// @ts-check
'use strict';

const promisify = require('util').promisify;

const vm = require('vm');
const fs = require('fs');
const _ = require('lodash');
const path = require('path');
const { CachedChildCompilation } = require('./lib/cached-child-compiler');

const { createHtmlTagObject, htmlTagObjectToString, HtmlTagArray } = require('./lib/html-tags');
const prettyError = require('./lib/errors.js');
const chunkSorter = require('./lib/chunksorter.js');
const getHtmlWebpackPluginHooks = require('./lib/hooks.js').getHtmlWebpackPluginHooks;

/** @typedef {import("./typings").HtmlTagObject} HtmlTagObject */
/** @typedef {import("./typings").Options} HtmlWebpackOptions */
/** @typedef {import("./typings").ProcessedOptions} ProcessedHtmlWebpackOptions */
/** @typedef {import("./typings").TemplateParameter} TemplateParameter */
/** @typedef {import("webpack").Compiler} Compiler */
/** @typedef {ReturnType<Compiler["getInfrastructureLogger"]>} Logger */
/** @typedef {import("webpack/lib/Compilation.js")} Compilation */
/** @typedef {Array<{ name: string, source: import('webpack').sources.Source, info?: import('webpack').AssetInfo }>} PreviousEmittedAssets */
/** @typedef {{ publicPath: string, js: Array<string>, css: Array<string>, manifest?: string, favicon?: string }} AssetsInformationByGroups */

class HtmlWebpackPlugin {
  /**
   * @param {HtmlWebpackOptions} [options]
   */
  constructor (options) {
    /** @type {HtmlWebpackOptions} */
    // TODO remove me in the next major release
    this.userOptions = options || {};
    this.version = HtmlWebpackPlugin.version;

    // Default options
    /** @type {ProcessedHtmlWebpackOptions} */
    const defaultOptions = {
      template: 'auto',
      templateContent: false,
      templateParameters: templateParametersGenerator,
      filename: 'index.html',
      publicPath: this.userOptions.publicPath === undefined ? 'auto' : this.userOptions.publicPath,
      hash: false,
      inject: this.userOptions.scriptLoading === 'blocking' ? 'body' : 'head',
      scriptLoading: 'defer',
      compile: true,
      favicon: false,
      minify: 'auto',
      cache: true,
      showErrors: true,
      chunks: 'all',
      excludeChunks: [],
      chunksSortMode: 'auto',
      meta: {},
      base: false,
      title: 'Webpack App',
      xhtml: false
    };

    /** @type {ProcessedHtmlWebpackOptions} */
    this.options = Object.assign(defaultOptions, this.userOptions);
  }

  /**
   *
   * @param {Compiler} compiler
   * @returns {void}
   */
  apply (compiler) {
    this.logger = compiler.getInfrastructureLogger('HtmlWebpackPlugin');

    // Wait for configuration preset plugions to apply all configure webpack defaults
    compiler.hooks.initialize.tap('HtmlWebpackPlugin', () => {
      const options = this.options;

      options.template = this.getTemplatePath(this.options.template, compiler.context);

      // Assert correct option spelling
      if (options.scriptLoading !== 'defer' && options.scriptLoading !== 'blocking' && options.scriptLoading !== 'module' && options.scriptLoading !== 'systemjs-module') {
        /** @type {Logger} */
        (this.logger).error('The "scriptLoading" option need to be set to "defer", "blocking" or "module" or "systemjs-module"');
      }

      if (options.inject !== true && options.inject !== false && options.inject !== 'head' && options.inject !== 'body') {
        /** @type {Logger} */
        (this.logger).error('The `inject` option needs to be set to true, false, "head" or "body');
      }

      if (
        this.options.templateParameters !== false &&
        typeof this.options.templateParameters !== 'function' &&
        typeof this.options.templateParameters !== 'object'
      ) {
        /** @type {Logger} */
        (this.logger).error('The `templateParameters` has to be either a function or an object or false');
      }

      // Default metaOptions if no template is provided
      if (!this.userOptions.template && options.templateContent === false && options.meta) {
        options.meta = Object.assign(
          {},
          options.meta,
          {
            // TODO remove in the next major release
            // From https://developer.mozilla.org/en-US/docs/Mozilla/Mobile/Viewport_meta_tag
            viewport: 'width=device-width, initial-scale=1'
          },
          this.userOptions.meta
        );
      }

      // entryName to fileName conversion function
      const userOptionFilename = this.userOptions.filename || this.options.filename;
      const filenameFunction = typeof userOptionFilename === 'function'
        ? userOptionFilename
        // Replace '[name]' with entry name
        : (entryName) => userOptionFilename.replace(/\[name\]/g, entryName);

      /** output filenames for the given entry names */
      const entryNames = Object.keys(compiler.options.entry);
      const outputFileNames = new Set((entryNames.length ? entryNames : ['main']).map(filenameFunction));

      // Hook all options into the webpack compiler
      outputFileNames.forEach((outputFileName) => {
        // Instance variables to keep caching information for multiple builds
        const assetJson = { value: undefined };
        /**
         * store the previous generated asset to emit them even if the content did not change
         * to support watch mode for third party plugins like the clean-webpack-plugin or the compression plugin
         * @type {PreviousEmittedAssets}
         */
        const previousEmittedAssets = [];

        // Inject child compiler plugin
        const childCompilerPlugin = new CachedChildCompilation(compiler);

        if (!this.options.templateContent) {
          childCompilerPlugin.addEntry(this.options.template);
        }

