using System.IO;
using System.Data;
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.HSSF.Util;
using NPOI.XSSF.UserModel;
using System;
using UAS_LabelMachine.Entity;
using UAS_LabelMachine.PublicMethod;

namespace UAS_LabelMachine
{
    class ExcelHandler
    {
        DataHelper dh = SystemInf.dh;

        /// <summary>
        /// 导出Excel,返回文件在客户端的路径
        /// </summary>
        public string ExportExcel(DataTable dt, string FolderPath, string FileName)
        {
            //创建一个内存流，用来接收转换成Excel的内容
            MemoryStream ms;
            ms = DataTableToExcel(dt);
            //以系统当前时间命名文件，FileMode.Create表示创建文件，FileAccess.Write表示拥有写的权限
            string filePath = @FolderPath + "\\" + FileName + ".xls";
            FileStream fs = new FileStream(filePath, FileMode.Create, FileAccess.Write);
            byte[] data = ms.ToArray();
            fs.Write(data, 0, data.Length);
            fs.Flush();
            //释放当前Excel文件，否则打开文件的时候会显示文件被占用
            ms.Dispose();
            fs.Dispose();
            return filePath;
        }

        /// <summary>
        /// 导入Excel
        /// </summary>
        public void ImportExcel(DataTable DataTable, string TableName)
        {
            int columnNum = DataTable.Columns.Count;
            int rowNum = DataTable.Columns.Count;
            string[] field = new string[columnNum];
            for (int i = 0; i < columnNum; i++)
            {
                field[i] = DataTable.Rows[0][i].ToString();
            }
        }

        public static DataTable ExcelToDataTable(string filePath, bool isColumnName)
        {
            DataTable dataTable = null;
            FileStream fs = null;
            DataColumn column = null;
            DataRow dataRow = null;
            IWorkbook workbook = null;
            ISheet sheet = null;
            IRow row = null;
            ICell cell = null;
            int startRow = 0;
            try
            {
                using (fs = File.OpenRead(filePath))
                {
                    // 2007版本
                    if (filePath.IndexOf(".xlsx") > 0)
                    {
                        workbook = new XSSFWorkbook(fs);
                    }
                    // 2003版本
                    else if (filePath.IndexOf(".xls") > 0)
                    {
                        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);
                                }
                            }
                        }
                    }
                }
                return dataTable;
            }
            catch (Exception)
            {
                if (fs != null)
                {
                    fs.Close();
                }
                return null;
            }
        }

        /// <summary>
        /// 将DataTable形式的数据转成Excel格式的，然后用字节流的形式写入文件
        /// </summary>
        /// <param name="DataTable"></param>
        /// <returns></returns>
        public MemoryStream DataTableToExcel(DataTable DataTable)
        {
            //创建内存流
            MemoryStream ms = new MemoryStream();
            //创建一个Book，相当于一个Excel文件
            HSSFWorkbook book = new HSSFWorkbook();
            //Excel中的Sheet
            ISheet sheet = book.CreateSheet("sheet1");
            //获取行数量和列数量
            int rowNum = DataTable.Rows.Count;
            int columnNum = DataTable.Columns.Count;
            //设置列的宽度，根据首行的列的内容的长度来设置
            for (int i = 0; i < columnNum; i++)
            {
                int dataLength;
                //如果内容比标题短则取标题长度
                if (DataTable.Rows[0][i].ToString().Length < DataTable.Columns[i].ColumnName.Length)
                {
                    dataLength = DataTable.Columns[i].ColumnName.Length;
                    dataLength = dataLength * 600;
                }
                else
                {
                    dataLength = DataTable.Rows[0][i].ToString().Length;
                    dataLength = dataLength * 500;
                }
                sheet.SetColumnWidth(i, dataLength);
            }
            //首先画好第一行带颜色的，单独写出来，避免写在循环里面
            IRow row = sheet.CreateRow(0);
            //冻结第一行
            sheet.CreateFreezePane(0, 1, 0, 1);
            ICellStyle style = book.CreateCellStyle();
            style.FillForegroundColor = HSSFColor.PaleBlue.Index;
            style.FillPattern = FillPattern.BigSpots;
            style.FillBackgroundColor = HSSFColor.LightGreen.Index;
            //设置边框
            style.BorderBottom = BorderStyle.Thick;
            style.BorderLeft = BorderStyle.Thick;
            style.BorderRight = BorderStyle.Thick;
            style.BorderTop = BorderStyle.Thick;
            row.HeightInPoints = 20;
            //固定第一行
            //row.RowStyle.IsLocked=true;
            //给第一行的标签赋值样式和值
            for (int j = 0; j < columnNum; j++)
            {
                row.CreateCell(j);
                row.Cells[j].CellStyle = style;
                row.Cells[j].CellStyle.VerticalAlignment = VerticalAlignment.Center;
                row.Cells[j].CellStyle.Alignment = HorizontalAlignment.Center;
                row.Cells[j].SetCellValue(DataTable.Columns[j].ColumnName);
            }
            //将DataTable的值循环赋值给book，Aligment设置居中
            //之前已经画了带颜色的第一行，所以从i=1开始画
            for (int i = 0; i < rowNum; i++)
            {
                IRow row1 = sheet.CreateRow(i + 1);
                row1.HeightInPoints = 20;
                for (int j = 0; j < columnNum; j++)
                {
                    row1.CreateCell(j);
                    row1.Cells[j].SetCellValue(DataTable.Rows[i][j].ToString());
                    row1.GetCell(j).CellStyle.VerticalAlignment = VerticalAlignment.Center;
                }
            }
            //将book的内容写入内存流中返回
            book.Write(ms);
            return ms;
        }
    }
}