import { Injectable } from "@nestjs/common";
import { and, desc, eq, inArray, sql } from "drizzle-orm";
import { DatabaseService } from "../../database/database.service";
import {
	conversationParticipants,
	conversations,
	messages,
	users,
} from "../../database/schemas";

@Injectable()
export class MessagesRepository {
	constructor(private readonly databaseService: DatabaseService) {}

	async findConversationBetweenUsers(userId1: string, userId2: string) {
		const results = await this.databaseService.db
			.select({ id: conversations.id })
			.from(conversations)
			.innerJoin(
				conversationParticipants,
				eq(conversations.id, conversationParticipants.conversationId),
			)
			.where(inArray(conversationParticipants.userId, [userId1, userId2]))
			.groupBy(conversations.id)
			.having(sql`count(${conversations.id}) = 2`);

		return results[0];
	}

	async createConversation() {
		const [conv] = await this.databaseService.db
			.insert(conversations)
			.values({})
			.returning();
		return conv;
	}

	async addParticipant(conversationId: string, userId: string) {
		await this.databaseService.db
			.insert(conversationParticipants)
			.values({ conversationId, userId });
	}

	async createMessage(data: {
		conversationId: string;
		senderId: string;
		text: string;
	}) {
		const [msg] = await this.databaseService.db
			.insert(messages)
			.values(data)
			.returning();

		// Update conversation updatedAt
		await this.databaseService.db
			.update(conversations)
			.set({ updatedAt: new Date() })
			.where(eq(conversations.id, data.conversationId));

		return msg;
	}

	async findAllConversations(userId: string) {
		// Sous-requête pour trouver les IDs des conversations de l'utilisateur
		const userConvs = this.databaseService.db
			.select({ id: conversationParticipants.conversationId })
			.from(conversationParticipants)
			.where(eq(conversationParticipants.userId, userId));

		return this.databaseService.db
			.select({
				id: conversations.id,
				updatedAt: conversations.updatedAt,
				lastMessage: {
					text: messages.text,
					createdAt: messages.createdAt,
				},
				recipient: {
					uuid: users.uuid,
					username: users.username,
					displayName: users.displayName,
					avatarUrl: users.avatarUrl,
				},
			})
			.from(conversations)
			.innerJoin(
				conversationParticipants,
				eq(conversations.id, conversationParticipants.conversationId),
			)
			.innerJoin(users, eq(conversationParticipants.userId, users.uuid))
			.leftJoin(messages, eq(conversations.id, messages.conversationId))
			.where(
				and(
					inArray(conversations.id, userConvs),
					eq(conversationParticipants.userId, users.uuid),
					sql`${users.uuid} != ${userId}`,
				),
			)
			.orderBy(desc(conversations.updatedAt));
	}

	async findMessagesByConversationId(conversationId: string, limit = 50) {
		return this.databaseService.db
			.select({
				id: messages.id,
				text: messages.text,
				createdAt: messages.createdAt,
				senderId: messages.senderId,
				readAt: messages.readAt,
			})
			.from(messages)
			.where(eq(messages.conversationId, conversationId))
			.orderBy(desc(messages.createdAt))
			.limit(limit);
	}

	async isParticipant(conversationId: string, userId: string) {
		const [participant] = await this.databaseService.db
			.select()
			.from(conversationParticipants)
			.where(
				and(
					eq(conversationParticipants.conversationId, conversationId),
					eq(conversationParticipants.userId, userId),
				),
			);
		return !!participant;
	}

	async getParticipants(conversationId: string) {
		return this.databaseService.db
			.select({ userId: conversationParticipants.userId })
			.from(conversationParticipants)
			.where(eq(conversationParticipants.conversationId, conversationId));
	}

	async markAsRead(conversationId: string, userId: string) {
		await this.databaseService.db
			.update(messages)
			.set({ readAt: new Date() })
			.where(
				and(
					eq(messages.conversationId, conversationId),
					sql`${messages.senderId} != ${userId}`,
					sql`${messages.readAt} IS NULL`,
				),
			);
	}

	async countUnreadMessages(userId: string) {
		const result = await this.databaseService.db
			.select({ count: sql<number>`count(*)` })
			.from(messages)
			.innerJoin(
				conversationParticipants,
				eq(messages.conversationId, conversationParticipants.conversationId),
			)
			.where(
				and(
					eq(conversationParticipants.userId, userId),
					sql`${messages.senderId} != ${userId}`,
					sql`${messages.readAt} IS NULL`,
				),
			);
		return Number(result[0]?.count || 0);
	}
}