        // convert absolute filename into relative so that webpack can
        // generate it at correct location
        let filename = outputFileName;

        if (path.resolve(filename) === path.normalize(filename)) {
          const outputPath = /** @type {string} - Once initialized the path is always a string */(compiler.options.output.path);

          filename = path.relative(outputPath, filename);
        }

        compiler.hooks.thisCompilation.tap('HtmlWebpackPlugin',
          /**
           * Hook into the webpack compilation
           * @param {Compilation} compilation
           */
          (compilation) => {
            compilation.hooks.processAssets.tapAsync(
              {
                name: 'HtmlWebpackPlugin',
                stage:
                /**
                 * Generate the html after minification and dev tooling is done
                 */
                compiler.webpack.Compilation.PROCESS_ASSETS_STAGE_OPTIMIZE_INLINE
              },
              /**
               * Hook into the process assets hook
               * @param {any} _
               * @param {(err?: Error) => void} callback
               */
              (_, callback) => {
                this.generateHTML(compiler, compilation, filename, childCompilerPlugin, previousEmittedAssets, assetJson, callback);
              });
          });
      });
    });
  }

  /**
   * Helper to return the absolute template path with a fallback loader
   *
   * @private
   * @param {string} template The path to the template e.g. './index.html'
   * @param {string} context The webpack base resolution path for relative paths e.g. process.cwd()
   */
  getTemplatePath (template, context) {
    if (template === 'auto') {
      template = path.resolve(context, 'src/index.ejs');
      if (!fs.existsSync(template)) {
        template = path.join(__dirname, 'default_index.ejs');
      }
    }

    // If the template doesn't use a loader use the lodash template loader
    if (template.indexOf('!') === -1) {
      template = require.resolve('./lib/loader.js') + '!' + path.resolve(context, template);
    }

    // Resolve template path
    return template.replace(
      /([!])([^/\\][^!?]+|[^/\\!?])($|\?[^!?\n]+$)/,
      (match, prefix, filepath, postfix) => prefix + path.resolve(filepath) + postfix);
  }

  /**
   * Return all chunks from the compilation result which match the exclude and include filters
   *
   * @private
   * @param {any} chunks
   * @param {string[]|'all'} includedChunks
   * @param {string[]} excludedChunks
   */
  filterEntryChunks (chunks, includedChunks, excludedChunks) {
    return chunks.filter(chunkName => {
      // Skip if the chunks should be filtered and the given chunk was not added explicity
      if (Array.isArray(includedChunks) && includedChunks.indexOf(chunkName) === -1) {
        return false;
      }

      // Skip if the chunks should be filtered and the given chunk was excluded explicity
      if (Array.isArray(excludedChunks) && excludedChunks.indexOf(chunkName) !== -1) {
        return false;
      }

      // Add otherwise
      return true;
    });
  }

  /**
   * Helper to sort chunks
   *
   * @private
   * @param {string[]} entryNames
   * @param {string|((entryNameA: string, entryNameB: string) => number)} sortMode
   * @param {Compilation} compilation
   */
  sortEntryChunks (entryNames, sortMode, compilation) {
    // Custom function
    if (typeof sortMode === 'function') {
      return entryNames.sort(sortMode);
    }
    // Check if the given sort mode is a valid chunkSorter sort mode
    if (typeof chunkSorter[sortMode] !== 'undefined') {
      return chunkSorter[sortMode](entryNames, compilation, this.options);
    }
    throw new Error('"' + sortMode + '" is not a valid chunk sort mode');
  }

  /**
   * Encode each path component using `encodeURIComponent` as files can contain characters
   * which needs special encoding in URLs like `+ `.
   *
   * Valid filesystem characters which need to be encoded for urls:
   *
   * # pound, % percent, & ampersand, { left curly bracket, } right curly bracket,
   * \ back slash, < left angle bracket, > right angle bracket, * asterisk, ? question mark,
   * blank spaces, $ dollar sign, ! exclamation point, ' single quotes, " double quotes,
   * : colon, @ at sign, + plus sign, ` backtick, | pipe, = equal sign
   *
   * However the query string must not be encoded:
   *
   *  fo:demonstration-path/very fancy+name.js?path=/home?value=abc&value=def#zzz
   *    ^             ^    ^    ^     ^    ^  ^    ^^    ^     ^   ^     ^   ^
   *    |             |    |    |     |    |  |    ||    |     |   |     |   |
   *    encoded       |    |    encoded    |  |    ||    |     |   |     |   |
   *                 ignored              ignored  ignored     ignored   ignored
   *
   * @private
   * @param {string} filePath
   */
  urlencodePath (filePath) {
    // People use the filepath in quite unexpected ways.
    // Try to extract the first querystring of the url:
    //
    // some+path/demo.html?value=abc?def
    //
    const queryStringStart = filePath.indexOf('?');
    const urlPath = queryStringStart === -1 ? filePath : filePath.substr(0, queryStringStart);
    const queryString = filePath.substr(urlPath.length);
    // Encode all parts except '/' which are not part of the querystring:
    const encodedUrlPath = urlPath.split('/').map(encodeURIComponent).join('/');
    return encodedUrlPath + queryString;
  }

