/*
 * Copyright (C) 2020 Graylog, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the Server Side Public License, version 1,
 * as published by MongoDB, Inc.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * Server Side Public License for more details.
 *
 * You should have received a copy of the Server Side Public License
 * along with this program. If not, see
 * <http://www.mongodb.com/licensing/server-side-public-license>.
 */
const fs = require('fs');
const path = require('path');

const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const merge = require('webpack-merge');
const CopyWebpackPlugin = require('copy-webpack-plugin');
const TerserPlugin = require('terser-webpack-plugin');

const UniqueChunkIdPlugin = require('./webpack/UniqueChunkIdPlugin');

const ROOT_PATH = path.resolve(__dirname);
const APP_PATH = path.resolve(ROOT_PATH, 'src');
const BUILD_PATH = path.resolve(ROOT_PATH, 'target/web/build');
const MANIFESTS_PATH = path.resolve(ROOT_PATH, 'manifests');
const VENDOR_MANIFEST_PATH = path.resolve(MANIFESTS_PATH, 'vendor-manifest.json');
const TARGET = process.env.npm_lifecycle_event || 'build';
process.env.BABEL_ENV = TARGET;

const BABELRC = path.resolve(ROOT_PATH, 'babel.config.js');
const BABELOPTIONS = {
  cacheDirectory: 'target/web/cache',
  extends: BABELRC,
};

const BABELLOADER = { loader: 'babel-loader', options: BABELOPTIONS };

// eslint-disable-next-line import/no-dynamic-require
const BOOTSTRAPVARS = require(path.resolve(ROOT_PATH, 'public', 'stylesheets', 'bootstrap-config.json')).vars;

const getCssLoaderOptions = () => {
  // Development
  if (TARGET === 'start') {
    return {
      modules: {
        localIdentName: '[name]__[local]--[hash:base64:5]',
        mode: 'global',
      },
    };
  }

  return {
    modules: {
      mode: 'global',
    },
  };
};

const chunksSortMode = (c1, c2) => {
  // Render the polyfill chunk first
  if (c1 === 'polyfill') {
    return -1;
  }

  if (c2 === 'polyfill') {
    return 1;
  }

  if (c1 === 'app') {
    return 1;
  }

  if (c2 === 'app') {
    return -1;
  }

  return 0;
};

const webpackConfig = {
  name: 'app',
  dependencies: ['vendor'],
  entry: {
    app: APP_PATH,
    polyfill: [path.resolve(APP_PATH, 'polyfill.js')],
  },
  output: {
    path: BUILD_PATH,
    filename: '[name].[chunkhash].js',
  },
  module: {
    rules: [
      { test: /\.[jt]s(x)?$/, use: BABELLOADER, exclude: /node_modules|\.node_cache/ },
      {
        test: /\.(svg)(\?.+)?$/,
        type: 'asset/resource',
      },
      {
        test: /\.(woff(2)?|ttf|eot)(\?.+)?$/,
        type: 'asset/resource',
      },
      {
        test: /\.(png|gif|jpg)(\?.+)?$/,
        type: 'asset',
      },
      {
        test: /bootstrap\.less$/,
        use: [
          {
            loader: 'style-loader',
            options: {
              // implementation to insert at the top of the head tag: https://github.com/webpack-contrib/style-loader#function
              insert: function insertAtTop(element) {
                const parent = document.querySelector('head');
                // eslint-disable-next-line no-underscore-dangle
                const 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',
          {
            loader: 'less-loader',
            options: {
              lessOptions: {
                modifyVars: BOOTSTRAPVARS,
              },
            },
          },
        ],
      },
      { test: /\.less$/, use: ['style-loader', 'css-loader', 'less-loader'], exclude: /bootstrap\.less$/ },
      {
        test: /\.css$/,
        exclude: /(\.lazy|leaflet)\.css$/,
        use: [
          'style-loader',
          {
            loader: 'css-loader',
            options: getCssLoaderOptions(),
          },
        ],
      },
      {
        test: /(\.lazy|leaflet)\.css$/,
        use: [
          { loader: 'style-loader', options: { injectType: 'lazyStyleTag' } },
          {
            loader: 'css-loader',
            options: getCssLoaderOptions(),
          },
        ],
      },
    ],
  },
  resolve: {
    // you can now require('file') instead of require('file.coffee')
    extensions: ['.js', '.json', '.jsx', '.ts', '.tsx'],
    modules: [APP_PATH, 'node_modules', path.resolve(ROOT_PATH, 'public')],
    alias: {
      theme: path.resolve(APP_PATH, 'theme'),
    },
  },
  resolveLoader: { modules: [path.join(ROOT_PATH, 'node_modules')] },
  devtool: 'source-map',
  plugins: [
    new webpack.ProvidePlugin({
      Buffer: ['buffer', 'Buffer'],
    }),
    new UniqueChunkIdPlugin(),
    new webpack.ids.HashedModuleIdsPlugin({
      hashFunction: 'sha256',
      hashDigestLength: 8,
    }),
    new webpack.DllReferencePlugin({ manifest: VENDOR_MANIFEST_PATH, context: ROOT_PATH }),
    new HtmlWebpackPlugin({
      title: 'Graylog',
      favicon: path.resolve(ROOT_PATH, 'public/images/favicon.png'),
      filename: 'index.html',
      inject: false,
      template: path.resolve(ROOT_PATH, 'templates/index.html.template'),
      templateParameters: {
        vendorModule: () => JSON.parse(fs.readFileSync(path.resolve(BUILD_PATH, 'vendor-module.json'), 'utf8')),
      },
      chunksSortMode,
    }),
    new HtmlWebpackPlugin({
      filename: 'module.json',
      inject: false,
      template: path.resolve(ROOT_PATH, 'templates/module.json.template'),
      excludeChunks: ['config'],
      chunksSortMode,
    }),
    new webpack.DefinePlugin({
      FEATURES: JSON.stringify(process.env.FEATURES),
    }),
  ],
};

if (TARGET === 'start') {
  // eslint-disable-next-line no-console
  console.error('Running in development (no HMR) mode');

  module.exports = merge(webpackConfig, {
    mode: 'development',
    devtool: 'cheap-module-source-map',
    output: {
      path: BUILD_PATH,
      filename: '[name].js',
      publicPath: '/',
    },
    plugins: [
      new webpack.DefinePlugin({
        DEVELOPMENT: true,
        // Keep old env to avoid breaking developer setups
        GRAYLOG_API_URL: JSON.stringify(process.env.GRAYLOG_API_URL || process.env.GRAYLOG_HTTP_PUBLISH_URI),
        IS_CLOUD: process.env.IS_CLOUD,
      }),
      new CopyWebpackPlugin({ patterns: [{ from: 'config.js' }] }),
      new webpack.HotModuleReplacementPlugin(),
    ],
  });
}

if (TARGET.startsWith('build')) {
  // eslint-disable-next-line no-console
  console.error('Running in production mode');
  process.env.NODE_ENV = 'production';

  module.exports = merge(webpackConfig, {
    mode: 'production',
    optimization: {
      moduleIds: 'deterministic',
      minimizer: [new TerserPlugin({
        terserOptions: {
          compress: {
            warnings: false,
          },
          mangle: {
            reserved: ['$super', '$', 'exports', 'require'],
          },
        },
      })],
    },
    plugins: [
      new webpack.DefinePlugin({
        'process.env.NODE_ENV': JSON.stringify('production'),
      }),
    ],
  });
}

if (Object.keys(module.exports).length === 0) {
  module.exports = webpackConfig;
}