

import { isEmpty } from 'element-ui/lib/utils/util';
import ExcelJS from 'exceljs'
import * as FileSaver from 'file-saver'

export default function createWorkBook(header, title, data, foot, filename,sheets){
  const letter = ['A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'];
  let lcomun = 1;
  let worksheet ;

  const workBook = new ExcelJS.Workbook();
  let long = header.length;

/**
 *  创建工作薄
 * @param {*} sheets
 */
function createSheets(sheets) {
  let sheet = Array.isArray(sheets) ?  sheets[0] : sheets;
  let style = Array.isArray(sheets) ?  sheets[1] : {};
  worksheet = workBook.addWorksheet(sheet,style);
}

/**
 *  设置表名介绍等
 * @param {*} title
 * @param {*} long
 */
function setTitle(title,long){
  if (isEmpty(title)) return ;
  title = Array.isArray(title) ? title : title.split(',');
  for (let i = 0; i < title.length; i++) {
    let ti = worksheet.getRow(i + 1);
    ti.getCell(1).value = title[i];
    ti.height = 30;
    ti.font = {bold: true,size: 20,vertAlign: 'subscript',};
    ti.alignment = { vertical: 'bottom', horizontal: 'center' };
    ti.outlineLevel = 1;
    worksheet.mergeCells(i + 1 , 1, i + 1, long)
    ti.commit();
    lcomun++;
  }
}
/**
 *  设置表头行
 * @param {*} header
 */
function setHeader(header){
  if (isEmpty(header)) return ;
  const headerRow = worksheet.getRow(lcomun);
  for (let index = 1; index <= header.length; index++) {
    headerRow.getCell(index).value = header[index - 1];
  }
  headerRow.height = 25;
  headerRow.width = 50;
  headerRow.font = {bold: true,  size: 18,vertAlign: 'subscript',};
  headerRow.alignment = { vertical: 'bottom', horizontal: 'center' };
  headerRow.outlineLevel = 1;
  headerRow.commit();
  lcomun++;
}

/**
 * 导出内容
 * @param {*} data
 */
function setContent(data){
  if (isEmpty(data)) return ;
  for (let h = 0; h < data.length; h++) {
    let satarLcomun = lcomun;
    let lcomunNow = worksheet.getRow(lcomun);
    let hasMerge = false;
    let starKey = 0;
    let endKey = 0;
    /** 循环列 */
    //需要操作第几列
    let sk = 0;
    for (let l = 0; l < data[h].length; l++) {
      if (Array.isArray(data[h][l])) {
        //数组长度
        starKey = sk;
        hasMerge = true;
        setArrayContent(data[h][l],sk);
        sk = sk + data[h][l][0].length
        endKey =sk;
      } else {
        //不是数组
        lcomunNow.getCell(getLetter(sk)).value = data[h][l];
        lcomunNow.getCell(getLetter(sk)).border = {top: {style:'thin'},left: {style:'thin'},bottom: {style:'thin'},right: {style:'thin'}};
        lcomunNow.alignment = { vertical: 'middle', horizontal: 'center' };
        sk++
      }
    }
    if (hasMerge)  setMergeLcomun(satarLcomun, lcomun, starKey, endKey);
    lcomunNow.height = 25;
    lcomunNow.commit();
    lcomun++
  }
}
/**
 * 占多行的数组
 * @param {*} arr
 * @param {*} sk
 */
function setArrayContent(arr, sk) {
  /**
   *  循环二维数组,在循环行
   */
  let al = arr.length;
  let sl = al - 1 ;
  for (let i = 0; i < arr.length; i++ ) {
    let lcomunNow = worksheet.getRow(lcomun);
    for(let v = 0; v < arr[i].length; v++) {
      lcomunNow.getCell(getLetter(sk+v)).value = arr[i][v];
      lcomunNow.getCell(getLetter(sk+v)).border = {top: {style:'thin'},left: {style:'thin'},bottom: {style:'thin'},right: {style:'thin'}};
      lcomunNow.alignment = { vertical: 'middle', horizontal: 'center' };
    }
    lcomunNow.height = 25;
    lcomunNow.commit()
    if (i < sl) lcomun++
  }
}
/**
 *  合并操作
 * @param {*} satarLcomun
 * @param {*} endLcomun
 * @param {*} starKey
 * @param {*} endKey
 */
function setMergeLcomun(satarLcomun, endLcomun, starKey, endKey){
  for(let ml = 0 ; ml < long ; ml++ ){
    if (ml < starKey || ml >= endKey) {
      worksheet.mergeCells(getLetter(ml) + satarLcomun +':'+getLetter(ml) + endLcomun)
    }
  }
}

/**
 * 设置表末尾统计备注等
 * @param {*} footData
 */
function setFoot(footData){
  if (isEmpty(footData)) return ;
  if (Array.isArray(footData)) {
    for (let f = 0; f < footData.length; f++) {
      let lcomunNow = worksheet.getRow(lcomun);
      lcomunNow.getCell(1).value = footData[f];
      lcomunNow.getCell(1).border = {top: {style:'thin'},left: {style:'thin'},bottom: {style:'thin'},right: {style:'thin'}};
      lcomunNow.alignment = { vertical: 'middle', horizontal: 'left' };
      worksheet.mergeCells('A' + lcomun +':'+getLetter(long-1) + lcomun)
      lcomun++
    }
  } else {
    let lcomunNow = worksheet.getRow(lcomun);
    lcomunNow.getCell(1).value = footData[f];
    lcomunNow.getCell(1).border = {top: {style:'thin'},left: {style:'thin'},bottom: {style:'thin'},right: {style:'thin'}};
    lcomunNow.alignment = { vertical: 'middle', horizontal: 'left' };
    worksheet.mergeCells('A' + lcomun +':'+getLetter(long-1) + lcomun)
  }
}

/**
 *  处理超过26个字母的列
 * @param {*} number
 * @returns
 */
function getLetter(number){
  if (number < 26) {
    return letter[number];
  } else {
    let n = number % 26
    let l = Math.floor(number % 26)
    return letter[l]+letter[n]
  }
}

/**
 *  导出下载
 * @param {*} filename
 */
function saveAndDowloade(filename){
  if (!filename) filename = new Date().getTime();
  workBook.xlsx.writeBuffer().then(data => {
    const blob = new Blob([data], {type: 'application/octet-stream'})
    FileSaver.saveAs(blob, filename + '.xlsx')
  })
}

  createSheets(sheets);
  setTitle(title,long);
  setHeader(header);
  setContent(data);
  setFoot(foot);
  saveAndDowloade(filename);

}
