/**
 * Copyright (c) Microsoft Corporation.
 *
 * 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.
 */

import * as crypto from 'crypto';
import type stream from 'stream';
import * as URL from 'url';
import v8 from 'v8';

type NameValue = {
  name: string,
  value: string,
};

// See https://joel.tools/microtasks/
export function makeWaitForNextTask() {
  // As of Mar 2021, Electron v12 doesn't create new task with `setImmediate` despite
  // using Node 14 internally, so we fallback to `setTimeout(0)` instead.
  // @see https://github.com/electron/electron/issues/28261
  if ((process.versions as any).electron)
    return (callback: () => void) => setTimeout(callback, 0);
  if (parseInt(process.versions.node, 10) >= 11)
    return setImmediate;

  // Unlike Node 11, Node 10 and less have a bug with Task and MicroTask execution order:
  // - https://github.com/nodejs/node/issues/22257
  //
  // So we can't simply run setImmediate to dispatch code in a following task.
  // However, we can run setImmediate from-inside setImmediate to make sure we're getting
  // in the following task.

  let spinning = false;
  const callbacks: (() => void)[] = [];
  const loop = () => {
    const callback = callbacks.shift();
    if (!callback) {
      spinning = false;
      return;
    }
    setImmediate(loop);
    // Make sure to call callback() as the last thing since it's
    // untrusted code that might throw.
    callback();
  };

  return (callback: () => void) => {
    callbacks.push(callback);
    if (!spinning) {
      spinning = true;
      setImmediate(loop);
    }
  };
}

export function assert(value: any, message?: string): asserts value {
  if (!value)
    throw new Error(message || 'Assertion error');
}

export function debugAssert(value: any, message?: string): asserts value {
  if (isUnderTest() && !value)
    throw new Error(message);
}

export function isString(obj: any): obj is string {
  return typeof obj === 'string' || obj instanceof String;
}

export function isRegExp(obj: any): obj is RegExp {
  return obj instanceof RegExp || Object.prototype.toString.call(obj) === '[object RegExp]';
}

export function isObject(obj: any): obj is NonNullable<object> {
  return typeof obj === 'object' && obj !== null;
}

export function isError(obj: any): obj is Error {
  return obj instanceof Error || (obj && obj.__proto__ && obj.__proto__.name === 'Error');
}

const debugEnv = getFromENV('PWDEBUG') || '';
export function debugMode() {
  if (debugEnv === 'console')
    return 'console';
  if (debugEnv === '0' || debugEnv === 'false')
    return '';
  return debugEnv ? 'inspector' : '';
}

let _isUnderTest = false;
export function setUnderTest() {
  _isUnderTest = true;
}
export function isUnderTest(): boolean {
  return _isUnderTest;
}

export function getFromENV(name: string): string | undefined {
  let value = process.env[name];
  value = value === undefined ? process.env[`npm_config_${name.toLowerCase()}`] : value;
  value = value === undefined ?  process.env[`npm_package_config_${name.toLowerCase()}`] : value;
  return value;
}

export function getAsBooleanFromENV(name: string): boolean {
  const value = getFromENV(name);
  return !!value && value !== 'false' && value !== '0';
}

type HeadersArray = { name: string, value: string }[];
type HeadersObject = { [key: string]: string };

export function headersObjectToArray(headers: HeadersObject, separator?: string, setCookieSeparator?: string): HeadersArray {
  if (!setCookieSeparator)
    setCookieSeparator = separator;
  const result: HeadersArray = [];
  for (const name in headers) {
    const values = headers[name];
    if (values === undefined)
      continue;
    if (separator) {
      const sep = name.toLowerCase() === 'set-cookie' ? setCookieSeparator : separator;
      for (const value of values.split(sep!))
        result.push({ name, value: value.trim() });
    } else {
      result.push({ name, value: values });
    }
  }
  return result;
}

export function headersArrayToObject(headers: HeadersArray, lowerCase: boolean): HeadersObject {
  const result: HeadersObject = {};
  for (const { name, value } of headers)
    result[lowerCase ? name.toLowerCase() : name] = value;
  return result;
}

export function monotonicTime(): number {
  const [seconds, nanoseconds] = process.hrtime();
  return seconds * 1000 + (nanoseconds / 1000 | 0) / 1000;
}

export function objectToArray(map?:  { [key: string]: any }): NameValue[] | undefined {
  if (!map)
    return undefined;
  const result = [];
  for (const [name, value] of Object.entries(map))
    result.push({ name, value: String(value) });
  return result;
}

export function arrayToObject(array?: NameValue[]): { [key: string]: string } | undefined {
  if (!array)
    return undefined;
  const result: { [key: string]: string } = {};
  for (const { name, value } of array)
    result[name] = value;
  return result;
}

export function calculateSha1(buffer: Buffer | string): string {
  const hash = crypto.createHash('sha1');
  hash.update(buffer);
  return hash.digest('hex');
}

export function createGuid(): string {
  return crypto.randomBytes(16).toString('hex');
}

export function constructURLBasedOnBaseURL(baseURL: string | undefined, givenURL: string): string {
  try {
    return (new URL.URL(givenURL, baseURL)).toString();
  } catch (e) {
    return givenURL;
  }
}

export function wrapInASCIIBox(text: string, padding = 0): string {
  const lines = text.split('\n');
  const maxLength = Math.max(...lines.map(line => line.length));
  return [
    '╔' + '═'.repeat(maxLength + padding * 2) + '╗',
    ...lines.map(line => '║' + ' '.repeat(padding) + line + ' '.repeat(maxLength - line.length + padding) + '║'),
    '╚' + '═'.repeat(maxLength + padding * 2) + '╝',
  ].join('\n');
}

export function isFilePayload(value: any): boolean {
  return typeof value === 'object' && value['name'] && value['mimeType'] && value['buffer'];
}

export function streamToString(stream: stream.Readable): Promise<string> {
  return new Promise<string>((resolve, reject) => {
    const chunks: Buffer[] = [];
    stream.on('data', chunk => chunks.push(Buffer.from(chunk)));
    stream.on('error', reject);
    stream.on('end', () => resolve(Buffer.concat(chunks).toString('utf8')));
  });
}

export const isLikelyNpxGlobal = () => process.argv.length >= 2 && process.argv[1].includes('_npx');

export function deepCopy<T>(obj: T): T {
  return v8.deserialize(v8.serialize(obj));
}
