const { resolve } = require('path')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const HtmlWebpackInlineSourcePlugin = require('html-webpack-inline-source-plugin')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const OptimizeCssAssetsWebpackPlugin = require('optimize-css-assets-webpack-plugin')
const webpackMerge = require('webpack-merge')

const isProduction = process.env.NODE_ENV === 'production'

const projectRoot = resolve(__dirname)
const sourceFolder = resolve(projectRoot, 'src')
const buildFolder = resolve(projectRoot, 'dist')
const htmlTemplateFile = resolve(sourceFolder, 'index.html')

const babelRule = {
    test: /\.(js|tsx?)$/,
    use: 'babel-loader'
}

const fileRule = {
    test: /\.(png|svg|jpg|gif)$/,
    use: ['file-loader']
}

const cssAndSass = [
    isProduction
        ? MiniCssExtractPlugin.loader
        : {
              loader: 'style-loader',
              options: {
                  singleton: true
              }
          },
    'css-loader'
]

const cssRule = {
    test: /\.css$/,
    use: cssAndSass
}

const sassRule = {
    test: /\.scss$/,
    use: [
        ...cssAndSass,
        {
            loader: 'sass-loader',
            options: {
                includePaths: [sourceFolder]
            }
        }
    ]
}

const baseConfig = {
    mode: 'none',
    entry: ['babel-regenerator-runtime', resolve(sourceFolder, 'main')],
    output: {
        filename: 'js/[name].js',
        path: buildFolder,
        publicPath: '/'
    },
    module: {
        rules: [babelRule, sassRule, cssRule, fileRule]
    },
    resolve: {
        extensions: [
            '.js',
            '.ts',
            '.tsx',
            '.scss',
            '.png',
            '.svg',
            '.jpg',
            '.gif'
        ]
    },
    plugins: []
}

const devConfig = {
    mode: 'development',
    plugins: [
        new HtmlWebpackPlugin({
            template: htmlTemplateFile,
            chunksSortMode: 'dependency'
        })
    ],
    devtool: 'inline-source-map',
    devServer: {
        historyApiFallback: true
    }
}

const prodConfig = {
    mode: 'production',
    optimization: {
        minimize: true,
        nodeEnv: 'production'
    },
    plugins: [
        new MiniCssExtractPlugin({
            filename: 'css/[name].min.css'
        }),
        new OptimizeCssAssetsWebpackPlugin(),
        new HtmlWebpackPlugin({
            template: htmlTemplateFile,
            minify: {
                removeComments: true,
                collapseWhitespace: true,
                removeRedundantAttributes: true,
                useShortDoctype: true,
                removeEmptyAttributes: true,
                removeStyleLinkTypeAttributes: true,
                keepClosingSlash: true,
                minifyJS: true,
                minifyCSS: true,
                minifyURLs: true
            },
            inject: true
        }),
        new HtmlWebpackInlineSourcePlugin()
    ],
    devtool: 'source-map'
}

function getFinalConfig() {
    if (process.env.NODE_ENV === 'production') {
        console.info('Running production config')
        return webpackMerge(baseConfig, prodConfig)
    }

    console.info('Running development config')
    return webpackMerge(baseConfig, devConfig)
}

module.exports = getFinalConfig()