productController.js

import asyncHandler from '../middleware/asyncHandler.js';
import Product from '../models/productModel.js';



// @desc   Fetch all products
// @route  GET /api/products
// @access Public
const getProducts = asyncHandler(async (req, res) => {
    const pageSize = process.env.PAGINATION_LIMIT || 8;
    const page = Number(req.query.pageNumber) || 1;

    const keyword = req.query.keyword ? {name: { $regex: req.query.keyword, $options: 'i' }} : {};

    const count = await Product.countDocuments({...keyword});

    const products = await Product.find({...keyword})
        .limit(pageSize)
        .skip(pageSize * (page - 1));
    res.json({products, page, pages: Math.ceil(count / pageSize)});
});


// @desc   Create a product
// @route  POST /api/products
// @access Private/Admin
const createProduct = asyncHandler(async (req, res) => {
    const product = new Product({
        name: 'Sample name',
        price: 0,
        user: req.user._id,
        image: '/images/sample.jpg',
        brand: 'Sample brand',
        category: 'Sample category',
        countInStock: 0,
        numReviews: 0,
        description: 'Sample description'
    });

    const createdProduct = await product.save();
    res.status(201).json(createdProduct);
});



// @desc   Fetch single product
// @route  GET /api/products/:id
// @access Public
const getProductById = asyncHandler(async (req, res) => {
    const product = await Product.findById(req.params.id);
    if (product) {
       return res.json(product);
    } else {
        res.status(404);
        throw new Error('Resource not found');
    }
});

// @desc   Update a product
// @route  PUT /api/products/:id
// @access Private/Admin
const updateProduct = asyncHandler(async (req, res) => {
    const { name, price, description, image, brand, category, countInStock } = req.body;

    const product = await Product.findById(req.params.id);

    if (product) {
        product.name = name;
        product.price = price;
        product.description = description;
        product.image = image;
        product.brand = brand;
        product.category = category;
        product.countInStock = countInStock;

        const updatedProduct = await product.save();
        res.json(updatedProduct);
    } else {
        res.status(404);
        throw new Error('Product not found');
    }

});

// @desc   Delete a product
// @route  DELETE /api/products/:id
// @access Private/Admin
const deleteProduct = asyncHandler(async (req, res) => {

    const product = await Product.findById(req.params.id);

    if (product) {
        await Product.deleteOne({_id: product._id});
        res.status(200).json({message: 'Product deleted successfully'});

    } else {
        res.status(404);
        throw new Error('Product not found');
    }

});

// @desc   Create a new review
// @route  POST /api/products/:id/reviews
// @access Private
const createProductReview = asyncHandler(async (req, res) => {

    const { rating, comment } = req.body;

    const product = await Product.findById(req.params.id);

    if (product) {

            const alreadyReviewed = product.reviews.find(review => review.user.toString() === req.user._id.toString());

            if (alreadyReviewed) {
                res.status(400);
                throw new Error('Product already reviewed');
            }

            const review = {
                name: req.user.name,
                rating: Number(rating),
                comment,
                user: req.user._id
            };

            product.reviews.push(review);

            product.numReviews = product.reviews.length;

            product.rating = product.reviews.reduce((acc, item) => item.rating + acc, 0) / product.reviews.length;

            await product.save();

            res.status(201).json({message: 'Review added'});

    } else {
        res.status(404);
        throw new Error('Product not found');
    }

});

// @desc   Get top rated products
// @route  GET /api/products/top
// @access Public
const getTopProducts = asyncHandler(async (req, res) => {
    const products = await Product.find({}).sort({rating: -1}).limit(3);
    res.status(200).json(products);
});

export {
    getProducts,
    getProductById,
    createProduct,
    updateProduct,
    deleteProduct,
    createProductReview,
    getTopProducts
};