/*
 * Copyright (C) 2019 StApps
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

import {
  SCInternalServerErrorResponse,
  SCPluginMetaData,
  SCValidationErrorResponse,
} from '@openstapps/core';
import {Request} from 'express';
import * as got from 'got';
import {isTestEnvironment, validator} from '../common';

/**
 * Number of milliseconds after which external request will fail
 */
export const EXTERNAL_REQUEST_TIMEOUT = 5000;

/**
 * Generic route function used to proxy actual requests to plugins
 *
 * @param req The request for a plugin resource
 * @param plugin Meta data of the plugin
 * @throws {SCInternalServerErrorResponse} On request/response validation or response from the plugin errors
 */
export async function virtualPluginRoute(req: Request, plugin: SCPluginMetaData): Promise<object> {
  let responseBody: object;
  try {
    const requestValidation = validator.validate(req.body, plugin.requestSchema);
    if (requestValidation.errors.length > 0) {
      throw new SCValidationErrorResponse(requestValidation.errors, isTestEnvironment);
    }
    // send the request to the plugin (forward the body) and save the response
    const pluginResponse = await got.post(
      plugin.route,
      {
        baseUrl: plugin.address,
        body: req.body,
        json: true,
        timeout: EXTERNAL_REQUEST_TIMEOUT,
      },
    );
    responseBody = pluginResponse.body;
    const responseValidation = validator.validate(responseBody, plugin.responseSchema);
    if (responseValidation.errors.length > 0) {
      throw new SCValidationErrorResponse(responseValidation.errors, isTestEnvironment);
    }
  } catch (e) {
    // wrap exact error inside of the internal server error response
    throw new SCInternalServerErrorResponse(e, isTestEnvironment);
  }

  return responseBody;
}