import { Injectable, Logger, Inject } from "@nestjs/common";
import { CACHE_MANAGER } from "@nestjs/cache-manager";
import { Cache } from "cache-manager";
import { eq, sql } from "drizzle-orm";
import { CryptoService } from "../crypto/crypto.service";
import { DatabaseService } from "../database/database.service";
import {
	contents,
	favorites,
	users,
} from "../database/schemas";
import { UpdateUserDto } from "./dto/update-user.dto";

@Injectable()
export class UsersService {
	private readonly logger = new Logger(UsersService.name);

	constructor(
		private readonly databaseService: DatabaseService,
		private readonly cryptoService: CryptoService,
		@Inject(CACHE_MANAGER) private cacheManager: Cache,
	) {}

	private async clearUserCache(username?: string) {
		if (username) {
			await this.cacheManager.del(`users/profile/${username}`);
		}
	}

	async create(data: {
		username: string;
		email: string;
		passwordHash: string;
		emailHash: string;
	}) {
		const [newUser] = await this.databaseService.db
			.insert(users)
			.values({
				username: data.username,
				email: data.email,
				emailHash: data.emailHash,
				passwordHash: data.passwordHash,
			})
			.returning();

		return newUser;
	}

	async findByEmailHash(emailHash: string) {
		const result = await this.databaseService.db
			.select({
				uuid: users.uuid,
				username: users.username,
				email: users.email,
				passwordHash: users.passwordHash,
				status: users.status,
				isTwoFactorEnabled: users.isTwoFactorEnabled,
			})
			.from(users)
			.where(eq(users.emailHash, emailHash))
			.limit(1);

		return result[0] || null;
	}

	async findOneWithPrivateData(uuid: string) {
		const result = await this.databaseService.db
			.select({
				uuid: users.uuid,
				username: users.username,
				email: users.email,
				displayName: users.displayName,
				status: users.status,
				isTwoFactorEnabled: users.isTwoFactorEnabled,
				createdAt: users.createdAt,
				updatedAt: users.updatedAt,
			})
			.from(users)
			.where(eq(users.uuid, uuid))
			.limit(1);

		return result[0] || null;
	}

	async findAll(limit: number, offset: number) {
		const totalCountResult = await this.databaseService.db
			.select({ count: sql<number>`count(*)` })
			.from(users);

		const totalCount = Number(totalCountResult[0].count);

		const data = await this.databaseService.db
			.select({
				uuid: users.uuid,
				username: users.username,
				displayName: users.displayName,
				status: users.status,
				createdAt: users.createdAt,
			})
			.from(users)
			.limit(limit)
			.offset(offset);

		return { data, totalCount };
	}

	async findPublicProfile(username: string) {
		const result = await this.databaseService.db
			.select({
				uuid: users.uuid,
				username: users.username,
				displayName: users.displayName,
				createdAt: users.createdAt,
			})
			.from(users)
			.where(eq(users.username, username))
			.limit(1);

		return result[0] || null;
	}

	async findOne(uuid: string) {
		const result = await this.databaseService.db
			.select()
			.from(users)
			.where(eq(users.uuid, uuid))
			.limit(1);

		return result[0] || null;
	}

	async update(uuid: string, data: UpdateUserDto) {
		this.logger.log(`Updating user profile for ${uuid}`);
		const result = await this.databaseService.db
			.update(users)
			.set({ ...data, updatedAt: new Date() })
			.where(eq(users.uuid, uuid))
			.returning();

		if (result[0]) {
			await this.clearUserCache(result[0].username);
		}
		return result;
	}

	async updateConsent(
		uuid: string,
		termsVersion: string,
		privacyVersion: string,
	) {
		return await this.databaseService.db
			.update(users)
			.set({
				termsVersion,
				privacyVersion,
				gdprAcceptedAt: new Date(),
				updatedAt: new Date(),
			})
			.where(eq(users.uuid, uuid))
			.returning();
	}

	async setTwoFactorSecret(uuid: string, secret: string) {
		return await this.databaseService.db
			.update(users)
			.set({
				twoFactorSecret: secret,
				updatedAt: new Date(),
			})
			.where(eq(users.uuid, uuid))
			.returning();
	}

	async toggleTwoFactor(uuid: string, enabled: boolean) {
		return await this.databaseService.db
			.update(users)
			.set({
				isTwoFactorEnabled: enabled,
				updatedAt: new Date(),
			})
			.where(eq(users.uuid, uuid))
			.returning();
	}

	async getTwoFactorSecret(uuid: string): Promise<string | null> {
		const result = await this.databaseService.db
			.select({
				secret: users.twoFactorSecret,
			})
			.from(users)
			.where(eq(users.uuid, uuid))
			.limit(1);

		return result[0]?.secret || null;
	}

	async exportUserData(uuid: string) {
		const user = await this.findOneWithPrivateData(uuid);
		if (!user) return null;

		const userContents = await this.databaseService.db
			.select()
			.from(contents)
			.where(eq(contents.userId, uuid));

		const userFavorites = await this.databaseService.db
			.select()
			.from(favorites)
			.where(eq(favorites.userId, uuid));

		return {
			profile: user,
			contents: userContents,
			favorites: userFavorites,
			exportedAt: new Date(),
		};
	}

	async remove(uuid: string) {
		return await this.databaseService.db.transaction(async (tx) => {
			// Soft delete de l'utilisateur
			const userResult = await tx
				.update(users)
				.set({ status: "deleted", deletedAt: new Date() })
				.where(eq(users.uuid, uuid))
				.returning();

			// Soft delete de tous ses contenus
			await tx
				.update(contents)
				.set({ deletedAt: new Date() })
				.where(eq(contents.userId, uuid));

			return userResult;
		});
	}
}