/**
 * 事件辅助类
 * @module zrender/core/event
 * @author Kener (@Kener-林峰, kener.linfeng@gmail.com)
 */

import Eventful from '../mixin/Eventful';
import env from './env';

var isDomLevel2 = (typeof window !== 'undefined') && !!window.addEventListener;

var MOUSE_EVENT_REG = /^(?:mouse|pointer|contextmenu|drag|drop)|click/;

function getBoundingClientRect(el) {
    // BlackBerry 5, iOS 3 (original iPhone) don't have getBoundingRect
    return el.getBoundingClientRect ? el.getBoundingClientRect() : {left: 0, top: 0};
}

// `calculate` is optional, default false
export function clientToLocal(el, e, out, calculate) {
    out = out || {};

    // According to the W3C Working Draft, offsetX and offsetY should be relative
    // to the padding edge of the target element. The only browser using this convention
    // is IE. Webkit uses the border edge, Opera uses the content edge, and FireFox does
    // not support the properties.
    // (see http://www.jacklmoore.com/notes/mouse-position/)
    // In zr painter.dom, padding edge equals to border edge.

    // FIXME
    // When mousemove event triggered on ec tooltip, target is not zr painter.dom, and
    // offsetX/Y is relative to e.target, where the calculation of zrX/Y via offsetX/Y
    // is too complex. So css-transfrom dont support in this case temporarily.
    if (calculate || !env.canvasSupported) {
        defaultGetZrXY(el, e, out);
    }
    // Caution: In FireFox, layerX/layerY Mouse position relative to the closest positioned
    // ancestor element, so we should make sure el is positioned (e.g., not position:static).
    // BTW1, Webkit don't return the same results as FF in non-simple cases (like add
    // zoom-factor, overflow / opacity layers, transforms ...)
    // BTW2, (ev.offsetY || ev.pageY - $(ev.target).offset().top) is not correct in preserve-3d.
    // <https://bugs.jquery.com/ticket/8523#comment:14>
    // BTW3, In ff, offsetX/offsetY is always 0.
    else if (env.browser.firefox && e.layerX != null && e.layerX !== e.offsetX) {
        out.zrX = e.layerX;
        out.zrY = e.layerY;
    }
    // For IE6+, chrome, safari, opera. (When will ff support offsetX?)
    else if (e.offsetX != null) {
        out.zrX = e.offsetX;
        out.zrY = e.offsetY;
    }
    // For some other device, e.g., IOS safari.
    else {
        defaultGetZrXY(el, e, out);
    }

    return out;
}

function defaultGetZrXY(el, e, out) {
    // This well-known method below does not support css transform.
    var box = getBoundingClientRect(el);
    out.zrX = e.clientX - box.left;
    out.zrY = e.clientY - box.top;
}

/**
 * 如果存在第三方嵌入的一些dom触发的事件，或touch事件，需要转换一下事件坐标.
 * `calculate` is optional, default false.
 */
export function normalizeEvent(el, e, calculate) {

    e = e || window.event;

    if (e.zrX != null) {
        return e;
    }

    var eventType = e.type;
    var isTouch = eventType && eventType.indexOf('touch') >= 0;

    if (!isTouch) {
        clientToLocal(el, e, e, calculate);
        e.zrDelta = (e.wheelDelta) ? e.wheelDelta / 120 : -(e.detail || 0) / 3;
    }
    else {
        var touch = eventType != 'touchend'
            ? e.targetTouches[0]
            : e.changedTouches[0];
        touch && clientToLocal(el, touch, e, calculate);
    }

    // Add which for click: 1 === left; 2 === middle; 3 === right; otherwise: 0;
    // See jQuery: https://github.com/jquery/jquery/blob/master/src/event.js
    // If e.which has been defined, if may be readonly,
    // see: https://developer.mozilla.org/en-US/docs/Web/API/MouseEvent/which
    var button = e.button;
    if (e.which == null && button !== undefined && MOUSE_EVENT_REG.test(e.type)) {
        e.which = (button & 1 ? 1 : (button & 2 ? 3 : (button & 4 ? 2 : 0)));
    }

    return e;
}

/**
 * @param {HTMLElement} el
 * @param {string} name
 * @param {Function} handler
 */
export function addEventListener(el, name, handler) {
    if (isDomLevel2) {
        // Reproduct the console warning:
        // [Violation] Added non-passive event listener to a scroll-blocking <some> event.
        // Consider marking event handler as 'passive' to make the page more responsive.
        // Just set console log level: verbose in chrome dev tool.
        // then the warning log will be printed when addEventListener called.
        // See https://github.com/WICG/EventListenerOptions/blob/gh-pages/explainer.md
        // We have not yet found a neat way to using passive. Because in zrender the dom event
        // listener delegate all of the upper events of element. Some of those events need
        // to prevent default. For example, the feature `preventDefaultMouseMove` of echarts.
        // Before passive can be adopted, these issues should be considered:
        // (1) Whether and how a zrender user specifies an event listener passive. And by default,
        // passive or not.
        // (2) How to tread that some zrender event listener is passive, and some is not. If
        // we use other way but not preventDefault of mousewheel and touchmove, browser
        // compatibility should be handled.

        // var opts = (env.passiveSupported && name === 'mousewheel')
        //     ? {passive: true}
        //     // By default, the third param of el.addEventListener is `capture: false`.
        //     : void 0;
        // el.addEventListener(name, handler /* , opts */);
        el.addEventListener(name, handler);
    }
    else {
        el.attachEvent('on' + name, handler);
    }
}

export function removeEventListener(el, name, handler) {
    if (isDomLevel2) {
        el.removeEventListener(name, handler);
    }
    else {
        el.detachEvent('on' + name, handler);
    }
}

/**
 * preventDefault and stopPropagation.
 * Notice: do not do that in zrender. Upper application
 * do that if necessary.
 *
 * @memberOf module:zrender/core/event
 * @method
 * @param {Event} e : event对象
 */
export var stop = isDomLevel2
    ? function (e) {
        e.preventDefault();
        e.stopPropagation();
        e.cancelBubble = true;
    }
    : function (e) {
        e.returnValue = false;
        e.cancelBubble = true;
    };

export function notLeftMouse(e) {
    // If e.which is undefined, considered as left mouse event.
    return e.which > 1;
}

// 做向上兼容
export {Eventful as Dispatcher};