/**
 * @license
 * Copyright (C) 2017 The Android Open Source Project
 *
 * 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.
 */

let restApi;

export function _testOnlyResetRestApi() {
  restApi = null;
}

function getRestApi() {
  if (!restApi) {
    restApi = document.createElement('gr-rest-api-interface');
  }
  return restApi;
}

export function GrPluginRestApi(opt_prefix) {
  this.opt_prefix = opt_prefix || '';
}

GrPluginRestApi.prototype.getLoggedIn = function() {
  return getRestApi().getLoggedIn();
};

GrPluginRestApi.prototype.getVersion = function() {
  return getRestApi().getVersion();
};

GrPluginRestApi.prototype.getConfig = function() {
  return getRestApi().getConfig();
};

GrPluginRestApi.prototype.invalidateReposCache = function() {
  getRestApi().invalidateReposCache();
};

GrPluginRestApi.prototype.getAccount = function() {
  return getRestApi().getAccount();
};

GrPluginRestApi.prototype.getAccountCapabilities = function(capabilities) {
  return getRestApi().getAccountCapabilities(capabilities);
};

GrPluginRestApi.prototype.getRepos =
  function(filter, reposPerPage, opt_offset) {
    return getRestApi().getRepos(filter, reposPerPage, opt_offset);
  };

/**
 * Fetch and return native browser REST API Response.
 *
 * @param {string} method HTTP Method (GET, POST, etc)
 * @param {string} url URL without base path or plugin prefix
 * @param {Object=} payload Respected for POST and PUT only.
 * @param {?function(?Response, string=)=} opt_errFn
 *    passed as null sometimes.
 * @return {!Promise}
 */
GrPluginRestApi.prototype.fetch = function(method, url, opt_payload,
    opt_errFn, opt_contentType) {
  return getRestApi().send(method, this.opt_prefix + url, opt_payload,
      opt_errFn, opt_contentType);
};

/**
 * Fetch and parse REST API response, if request succeeds.
 *
 * @param {string} method HTTP Method (GET, POST, etc)
 * @param {string} url URL without base path or plugin prefix
 * @param {Object=} payload Respected for POST and PUT only.
 * @param {?function(?Response, string=)=} opt_errFn
 *    passed as null sometimes.
 * @return {!Promise} resolves on success, rejects on error.
 */
GrPluginRestApi.prototype.send = function(method, url, opt_payload,
    opt_errFn, opt_contentType) {
  return this.fetch(method, url, opt_payload, opt_errFn, opt_contentType)
      .then(response => {
        if (response.status < 200 || response.status >= 300) {
          return response.text().then(text => {
            if (text) {
              return Promise.reject(new Error(text));
            } else {
              return Promise.reject(new Error(response.status));
            }
          });
        } else {
          return getRestApi().getResponseObject(response);
        }
      });
};

/**
 * @param {string} url URL without base path or plugin prefix
 * @return {!Promise} resolves on success, rejects on error.
 */
GrPluginRestApi.prototype.get = function(url) {
  return this.send('GET', url);
};

/**
 * @param {string} url URL without base path or plugin prefix
 * @return {!Promise} resolves on success, rejects on error.
 */
GrPluginRestApi.prototype.post = function(url, opt_payload, opt_errFn,
    opt_contentType) {
  return this.send('POST', url, opt_payload, opt_errFn, opt_contentType);
};

/**
 * @param {string} url URL without base path or plugin prefix
 * @return {!Promise} resolves on success, rejects on error.
 */
GrPluginRestApi.prototype.put = function(url, opt_payload, opt_errFn,
    opt_contentType) {
  return this.send('PUT', url, opt_payload, opt_errFn, opt_contentType);
};

/**
 * @param {string} url URL without base path or plugin prefix
 * @return {!Promise} resolves on 204, rejects on error.
 */
GrPluginRestApi.prototype.delete = function(url) {
  return this.fetch('DELETE', url).then(response => {
    if (response.status !== 204) {
      return response.text().then(text => {
        if (text) {
          return Promise.reject(new Error(text));
        } else {
          return Promise.reject(new Error(response.status));
        }
      });
    }
    return response;
  });
};