var checkData = [];
window.sort=require('../utilities/sort');
window.Header = function getHeader(object) {
    let _targetDom = object.el ? document.getElementById(object.el) : document.getElementsByTagName("table")[0];//基点元素
    let _columns = object.column;   //列名
    let _fixedTop = object.fixedTop || 0;  //同级浮动元素高度，使当前元素追加该元素高度浮动
    let _isCheckAllBox = object.isCheckAllBox || true;//是否开启全选框
    let _data = object.data || [];   //被排序数据
    let _restorationColumn = object.restorationColumn || 'id'; //恢复原数据基准字段
    let _is_restorationColumn_asc = object.is_restorationColumn_asc || false;    //恢复原数据基准字段的排序类型 true:asc false:desc
    let _before = object.before;

    let sortType = {};
    let columnArr = [];

    let table = document.createElement("table");

    function getTargetChildNode(dom) {
        if (!dom || dom.tagName==='INPUT')return dom;
        return getTargetChildNode(dom.firstElementChild);
    }
    function createHeaderBefore() {
        let tr = document.createElement("tr");
        _before.forEach(be=>{
            let th = document.createElement("th");
            if (be.colspan)th.colSpan = be.colspan;
            if (be.font){
                let font = document.createElement("span");
                font.className = be.font;
                th.appendChild(font);
            }
            if (be.value)th.appendChild(document.createTextNode(be.value));
            if (be.class)th.className = be.class;
            tr.appendChild(th);
        });
        table.appendChild(tr);
    }
    function createHeader() {
        let div = document.createElement("div");
        div.style.position = "sticky";
        div.style.position = "-webkit-sticky";
        div.style.top = _fixedTop+"px";
        div.style.backgroundColor = "white";
        div.style.zIndex = "1030";
        table.className = "table table-bordered mb-0 text-center";
        let tr = document.createElement("tr");
        let firstTr = _targetDom.getElementsByTagName("tr")[0];
        let tds = [];
            if (!firstTr){
            tr.className = "text-nowrap";
        }else tds = firstTr.children;
        if (_isCheckAllBox){
            let th = document.createElement("th");
            if (firstTr) th.style.minWidth = tds[0].offsetWidth+"px";
            let check = document.createElement("input");
            check.type = "checkbox";
            check.id = "checkAll";
            let trs = _targetDom.getElementsByTagName("tr");
            check.onchange = function () {
                if (event.target.checked){
                    for (let i=0;i<trs.length;i++){
                        let checkbox = getTargetChildNode(trs[i].getElementsByTagName("td")[0]);
                        if (!checkbox.checked){
                            checkData.push(checkbox.value);
                            checkbox.checked = true;
                        }
                    }
                }else{
                    checkData = [];
                    for (let i=0;i<trs.length;i++){
                        let checkbox = getTargetChildNode(trs[i].getElementsByTagName("td")[0]);
                        if (checkbox.checked)checkbox.checked = false;
                    }
                }
            };
            for (let i=0;i<trs.length;i++){
                let checkbox = getTargetChildNode(trs[i].getElementsByTagName("td")[0]);
                if (checkbox) checkbox.onchange = function () {
                    if (event.target.checked)checkData.push(checkbox.value);
                    else checkData.splice(checkData.indexOf(checkbox.value),1);
                    if (checkData.length === _data.length && !check.checked)check.checked=true;
                    if (checkData.length !== _data.length && check.checked) check.checked=false;
                }
            }
            th.appendChild(check);
            tr.appendChild(th);
        }
        let i = (_isCheckAllBox && firstTr) ? 1 : 0;
        for (i;i<(tds.length>0 ? tds.length : _columns.length);i++){
            let th = document.createElement("th");
            if (firstTr) th.style.minWidth = (tds[i].offsetWidth-0.3)+"px";
            let column = _columns[_isCheckAllBox ? i-1 : i];
            if (_columns && column){
                if (column.style)for (let key in column.style)if (column.style.hasOwnProperty(key)) th.style[key] = column.style[key];
                if (column.class)th.className =  column.class;
                let span = document.createElement("span");
                span.style.display = "inline-block";
                if (!column.neglect){
                    th.style.cursor = "pointer";
                    let font = document.createElement("span");
                    font.className = "fa fa-sort";
                    span.appendChild(font);
                    th.onclick = rule(column,font);
                }
                span.appendChild(document.createTextNode((column.value ? column.value : '')));
                th.appendChild(span);
            }
            tr.appendChild(th);
        }
        table.appendChild(tr);
        div.appendChild(table);
        _targetDom.parentNode.insertBefore(div,_targetDom);
    }

    //点击事件触发的排序规则
    function rule(column,columnSort) {
        return function () {
            if (!sortType[column.name]){
                sortType[column.name] = 'asc';
                columnArr.push(column.name);
                columnSort.className = "fa fa-sort-asc";
                let columnArrTemp = [];
                columnArrTemp.push.apply(columnArrTemp,columnArr);
                window.sort.sort(_data,columnArrTemp,sortType);
                return ;
            }
            if (sortType[column.name] === 'asc'){
                sortType[column.name] = 'desc';
                columnSort.className = "fa fa-sort-desc";
                let columnArrTemp = [];
                columnArrTemp.push.apply(columnArrTemp,columnArr);
                window.sort.sort(_data,columnArrTemp,sortType);
                return ;
            }
            if (sortType[column.name] === 'desc'){
                delete sortType[column.name];
                columnArr.some(function (name, index) {
                    if (name === column.name){
                        columnArr.splice(index,1);
                        return true;
                    }
                });
                columnSort.className = "fa fa-sort";
                if (columnArr.length === 0){
                    //希尔排序
                    let arr = [];
                    arr.push.apply(arr,_data);
                    let len = arr.length;
                    for(let gap = Math.floor(len / 2); gap > 0; gap = Math.floor(gap / 2)) {
                        for(let i = gap; i < len; i++) {
                            let j = i;
                            let current = arr[i];
                            if (_is_restorationColumn_asc){
                                while(j - gap >= 0 && Number(current[_restorationColumn]) < Number(arr[j - gap][_restorationColumn])) {
                                    arr[j] = arr[j - gap];
                                    j = j - gap;
                                }
                            }else{
                                while(j - gap >= 0 && Number(current[_restorationColumn]) > Number(arr[j - gap][_restorationColumn])) {
                                    arr[j] = arr[j - gap];
                                    j = j - gap;
                                }
                            }
                            arr[j] = current;
                        }
                    }
                    _data.length = 0;
                    _data.push.apply(_data,arr);
                    return;
                }
                let columnArrTemp = [];
                columnArrTemp.push.apply(columnArrTemp,columnArr);
                window.sort.sort(_data,columnArrTemp,sortType);
            }
        }
    }
    //初始化
    this.init = function() {
        if (_before)createHeaderBefore();
        createHeader();
    };
};