var XLSX = require('xlsx')
// 读取本地excel文件
function readWorkbookFromLocalFile(file, callback) {
    var reader = new FileReader();
    reader.onload = function (e) {
        var data = e.target.result;
        var workbook = XLSX.read(data, { type: 'binary' });
        if (callback) callback(workbook);
    };
    reader.readAsBinaryString(file);
}
/**
     * 通用的打开下载对话框方法，没有测试过具体兼容性
     * @param url 下载地址，也可以是一个blob对象，必选
     * @param saveName 保存文件名，可选
     */
function openDownloadDialog(url, saveName) {
    if (typeof url == 'object' && url instanceof Blob) {
        url = URL.createObjectURL(url); // 创建blob地址
    }
    var aLink = document.createElement('a');
    aLink.href = url;
    aLink.download = saveName || ''; // HTML5新增的属性，指定保存文件名，可以不要后缀，注意，file:///模式下不会生效
    var event;
    if (window.MouseEvent) event = new MouseEvent('click');
    else {
        event = document.createEvent('MouseEvents');
        event.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
    }
    aLink.dispatchEvent(event);
}

// 将一个sheet转成最终的excel文件的blob对象，然后利用URL.createObjectURL下载
function sheet2blob(sheet, sheetName) {
    sheetName = sheetName || 'sheet1';
    var workbook = {
        SheetNames: [sheetName],
        Sheets: {}
    };
    workbook.Sheets[sheetName] = sheet;
    // 生成excel的配置项
    var wopts = {
        bookType: 'xlsx', // 要生成的文件类型
        bookSST: false, // 是否生成Shared String Table，官方解释是，如果开启生成速度会下降，但在低版本IOS设备上有更好的兼容性
        type: 'binary'
    };
    var wbout = XLSX.write(workbook, wopts);
    var blob = new Blob([s2ab(wbout)], { type: "application/octet-stream" });
    // 字符串转ArrayBuffer
    function s2ab(s) {
        var buf = new ArrayBuffer(s.length);
        var view = new Uint8Array(buf);
        for (var i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF;
        return buf;
    }
    return blob;
}


function exportSpecialExcel() {
    var aoa = [
        ['扣款方id', '扣款方姓名', '收款方id', '收款方姓名', '调整款金额(元)'],
        // ['A1', '张三', 'A2', '李四', 100],
    ];
    var sheet = XLSX.utils.aoa_to_sheet(aoa);

    var wscols = [
        { wch: 20 },
        { wch: 20 },
        { wch: 20 },
        { wch: 20 },
        { wch: 20 }
    ];

    sheet['!cols'] = wscols;
    openDownloadDialog(sheet2blob(sheet), '调整款模板.xlsx');
}


function exportExcel(data,colSetting,fileName){
    var aoa = [
        ...data
    ];
    var sheet = XLSX.utils.aoa_to_sheet(aoa);

    var wscols = [
        ...colSetting
    ];

    sheet['!cols'] = wscols;
    openDownloadDialog(sheet2blob(sheet), fileName+'.xlsx');
}

function readWorkbook2(workbook) {
    var sheetNames = workbook.SheetNames; // 工作表名称集合
    var worksheet = workbook.Sheets[sheetNames[0]]; // 这里我们只读取第一张sheet
    var csv = XLSX.utils.sheet_to_csv(worksheet);
    let getTabelData = csv2table(csv)
}

function csv2table(csv){

    let array = [];
    var rows = csv.split('\n');
	rows.pop(); // 最后一行没用的
    rows.forEach(function(row, idx) {
        var columns = row.split(',');
        if(idx > 0){
            let params = {
                c_merchant_id:columns[0],
                charge_name:columns[1],
                r_merchant_id:columns[2],
                receive_name:columns[3],
                adjust_cash:columns[4],
            }
            array.push(params)
        }  
    })
    return array
}

export const downloadFile = exportSpecialExcel

export const loadFile = readWorkbookFromLocalFile

export const readWorkbook = readWorkbook2 

export const exportExcelFile = exportExcel