using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WIDESEAWCS_Common.Utilities
{
    public class ImportExcelHelper : IDisposable
    {
        private string fileName = null; //文件名
        private IWorkbook workbook = null;
        private FileStream fs = null;
        private bool disposed;

        public ImportExcelHelper(string fileName)
        {
            this.fileName = fileName;
            disposed = false;
        }

        /// <summary>
        /// 将DataTable数据导入到excel中
        /// </summary>
        /// <param name="data">要导入的数据</param>
        /// <param name="isColumnWritten">DataTable的列名是否要导入</param>
        /// <param name="sheetName">要导入的excel的sheet的名称</param>
        /// <returns>导入数据行数(包含列名那一行)</returns>
        public int DataTableToExcel(DataTable data, string sheetName, bool isColumnWritten)
        {
            int i = 0;
            int j = 0;
            int count = 0;
            ISheet sheet = null;

            fs = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);
            if (fileName.IndexOf(".xlsx") > 0) // 2007版本
                workbook = new XSSFWorkbook();
            else if (fileName.IndexOf(".xls") > 0) // 2003版本
                workbook = new HSSFWorkbook();

            try
            {
                if (workbook != null)
                {
                    sheet = workbook.CreateSheet(sheetName);
                }
                else
                {
                    return -1;
                }

                if (isColumnWritten == true) //写入DataTable的列名
                {
                    IRow row = sheet.CreateRow(0);
                    for (j = 0; j < data.Columns.Count; ++j)
                    {
                        row.CreateCell(j).SetCellValue(data.Columns[j].ColumnName);
                    }
                    count = 1;
                }
                else
                {
                    count = 0;
                }

                for (i = 0; i < data.Rows.Count; ++i)
                {
                    IRow row = sheet.CreateRow(count);
                    for (j = 0; j < data.Columns.Count; ++j)
                    {
                        row.CreateCell(j).SetCellValue(data.Rows[i][j].ToString());
                    }
                    ++count;
                }
                workbook.Write(fs, true); //写入到excel
                return count;
            }
            catch (Exception ex)
            {
                Console.WriteLine("Exception: " + ex.Message);
                return -1;
            }
        }

        /// <summary>
        /// 将excel中的数据导入到DataTable中
        /// </summary>
        /// <param name="sheetName">excel工作薄sheet的名称</param>
        /// <param name="isFirstRowColumn">第一行是否是DataTable的列名</param>
        /// <returns>返回的DataTable</returns>
        //public DataTable ExcelToDataTable(string sheetName = null, bool isFirstRowColumn = true)
        //{
        //    ISheet sheet = null;
        //    DataTable data = new DataTable();
        //    int startRow = 0;
        //    try
        //    {
        //        fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
        //        if (fileName.IndexOf(".xlsx") > 0) // 2007版本
        //            workbook = new XSSFWorkbook(fs);
        //        else if (fileName.IndexOf(".xls") > 0) // 2003版本
        //            workbook = new HSSFWorkbook(fs);

        //        if (sheetName != null)
        //        {
        //            sheet = workbook.GetSheet("Sheet1");
        //        }
        //        else
        //        {
        //            sheet = workbook.GetSheetAt(0);
        //        }
        //        if (sheet != null)
        //        {
        //            IRow firstRow = sheet.GetRow(0);
        //            int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数

        //            if (isFirstRowColumn)
        //            {
        //                for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
        //                {
        //                    DataColumn column = new DataColumn(firstRow.GetCell(i).StringCellValue);
        //                    data.Columns.Add(column);
        //                }
        //                startRow = sheet.FirstRowNum + 1;
        //            }
        //            else
        //            {
        //                startRow = sheet.FirstRowNum;
        //            }

        //            //最后一列的标号
        //            int rowCount = sheet.LastRowNum;
        //            for (int i = startRow; i <= rowCount; ++i)
        //            {
        //                IRow row = sheet.GetRow(i);
        //                if (row == null) continue; //没有数据的行默认是null　　　　　　　

