/**
 * Slightly modified from Shopify/quilt/jest-koa-mock:
 * https://github.com/Shopify/quilt/blob/master/packages/jest-koa-mocks/src/create-mock-context/create-mock-context.ts
 *
 * License: https://github.com/Shopify/quilt/blob/master/LICENSE.md
 */

import { URL } from 'url';
import * as stream from 'stream';
import * as httpMocks from 'node-mocks-http';
import * as sinon from 'sinon';
import { IncomingMessage } from 'http';
import { NowRequest } from '@now/node';
import { ApiContext } from 'src/server';

export interface Dictionary<T> {
  [key: string]: T;
}

export interface Options<
  CustomProperties extends object,
  RequestBody = undefined
> {
  url?: string;
  method?: httpMocks.RequestMethod;
  statusCode?: number;
  headers?: Dictionary<string>;
  cookies?: Dictionary<string>;
  state?: ApiContext['state'];
  encrypted?: boolean;
  host?: string;
  requestBody?: RequestBody;
}

export function createContext<
  CustomProperties extends object,
  RequestBody = undefined
>(options: Options<CustomProperties, RequestBody> = {}): ApiContext {
  const {
    method,
    statusCode,
    requestBody,
    url = '',
    host = 'test.com',
    encrypted = false,
    headers = {},
    state = {},
  } = options;

  const protocolFallback = encrypted ? 'https' : 'http';
  const urlObject = new URL(url, `${protocolFallback}://${host}`);
  const socket = new stream.Duplex() as any;
  const request = new IncomingMessage(socket) as NowRequest;

  // Some functions we call in the implementations will perform checks for `req.encrypted`, which delegates to the socket.
  Object.defineProperty(request.socket, 'encrypted', {
    writable: false,
    value: urlObject.protocol === 'https:',
  });
  request.url = urlObject.toString();
  request.method = method;
  request.statusCode = statusCode;
  request.headers = headers;
  request.body = requestBody;

  const context: ApiContext = {
    request,
    state,
  };

  return context;
}