controllers/favoriteController.js

const Favorite = require('../models/favoriteModel');
const Product = require('../models/productModel');

exports.addToFavorites = async (req, res) => {
  try {
    const { productId } = req.body;

    // Check product exists
    const productExists = await Product.findById(productId);
    if (!productExists) {
      return res.status(404).json({ message: 'Product not found' });
    }

    // Check if user has favorite list
    let fav = await Favorite.findOne({ user: req.user._id });

    if (!fav) {
      fav = await Favorite.create({
        user: req.user._id,
        products: [productId],
      });
    } else {
      if (fav.products.some((p) => p.toString() === productId.toString())) {
        return res
          .status(400)
          .json({ message: 'Product already in favorites' });
      }

      fav.products.push(productId);
      await fav.save();
    }

    res.status(200).json({
      status: 'success',
      favorites: fav,
    });
  } catch (err) {
    res.status(500).json({ message: 'Failed to add', error: err.message });
  }
};

exports.removeFromFavorites = async (req, res) => {
  try {
    const { productId } = req.body;

    const fav = await Favorite.findOne({ user: req.user._id });

    if (!fav) {
      return res.status(404).json({ message: 'Favorites list not found' });
    }

    fav.products = fav.products.filter(
      (p) => p.toString() !== productId.toString(),
    );

    await fav.save();

    res.status(200).json({
      status: 'success',
      message: 'Product removed',
      favorites: fav,
    });
  } catch (err) {
    res.status(500).json({ message: 'Failed to remove', error: err.message });
  }
};

exports.getFavorites = async (req, res) => {
  try {
    const fav = await Favorite.findOne({ user: req.user._id }).populate(
      'products',
    );

    res.status(200).json({
      status: 'success',
      favorites: fav || { user: req.user._id, products: [] },
    });
  } catch (err) {
    res
      .status(500)
      .json({ message: 'Failed to load favorites', error: err.message });
  }
};

exports.clearFavorites = async (req, res) => {
  try {
    const fav = await Favorite.findOne({ user: req.user._id });

    if (!fav) {
      return res.status(404).json({ message: 'Favorites list not found' });
    }

    fav.products = [];
    await fav.save();

    res.status(200).json({
      status: 'success',
      message: 'All products removed from favorites',
      favorites: fav,
    });
  } catch (err) {
    res
      .status(500)
      .json({ message: 'Failed to clear favorites', error: err.message });
  }
};