        //                DataRow dataRow = data.NewRow();
        //                for (int j = row.FirstCellNum; j < cellCount; ++j)
        //                {
        //                    if (row.GetCell(j) != null) //同理，没有数据的单元格都默认是null
        //                        dataRow[j] = row.GetCell(j).ToString();
        //                }
        //                data.Rows.Add(dataRow);
        //            }
        //        }

        //        return data;
        //    }
        //    catch (Exception ex)
        //    {
        //        Console.WriteLine("Exception: " + ex.Message);
        //        return null;
        //    }
        //}

        public DataTable ExcelToDataTable(string sheetName = null, bool isFirstRowColumn = true)
        {
            ISheet sheet = null;
            DataTable data = new DataTable();
            int startRow = 0;

            try
            {
                using (fs = new FileStream(fileName, FileMode.Open, FileAccess.Read))
                {
                    if (fileName.IndexOf(".xlsx", StringComparison.OrdinalIgnoreCase) > 0)
                        workbook = new XSSFWorkbook(fs);
                    else if (fileName.IndexOf(".xls", StringComparison.OrdinalIgnoreCase) > 0)
                        workbook = new HSSFWorkbook(fs);

                    // 修复sheet选择逻辑
                    if (!string.IsNullOrEmpty(sheetName))
                    {
                        sheet = workbook.GetSheet(sheetName);  // 使用传入的sheetName
                    }
                    else
                    {
                        sheet = workbook.GetSheetAt(0);  // 默认第一个sheet
                    }

                    if (sheet == null)
                    {
                        Console.WriteLine("未找到指定的工作表");
                        return null;
                    }

                    IRow firstRow = sheet.GetRow(0);
                    if (firstRow == null)
                    {
                        Console.WriteLine("工作表为空");
                        return null;
                    }

                    int cellCount = firstRow.LastCellNum;

                    if (isFirstRowColumn)
                    {
                        for (int i = firstRow.FirstCellNum; i < cellCount; i++)
                        {
                            ICell cell = firstRow.GetCell(i);
                            string columnName = (cell != null) ? cell.ToString() : $"Column{i}";
                            data.Columns.Add(columnName);
                        }
                        startRow = 1;  // 从第二行开始（跳过标题行）
                    }
                    else
                    {
                        for (int i = 0; i < cellCount; i++)
                        {
                            data.Columns.Add($"Column{i}");
                        }
                        startRow = 0;
                    }

                    // 读取数据行
                    for (int i = startRow; i <= sheet.LastRowNum; i++)
                    {
                        IRow row = sheet.GetRow(i);
                        if (row == null) continue;

                        DataRow dataRow = data.NewRow();
                        for (int j = 0; j < cellCount; j++)
                        {
                            ICell cell = row.GetCell(j);
                            if (cell != null)
                            {
                                // 根据单元格类型正确处理数据
                                switch (cell.CellType)
                                {
                                    case CellType.String:
                                        dataRow[j] = cell.StringCellValue;
                                        break;
                                    case CellType.Numeric:
                                        if (DateUtil.IsCellDateFormatted(cell))
                                            dataRow[j] = cell.DateCellValue;
                                        else
                                            dataRow[j] = cell.NumericCellValue;
                                        break;
                                    case CellType.Boolean:
                                        dataRow[j] = cell.BooleanCellValue;
                                        break;
                                    case CellType.Formula:
                                        dataRow[j] = cell.ToString(); // 或者处理公式结果
                                        break;
                                    default:
                                        dataRow[j] = cell.ToString();
                                        break;
                                }
                            }
                        }
                        data.Rows.Add(dataRow);
                    }
                }
                return data;
            }
            catch (Exception ex)
            {
                Console.WriteLine($"读取Excel异常: {ex.Message}");
                return null;
            }
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        protected virtual void Dispose(bool disposing)
        {
            if (!this.disposed)
            {
                if (disposing)
                {
                    if (fs != null)
                        fs.Close();
                }

                fs = null;
                disposed = true;
            }
        }
    }
}