/**
 * @license
 * Copyright 2017 Google Inc.
 * SPDX-License-Identifier: Apache-2.0
 */

import type FS from 'fs/promises';
import type {Readable} from 'stream';

import {map, NEVER, Observable, timer} from '../../third_party/rxjs/rxjs.js';
import type {CDPSession} from '../api/CDPSession.js';
import {isNode} from '../environment.js';
import {assert} from '../util/assert.js';
import {isErrorLike} from '../util/ErrorLike.js';

import {debug} from './Debug.js';
import {TimeoutError} from './Errors.js';
import type {EventEmitter, EventType} from './EventEmitter.js';
import type {
  LowerCasePaperFormat,
  ParsedPDFOptions,
  PDFOptions,
} from './PDFOptions.js';
import {paperFormats} from './PDFOptions.js';

/**
 * @internal
 */
export const debugError = debug('puppeteer:error');

/**
 * @internal
 */
export const DEFAULT_VIEWPORT = Object.freeze({width: 800, height: 600});

/**
 * @internal
 */
const SOURCE_URL = Symbol('Source URL for Puppeteer evaluation scripts');

/**
 * @internal
 */
export class PuppeteerURL {
  static INTERNAL_URL = 'pptr:internal';

  static fromCallSite(
    functionName: string,
    site: NodeJS.CallSite
  ): PuppeteerURL {
    const url = new PuppeteerURL();
    url.#functionName = functionName;
    url.#siteString = site.toString();
    return url;
  }

  static parse = (url: string): PuppeteerURL => {
    url = url.slice('pptr:'.length);
    const [functionName = '', siteString = ''] = url.split(';');
    const puppeteerUrl = new PuppeteerURL();
    puppeteerUrl.#functionName = functionName;
    puppeteerUrl.#siteString = decodeURIComponent(siteString);
    return puppeteerUrl;
  };

  static isPuppeteerURL = (url: string): boolean => {
    return url.startsWith('pptr:');
  };

  #functionName!: string;
  #siteString!: string;

  get functionName(): string {
    return this.#functionName;
  }

  get siteString(): string {
    return this.#siteString;
  }

  toString(): string {
    return `pptr:${[
      this.#functionName,
      encodeURIComponent(this.#siteString),
    ].join(';')}`;
  }
}

/**
 * @internal
 */
export const withSourcePuppeteerURLIfNone = <T extends NonNullable<unknown>>(
  functionName: string,
  object: T
): T => {
  if (Object.prototype.hasOwnProperty.call(object, SOURCE_URL)) {
    return object;
  }
  const original = Error.prepareStackTrace;
  Error.prepareStackTrace = (_, stack) => {
    // First element is the function.
    // Second element is the caller of this function.
    // Third element is the caller of the caller of this function
    // which is precisely what we want.
    return stack[2];
  };
  const site = new Error().stack as unknown as NodeJS.CallSite;
  Error.prepareStackTrace = original;
  return Object.assign(object, {
    [SOURCE_URL]: PuppeteerURL.fromCallSite(functionName, site),
  });
};

/**
 * @internal
 */
export const getSourcePuppeteerURLIfAvailable = <
  T extends NonNullable<unknown>,
>(
  object: T
): PuppeteerURL | undefined => {
  if (Object.prototype.hasOwnProperty.call(object, SOURCE_URL)) {
    return object[SOURCE_URL as keyof T] as PuppeteerURL;
  }
  return undefined;
};

/**
 * @internal
 */
export const isString = (obj: unknown): obj is string => {
  return typeof obj === 'string' || obj instanceof String;
};

/**
 * @internal
 */
export const isNumber = (obj: unknown): obj is number => {
  return typeof obj === 'number' || obj instanceof Number;
};

/**
 * @internal
 */
export const isPlainObject = (obj: unknown): obj is Record<any, unknown> => {
  return typeof obj === 'object' && obj?.constructor === Object;
};

/**
 * @internal
 */
export const isRegExp = (obj: unknown): obj is RegExp => {
  return typeof obj === 'object' && obj?.constructor === RegExp;
};

/**
 * @internal
 */
export const isDate = (obj: unknown): obj is Date => {
  return typeof obj === 'object' && obj?.constructor === Date;
};

/**
 * @internal
 */
export function evaluationString(
  fun: Function | string,
  ...args: unknown[]
): string {
  if (isString(fun)) {
    assert(args.length === 0, 'Cannot evaluate a string with arguments');
    return fun;
  }

  function serializeArgument(arg: unknown): string {
    if (Object.is(arg, undefined)) {
      return 'undefined';
    }
    return JSON.stringify(arg);
  }

  return `(${fun})(${args.map(serializeArgument).join(',')})`;
}

/**
 * @internal
 */
let fs: typeof FS | null = null;
/**
 * @internal
 */
export async function importFSPromises(): Promise<typeof FS> {
  if (!fs) {
    try {
      fs = await import('fs/promises');
    } catch (error) {
      if (error instanceof TypeError) {
        throw new Error(
          'Cannot write to a path outside of a Node-like environment.'
        );
      }
      throw error;
    }
  }
  return fs;
}

/**
 * @internal
 */
export async function getReadableAsBuffer(
  readable: Readable,
  path?: string
): Promise<Buffer | null> {
  const buffers = [];
  if (path) {
    const fs = await importFSPromises();
    const fileHandle = await fs.open(path, 'w+');
    try {
      for await (const chunk of readable) {
        buffers.push(chunk);
        await fileHandle.writeFile(chunk);
      }
    } finally {
      await fileHandle.close();
    }
  } else {
    for await (const chunk of readable) {
      buffers.push(chunk);
    }
  }
  try {
    return Buffer.concat(buffers);
  } catch (error) {
    return null;
  }
}