  /**
   * Appends a cache busting hash to the query string of the url
   * E.g. http://localhost:8080/ -> http://localhost:8080/?50c9096ba6183fd728eeb065a26ec175
   *
   * @private
   * @param {string} url
   * @param {string} hash
   */
  appendHash (url, hash) {
    if (!url) {
      return url;
    }
    return url + (url.indexOf('?') === -1 ? '?' : '&') + hash;
  }

  /**
   * Generate the relative or absolute base url to reference images, css, and javascript files
   * from within the html file - the publicPath
   *
   * @private
   * @param {Compilation} compilation
   * @param {string} filename
   * @param {string | 'auto'} customPublicPath
   * @returns {string}
   */
  getPublicPath (compilation, filename, customPublicPath) {
    /**
     * @type {string} the configured public path to the asset root
     * if a path publicPath is set in the current webpack config use it otherwise
     * fallback to a relative path
     */
    const webpackPublicPath = compilation.getAssetPath(compilation.outputOptions.publicPath, { hash: compilation.hash });
    // Webpack 5 introduced "auto" as default value
    const isPublicPathDefined = webpackPublicPath !== 'auto';

    let publicPath =
      // If the html-webpack-plugin options contain a custom public path uset it
      customPublicPath !== 'auto'
        ? customPublicPath
        : (isPublicPathDefined
          // If a hard coded public path exists use it
          ? webpackPublicPath
          // If no public path was set get a relative url path
          : path.relative(path.resolve(compilation.options.output.path, path.dirname(filename)), compilation.options.output.path)
            .split(path.sep).join('/')
        );

    if (publicPath.length && publicPath.substr(-1, 1) !== '/') {
      publicPath += '/';
    }

    return publicPath;
  }

  /**
   * The getAssetsForHTML extracts the asset information of a webpack compilation for all given entry names.
   *
   * @private
   * @param {Compilation} compilation
   * @param {string} outputName
   * @param {string[]} entryNames
   * @returns {AssetsInformationByGroups}
   */
  getAssetsInformationByGroups (compilation, outputName, entryNames) {
    /** The public path used inside the html file */
    const publicPath = this.getPublicPath(compilation, outputName, this.options.publicPath);
    /**
     * @type {AssetsInformationByGroups}
     */
    const assets = {
      // The public path
      publicPath,
      // Will contain all js and mjs files
      js: [],
      // Will contain all css files
      css: [],
      // Will contain the html5 appcache manifest files if it exists
      manifest: Object.keys(compilation.assets).find(assetFile => path.extname(assetFile) === '.appcache'),
      // Favicon
      favicon: undefined
    };

    // Append a hash for cache busting
    if (this.options.hash && assets.manifest) {
      assets.manifest = this.appendHash(assets.manifest, /** @type {string} */ (compilation.hash));
    }

    // Extract paths to .js, .mjs and .css files from the current compilation
    const entryPointPublicPathMap = {};
    const extensionRegexp = /\.(css|js|mjs)(\?|$)/;

    for (let i = 0; i < entryNames.length; i++) {
      const entryName = entryNames[i];
      /** entryPointUnfilteredFiles - also includes hot module update files */
      const entryPointUnfilteredFiles = compilation.entrypoints.get(entryName).getFiles();
      const entryPointFiles = entryPointUnfilteredFiles.filter((chunkFile) => {
        const asset = compilation.getAsset(chunkFile);

        if (!asset) {
          return true;
        }

        // Prevent hot-module files from being included:
        const assetMetaInformation = asset.info || {};

        return !(assetMetaInformation.hotModuleReplacement || assetMetaInformation.development);
      });
      // Prepend the publicPath and append the hash depending on the
      // webpack.output.publicPath and hashOptions
      // E.g. bundle.js -> /bundle.js?hash
      const entryPointPublicPaths = entryPointFiles
        .map(chunkFile => {
          const entryPointPublicPath = publicPath + this.urlencodePath(chunkFile);
          return this.options.hash
            ? this.appendHash(entryPointPublicPath, compilation.hash)
            : entryPointPublicPath;
        });

      entryPointPublicPaths.forEach((entryPointPublicPath) => {
        const extMatch = extensionRegexp.exec(entryPointPublicPath);

        // Skip if the public path is not a .css, .mjs or .js file
        if (!extMatch) {
          return;
        }

        // Skip if this file is already known
        // (e.g. because of common chunk optimizations)
        if (entryPointPublicPathMap[entryPointPublicPath]) {
          return;
        }

        entryPointPublicPathMap[entryPointPublicPath] = true;

        // ext will contain .js or .css, because .mjs recognizes as .js
        const ext = extMatch[1] === 'mjs' ? 'js' : extMatch[1];

        assets[ext].push(entryPointPublicPath);
      });
    }

    return assets;
  }

  /**
   * Once webpack is done with compiling the template into a NodeJS code this function
   * evaluates it to generate the html result
   *
   * The evaluateCompilationResult is only a class function to allow spying during testing.
   * Please change that in a further refactoring
   *
   * @param {string} source
   * @param {string} publicPath
   * @param {string} templateFilename
   * @returns {Promise<string | (() => string | Promise<string>)>}
   */
  evaluateCompilationResult (source, publicPath, templateFilename) {
    if (!source) {
      return Promise.reject(new Error('The child compilation didn\'t provide a result'));
    }

