/*
 * Copyright (c) 2016 Michael Krotscheck.
 *
 * 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 AbstractService from './util/abstractService'

/**
 * A list of all supported versions. Please keep this array sorted by most recent.
 *
 * @type {Array}
 * @ignore
 */
const supportedNovaVersions = [
  'v2.1'
]

export default class Nova extends AbstractService {
  /**
   * This class provides direct, idempotent, low-level access to the Nova API of a specific
   * cloud. The constructor requires that you provide a specific nova interface endpoint
   * descriptor, as received from keystone's catalog list.
   *
   * @example
   * {
   *   region_id: "RegionOne",
   *   url: "http://127.0.0.1:8774/",
   *   region: "RegionOne",
   *   interface: "admin",
   *   id: "0b8b5f0f14904136ab5a4f83f27ec49a"
   * }
   * @param {{}} endpointConfig The configuration element for a specific nova endpoint.
   */
  constructor (endpointConfig) {
    // Sanity checks.
    if (!endpointConfig || !endpointConfig.url) {
      throw new Error('An endpoint configuration is required.')
    }
    // Clone the config, so that this instance is immutable
    // at runtime (no modifying the config after the fact).
    endpointConfig = Object.assign({}, endpointConfig)

    super(endpointConfig.url, supportedNovaVersions)
    this._config = endpointConfig
  }

  /**
   * List the flavors available on nova.
   *
   * @param {String} token An authorization token, or a promise which will resolve into one.
   * @returns {Promise.<T>} A promise which will resolve with the list of flavors.
   */
  flavorList (token = null) {
    return this
      ._requestComponents(token)
      .then(([url, headers]) => this.http.httpRequest('GET', `${url}flavors`, headers))
      .then((response) => response.json())
      .then((body) => body.flavors)
  }
}