using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;

namespace TProduct.Common
{
    public static class ExcelHelperEx
    {
        /// <summary>
        /// 将excel导入到datatable
        /// </summary>
        /// <param name="fs">Stream文件流</param>
        /// <param name="isColumnName">第一行是否是列名</param>
        /// <param name="isReplace">是否替换表头</param>
        /// <returns>返回datatable</returns>
        public static DataTable ExcelToDataTable(string fileName, Dictionary<string, object> list = null, bool isColumnName = true, bool isReplace = true)
        {
            DataTable dataTable = null;
            DataColumn column = null;
            DataRow dataRow = null;
            IWorkbook workbook = null;
            ISheet sheet = null;
            IRow row = null;
            ICell cell = null;
            int startRow = 0;
            FileStream fs = null;
            try
            {
                fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
                workbook = new HSSFWorkbook(fs);

                if (workbook != null)
                {
                    sheet = workbook.GetSheetAt(0);//读取第一个sheet，当然也可以循环读取每个sheet
                    dataTable = new DataTable();
                    if (sheet != null)
                    {
                        int rowCount = sheet.LastRowNum;//总行数
                        if (rowCount > 0)
                        {
                            IRow firstRow = sheet.GetRow(0);//第一行
                            int cellCount = firstRow.LastCellNum;//列数

                            //构建datatable的列
                            if (isColumnName)
                            {
                                startRow = 1;//如果第一行是列名，则从第二行开始读取
                                for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
                                {
                                    cell = firstRow.GetCell(i);
                                    if (cell != null)
                                    {
                                        if (cell.StringCellValue != null)
                                        {
                                            column = new DataColumn(cell.StringCellValue);
                                            dataTable.Columns.Add(column);
                                        }
                                    }
                                }
                            }
                            else
                            {
                                for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
                                {
                                    column = new DataColumn("column" + (i + 1));
                                    dataTable.Columns.Add(column);
                                }
                            }

                            //填充行
                            for (int i = startRow; i <= rowCount; ++i)
                            {
                                row = sheet.GetRow(i);
                                if (row == null) continue;

                                dataRow = dataTable.NewRow();
                                for (int j = row.FirstCellNum; j < cellCount; ++j)
                                {
                                    cell = row.GetCell(j);
                                    if (cell == null)
                                    {
                                        dataRow[j] = "";
                                    }
                                    else
                                    {
                                        //CellType(Unknown = -1,Numeric = 0,String = 1,Formula = 2,Blank = 3,Boolean = 4,Error = 5,)
                                        switch (cell.CellType)
                                        {
                                            case CellType.Blank:
                                                dataRow[j] = "";
                                                break;

                                            case CellType.Numeric:
                                                short format = cell.CellStyle.DataFormat;
                                                //对时间格式（2015.12.5、2015/12/5、2015-12-5等）的处理
                                                if (format == 14 || format == 31 || format == 57 || format == 58)
                                                    dataRow[j] = cell.DateCellValue;
                                                else
                                                    dataRow[j] = cell.NumericCellValue;
                                                break;

                                            case CellType.String:
                                                dataRow[j] = cell.StringCellValue;
                                                break;
                                        }
                                    }
                                }
                                dataTable.Rows.Add(dataRow);
                            }
                        }
                    }
                }

                if (isReplace)
                {
                    if (dataTable != null)
                    {
                        if (list != null)
                        {
                            //循环datatable
                            for (int i = 0; i < dataTable.Columns.Count; i++)
                            {
                                //获取datatable的标头
                                var s = dataTable.Columns[i].ColumnName.Trim();
                                foreach (var item1 in list)
                                {
                                    //判断标头与key是否相等
                                    if (s.Equals(item1.Value.ToString().Trim()))
                                    {
                                        //相等替换掉原来的标头
                                        dataTable.Columns[i].ColumnName = item1.Key.ToString().Trim();
                                    }
                                }
                            }
                        }
                    }
                }
                return dataTable;
            }
            catch (Exception)
            {
                if (fs != null)
                {
                    fs.Close();
                }
                return null;
            }
        }

    }
}