import path from "path";
import { fileURLToPath } from "url";
import webpack from "webpack";
import AssetsManifestPlugin from "webpack-assets-manifest";
import { BundleAnalyzerPlugin } from "webpack-bundle-analyzer";
import { LicenseWebpackPlugin as LicensePlugin } from "license-webpack-plugin";
import CopyPlugin from "copy-webpack-plugin";
import MiniCssExtractPlugin from "mini-css-extract-plugin";
import CssMinimizerPlugin from "css-minimizer-webpack-plugin";
import TerserPlugin from "terser-webpack-plugin";

// PostCSS stuff:
import autoprefixer from "autoprefixer";
import postcssSvgo from "postcss-svgo";
import postcssFocus from "postcss-focus";

// https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c#what-do-i-use-instead-of-__dirname-and-__filename
const __dirname = path.dirname(fileURLToPath(import.meta.url));

export default (env, argv) => {
  const isProd = argv.mode === "production";
  const globalBannerText = `Licensed under MIT. Copyright (c) 2015-${new Date().getFullYear()} Jake Jarvis <https://jarv.is/>.`;

  return {
    entry: [path.resolve(__dirname, "assets/js/main.js"), path.resolve(__dirname, "assets/sass/main.scss")],
    mode: isProd ? "production" : "development",
    devtool: isProd ? "source-map" : "inline-source-map",
    output: {
      filename: isProd ? "js/[name]-[contenthash:6].js" : "js/[name].js",
      path: path.resolve(__dirname, "static/assets/"),
      publicPath: "/assets/",
      clean: true,
      environment: {
        // https://github.com/babel/babel-loader#top-level-function-iife-is-still-arrow-on-webpack-5
        arrowFunction: false,
      },
      devtoolModuleFilenameTemplate: "webpack:///[resource-path]",
    },
    resolve: {
      alias: {
        // https://preactjs.com/guide/v10/getting-started#aliasing-in-webpack
        react: "preact/compat",
        "react-dom/test-utils": "preact/test-utils",
        "react-dom": "preact/compat",
        "react/jsx-runtime": "preact/jsx-runtime",
      },
    },
    plugins: [
      new MiniCssExtractPlugin({
        filename: isProd ? "css/[name]-[contenthash:6].css" : "css/[name].css",
      }),
      new webpack.BannerPlugin({
        banner: `/*! ${globalBannerText} */`,
        raw: true,
      }),
      new LicensePlugin({
        outputFilename: "third_party.txt",
        perChunkOutput: false,
        addBanner: true,
        renderBanner: (filename) => `/*!
 * ${globalBannerText}
 * See here for third-party libraries: https://jarv.is/assets/${filename}
 */`,
        additionalModules: [
          {
            name: "twemoji",
            directory: path.resolve(__dirname, "node_modules/twemoji/"),
          },
        ],
        licenseFileOverrides: {
          twemoji: "LICENSE-GRAPHICS", // we only use the emojis, not the bundled code
        },
        excludedPackageTest: (packageName) => packageName.startsWith("preact-"),
      }),
      new CopyPlugin({
        patterns: [
          {
            from: path.resolve(__dirname, "assets/images/"),
            to: "images/",
            globOptions: {
              dot: false,
            },
          },
          {
            from: path.resolve(__dirname, "node_modules/twemoji-emojis/vendor/svg/"),
            to: "emoji/",
            globOptions: {
              dot: false,
            },
          },
        ],
      }),
      new webpack.EnvironmentPlugin({
        // we need to dynamically inject the hcaptcha site key into the contact form
        // fall back to the developer test key: https://docs.hcaptcha.com/#test-key-set-publisher-account
        HCAPTCHA_SITE_KEY: "10000000-ffff-ffff-ffff-000000000001",
      }),
      new AssetsManifestPlugin({
        writeToDisk: true, // allow Hugo to access file in dev mode
        output: path.resolve(__dirname, "data/manifest.json"),
        publicPath: true,
        integrity: true,
        integrityHashes: ["sha384"],
        customize: (entry) => {
          // don't add thousands of unneeded twemoji graphics to the manifest
          if (entry.key.startsWith("emoji/") || entry.key.endsWith(".map")) return false;
        },
