const express = require("express");
const mongoose = require("mongoose");
const Street = require("../models/Street");
const User = require("../models/User");
const auth = require("../middleware/auth");
const { asyncHandler } = require("../middleware/errorHandler");
const {
  createStreetValidation,
  streetIdValidation,
} = require("../middleware/validators/streetValidator");
const {
  awardStreetAdoptionPoints,
  checkAndAwardBadges,
} = require("../services/gamificationService");

const router = express.Router();

// Get all streets (with pagination)
router.get(
  "/",
  asyncHandler(async (req, res) => {
    const { paginate, buildPaginatedResponse } = require("../middleware/pagination");

    // Parse pagination params
    const page = parseInt(req.query.page) || 1;
    const limit = Math.min(parseInt(req.query.limit) || 10, 100);
    const skip = (page - 1) * limit;

    const streets = await Street.find()
      .sort({ name: 1 })
      .skip(skip)
      .limit(limit)
      .populate("adoptedBy", ["name", "profilePicture"]);

    const totalCount = await Street.countDocuments();

    res.json(buildPaginatedResponse(streets, totalCount, page, limit));
  }),
);

// Get single street
router.get(
  "/:id",
  streetIdValidation,
  asyncHandler(async (req, res) => {
    const street = await Street.findById(req.params.id);
    if (!street) {
      return res.status(404).json({ msg: "Street not found" });
    }
    res.json(street);
  }),
);

// Create a street
router.post(
  "/",
  auth,
  createStreetValidation,
  asyncHandler(async (req, res) => {
    const { name, location } = req.body;

    const newStreet = new Street({
      name,
      location,
    });

    const street = await newStreet.save();
    res.json(street);
  }),
);

// Adopt a street
router.put(
  "/adopt/:id",
  auth,
  streetIdValidation,
  asyncHandler(async (req, res) => {
    const session = await mongoose.startSession();
    session.startTransaction();

    try {
      const street = await Street.findById(req.params.id).session(session);
      if (!street) {
        await session.abortTransaction();
        session.endSession();
        return res.status(404).json({ msg: "Street not found" });
      }

      if (street.status === "adopted") {
        await session.abortTransaction();
        session.endSession();
        return res.status(400).json({ msg: "Street already adopted" });
      }

      // Check if user has already adopted this street
      const user = await User.findById(req.user.id).session(session);
      if (user.adoptedStreets.includes(req.params.id)) {
        await session.abortTransaction();
        session.endSession();
        return res
          .status(400)
          .json({ msg: "You have already adopted this street" });
      }

      // Update street
      street.adoptedBy = req.user.id;
      street.status = "adopted";
      await street.save({ session });

      // Update user's adoptedStreets array
      user.adoptedStreets.push(street._id);
      await user.save({ session });

      // Award points for street adoption
      const { transaction } = await awardStreetAdoptionPoints(
        req.user.id,
        street._id,
        session,
      );

      // Check and award badges
      const newBadges = await checkAndAwardBadges(req.user.id, session);

      await session.commitTransaction();
      session.endSession();

      res.json({
        street,
        pointsAwarded: transaction.amount,
        newBalance: transaction.balanceAfter,
        badgesEarned: newBadges,
      });
    } catch (err) {
      await session.abortTransaction();
      session.endSession();
      throw err;
    }
  }),
);

module.exports = router;