/*
  Copyright 2018 Google LLC

  Use of this source code is governed by an MIT-style
  license that can be found in the LICENSE file or at
  https://opensource.org/licenses/MIT.
*/

import {assert} from 'workbox-core/_private/assert.js';
import {WorkboxError} from 'workbox-core/_private/WorkboxError.js';
import {getFriendlyURL} from 'workbox-core/_private/getFriendlyURL.js';
import {logger} from 'workbox-core/_private/logger.js';
import './_version.js';


export interface CacheableResponseOptions {
  statuses?: number[];
  headers?: {[headerName: string]: string};
}

/**
 * This class allows you to set up rules determining what
 * status codes and/or headers need to be present in order for a
 * [`Response`](https://developer.mozilla.org/en-US/docs/Web/API/Response)
 * to be considered cacheable.
 *
 * @memberof module:workbox-cacheable-response
 */
class CacheableResponse {
  private readonly _statuses?: CacheableResponseOptions['statuses'];
  private readonly _headers?: CacheableResponseOptions['headers'];

  /**
   * To construct a new CacheableResponse instance you must provide at least
   * one of the `config` properties.
   *
   * If both `statuses` and `headers` are specified, then both conditions must
   * be met for the `Response` to be considered cacheable.
   *
   * @param {Object} config
   * @param {Array<number>} [config.statuses] One or more status codes that a
   * `Response` can have and be considered cacheable.
   * @param {Object<string,string>} [config.headers] A mapping of header names
   * and expected values that a `Response` can have and be considered cacheable.
   * If multiple headers are provided, only one needs to be present.
   */
  constructor(config: CacheableResponseOptions = {}) {
    if (process.env.NODE_ENV !== 'production') {
      if (!(config.statuses || config.headers)) {
        throw new WorkboxError('statuses-or-headers-required', {
          moduleName: 'workbox-cacheable-response',
          className: 'CacheableResponse',
          funcName: 'constructor',
        });
      }

      if (config.statuses) {
        assert!.isArray(config.statuses, {
          moduleName: 'workbox-cacheable-response',
          className: 'CacheableResponse',
          funcName: 'constructor',
          paramName: 'config.statuses',
        });
      }

      if (config.headers) {
        assert!.isType(config.headers, 'object', {
          moduleName: 'workbox-cacheable-response',
          className: 'CacheableResponse',
          funcName: 'constructor',
          paramName: 'config.headers',
        });
      }
    }

    this._statuses = config.statuses;
    this._headers = config.headers;
  }

  /**
   * Checks a response to see whether it's cacheable or not, based on this
   * object's configuration.
   *
   * @param {Response} response The response whose cacheability is being
   * checked.
   * @return {boolean} `true` if the `Response` is cacheable, and `false`
   * otherwise.
   */
  isResponseCacheable(response: Response): boolean {
    if (process.env.NODE_ENV !== 'production') {
      assert!.isInstance(response, Response, {
        moduleName: 'workbox-cacheable-response',
        className: 'CacheableResponse',
        funcName: 'isResponseCacheable',
        paramName: 'response',
      });
    }

    let cacheable = true;

    if (this._statuses) {
      cacheable = this._statuses.includes(response.status);
    }

    if (this._headers && cacheable) {
      cacheable = Object.keys(this._headers).some((headerName) => {
        return response.headers.get(headerName) === this._headers![headerName];
      });
    }

    if (process.env.NODE_ENV !== 'production') {
      if (!cacheable) {
        logger.groupCollapsed(`The request for ` +
          `'${getFriendlyURL(response.url)}' returned a response that does ` +
          `not meet the criteria for being cached.`);

        logger.groupCollapsed(`View cacheability criteria here.`);
        logger.log(`Cacheable statuses: ` +
          JSON.stringify(this._statuses));
        logger.log(`Cacheable headers: ` +
          JSON.stringify(this._headers, null, 2));
        logger.groupEnd();

        const logFriendlyHeaders: {[key: string]: string} = {};
        response.headers.forEach((value, key) => {
          logFriendlyHeaders[key] = value;
        });

        logger.groupCollapsed(`View response status and headers here.`);
        logger.log(`Response status: ` + response.status);
        logger.log(`Response headers: ` +
          JSON.stringify(logFriendlyHeaders, null, 2));
        logger.groupEnd();

        logger.groupCollapsed(`View full response details here.`);
        logger.log(response.headers);
        logger.log(response);
        logger.groupEnd();

        logger.groupEnd();
      }
    }

    return cacheable;
  }
}

export {CacheableResponse};