/*
 * @Author: GeekQiaQia
 * @Date: 2021-12-31 14:08:19
 * @LastEditTime: 2022-02-21 18:05:15
 * @LastEditors: GeekQiaQia
 * @Description:
 * @FilePath: /test-vue3/src/hooks/useExportExcel.ts
 */

/**
 * @description
 * https://www.npmjs.com/package/xlsx#writing-examples
 *
 */

import { saveAs } from 'file-saver'
import * as XLSX from 'xlsx'

interface jsonTypes {
  multiHeader: any[]
  header: any[]
  data: any[][]
  filename: string
  merges: []
  autoWidth: boolean
  bookType: XLSX.BookType
}
declare type ws = {
  [key: string]: any
}
declare type cellType = {
  [key: string]: any
}
declare type dateType = string | number | Date
/**
 * @description 生成excel array
 */
function generateArray(table: HTMLElement | null) {
  const out = []
  // eslint-disable-next-line no-undef
  const rows = table?.querySelectorAll('tr') as NodeListOf<HTMLTableRowElement>
  const ranges = []
  for (let R = 0; R < rows.length; ++R) {
    const outRow = []
    const row = rows[R]
    const columns = row.querySelectorAll('td')
    for (let C = 0; C < columns.length; ++C) {
      // eslint-disable-next-line no-undef
      const cell: HTMLTableDataCellElement = columns[C]
      let colspan: string | number | null = cell.getAttribute('colspan')
      let rowspan: string | number | null = cell.getAttribute('rowspan')
      let cellValue: string | number = cell.innerText
      if (typeof cellValue === 'number' && cellValue === Number(cellValue)) cellValue = Number(cellValue)

      // Skip ranges
      ranges.forEach((range) => {
        if (R >= range.s.r && R <= range.e.r && outRow.length >= range.s.c && outRow.length <= range.e.c) {
          for (let i = 0; i <= range.e.c - range.s.c; ++i) outRow.push(null)
        }
      })

      // Handle Row Span
      if (rowspan || colspan) {
        rowspan = rowspan || 1
        colspan = colspan || 1
        ranges.push({
          s: {
            r: R,
            c: outRow.length
          },
          e: {
            r: R + (rowspan as number) - 1,
            c: outRow.length + (colspan as number) - 1
          }
        })
      }

      // Handle Value
      outRow.push(cellValue !== '' ? cellValue : null)

      // Handle Colspan
      if (colspan) for (let k = 0; k < (colspan as number) - 1; ++k) outRow.push(null)
    }
    out.push(outRow)
  }
  return [out, ranges]
}

function datenum(date: dateType, date1904?: undefined) {
  // eslint-disable-next-line no-param-reassign
  if (date1904) date = Number(date) + 1462
  const epoch = Date.parse(String(date))
  return (epoch - Date.parse(String(new Date(Date.UTC(1899, 11, 30))))) / (24 * 60 * 60 * 1000)
}

/**
 * @description sheet  General Structures
 * - 单元格地址对象存储为{c: C, r: R}，其中C和R是0索引的列和行号，
 * 例如，单元格地址B5由对象{c:1, r:4}表示。
 * - 单元格范围对象存储为{s: S, e: E}，其中S是range范围内的第一个单元格，E是最后一个单元格。
 * 范围range是包含的。例如，范围A3:B7用对象{s:{c:0, r:2}， e:{c:1, r:6}}表示
 *
 */
function sheetFromArrayOfArrays(data: string | any[]) {
  const worksheet: ws = {}
  const range = {
    s: {
      c: 10000000,
      r: 10000000
    },
    e: {
      c: 0,
      r: 0
    }
  }
  for (let R = 0; R !== data.length; ++R) {
    for (let C = 0; C !== data[R].length; ++C) {
      if (range.s.r > R) range.s.r = R
      if (range.s.c > C) range.s.c = C
      if (range.e.r < R) range.e.r = R
      if (range.e.c < C) range.e.c = C
      const cell: cellType = {
        v: data[R][C]
      }
      if (cell.v !== null) {
        const cellRef = XLSX.utils.encode_cell({
          c: C,
          r: R
        })

        if (typeof cell.v === 'number') cell.t = 'n'
        else if (typeof cell.v === 'boolean') cell.t = 'b'
        else if (cell.v instanceof Date) {
          cell.t = 'n'
          const z = XLSX.SSF.parse_date_code(14)
          cell.z = z
          cell.v = datenum(cell.v)
        } else cell.t = 's'

        worksheet[cellRef] = cell
      }
    }
  }
  if (range.s.c < 10000000) worksheet['!ref'] = XLSX.utils.encode_range(range)
  return worksheet
}