    // The LibraryTemplatePlugin stores the template result in a local variable.
    // By adding it to the end the value gets extracted during evaluation
    if (source.indexOf('HTML_WEBPACK_PLUGIN_RESULT') >= 0) {
      source += ';\nHTML_WEBPACK_PLUGIN_RESULT';
    }

    const templateWithoutLoaders = templateFilename.replace(/^.+!/, '').replace(/\?.+$/, '');
    const vmContext = vm.createContext({
      ...global,
      HTML_WEBPACK_PLUGIN: true,
      require: require,
      htmlWebpackPluginPublicPath: publicPath,
      __filename: templateWithoutLoaders,
      __dirname: path.dirname(templateWithoutLoaders),
      AbortController: global.AbortController,
      AbortSignal: global.AbortSignal,
      Blob: global.Blob,
      Buffer: global.Buffer,
      ByteLengthQueuingStrategy: global.ByteLengthQueuingStrategy,
      BroadcastChannel: global.BroadcastChannel,
      CompressionStream: global.CompressionStream,
      CountQueuingStrategy: global.CountQueuingStrategy,
      Crypto: global.Crypto,
      CryptoKey: global.CryptoKey,
      CustomEvent: global.CustomEvent,
      DecompressionStream: global.DecompressionStream,
      Event: global.Event,
      EventTarget: global.EventTarget,
      File: global.File,
      FormData: global.FormData,
      Headers: global.Headers,
      MessageChannel: global.MessageChannel,
      MessageEvent: global.MessageEvent,
      MessagePort: global.MessagePort,
      PerformanceEntry: global.PerformanceEntry,
      PerformanceMark: global.PerformanceMark,
      PerformanceMeasure: global.PerformanceMeasure,
      PerformanceObserver: global.PerformanceObserver,
      PerformanceObserverEntryList: global.PerformanceObserverEntryList,
      PerformanceResourceTiming: global.PerformanceResourceTiming,
      ReadableByteStreamController: global.ReadableByteStreamController,
      ReadableStream: global.ReadableStream,
      ReadableStreamBYOBReader: global.ReadableStreamBYOBReader,
      ReadableStreamBYOBRequest: global.ReadableStreamBYOBRequest,
      ReadableStreamDefaultController: global.ReadableStreamDefaultController,
      ReadableStreamDefaultReader: global.ReadableStreamDefaultReader,
      Response: global.Response,
      Request: global.Request,
      SubtleCrypto: global.SubtleCrypto,
      DOMException: global.DOMException,
      TextDecoder: global.TextDecoder,
      TextDecoderStream: global.TextDecoderStream,
      TextEncoder: global.TextEncoder,
      TextEncoderStream: global.TextEncoderStream,
      TransformStream: global.TransformStream,
      TransformStreamDefaultController: global.TransformStreamDefaultController,
      URL: global.URL,
      URLSearchParams: global.URLSearchParams,
      WebAssembly: global.WebAssembly,
      WritableStream: global.WritableStream,
      WritableStreamDefaultController: global.WritableStreamDefaultController,
      WritableStreamDefaultWriter: global.WritableStreamDefaultWriter
    });

    const vmScript = new vm.Script(source, { filename: templateWithoutLoaders });

    // Evaluate code and cast to string
    let newSource;

    try {
      newSource = vmScript.runInContext(vmContext);
    } catch (e) {
      return Promise.reject(e);
    }

    if (typeof newSource === 'object' && newSource.__esModule && newSource.default) {
      newSource = newSource.default;
    }

    return typeof newSource === 'string' || typeof newSource === 'function'
      ? Promise.resolve(newSource)
      : Promise.reject(new Error('The loader "' + templateWithoutLoaders + '" didn\'t return html.'));
  }

  /**
   * Add toString methods for easier rendering inside the template
   *
   * @private
   * @param {Array<HtmlTagObject>} assetTagGroup
   * @returns {Array<HtmlTagObject>}
   */
  prepareAssetTagGroupForRendering (assetTagGroup) {
    const xhtml = this.options.xhtml;
    return HtmlTagArray.from(assetTagGroup.map((assetTag) => {
      const copiedAssetTag = Object.assign({}, assetTag);
      copiedAssetTag.toString = function () {
        return htmlTagObjectToString(this, xhtml);
      };
      return copiedAssetTag;
    }));
  }

  /**
   * Generate the template parameters for the template function
   *
   * @private
   * @param {Compilation} compilation
   * @param {AssetsInformationByGroups} assetsInformationByGroups
   * @param {{
       headTags: HtmlTagObject[],
       bodyTags: HtmlTagObject[]
     }} assetTags
   * @returns {Promise<{[key: any]: any}>}
   */
  getTemplateParameters (compilation, assetsInformationByGroups, assetTags) {
    const templateParameters = this.options.templateParameters;

    if (templateParameters === false) {
      return Promise.resolve({});
    }

    if (typeof templateParameters !== 'function' && typeof templateParameters !== 'object') {
      throw new Error('templateParameters has to be either a function or an object');
    }

    const templateParameterFunction = typeof templateParameters === 'function'
      // A custom function can overwrite the entire template parameter preparation
      ? templateParameters
      // If the template parameters is an object merge it with the default values
      : (compilation, assetsInformationByGroups, assetTags, options) => Object.assign({},
        templateParametersGenerator(compilation, assetsInformationByGroups, assetTags, options),
        templateParameters
      );
    const preparedAssetTags = {
      headTags: this.prepareAssetTagGroupForRendering(assetTags.headTags),
      bodyTags: this.prepareAssetTagGroupForRendering(assetTags.bodyTags)
    };
    return Promise
      .resolve()
      .then(() => templateParameterFunction(compilation, assetsInformationByGroups, preparedAssetTags, this.options));
  }

