/* *
 *
 * (c) 2009-2019 Øystein Moseng
 *
 * Keyboard navigation handler base class definition
 *
 * License: www.highcharts.com/license
 *
 * */

'use strict';

import H from '../../parts/Globals.js';
var find = H.find;


/**
 * Define a keyboard navigation handler for use with a
 * Highcharts.AccessibilityComponent instance. This functions as an abstraction
 * layer for keyboard navigation, and defines a map of keyCodes to handler
 * functions.
 *
 * @requires module:modules/accessibility
 *
 * @sample highcharts/accessibility/custom-component
 *     Custom accessibility component
 *
 * @class
 * @name Highcharts.KeyboardNavigationHandler
 *
 * @param {Highcharts.Chart} chart The chart this module should act on.
 * @param {object} options
 * @param {Array<Array<Number>, Function>} options.keyCodeMap
 *   An array containing pairs of an array of keycodes, mapped to a handler
 *   function. When the keycode is received, the handler is called with the
 *   keycode as parameter.
 * @param {Function} [options.init]
 *   Function to run on initialization of module
 * @param {Function} [options.validate]
 *   Function to run to validate module. Should return false if module should
 *   not run, true otherwise. Receives chart as parameter.
 * @param {Function} [options.terminate]
 *   Function to run before moving to next/prev module. Receives moving
 *   direction as parameter: +1 for next, -1 for previous.
 * @param {Function} [options.init]
 *   Function to run on initialization of module
 */
function KeyboardNavigationHandler(chart, options) {
  this.chart = chart;
  this.keyCodeMap = options.keyCodeMap || [];
  this.validate = options.validate;
  this.init = options.init;
  this.terminate = options.terminate;
  // Response enum
  this.response = {
    success: 1, // Keycode was handled
    prev: 2, // Move to prev module
    next: 3, // Move to next module
    noHandler: 4, // There is no handler for this keycode
    fail: 5 // Handler failed
  };
}
KeyboardNavigationHandler.prototype = {

  /**
   * Find handler function(s) for key code in the keyCodeMap and run it.
   *
   * @function KeyboardNavigationHandler#run
   * @param {global.Event} e
   * @return {number} Returns a response code indicating whether the run was
   *   a success/fail/unhandled, or if we should move to next/prev module.
   */
  run: function (e) {
    var keyCode = e.which || e.keyCode,
      response = this.response.noHandler,
      handlerCodeSet = find(this.keyCodeMap, function (codeSet) {
        return codeSet[0].indexOf(keyCode) > -1;
      });

    if (handlerCodeSet) {
      response = handlerCodeSet[1].call(this, keyCode, e);
    } else if (keyCode === 9) {
      // Default tab handler, move to next/prev module
      response = this.response[e.shiftKey ? 'prev' : 'next'];
    } else if (keyCode === 27) {
      // Default esc handler, hide tooltip
      if (this.chart && this.chart.tooltip) {
        this.chart.tooltip.hide(0);
      }
      response = this.response.success;
    }

    return response;
  }

};

export default KeyboardNavigationHandler;