/**
 * @description Workbook 类声明
 */
class Workbook implements XLSX.WorkBook {
  public SheetNames: any[]

  public Sheets: any

  constructor(nameParams = [], sheetsParams = {}) {
    this.SheetNames = nameParams
    this.Sheets = sheetsParams
  }
}

/**
 * @description 将string 转化为arrayBuffer
 * 0x代表16进制数,0xff表示的数二进制1111 1111 占一个字节.和其进行&操作的数,最低8位,不会发生变化.
 */
function s2ab(s: string) {
  const buf = new ArrayBuffer(s.length)
  const view = new Uint8Array(buf)
  for (let i = 0; i !== s.length; ++i) view[i] = s.charCodeAt(i) & 0xff
  return buf
}

/**
 * @description 将表格导出为Excel
 */
export function exportTableToExcel(id: string) {
  const table = document.getElementById(id)
  const excelArray = generateArray(table)
  const ranges = excelArray[1]

  /* original data */
  const data = excelArray[0]
  const wsName = 'SheetJS'

  const wb = new Workbook()
  const worksheet = sheetFromArrayOfArrays(data)

  /* add ranges to worksheet */
  // ws['!cols'] = ['apple', 'banan'];
  worksheet['!merges'] = ranges

  /* add worksheet to workbook */
  wb.SheetNames.push(wsName)
  wb.Sheets[wsName] = worksheet

  const wbOutput = XLSX.write(wb, {
    bookType: 'xlsx',
    bookSST: false,
    type: 'binary'
  })

  saveAs(
    new Blob([s2ab(wbOutput)], {
      type: 'application/octet-stream'
    }),
    'test.xlsx'
  )
}

/**
 * @description 将json对象导出到Excel
 */
export function exportJsonToExcel(params: jsonTypes) {
  /* original data */
  const filename = params?.filename ?? 'defaultExcel'
  const bookType = params?.bookType ?? 'xlsx'
  const multiHeader = params?.multiHeader ?? []
  const merges = params?.merges ?? []
  const autoWidth = params.autoWidth ?? true
  const data = [...params.data]
  data.unshift(params.header)

  for (let i = multiHeader.length - 1; i > -1; i--) {
    data.unshift(multiHeader[i])
  }

  const wsName = 'SheetJS'
  const wb = new Workbook()
  const worksheet = sheetFromArrayOfArrays(data)

  if (merges.length > 0) {
    if (!worksheet['!merges']) worksheet['!merges'] = []
    merges.forEach((item) => {
      worksheet['!merges'].push(XLSX.utils.decode_range(item))
    })
  }

  if (autoWidth) {
    /* 设置worksheet每列的最大宽度 */
    // eslint-disable-next-line no-unused-vars
    const colWidth = data.map((row: ({ toString: () => { (): any; new (): any; charCodeAt: { (arg0: number): number; new (): any }; length: number } } | null)[]) =>
      // eslint-disable-next-line no-unused-vars
      row.map((val: { toString: () => { (): any; new (): any; charCodeAt: { (arg0: number): number; new (): any }; length: number } } | null) => {
        /* 先判断是否为null/undefined */
        if (val == null) {
          return {
            wch: 10
          }
        }
        /* 再判断是否为中文 */
        if (val.toString().charCodeAt(0) > 255) {
          return {
            wch: val.toString().length * 2
          }
        }
        return {
          wch: val.toString().length
        }
      })
    )
    /* 以第一行为初始值 */
    const result = colWidth[0]
    for (let i = 1; i < colWidth.length; i++) {
      for (let j = 0; j < colWidth[i].length; j++) {
        if (result[j].wch < colWidth[i][j].wch) {
          result[j].wch = colWidth[i][j].wch
        }
      }
    }
    worksheet['!cols'] = result
  }

  /* add worksheet to workbook */
  wb.SheetNames.push(wsName)
  wb.Sheets[wsName] = worksheet

  /** Attempts to write the workbook data */
  const wbData = XLSX.write(wb, {
    bookType,
    bookSST: false,
    type: 'binary'
  })
  // save Blob data
  saveAs(
    new Blob([s2ab(wbData)], {
      type: 'application/octet-stream'
    }),
    `${filename}.${bookType}`
  )
}

export default { exportTableToExcel, exportJsonToExcel }