using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System.Data;
using System.IO;

namespace DeviceRepairAndOptimization.Utils
{
    public static class ExcelExport
    {


        /// <summary>
        /// DataTable 导出到 Excel
        /// </summary>
        /// <param name="dataTable">数据</param>
        /// <returns></returns>
        public static byte[] Export(this DataTable dataTable)
        {
            IWorkbook workbook = new XSSFWorkbook();
            string sheetName = string.IsNullOrEmpty(dataTable.TableName) ? "Sheet1" : dataTable.TableName;
            ISheet sheet = workbook.CreateSheet(sheetName);

            // 创建表头
            IRow headerRow = sheet.CreateRow(0);
            for (int i = 0; i < dataTable.Columns.Count; i++)
            {
                headerRow.CreateCell(i).SetCellValue(dataTable.Columns[i].ColumnName);
            }

            // 填充数据
            for (int i = 0; i < dataTable.Rows.Count; i++)
            {
                IRow dataRow = sheet.CreateRow(i + 1);
                for (int j = 0; j < dataTable.Columns.Count; j++)
                {
                    dataRow.CreateCell(j).SetCellValue(dataTable.Rows[i][j].ToString());
                }
            }

            // 转换为byte[]
            using (MemoryStream stream = new MemoryStream())
            {
                workbook.Write(stream);
                return stream.ToArray();
            }
        }

        /// <summary>
        /// DataSet 导出到 Excel
        /// </summary>
        /// <param name="dataSet"></param>
        /// <returns></returns>
        public static byte[] Export(this DataSet dataSet)
        {
            IWorkbook workbook = new XSSFWorkbook();


            if (dataSet == null || dataSet.Tables.Count == 0)
                return null;

            for (int i = 0; i < dataSet.Tables.Count; i++)
            {
                DataTable dataTable = dataSet.Tables[i];
                string sheetName = string.IsNullOrEmpty(dataTable.TableName) ? "sheet" + (i + 1).ToString() : dataTable.TableName;
                ISheet sheet = workbook.CreateSheet(sheetName);

                // 创建表头
                IRow headerRow = sheet.CreateRow(0);
                for (int j = 0; j < dataTable.Columns.Count; j++)
                {
                    headerRow.CreateCell(j).SetCellValue(dataTable.Columns[j].ColumnName);
                }

                // 填充数据
                for (int j = 0; j < dataTable.Rows.Count; j++)
                {
                    IRow dataRow = sheet.CreateRow(j + 1);
                    for (int k = 0; k < dataTable.Columns.Count; k++)
                    {
                        dataRow.CreateCell(k).SetCellValue(dataTable.Rows[j][k].ToString());
                    }
                }
            }

            // 转换为byte[]
            using (MemoryStream stream = new MemoryStream())
            {
                workbook.Write(stream);
                return stream.ToArray();
            }
        }
    }

}