/*!
 * Copyright 2018 Google Inc. All Rights Reserved.
 *
 * 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.
 */

'use strict';

const common = require('@google-cloud/common');
const {promisifyAll} = require('@google-cloud/promisify');

/**
 * An Image object allows you to interact with a Google Compute Engine image.
 *
 * @see [Images Overview]{@link https://cloud.google.com/compute/docs/images}
 * @see [Image Resource]{@link https://cloud.google.com/compute/docs/reference/v1/images}
 *
 * @class
 * @param {Compute} compute - The parent Compute instance this Image belongs to.
 * @param {string} name - Image name.
 *
 * @example
 * const Compute = require('@google-cloud/compute');
 * const compute = new Compute();
 * const image = compute.image('image-name');
 */
class Image extends common.ServiceObject {
  constructor(compute, name) {
    const methods = {
      /**
       * Create an image.
       *
       * @method Image#create
       * @param {Disk} disk - See {@link Compute#createImage}.
       * @param {object} [options] - See {@link Compute#createImage}.
       *
       * @example
       * const Compute = require('@google-cloud/compute');
       * const compute = new Compute();
       * const zone = compute.zone('us-central1-a');
       * const disk = zone.disk('disk1');
       * const image = compute.image('image-name');
       *
       * image.create(disk, function(err, image, operation, apiResponse) {
       *   // `image` is an Image object.
       *
       *   // `operation` is an Operation object that can be used to check the
       *   // status of the request.
       * });
       *
       * //-
       * // If the callback is omitted, we'll return a Promise.
       * //-
       * image.create(disk).then(function(data) {
       *   const image = data[0];
       *   const operation = data[1];
       *   const apiResponse = data[2];
       * });
       */
      create: true,
      /**
       * Check if the image exists.
       *
       * @method Image#exists
       * @param {function} callback - The callback function.
       * @param {?error} callback.err - An error returned while making this
       *     request.
       * @param {boolean} callback.exists - Whether the image exists or not.
       *
       * @example
       * const Compute = require('@google-cloud/compute');
       * const compute = new Compute();
       * const image = compute.image('image-name');
       *
       * image.exists(function(err, exists) {});
       *
       * //-
       * // If the callback is omitted, we'll return a Promise.
       * //-
       * image.exists().then(function(data) {
       *   const exists = data[0];
       * });
       */
      exists: true,
      /**
       * Get an image if it exists.
       *
       * @method Image#get
       * @param {options=} options - Configuration object.
       *
       * @example
       * const Compute = require('@google-cloud/compute');
       * const compute = new Compute();
       * const image = compute.image('image-name');
       *
       * image.get(function(err, image, apiResponse) {
       *   // `image` is an Image object.
       * });
       *
       * //-
       * // If the callback is omitted, we'll return a Promise.
       * //-
       * image.get().then(function(data) {
       *   const image = data[0];
       *   const apiResponse = data[1];
       * });
       */
      get: true,
      /**
       * Get the image's metadata.
       *
       * @see [Images: get API Documentation]{@link https://cloud.google.com/compute/docs/reference/v1/images/get}
       * @see [Image Resource]{@link https://cloud.google.com/compute/docs/reference/v1/images}
       *
       * @method Image#getMetadata
       * @param {function=} callback - The callback function.
       * @param {?error} callback.err - An error returned while making this
       *     request.
       * @param {object} callback.metadata - The image's metadata.
       * @param {object} callback.apiResponse - The full API response.
       *
       * @example
       * const Compute = require('@google-cloud/compute');
       * const compute = new Compute();
       * const image = compute.image('image-name');
       *
       * image.getMetadata(function(err, metadata, apiResponse) {});
       *
       * //-
       * // If the callback is omitted, we'll return a Promise.
       * //-
       * image.getMetadata().then(function(data) {
       *   const metadata = data[0];
       *   const apiResponse = data[1];
       * });
       */
      getMetadata: true,
    };
    super({
      parent: compute,
      baseUrl: '/global/images',
      /**
       * @name Image#id
       * @type {string}
       */
      id: name,
      createMethod: compute.createImage.bind(compute),
      methods: methods,
    });
  }
  /**
   * Delete the image.
   *
   * @see [Images: delete API Documentation]{@link https://cloud.google.com/compute/docs/reference/v1/images/delete}
   *
   * @param {function=} callback - The callback function.
   * @param {?error} callback.err - An error returned while making this request.
   * @param {Operation} callback.operation - An operation object
   *     that can be used to check the status of the request.
   * @param {object} callback.apiResponse - The full API response.
   *
   * @example
   * const Compute = require('@google-cloud/compute');
   * const compute = new Compute();
   * const image = compute.image('image-name');
   *
   * image.delete(function(err, operation, apiResponse) {
   *   // `operation` is an Operation object that can be used to check the status
   *   // of the request.
   * });
   *
   * //-
   * // If the callback is omitted, we'll return a Promise.
   * //-
   * image.delete().then(function(data) {
   *   const operation = data[0];
   *   const apiResponse = data[1];
   * });
   */
  delete(callback) {
    const compute = this.parent;
    callback = callback || common.util.noop;
    super.delete(function(err, resp) {
      if (err) {
        callback(err, null, resp);
        return;
      }
      const operation = compute.operation(resp.name);
      operation.metadata = resp;
      callback(null, operation, resp);
    });
  }
}

/*! Developer Documentation
 *
 * All async methods (except for streams) will return a Promise in the event
 * that a callback is omitted.
 */
promisifyAll(Image);

/**
 * Reference to the {@link Image} class.
 * @name module:@google-cloud/compute.Image
 * @see Image
 */
module.exports = Image;