {
		yield* requireOneOf(WRITE_ACCESS);
		const db = yield* Database.Database;

		yield* db
			.deleteFrom("Attachment")
			.where("attachmentId", "=", attachmentId)
			.returning("attachmentId")
			.$call(Database.executeTakeFirst)
			.pipe(Effect.mapError(() => NotFound.make()));
	}),

	// --- Repertoire CRUD ---

	createRepertoire: (repertoire) => Effect.gen(function* () {
		const { userId } = yield* requireOneOf(WRITE_ACCESS);
		const db = yield* Database.Database;

		const repertoireId = RepertoireId.make(uuid.v7());

		const res = yield* db
			.insertInto("Repertoire")
			.values({
				repertoireId,
				name: repertoire.name,
				createdBy: userId,
				createdAt: sql`datetime()`,
			})
			.returningAll()
			.$call(Database.executeTakeFirstOrDie);

		const entries = yield* pipe(
			repertoire.entries,
			Effect.forEach((pieceId, i) => db
				.insertInto("RepertoireEntry")
				.values({ pieceId, repertoireId, order: i })
				.returningAll()
				.$call(Database.executeTakeFirstOrDie)
				.pipe(Effect.map(({ pieceId }) => pieceId)),
			),
		);

		return {
			repertoireId: res.repertoireId,
			name: res.name,
			entries,
			createdBy: Option.fromNullable(res.createdBy),
			createdAt: DateTime.unsafeMake(res.createdAt),
			modifiedBy: Option.fromNullable(res.modifiedBy),
			modifiedAt: pipe(
				res.modifiedAt,
				Option.fromNullable,
				Option.map(DateTime.unsafeMake),
			),
		};
	}),
	getRepertoire: (repertoireId) => Effect.gen(function* () {
		yield* requireOneOf(READ_ACCESS);
		const db = yield* Database.Database;

		const repertoire = yield* db
			.selectFrom("Repertoire")
			.selectAll()
			.where("repertoireId", "=", repertoireId)
			.$call(Database.executeTakeFirst)
			.pipe(Effect.mapError(() => NotFound.make()));

		const entries = yield* db
			.selectFrom("RepertoireEntry")
			.select("pieceId")
			.where("repertoireId", "=", repertoireId)
			.orderBy("order")
			.$call(Database.execute);

		return {
			repertoireId: repertoire.repertoireId,
			name: repertoire.name,
			entries: entries.map(({ pieceId }) => pieceId),
			createdBy: Option.fromNullable(repertoire.createdBy),
			createdAt: DateTime.unsafeMake(repertoire.createdAt),
			modifiedBy: Option.fromNullable(repertoire.modifiedBy),
			modifiedAt: pipe(
				repertoire.modifiedAt,
				Option.fromNullable,
				Option.map(DateTime.unsafeMake),
			),
		};
	}),
	queryRepertoires: ({ name, offset, limit }) => Effect.gen(function* () {
		yield* requireOneOf(READ_ACCESS);
		const db = yield* Database.Database;

		let query = db
			.selectFrom("Repertoire")
			.select("repertoireId")
			.orderBy("name")
			.offset(offset)
			.limit(limit);

		query = Option.match(name, {
			onNone: () => query,
			onSome: (name) => query.where("name", "like", "%" + name + "%"),
		});

		const res = yield* query.$call(Database.execute);
		return res.map(({ repertoireId }) => repertoireId);
	}),
	updateRepertoire: ({ repertoireId, ...repertoire }) => Effect.gen(function* () {
		const { userId } = yield* requireOneOf(WRITE_ACCESS);
		const db = yield* Database.Database;

		const res = yield* db
			.updateTable("Repertoire")
			.set({
				name: repertoire.name,
				modifiedBy: userId,
				modifiedAt: sql`datetime()`,
			})
			.where("repertoireId", "=", repertoireId)
			.returningAll()
			.$call(Database.executeTakeFirst)
			.pipe(Effect.mapError(() => NotFound.make()));

		yield* db
			.deleteFrom("RepertoireEntry")
			.where("repertoireId", "=", repertoireId)
			.$call(Database.execute);

		const entries = yield* pipe(
			repertoire.entries,
			Effect.forEach((pieceId, i) => db
				.insertInto("RepertoireEntry")
				.values({ pieceId, repertoireId, order: i })
				.returningAll()
				.$call(Database.executeTakeFirstOrDie)
				.pipe(Effect.map(({ pieceId }) => pieceId)),
			),
		);

		return {
			repertoireId: res.repertoireId,
			name: res.name,
			entries,
			createdBy: Option.fromNullable(res.createdBy),
			createdAt: DateTime.unsafeMake(res.createdAt),
			modifiedBy: Option.fromNullable(res.modifiedBy),
			modifiedAt: pipe(
				res.modifiedAt,
				Option.fromNullable,
				Option.map(DateTime.unsafeMake),
			),
		};
	}),
	deleteRepertoire: (repertoireId) => Effect.gen(function* () {
		yield* requireOneOf(WRITE_ACCESS);
		const db = yield* Database.Database;

		yield* db
			.deleteFrom("Repertoire")
			.where("repertoireId", "=", repertoireId)
			.returning("repertoireId")
			.$call(Database.executeTakeFirst)
			.pipe(Effect.mapError(() => NotFound.make()));
	}),
});