/**
 * @internal
 */
export async function getReadableFromProtocolStream(
  client: CDPSession,
  handle: string
): Promise<Readable> {
  // TODO: Once Node 18 becomes the lowest supported version, we can migrate to
  // ReadableStream.
  if (!isNode) {
    throw new Error('Cannot create a stream outside of Node.js environment.');
  }

  const {Readable} = await import('stream');

  let eof = false;
  return new Readable({
    async read(size: number) {
      if (eof) {
        return;
      }

      try {
        const response = await client.send('IO.read', {handle, size});
        this.push(response.data, response.base64Encoded ? 'base64' : undefined);
        if (response.eof) {
          eof = true;
          await client.send('IO.close', {handle});
          this.push(null);
        }
      } catch (error) {
        if (isErrorLike(error)) {
          this.destroy(error);
          return;
        }
        throw error;
      }
    },
  });
}

/**
 * @internal
 */
export function validateDialogType(
  type: string
): 'alert' | 'confirm' | 'prompt' | 'beforeunload' {
  let dialogType = null;
  const validDialogTypes = new Set([
    'alert',
    'confirm',
    'prompt',
    'beforeunload',
  ]);

  if (validDialogTypes.has(type)) {
    dialogType = type;
  }
  assert(dialogType, `Unknown javascript dialog type: ${type}`);
  return dialogType as 'alert' | 'confirm' | 'prompt' | 'beforeunload';
}

/**
 * @internal
 */
export function timeout(ms: number): Observable<never> {
  return ms === 0
    ? NEVER
    : timer(ms).pipe(
        map(() => {
          throw new TimeoutError(`Timed out after waiting ${ms}ms`);
        })
      );
}

/**
 * @internal
 */
export const UTILITY_WORLD_NAME = '__puppeteer_utility_world__';

/**
 * @internal
 */
export const SOURCE_URL_REGEX = /^[\040\t]*\/\/[@#] sourceURL=\s*(\S*?)\s*$/m;
/**
 * @internal
 */
export function getSourceUrlComment(url: string): string {
  return `//# sourceURL=${url}`;
}

/**
 * @internal
 */
export const NETWORK_IDLE_TIME = 500;

/**
 * @internal
 */
export function parsePDFOptions(
  options: PDFOptions = {},
  lengthUnit: 'in' | 'cm' = 'in'
): ParsedPDFOptions {
  const defaults: Omit<ParsedPDFOptions, 'width' | 'height' | 'margin'> = {
    scale: 1,
    displayHeaderFooter: false,
    headerTemplate: '',
    footerTemplate: '',
    printBackground: false,
    landscape: false,
    pageRanges: '',
    preferCSSPageSize: false,
    omitBackground: false,
    tagged: false,
    outline: false,
  };

  let width = 8.5;
  let height = 11;
  if (options.format) {
    const format =
      paperFormats[options.format.toLowerCase() as LowerCasePaperFormat];
    assert(format, 'Unknown paper format: ' + options.format);
    width = format.width;
    height = format.height;
  } else {
    width = convertPrintParameterToInches(options.width, lengthUnit) ?? width;
    height =
      convertPrintParameterToInches(options.height, lengthUnit) ?? height;
  }

  const margin = {
    top: convertPrintParameterToInches(options.margin?.top, lengthUnit) || 0,
    left: convertPrintParameterToInches(options.margin?.left, lengthUnit) || 0,
    bottom:
      convertPrintParameterToInches(options.margin?.bottom, lengthUnit) || 0,
    right:
      convertPrintParameterToInches(options.margin?.right, lengthUnit) || 0,
  };

  // Quirk https://bugs.chromium.org/p/chromium/issues/detail?id=840455#c44
  if (options.outline) {
    options.tagged = true;
  }

  return {
    ...defaults,
    ...options,
    width,
    height,
    margin,
  };
}

/**
 * @internal
 */
export const unitToPixels = {
  px: 1,
  in: 96,
  cm: 37.8,
  mm: 3.78,
};

function convertPrintParameterToInches(
  parameter?: string | number,
  lengthUnit: 'in' | 'cm' = 'in'
): number | undefined {
  if (typeof parameter === 'undefined') {
    return undefined;
  }
  let pixels;
  if (isNumber(parameter)) {
    // Treat numbers as pixel values to be aligned with phantom's paperSize.
    pixels = parameter;
  } else if (isString(parameter)) {
    const text = parameter;
    let unit = text.substring(text.length - 2).toLowerCase();
    let valueText = '';
    if (unit in unitToPixels) {
      valueText = text.substring(0, text.length - 2);
    } else {
      // In case of unknown unit try to parse the whole parameter as number of pixels.
      // This is consistent with phantom's paperSize behavior.
      unit = 'px';
      valueText = text;
    }
    const value = Number(valueText);
    assert(!isNaN(value), 'Failed to parse parameter value: ' + text);
    pixels = value * unitToPixels[unit as keyof typeof unitToPixels];
  } else {
    throw new Error(
      'page.pdf() Cannot handle parameter type: ' + typeof parameter
    );
  }
  return pixels / unitToPixels[lengthUnit];
}

/**
 * @internal
 */
export function fromEmitterEvent<
  Events extends Record<EventType, unknown>,
  Event extends keyof Events,
>(emitter: EventEmitter<Events>, eventName: Event): Observable<Events[Event]> {
  return new Observable(subscriber => {
    const listener = (event: Events[Event]) => {
      subscriber.next(event);
    };
    emitter.on(eventName, listener);
    return () => {
      emitter.off(eventName, listener);
    };
  });
}