      }),
      new BundleAnalyzerPlugin({
        analyzerMode: "disabled", // this is done in gulp via `yarn analyze-bundle` instead
        generateStatsFile: true,
        statsFilename: path.resolve(__dirname, "webpack_stats.json"),
      }),
    ],
    module: {
      rules: [
        {
          test: /\.m?js$/,
          enforce: "pre", // source-map-loader needs to come before everything else
          use: ["source-map-loader"],
        },
        {
          test: /\.m?js$/,
          exclude: /node_modules/,
          use: ["babel-loader"],
        },
        {
          // TODO: make SVGs co-exist here *and* amongst the other `asset/resources` image extensions below
          test: /\.svg$/,
          issuer: /\.js$/,
          use: ["@svgr/webpack"],
        },
        {
          test: /\.(sa|sc|c)ss$/,
          use: [
            MiniCssExtractPlugin.loader,
            {
              loader: "css-loader",
              options: {
                sourceMap: true,
              },
            },
            {
              loader: "postcss-loader",
              options: {
                sourceMap: true,
                postcssOptions: {
                  config: false,
                  plugins: [
                    autoprefixer(),
                    postcssSvgo({
                      encode: true,
                    }),
                    postcssFocus(),
                  ],
                },
              },
            },
            {
              loader: "sass-loader",
              options: {
                sourceMap: true,
              },
            },
          ],
        },
        {
          test: /\.(png|jp(e*)g|gif|ico)$/,
          type: "asset/resource",
          generator: {
            filename: isProd ? "images/[name]-[contenthash:6][ext]" : "images/[name][ext]",
          },
        },
        {
          test: /\.(woff(2)?|ttf|otf|eot)$/,
          type: "asset/resource",
          generator: {
            filename: isProd ? "fonts/[name]-[contenthash:6][ext]" : "fonts/[name][ext]",
          },
        },
      ],
    },
    performance: {
      // only evaluate JS and CSS file sizes (ignore source maps, images, etc.)
      assetFilter: (assetFilename) => /\.js$|\.css$/.test(assetFilename),
      maxAssetSize: 990000, // ~99 KiB
    },
    optimization: {
      sideEffects: true,
      minimize: isProd,
      minimizer: [
        new TerserPlugin({
          test: /\.js$/,
          parallel: true,
          terserOptions: {
            sourceMap: true,
            compress: {
              drop_console: true,
              passes: 3,
            },
            format: {
              // cut all comments except for the banner declared above via LicensePlugin:
              comments: (_astNode, comment) => comment.value.toLowerCase().includes("third-party libraries"),
              ascii_only: true, // some symbols get disfigured otherwise
            },
            mangle: true,
          },
          extractComments: false,
        }),
        new CssMinimizerPlugin({
          test: /\.css$/,
          minify: CssMinimizerPlugin.cleanCssMinify,
          minimizerOptions: {
            compatibility: "*",
            level: 2,
            processImport: false,
            sourceMap: true,
            format: {
              breaks: {
                afterAtRule: true,
                afterBlockBegins: true,
                afterBlockEnds: true,
                afterComment: true,
                afterRuleEnds: true,
                beforeBlockEnds: true,
              },
              spaces: {
                beforeBlockBegins: true,
              },
              semicolonAfterLastProperty: true,
            },
          },
        }),
      ],
    },
    devServer: {
      static: {
        directory: path.resolve(__dirname, "public"),
        watch: true,
      },
      host: "0.0.0.0", // weird docker bind behavior
      port: process.env.PORT || 1337,
      compress: true,
      liveReload: true,
      setupExitSignals: false, // prevent dangling server when started via gulp
    },
  };
};