import { configurable } from "../utils";
import { RandomizerRequiredException } from "../exceptions";
/**
 * The clicker gremlin clicks anywhere on the visible area of the document
 *
 * The clicker gremlin triggers mouse events (click, dblclick, mousedown,
 * mouseup, mouseover, mouseover, mouseover, mousemove, and mouseout) on
 * random targets displayed on the viewport.
 *
 * By default, the clicker gremlin activity is showed by a red circle.
 *
 *   var clickerGremlin = gremlins.species.clicker();
 *   horde.gremlin(clickerGremlin);
 *
 * The clicker gremlin can be customized as follows:
 *
 *   clickerGremlin.clickTypes(['click', 'mouseover']); // the mouse event types to trigger
 *   clickerGremlin.positionSelector(function() { // find a random pair of coordinates to click });
 *   clickerGremlin.showAction(function(x, y) { // show the gremlin activity on screen });
 *   clickerGremlin.canClick(function(element) { return true }); // to limit where the gremlin can click
 *   clickerGremlin.maxNbTries(5); // How many times the gremlin must look for a clickable element before quitting
 *   clickerGremlin.logger(loggerObject); // inject a logger
 *   clickerGremlin.randomizer(randomizerObject); // inject a randomizer
 *
 * Example usage:
 *
 *   horde.gremlin(gremlins.species.clicker()
 *     .clickTypes(['click'])
 *     .positionSelector(function() {
 *        // only click inside the foo element area
 *        var $el = $('#foo');
 *        var offset = $el.offset();
 *        return [
 *          parseInt(Math.random() * $el.outerWidth() + offset.left),
 *          parseInt(Math.random() * $el.outerHeight() + offset.top)
 *        ];
 *     })
 *     .canClick(function(element) {
 *       // only click elements in bar
 *       return $(element).parents('#bar').length;
 *       // when canClick returns false, the gremlin will look for another
 *       // element to click on until maxNbTries is reached
 *     })
 *     . showAction(function(x, y) {
 *       // do nothing (hide the gremlin action on screen)
 *     })
 *   );
 */
const defaultClickTypes = [
  ...Array(6).fill("click"),
  ...Array(2).fill("dblclick"),
  ...Array(1).fill("mousedown"),
  ...Array(1).fill("mouseup"),
  ...Array(3).fill("mouseover"),
  ...Array(1).fill("mousemove"),
  ...Array(1).fill("mouseout")
];
function defaultCanClick() {
  return true;
}

type Config = {
  clickTypes: string[];
  logger: typeof console;
  randomizer: Chance.Chance | null;
  positionSelector: () => [number, number];
  showAction: (x: number, y: number, clickType: string) => void;
  canClick: (elment: Element) => boolean;
  maxNbTries: number;
};

export function clicker() {
  const { document } = window;
  const { body } = document;

  const config: Config = {
    clickTypes: defaultClickTypes,
    positionSelector: defaultPositionSelector,
    showAction: defaultShowAction,
    canClick: defaultCanClick,
    maxNbTries: 10,
    logger: console,
    randomizer: null
  };

  function defaultPositionSelector(): [number, number] {
    if (!config.randomizer) {
      return [0, 0];
    }
    return [
      config.randomizer.natural({
        max: document.documentElement.clientWidth - 1
      }),
      config.randomizer.natural({
        max: document.documentElement.clientHeight - 1
      })
    ];
  }

  function defaultShowAction(x: number, y: number) {
    const clickSignal: HTMLDivElement = document.createElement("div");

    clickSignal.style.zIndex = "2000";
    clickSignal.style.border = "3px solid red";
    clickSignal.style.borderRadius = "50%"; // Mozilla
    clickSignal.style.width = "40px";
    clickSignal.style.height = "40px";
    clickSignal.style.boxSizing = "border-box";
    clickSignal.style.position = "absolute";
    clickSignal.style.transition = "opacity 1s ease-out";
    clickSignal.style.left = x - 20 + "px";
    clickSignal.style.top = y - 20 + "px";

    const element = body.appendChild(clickSignal);

    setTimeout(() => {
      body.removeChild(element);
    }, 1000);
    setTimeout(() => {
      element.style.opacity = "0";
    }, 50);
  }

  function clickerGremlin() {
    if (!config.randomizer) {
      throw new RandomizerRequiredException();
    }
    var position,
      posX,
      posY,
      targetElement,
      nbTries = 0;
    do {
      position = config.positionSelector();
      posX = position[0];
      posY = position[1];
      targetElement = document.elementFromPoint(posX, posY);
      nbTries++;
      if (nbTries > config.maxNbTries) return false;
    } while (!targetElement || !config.canClick(targetElement));

    var evt = document.createEvent("MouseEvents");
    var clickType = config.randomizer.pick(config.clickTypes);
    evt.initMouseEvent(
      clickType,
      true,
      true,
      window,
      0,
      0,
      0,
      posX,
      posY,
      false,
      false,
      false,
      false,
      0,
      null
    );
    targetElement.dispatchEvent(evt);

    if (typeof config.showAction == "function") {
      config.showAction(posX, posY, clickType);
    }

    if (config.logger && typeof config.logger.log == "function") {
      config.logger.log("gremlin", "clicker   ", clickType, "at", posX, posY);
    }
  }

  configurable(clickerGremlin, config);

  return clickerGremlin;
}