  /**
   * This function renders the actual html by executing the template function
   *
   * @private
   * @param {(templateParameters) => string | Promise<string>} templateFunction
   * @param {AssetsInformationByGroups} assetsInformationByGroups
   * @param {{
       headTags: HtmlTagObject[],
       bodyTags: HtmlTagObject[]
     }} assetTags
   * @param {Compilation} compilation
   * @returns Promise<string>
   */
  executeTemplate (templateFunction, assetsInformationByGroups, assetTags, compilation) {
    // Template processing
    const templateParamsPromise = this.getTemplateParameters(compilation, assetsInformationByGroups, assetTags);

    return templateParamsPromise.then((templateParams) => {
      try {
        // If html is a promise return the promise
        // If html is a string turn it into a promise
        return templateFunction(templateParams);
      } catch (e) {
        compilation.errors.push(new Error('Template execution failed: ' + e));
        return Promise.reject(e);
      }
    });
  }

  /**
   * Html Post processing
   *
   * @private
   * @param {Compiler} compiler The compiler instance
   * @param {any} originalHtml The input html
   * @param {AssetsInformationByGroups} assetsInformationByGroups
   * @param {{headTags: HtmlTagObject[], bodyTags: HtmlTagObject[]}} assetTags The asset tags to inject
   * @returns {Promise<string>}
   */
  postProcessHtml (compiler, originalHtml, assetsInformationByGroups, assetTags) {
    let html = originalHtml;

    if (typeof html !== 'string') {
      return Promise.reject(new Error('Expected html to be a string but got ' + JSON.stringify(html)));
    }

    if (this.options.inject) {
      const htmlRegExp = /(<html[^>]*>)/i;
      const headRegExp = /(<\/head\s*>)/i;
      const bodyRegExp = /(<\/body\s*>)/i;
      const metaViewportRegExp = /<meta[^>]+name=["']viewport["'][^>]*>/i;
      const body = assetTags.bodyTags.map((assetTagObject) => htmlTagObjectToString(assetTagObject, this.options.xhtml));
      const head = assetTags.headTags.filter((item) => {
        if (item.tagName === 'meta' && item.attributes && item.attributes.name === 'viewport' && metaViewportRegExp.test(html)) {
          return false;
        }

        return true;
      }).map((assetTagObject) => htmlTagObjectToString(assetTagObject, this.options.xhtml));

      if (body.length) {
        if (bodyRegExp.test(html)) {
          // Append assets to body element
          html = html.replace(bodyRegExp, match => body.join('') + match);
        } else {
          // Append scripts to the end of the file if no <body> element exists:
          html += body.join('');
        }
      }

      if (head.length) {
        // Create a head tag if none exists
        if (!headRegExp.test(html)) {
          if (!htmlRegExp.test(html)) {
            html = '<head></head>' + html;
          } else {
            html = html.replace(htmlRegExp, match => match + '<head></head>');
          }
        }

        // Append assets to head element
        html = html.replace(headRegExp, match => head.join('') + match);
      }

      // Inject manifest into the opening html tag
      if (assetsInformationByGroups.manifest) {
        html = html.replace(/(<html[^>]*)(>)/i, (match, start, end) => {
          // Append the manifest only if no manifest was specified
          if (/\smanifest\s*=/.test(match)) {
            return match;
          }
          return start + ' manifest="' + assetsInformationByGroups.manifest + '"' + end;
        });
      }
    }

    // TODO avoid this logic and use https://github.com/webpack-contrib/html-minimizer-webpack-plugin under the hood in the next major version
    // Check if webpack is running in production mode
    // @see https://github.com/webpack/webpack/blob/3366421f1784c449f415cda5930a8e445086f688/lib/WebpackOptionsDefaulter.js#L12-L14
    const isProductionLikeMode = compiler.options.mode === 'production' || !compiler.options.mode;
    const needMinify = this.options.minify === true || typeof this.options.minify === 'object' || (this.options.minify === 'auto' && isProductionLikeMode);

    if (!needMinify) {
      return Promise.resolve(html);
    }

    const minifyOptions = typeof this.options.minify === 'object'
      ? this.options.minify
      : {
        // https://www.npmjs.com/package/html-minifier-terser#options-quick-reference
        collapseWhitespace: true,
        keepClosingSlash: true,
        removeComments: true,
        removeRedundantAttributes: true,
        removeScriptTypeAttributes: true,
        removeStyleLinkTypeAttributes: true,
        useShortDoctype: true
      };

    try {
      html = require('html-minifier-terser').minify(html, minifyOptions);
    } catch (e) {
      const isParseError = String(e.message).indexOf('Parse Error') === 0;

      if (isParseError) {
        e.message = 'html-webpack-plugin could not minify the generated output.\n' +
          'In production mode the html minifcation is enabled by default.\n' +
          'If you are not generating a valid html output please disable it manually.\n' +
          'You can do so by adding the following setting to your HtmlWebpackPlugin config:\n|\n|' +
          '    minify: false\n|\n' +
          'See https://github.com/jantimon/html-webpack-plugin#options for details.\n\n' +
          'For parser dedicated bugs please create an issue here:\n' +
          'https://danielruf.github.io/html-minifier-terser/' +
          '\n' + e.message;
      }

      return Promise.reject(e);
    }

    return Promise.resolve(html);
  }

  /**
   * Helper to return a sorted unique array of all asset files out of the asset object
   * @private
   */
  getAssetFiles (assets) {
    const files = _.uniq(Object.keys(assets).filter(assetType => assetType !== 'chunks' && assets[assetType]).reduce((files, assetType) => files.concat(assets[assetType]), []));
    files.sort();
    return files;
  }

