(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
    typeof define === 'function' && define.amd ? define(factory) :
    (global = global || self, global.LockBodyScroll = factory());
  }(this, function () { 'use strict';
  
    /**
     * 解决滚动穿透问题
     */
    var eventInit = false;
    var hasPassiveEvents = false;
    var selector = '.can-scroll';
    var lockedList = new Set();
    // 检测浏览器是否支持passive events
    if (typeof window !== 'undefined') {
        var passiveTestOptions = {
            get passive() {
                hasPassiveEvents = true;
                return undefined;
            },
        };
        try {
            window.addEventListener('testPassive', null, passiveTestOptions);
            // @ts-ignore
            window.removeEventListener('testPassive', null, passiveTestOptions);
        }
        catch (e) { }
    }
    var LockBodyScroll = /** @class */ (function () {
        function LockBodyScroll(opts) {
            if (opts === void 0) { opts = { selector: '.can-scroll' }; }
            if (opts.selector) {
                selector = opts.selector;
            }
        }
        LockBodyScroll.prototype.lock = function () {
            lockedList.add(this);
            if (!eventInit) {
                if (typeof window !== 'undefined' && window.document) {
                    // 阻止整个document的滚动
                    document.addEventListener('touchmove', LockBodyScroll.preventDefault, hasPassiveEvents ? { passive: false } : undefined);
                    eventInit = true;
                    this.lockScrollOverflow(); // 对于可滚动元素，限制它的超出范围滚动
                }
            }
        };
        /**
         * 对于所有可滚动元素，需要限制它的滚动范围不能超出容器，否则还会触发滚动穿透
         */
        LockBodyScroll.prototype.lockScrollOverflow = function () {
            var scrollEl = document.querySelectorAll(selector);
            [].forEach.call(scrollEl, function (el) {
                var initialY = 0;
                el.ontouchstart = function (e) {
                    if (e.targetTouches.length === 1) {
                        // 单点滑动
                        initialY = e.targetTouches[0].clientY;
                    }
                };
                el.ontouchmove = function (e) {
                    if (e.targetTouches.length === 1) {
                        // 单点滑动
                        var clientY = e.targetTouches[0].clientY - initialY;
                        if (el.scrollHeight - 1 - el.scrollTop <= el.clientHeight &&
                            clientY < 0) {
                            // 向下滑至底部
                            return e.preventDefault();
                        }
                        if (el.scrollTop === 0 && clientY > 0) {
                            // 向上滑至顶部
                            return e.preventDefault();
                        }
                    }
                };
            });
        };
        LockBodyScroll.prototype.unlock = function () {
            lockedList.delete(this);
            if (lockedList.size <= 0) {
                this.destroy();
            }
        };
        LockBodyScroll.prototype.destroy = function () {
            if (typeof window !== 'undefined' && window.document) {
                document.removeEventListener('touchmove', LockBodyScroll.preventDefault, 
                // @ts-ignore
                hasPassiveEvents ? { passive: false } : undefined);
            }
            var scrollEl = document.querySelectorAll(selector);
            [].forEach.call(scrollEl, function (el) {
                el.ontouchstart = null;
                el.ontouchmove = null;
            });
            eventInit = false;
        };
        LockBodyScroll.preventDefault = function (e) {
            var scrollEl = document.querySelectorAll(selector);
            var isContain = [].some.call(scrollEl, function (el) {
                return el.contains(e.target);
            });
            if (isContain) {
                return true;
            }
            e.preventDefault();
        };
        return LockBodyScroll;
    }());
  
    return LockBodyScroll;
  
  }));