/// <reference types="webpack-dev-server" />

import path from "path";

import CssMinimizerPlugin from "css-minimizer-webpack-plugin";
import HtmlWebpackPlugin from "html-webpack-plugin";
import MiniCssExtractPlugin from "mini-css-extract-plugin";
import type webpack from "webpack";
import BundleTracker from "webpack-bundle-tracker";

import DebugRequirePlugin from "./tools/debug-require-webpack-plugin";
import assets from "./tools/webpack.assets.json";
import dev_assets from "./tools/webpack.dev-assets.json";

export default (env: {minimize?: boolean} = {}, argv: {mode?: string}): webpack.Configuration[] => {
    const production: boolean = argv.mode === "production";

    const baseConfig: webpack.Configuration = {
        mode: production ? "production" : "development",
        context: __dirname,
        cache: {
            type: "filesystem",
            buildDependencies: {
                config: [__filename],
            },
        },
        snapshot: {
            immutablePaths: ["/srv/zulip-npm-cache"],
        },
    };

    const frontendConfig: webpack.Configuration = {
        ...baseConfig,
        name: "frontend",
        entry: production
            ? assets
            : Object.fromEntries(
                  Object.entries({...assets, ...dev_assets}).map(([name, paths]) => [
                      name,
                      [...paths, "./static/js/debug"],
                  ]),
              ),
        module: {
            rules: [
                {
                    test: require.resolve("./static/js/zulip_test"),
                    loader: "expose-loader",
                    options: {exposes: "zulip_test"},
                },
                {
                    test: require.resolve("./tools/debug-require"),
                    loader: "expose-loader",
                    options: {exposes: "require"},
                },
                {
                    test: require.resolve("jquery"),
                    loader: "expose-loader",
                    options: {exposes: ["$", "jQuery"]},
                },
                // Generate webfont
                {
                    test: /\.font\.js$/,
                    use: [
                        MiniCssExtractPlugin.loader,
                        {
                            loader: "css-loader",
                            options: {
                                url: false, // webfonts-loader generates public relative URLs
                            },
                        },
                        {
                            loader: "webfonts-loader",
                            options: {
                                fileName: production
                                    ? "files/[fontname].[chunkhash].[ext]"
                                    : "files/[fontname].[ext]",
                                publicPath: "",
                            },
                        },
                    ],
                },
                // Transpile .js and .ts files with Babel
                {
                    test: /\.(js|ts)$/,
                    include: [
                        path.resolve(__dirname, "static/shared/js"),
                        path.resolve(__dirname, "static/js"),
                    ],
                    loader: "babel-loader",
                },
                // regular css files
                {
                    test: /\.css$/,
                    exclude: path.resolve(__dirname, "static/styles"),
                    use: [
                        MiniCssExtractPlugin.loader,
                        {
                            loader: "css-loader",
                            options: {
                                sourceMap: true,
                            },
                        },
                    ],
                },
                // PostCSS loader
                {
                    test: /\.css$/,
                    include: path.resolve(__dirname, "static/styles"),
                    use: [
                        MiniCssExtractPlugin.loader,
                        {
                            loader: "css-loader",
                            options: {
                                importLoaders: 1,
                                sourceMap: true,
                            },
                        },
                        {
                            loader: "postcss-loader",
                            options: {
                                sourceMap: true,
                            },
                        },
                    ],
                },
                {
                    test: /\.hbs$/,
                    loader: "handlebars-loader",
                    options: {
                        ignoreHelpers: true,
                        // Tell webpack not to explicitly require these.
                        knownHelpers: [
                            "if",
                            "unless",
                            "each",
                            "with",
                            // The ones below are defined in static/js/templates.js
                            "plural",
                            "eq",
                            "and",
                            "or",
                            "not",
                            "t",
                            "tr",
                            "rendered_markdown",
                        ],
                        preventIndent: true,
                    },
                },
                // load fonts and files
                {
                    test: /\.(eot|jpg|svg|ttf|otf|png|woff2?)$/,
                    type: "asset/resource",
                },
            ],
        },
        output: {
            path: path.resolve(__dirname, "static/webpack-bundles"),
            publicPath: "",
            filename: production ? "[name].[contenthash].js" : "[name].js",
            assetModuleFilename: production
                ? "files/[name].[hash][ext][query]"
                : // Avoid directory traversal bug that upstream won't fix
                  // (https://github.com/webpack/webpack/issues/11937)
                  (pathData) => "files" + path.join("/", pathData.filename!),
            chunkFilename: production ? "[contenthash].js" : "[id].js",
        },
        resolve: {
            ...baseConfig.resolve,
            extensions: [".ts", ".js"],
        },
        // We prefer cheap-module-source-map over any eval-* options
        // because stacktrace-gps doesn't currently support extracting
        // the source snippets with the eval-* options.
        devtool: production ? "source-map" : "cheap-module-source-map",
        optimization: {
            minimize: env.minimize ?? production,
            minimizer: [
                new CssMinimizerPlugin({
                    minify: CssMinimizerPlugin.cleanCssMinify,
                }),
                "...",
            ],
            splitChunks: {
                chunks: "all",
                // webpack/examples/many-pages suggests 20 requests for HTTP/2
                maxAsyncRequests: 20,
                maxInitialRequests: 20,
            },
        },
        plugins: [
            new DebugRequirePlugin(),
            new BundleTracker({
                filename: production
                    ? "webpack-stats-production.json"
                    : "var/webpack-stats-dev.json",
            }),
            // Extract CSS from files
            new MiniCssExtractPlugin({
                filename: production ? "[name].[contenthash].css" : "[name].css",
                chunkFilename: production ? "[contenthash].css" : "[id].css",
            }),
            new HtmlWebpackPlugin({
                filename: "5xx.html",
                template: "static/html/5xx.html",
                chunks: ["error-styles"],
            }),
        ],
        devServer: {
            devMiddleware: {
                publicPath: "/webpack/",
                stats: {
                    // We want just errors and a clear, brief notice
                    // whenever webpack compilation has finished.
                    preset: "minimal",
                    assets: false,
                    modules: false,
                },
            },
            headers: {
                "Access-Control-Allow-Origin": "*",
            },
        },
        infrastructureLogging: {
            level: "warn",
        },
        watchOptions: {
            ignored: [
                "**/node_modules/**",
                // Prevent Emacs file locks from crashing webpack-dev-server
                // https://github.com/webpack/webpack-dev-server/issues/2821
                "**/.#*",
            ],
        },
    };

    const serverConfig: webpack.Configuration = {
        ...baseConfig,
        name: "server",
        target: "node",
        entry: {
            "katex-cli": "shebang-loader!katex/cli",
        },
        output: {
            path: path.resolve(__dirname, "static/webpack-bundles"),
        },
    };

    return [frontendConfig, serverConfig];
};