  /**
   * Converts a favicon file from disk to a webpack resource and returns the url to the resource
   *
   * @private
   * @param {Compiler} compiler
   * @param {string|false} favicon
   * @param {Compilation} compilation
   * @param {string} publicPath
   * @param {PreviousEmittedAssets} previousEmittedAssets
   * @returns {Promise<string|undefined>}
   */
  generateFavicon (compiler, favicon, compilation, publicPath, previousEmittedAssets) {
    if (!favicon) {
      return Promise.resolve(undefined);
    }

    const filename = path.resolve(compilation.compiler.context, favicon);

    return promisify(compilation.inputFileSystem.readFile)(filename)
      .then((buf) => {
        const source = new compiler.webpack.sources.RawSource(/** @type {string | Buffer} */ (buf), false);
        const name = path.basename(filename);

        compilation.fileDependencies.add(filename);
        compilation.emitAsset(name, source);
        previousEmittedAssets.push({ name, source });

        const faviconPath = publicPath + name;

        if (this.options.hash) {
          return this.appendHash(faviconPath, /** @type {string} */ (compilation.hash));
        }

        return faviconPath;
      })
      .catch(() => Promise.reject(new Error('HtmlWebpackPlugin: could not load file ' + filename)));
  }

  /**
   * Generate all tags script for the given file paths
   *
   * @private
   * @param {Array<string>} jsAssets
   * @returns {Array<HtmlTagObject>}
   */
  generatedScriptTags (jsAssets) {
    // @ts-ignore
    return jsAssets.map(src => {
      const attributes = {};

      if (this.options.scriptLoading === 'defer') {
        attributes.defer = true;
      } else if (this.options.scriptLoading === 'module') {
        attributes.type = 'module';
      } else if (this.options.scriptLoading === 'systemjs-module') {
        attributes.type = 'systemjs-module';
      }

      attributes.src = src;

      return {
        tagName: 'script',
        voidTag: false,
        meta: { plugin: 'html-webpack-plugin' },
        attributes
      };
    });
  }

  /**
   * Generate all style tags for the given file paths
   *
   * @private
   * @param {Array<string>} cssAssets
   * @returns {Array<HtmlTagObject>}
   */
  generateStyleTags (cssAssets) {
    return cssAssets.map(styleAsset => ({
      tagName: 'link',
      voidTag: true,
      meta: { plugin: 'html-webpack-plugin' },
      attributes: {
        href: styleAsset,
        rel: 'stylesheet'
      }
    }));
  }

  /**
   * Generate an optional base tag
   *
   * @param {string | {[attributeName: string]: string}} base
   * @returns {Array<HtmlTagObject>}
   */
  generateBaseTag (base) {
    return [{
      tagName: 'base',
      voidTag: true,
      meta: { plugin: 'html-webpack-plugin' },
      // attributes e.g. { href:"http://example.com/page.html" target:"_blank" }
      attributes: typeof base === 'string' ? {
        href: base
      } : base
    }];
  }

  /**
   * Generate all meta tags for the given meta configuration
   *
   * @private
   * @param {false | {[name: string]:  false | string | {[attributeName: string]: string|boolean}}} metaOptions
   * @returns {Array<HtmlTagObject>}
   */
  generatedMetaTags (metaOptions) {
    if (metaOptions === false) {
      return [];
    }

    // Make tags self-closing in case of xhtml
    // Turn { "viewport" : "width=500, initial-scale=1" } into
    // [{ name:"viewport" content:"width=500, initial-scale=1" }]
    const metaTagAttributeObjects = Object.keys(metaOptions)
      .map((metaName) => {
        const metaTagContent = metaOptions[metaName];
        return (typeof metaTagContent === 'string') ? {
          name: metaName,
          content: metaTagContent
        } : metaTagContent;
      })
      .filter((attribute) => attribute !== false);

    // Turn [{ name:"viewport" content:"width=500, initial-scale=1" }] into
    // the html-webpack-plugin tag structure
    return metaTagAttributeObjects.map((metaTagAttributes) => {
      if (metaTagAttributes === false) {
        throw new Error('Invalid meta tag');
      }
      return {
        tagName: 'meta',
        voidTag: true,
        meta: { plugin: 'html-webpack-plugin' },
        attributes: metaTagAttributes
      };
    });
  }

  /**
   * Generate a favicon tag for the given file path
   *
   * @private
   * @param {string} favicon
   * @returns {Array<HtmlTagObject>}
   */
  generateFaviconTag (favicon) {
    return [{
      tagName: 'link',
      voidTag: true,
      meta: { plugin: 'html-webpack-plugin' },
      attributes: {
        rel: 'icon',
        href: favicon
      }
    }];
  }

  /**
   * Group assets to head and body tags
   *
   * @param {{
      scripts: Array<HtmlTagObject>;
      styles: Array<HtmlTagObject>;
      meta: Array<HtmlTagObject>;
    }} assetTags
   * @param {"body" | "head"} scriptTarget
   * @returns {{
      headTags: Array<HtmlTagObject>;
      bodyTags: Array<HtmlTagObject>;
    }}
   */
  groupAssetsByElements (assetTags, scriptTarget) {
    /** @type {{ headTags: Array<HtmlTagObject>; bodyTags: Array<HtmlTagObject>; }} */
    const result = {
      headTags: [
        ...assetTags.meta,
        ...assetTags.styles
      ],
      bodyTags: []
    };

