import express from "express";
import bcrypt from "bcryptjs";
import jwt from "jsonwebtoken";
import Vendor from "../models/Vendor.model.js";
import Store from "../models/Store.model.js";
import Invitation from "../models/Invitation.model.js";
import { protectVendor } from "../middleware/vendorAuthMiddleware.js";

const router = express.Router();

/**
 * Register a New Vendor (and create a corresponding Store)
 * @route  POST /api/auth/register
 */
router.post("/register", async (req, res) => {
  const { username, password, invitationCode } = req.body;

  try {
    if (!username || !password || !invitationCode) {
      return res.status(400).json({ error: "All fields are required." });
    }

    // Verify invitation code
    const invitation = await Invitation.findOne({
      code: invitationCode,
      isUsed: false,
    });

    console.log(`Invitation: ${invitation}`);
    
    if (!invitation) {
      return res.status(400).json({ error: "Invalid or used invitation code." });
    }

    // Check if vendor already exists
    const existingVendor = await Vendor.findOne({ username });
    if (existingVendor) {
      return res.status(400).json({ error: "Vendor already exists." });
    }

    // Hash the password
    const hashedPassword = await bcrypt.hash(password, 10);

    // Create the vendor
    const vendor = new Vendor({
      username,
      passwordHash: hashedPassword,
    });
    await vendor.save();

    // Create a store for this vendor
    const store = new Store({
      vendorId: vendor._id,
      storeName: `${username}'s Store`,
      welcomeMessage: "Welcome to my store!",
      categories: [],
    });
    await store.save();

    // Attach `storeId` to vendor
    vendor.storeId = store._id;
    await vendor.save();

    // Mark invitation as used
    invitation.isUsed = true;
    invitation.usedBy = vendor._id;
    invitation.usedAt = new Date();
    await invitation.save();

    return res
      .status(201)
      .json({ message: "Vendor registered successfully", store });
  } catch (error) {
    console.error("Error registering vendor:", error);
    return res.status(500).json({ error: error.message });
  }
});

/**
 * Vendor Login
 * @route  POST /api/auth/login
 */
router.post("/login", async (req, res) => {
  const { username, password } = req.body;

  try {
    if (!username || !password) {
      return res.status(400).json({ error: "Username and password are required." });
    }

    const vendor = await Vendor.findOne({ username });
    if (!vendor) {
      return res.status(401).json({ error: "Invalid credentials." });
    }

    const isMatch = await bcrypt.compare(password, vendor.passwordHash);
    if (!isMatch) {
      return res.status(401).json({ error: "Invalid credentials." });
    }

    // Generate a JWT
    const token = jwt.sign(
      { id: vendor._id, role: "vendor" },
      process.env.JWT_SECRET,
      { expiresIn: "7d" }
    );

    // Store the token in the DB to identify the current session
    vendor.currentToken = token;
    await vendor.save();

    return res.json({ token, role: "vendor" });
  } catch (error) {
    console.error("Error logging in vendor:", error);
    return res.status(500).json({ error: error.message });
  }
});

/**
 * Vendor Logout
 * @route  POST /api/auth/logout
 * @access Private (Vendors only)
 */
router.post("/logout", protectVendor, async (req, res) => {
  try {
    await Vendor.findByIdAndUpdate(req.user._id, { currentToken: null });
    return res.json({ message: "Successfully logged out." });
  } catch (error) {
    console.error("Error logging out vendor:", error);
    return res.status(500).json({ error: "Failed to log out." });
  }
});

/**
 * Get Vendor Info
 * @route  GET /api/auth/me
 * @access Private (Vendors only)
 */
router.get("/me", protectVendor, async (req, res) => {
  try {
    const vendor = await Vendor.findById(req.user._id).select("-passwordHash -currentToken");

    if (!vendor) {
      return res.status(404).json({ error: "Vendor not found." });
    }

    vendor.lastOnline = new Date();
    await vendor.save();

    const store = await Store.findOne({ vendorId: vendor._id });
    return res.json({ vendor, store });
  } catch (error) {
    console.error("Error fetching vendor info:", error);
    return res.status(500).json({ error: "Failed to fetch vendor data." });
  }
});

export default router;