/**
 * Copyright 2018 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

declare class Beasties {
  /**
   * Create an instance of Beasties with custom options.
   * The `.process()` method can be called repeatedly to re-use this instance and its cache.
   */
  constructor(options?: Options)
  /**
   * Process an HTML document to inline critical CSS from its stylesheets.
   * @param html String containing a full HTML document to be parsed.
   * @returns A modified copy of the provided HTML with critical CSS inlined.
   */
  process(html: string): Promise<string>
  /**
   * Read the contents of a file from the specified filesystem or disk.
   * Override this method to customize how stylesheets are loaded.
   */
  readFile(filename: string): Promise<string> | string
  /**
   * Given a stylesheet URL, returns the corresponding CSS asset.
   * Overriding this method requires doing your own URL normalization, so it's generally better to override `readFile()`.
   */
  getCssAsset(href: string): Promise<string | undefined> | string | undefined
}

interface Options {
  path?: string
  publicPath?: string
  external?: boolean
  inlineThreshold?: number
  minimumExternalSize?: number
  pruneSource?: boolean
  mergeStylesheets?: boolean
  additionalStylesheets?: string[]
  preload?: 'body' | 'media' | 'swap' | 'swap-high' | 'js' | 'js-lazy'
  noscriptFallback?: boolean
  inlineFonts?: boolean
  preloadFonts?: boolean
  fonts?: boolean
  keyframes?: string
  compress?: boolean
  logLevel?: 'info' | 'warn' | 'error' | 'trace' | 'debug' | 'silent'
  reduceInlineStyles?: boolean
  logger?: Logger
}

interface Logger {
  trace?: (message: string) => void
  debug?: (message: string) => void
  info?: (message: string) => void
  warn?: (message: string) => void
  error?: (message: string) => void
}

export { type Logger, type Options, Beasties as default };