/**
 * Copyright 2017 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.
 */
const path = require('path');
const {JSHandle} = require('./ExecutionContext');
const {helper} = require('./helper');

class ElementHandle extends JSHandle {
  /**
   * @param {!ExecutionContext} context
   * @param {!Session} client
   * @param {!Object} remoteObject
   * @param {!Mouse} mouse
   * @param {!Touchscreen} touchscreen;
   */
  constructor(context, client, remoteObject, mouse, touchscreen) {
    super(context, client, remoteObject);
    this._mouse = mouse;
    this._touchscreen = touchscreen;
  }

  /**
   * @override
   * @return {?ElementHandle}
   */
  asElement() {
    return this;
  }

  /**
   * @return {!Promise<{x: number, y: number}>}
   */
  async _visibleCenter() {
    const {center, error} = await this.executionContext().evaluate(element => {
      if (!element.ownerDocument.contains(element))
        return {center: null, error: 'Node is detached from document'};
      if (element.nodeType !== HTMLElement.ELEMENT_NODE)
        return {center: null, error: 'Node is not of type HTMLElement'};
      element.scrollIntoViewIfNeeded();
      const rect = element.getBoundingClientRect();
      const center = {
        x: (Math.max(rect.left, 0) + Math.min(rect.right, window.innerWidth)) / 2,
        y: (Math.max(rect.top, 0) + Math.min(rect.bottom, window.innerHeight)) / 2
      };
      return {center, error: null};
    }, this);
    if (error)
      throw new Error(error);
    return center;
  }

  async hover() {
    const {x, y} = await this._visibleCenter();
    await this._mouse.move(x, y);
  }

  /**
   * @param {!Object=} options
   */
  async click(options) {
    const {x, y} = await this._visibleCenter();
    await this._mouse.click(x, y, options);
  }

  /**
   * @param {!Array<string>} filePaths
   * @return {!Promise}
   */
  async uploadFile(...filePaths) {
    const files = filePaths.map(filePath => path.resolve(filePath));
    const objectId = this._remoteObject.objectId;
    return this._client.send('DOM.setFileInputFiles', { objectId, files });
  }

  async tap() {
    const {x, y} = await this._visibleCenter();
    await this._touchscreen.tap(x, y);
  }
}

module.exports = ElementHandle;
helper.tracePublicAPI(ElementHandle);