const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const CssnanoPlugin = require ('cssnano-webpack-plugin');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');

module.exports = env => {
	console.log(env);

	return {
		mode: env.production ? 'production' : 'development',
		target: 'web',
		entry: './src/js/index.js',
		output: {
			filename: env.production ? '[name].[contenthash].bundle.js' : '[name].bundle.js',
			path: path.resolve(__dirname, 'dist'),
		},
		devtool: env.production ? 'cheap-source-map' : 'inline-source-map',
		devServer: {
			contentBase: './dist',
			hot: true,
		},
		plugins: [
			new MiniCssExtractPlugin({
				filename: env.production ? '[name].[contenthash].css' : '[name].css',
			}),
			new CleanWebpackPlugin(),
			new HtmlWebpackPlugin({
				template: 'src/html/index.html'
			}),
		],
		module: {
			rules: [
				{
					test: /\.js?/,
					exclude: /node_modules/,
					use: {
						loader: 'babel-loader',
						options: {
							presets: ['@babel/preset-env']
						}
					}
				},
				{
					test: /\.inline\.css$/i,
					include: path.resolve(__dirname, 'src/css'),
					use: [
						{
							loader: 'style-loader',
							options: {
								insert: function insertAtTop(element) {
									var parent = document.querySelector('head');
									// eslint-disable-next-line no-underscore-dangle
									var lastInsertedElement =
										window._lastElementInsertedByStyleLoader;

									if (!lastInsertedElement) {
										parent.insertBefore(element, parent.firstChild);
									} else if (lastInsertedElement.nextSibling) {
										parent.insertBefore(element, lastInsertedElement.nextSibling);
									} else {
										parent.appendChild(element);
									}

									// eslint-disable-next-line no-underscore-dangle
									window._lastElementInsertedByStyleLoader = element;
								},
							},
						},
						'css-loader',
						'postcss-loader'],
				},
				{
					test: /\.css$/i,
					include: path.resolve(__dirname, 'src/css'),
					exclude: /\.inline\.css$/i,
					use: [MiniCssExtractPlugin.loader, 'css-loader', 'postcss-loader'],
				},
				{
					test: /.(png|svg|jpg|jpeg|gif)$/i,
					include: path.resolve(__dirname, 'src'),
					type: 'asset',
				},
			]
		},
		optimization: {
			minimizer: [
				new CssnanoPlugin({
					sourceMap: true,
				}),
				'...',  // access defaults (defaults are overridden when specifying minimizer: array)
			],
		},
	}
};