    // Add script tags to head or body depending on
    // the htmlPluginOptions
    if (scriptTarget === 'body') {
      result.bodyTags.push(...assetTags.scripts);
    } else {
      // If script loading is blocking add the scripts to the end of the head
      // If script loading is non-blocking add the scripts in front of the css files
      const insertPosition = this.options.scriptLoading === 'blocking' ? result.headTags.length : assetTags.meta.length;

      result.headTags.splice(insertPosition, 0, ...assetTags.scripts);
    }

    return result;
  }

  /**
   * Replace [contenthash] in filename
   *
   * @see https://survivejs.com/webpack/optimizing/adding-hashes-to-filenames/
   *
   * @private
   * @param {Compiler} compiler
   * @param {string} filename
   * @param {string|Buffer} fileContent
   * @param {Compilation} compilation
   * @returns {{ path: string, info: {} }}
   */
  replacePlaceholdersInFilename (compiler, filename, fileContent, compilation) {
    if (/\[\\*([\w:]+)\\*\]/i.test(filename) === false) {
      return { path: filename, info: {} };
    }

    const hash = compiler.webpack.util.createHash(compilation.outputOptions.hashFunction);

    hash.update(fileContent);

    if (compilation.outputOptions.hashSalt) {
      hash.update(compilation.outputOptions.hashSalt);
    }

    const contentHash = hash.digest(compilation.outputOptions.hashDigest).slice(0, compilation.outputOptions.hashDigestLength);

    return compilation.getPathWithInfo(
      filename,
      {
        contentHash,
        chunk: {
          hash: contentHash,
          contentHash
        }
      }
    );
  }

  /**
   * Function to generate HTML file.
   *
   * @private
   * @param {Compiler} compiler
   * @param {Compilation} compilation
   * @param {string} outputName
   * @param {CachedChildCompilation} childCompilerPlugin
   * @param {PreviousEmittedAssets} previousEmittedAssets
   * @param {{ value: string | undefined }} assetJson
   * @param {(err?: Error) => void} callback
   */
  generateHTML (
    compiler,
    compilation,
    outputName,
    childCompilerPlugin,
    previousEmittedAssets,
    assetJson,
    callback
  ) {
    // Get all entry point names for this html file
    const entryNames = Array.from(compilation.entrypoints.keys());
    const filteredEntryNames = this.filterEntryChunks(entryNames, this.options.chunks, this.options.excludeChunks);
    const sortedEntryNames = this.sortEntryChunks(filteredEntryNames, this.options.chunksSortMode, compilation);
    const templateResult = this.options.templateContent
      ? { mainCompilationHash: compilation.hash }
      : childCompilerPlugin.getCompilationEntryResult(this.options.template);

    if ('error' in templateResult) {
      compilation.errors.push(prettyError(templateResult.error, compiler.context).toString());
    }

    // If the child compilation was not executed during a previous main compile run
    // it is a cached result
    const isCompilationCached = templateResult.mainCompilationHash !== compilation.hash;
    /** Generated file paths from the entry point names */
    const assetsInformationByGroups = this.getAssetsInformationByGroups(compilation, outputName, sortedEntryNames);
    // If the template and the assets did not change we don't have to emit the html
    const newAssetJson = JSON.stringify(this.getAssetFiles(assetsInformationByGroups));

    if (isCompilationCached && this.options.cache && assetJson.value === newAssetJson) {
      previousEmittedAssets.forEach(({ name, source, info }) => {
        compilation.emitAsset(name, source, info);
      });
      return callback();
    } else {
      previousEmittedAssets.length = 0;
      assetJson.value = newAssetJson;
    }

    // The html-webpack plugin uses a object representation for the html-tags which will be injected
    // to allow altering them more easily
    // Just before they are converted a third-party-plugin author might change the order and content
    const assetsPromise = this.generateFavicon(compiler, this.options.favicon, compilation, assetsInformationByGroups.publicPath, previousEmittedAssets)
      .then((faviconPath) => {
        assetsInformationByGroups.favicon = faviconPath;
        return getHtmlWebpackPluginHooks(compilation).beforeAssetTagGeneration.promise({
          assets: assetsInformationByGroups,
          outputName,
          plugin: this
        });
      });

    // Turn the js and css paths into grouped HtmlTagObjects
    const assetTagGroupsPromise = assetsPromise
      // And allow third-party-plugin authors to reorder and change the assetTags before they are grouped
      .then(({ assets }) => getHtmlWebpackPluginHooks(compilation).alterAssetTags.promise({
        assetTags: {
          scripts: this.generatedScriptTags(assets.js),
          styles: this.generateStyleTags(assets.css),
          meta: [
            ...(this.options.base !== false ? this.generateBaseTag(this.options.base) : []),
            ...this.generatedMetaTags(this.options.meta),
            ...(assets.favicon ? this.generateFaviconTag(assets.favicon) : [])
          ]
        },
        outputName,
        publicPath: assetsInformationByGroups.publicPath,
        plugin: this
      }))
      .then(({ assetTags }) => {
        // Inject scripts to body unless it set explicitly to head
        const scriptTarget = this.options.inject === 'head' ||
        (this.options.inject !== 'body' && this.options.scriptLoading !== 'blocking') ? 'head' : 'body';
        // Group assets to `head` and `body` tag arrays
        const assetGroups = this.groupAssetsByElements(assetTags, scriptTarget);
        // Allow third-party-plugin authors to reorder and change the assetTags once they are grouped
        return getHtmlWebpackPluginHooks(compilation).alterAssetTagGroups.promise({
          headTags: assetGroups.headTags,
          bodyTags: assetGroups.bodyTags,
          outputName,
          publicPath: assetsInformationByGroups.publicPath,
          plugin: this
        });
      });

