import express from "express";
import pool from "../db/pool.js";

const router = express.Router();

// 1. CREATE User
router.post("/", async (req, res) => {
	const client = await pool.connect();
	try {
		await client.query("BEGIN");

		const {
			id, // Optional: if provided, use this UUID; otherwise generate one
			name,
			phone_number,
			avatar_url,
			language,
			timezone,
			country_code = "+91",
		} = req.body;

		// If id is provided, use it; otherwise let the database generate one
		const insertUserQuery = id
			? `
                INSERT INTO users (id, name, phone_number, avatar_url, language, timezone, country_code)
                VALUES ($1, $2, $3, $4, $5, $6, $7)
                RETURNING *
            `
			: `
                INSERT INTO users (name, phone_number, avatar_url, language, timezone, country_code)
                VALUES ($1, $2, $3, $4, $5, $6)
                RETURNING *
            `;

		const userValues = id
			? [id, name, phone_number, avatar_url, language, timezone, country_code]
			: [name, phone_number, avatar_url, language, timezone, country_code];

		const userResult = await client.query(insertUserQuery, userValues);

		await client.query("COMMIT");

		res.status(201).json(userResult.rows[0]);
	} catch (err) {
		await client.query("ROLLBACK");
		console.error("Error creating user:", err);

		if (err.code === "23505") {
			// Unique constraint violation
			return res.status(400).json({
				error: err.detail || "A user with this phone number or ID already exists",
			});
		}

		if (err.code === "23503") {
			// Foreign key violation
			return res.status(400).json({
				error: err.detail || "Foreign key constraint violation",
			});
		}

		res.status(500).json({ error: err.message || "Internal server error" });
	} finally {
		client.release();
	}
});

// 2. GET All Users
router.get("/", async (req, res) => {
	try {
		const { limit = 100, offset = 0 } = req.query;
		const queryText = `
            SELECT id, name, phone_number, avatar_url, language, timezone, country_code, 
                   is_active, created_at, updated_at
            FROM users 
            WHERE deleted = FALSE
            ORDER BY created_at DESC
            LIMIT $1 OFFSET $2
        `;
		const result = await pool.query(queryText, [limit, offset]);
		res.json(result.rows);
	} catch (err) {
		console.error("Error fetching users:", err);
		res.status(500).json({ error: "Internal server error" });
	}
});

// 3. GET Single User
router.get("/:id", async (req, res) => {
	try {
		const { id } = req.params;
		const queryText = `
            SELECT id, name, phone_number, avatar_url, language, timezone, country_code, 
                   is_active, created_at, updated_at
            FROM users 
            WHERE id = $1 AND deleted = FALSE
        `;
		const result = await pool.query(queryText, [id]);

		if (result.rows.length === 0) {
			return res.status(404).json({ error: "User not found" });
		}

		res.json(result.rows[0]);
	} catch (err) {
		console.error("Error fetching user:", err);
		res.status(500).json({ error: "Internal server error" });
	}
});

// 4. UPDATE User
router.put("/:id", async (req, res) => {
	try {
		const { id } = req.params;
		const { name, phone_number, avatar_url, language, timezone, country_code, is_active } = req.body;

		const updateQuery = `
            UPDATE users 
            SET name = COALESCE($1, name),
                phone_number = COALESCE($2, phone_number),
                avatar_url = COALESCE($3, avatar_url),
                language = COALESCE($4, language),
                timezone = COALESCE($5, timezone),
                country_code = COALESCE($6, country_code),
                is_active = COALESCE($7, is_active)
            WHERE id = $8 AND deleted = FALSE
            RETURNING *
        `;

		const values = [name, phone_number, avatar_url, language, timezone, country_code, is_active, id];

		const result = await pool.query(updateQuery, values);

		if (result.rows.length === 0) {
			return res.status(404).json({ error: "User not found" });
		}

		res.json(result.rows[0]);
	} catch (err) {
		console.error("Error updating user:", err);
		res.status(500).json({ error: "Internal server error" });
	}
});

// 5. DELETE User (Soft Delete)
router.delete("/:id", async (req, res) => {
	try {
		const { id } = req.params;
		const queryText = `
            UPDATE users 
            SET deleted = TRUE 
            WHERE id = $1 
            RETURNING id
        `;
		const result = await pool.query(queryText, [id]);

		if (result.rows.length === 0) {
			return res.status(404).json({ error: "User not found" });
		}

		res.json({ message: "User deleted successfully" });
	} catch (err) {
		console.error("Error deleting user:", err);
		res.status(500).json({ error: "Internal server error" });
	}
});

export default router;