    // Turn the compiled template into a nodejs function or into a nodejs string
    const templateEvaluationPromise = Promise.resolve()
      .then(() => {
        if ('error' in templateResult) {
          return this.options.showErrors ? prettyError(templateResult.error, compiler.context).toHtml() : 'ERROR';
        }

        // Allow to use a custom function / string instead
        if (this.options.templateContent !== false) {
          return this.options.templateContent;
        }

        // Once everything is compiled evaluate the html factory and replace it with its content
        if ('compiledEntry' in templateResult) {
          const compiledEntry = templateResult.compiledEntry;
          const assets = compiledEntry.assets;

          // Store assets from child compiler to reemit them later
          for (const name in assets) {
            previousEmittedAssets.push({ name, source: assets[name].source, info: assets[name].info });
          }

          return this.evaluateCompilationResult(compiledEntry.content, assetsInformationByGroups.publicPath, this.options.template);
        }

        return Promise.reject(new Error('Child compilation contained no compiledEntry'));
      });
    const templateExectutionPromise = Promise.all([assetsPromise, assetTagGroupsPromise, templateEvaluationPromise])
      // Execute the template
      .then(([assetsHookResult, assetTags, compilationResult]) => typeof compilationResult !== 'function'
        ? compilationResult
        : this.executeTemplate(compilationResult, assetsHookResult.assets, { headTags: assetTags.headTags, bodyTags: assetTags.bodyTags }, compilation));

    const injectedHtmlPromise = Promise.all([assetTagGroupsPromise, templateExectutionPromise])
      // Allow plugins to change the html before assets are injected
      .then(([assetTags, html]) => {
        const pluginArgs = { html, headTags: assetTags.headTags, bodyTags: assetTags.bodyTags, plugin: this, outputName };
        return getHtmlWebpackPluginHooks(compilation).afterTemplateExecution.promise(pluginArgs);
      })
      .then(({ html, headTags, bodyTags }) => {
        return this.postProcessHtml(compiler, html, assetsInformationByGroups, { headTags, bodyTags });
      });

    const emitHtmlPromise = injectedHtmlPromise
      // Allow plugins to change the html after assets are injected
      .then((html) => {
        const pluginArgs = { html, plugin: this, outputName };
        return getHtmlWebpackPluginHooks(compilation).beforeEmit.promise(pluginArgs)
          .then(result => result.html);
      })
      .catch(err => {
        // In case anything went wrong the promise is resolved
        // with the error message and an error is logged
        compilation.errors.push(prettyError(err, compiler.context).toString());
        return this.options.showErrors ? prettyError(err, compiler.context).toHtml() : 'ERROR';
      })
      .then(html => {
        const filename = outputName.replace(/\[templatehash([^\]]*)\]/g, require('util').deprecate(
          (match, options) => `[contenthash${options}]`,
          '[templatehash] is now [contenthash]')
        );
        const replacedFilename = this.replacePlaceholdersInFilename(compiler, filename, html, compilation);
        const source = new compiler.webpack.sources.RawSource(html, false);

        // Add the evaluated html code to the webpack assets
        compilation.emitAsset(replacedFilename.path, source, replacedFilename.info);
        previousEmittedAssets.push({ name: replacedFilename.path, source });

        return replacedFilename.path;
      })
      .then((finalOutputName) => getHtmlWebpackPluginHooks(compilation).afterEmit.promise({
        outputName: finalOutputName,
        plugin: this
      }).catch(err => {
        /** @type {Logger} */
        (this.logger).error(err);
        return null;
      }).then(() => null));

    // Once all files are added to the webpack compilation
    // let the webpack compiler continue
    emitHtmlPromise.then(() => {
      callback();
    });
  }
}

/**
 * The default for options.templateParameter
 * Generate the template parameters
 *
 * Generate the template parameters for the template function
 * @param {Compilation} compilation
 * @param {AssetsInformationByGroups} assets
 * @param {{
     headTags: HtmlTagObject[],
     bodyTags: HtmlTagObject[]
   }} assetTags
 * @param {ProcessedHtmlWebpackOptions} options
 * @returns {TemplateParameter}
 */
function templateParametersGenerator (compilation, assets, assetTags, options) {
  return {
    compilation: compilation,
    webpackConfig: compilation.options,
    htmlWebpackPlugin: {
      tags: assetTags,
      files: assets,
      options: options
    }
  };
}

// Statics:
/**
 * The major version number of this plugin
 */
HtmlWebpackPlugin.version = 5;

/**
 * A static helper to get the hooks for this plugin
 *
 * Usage: HtmlWebpackPlugin.getHooks(compilation).HOOK_NAME.tapAsync('YourPluginName', () => { ... });
 */
HtmlWebpackPlugin.getHooks = getHtmlWebpackPluginHooks;
HtmlWebpackPlugin.createHtmlTagObject = createHtmlTagObject;

module.exports = HtmlWebpackPlugin;