using System;
using System.Collections.Generic;
using System.Data;
using System.Data.OleDb;
using System.Diagnostics;
using System.Windows.Forms;

namespace CK.SCP.Utils
{
    public class ExcelReader

    {

        private DataSet _dsExcel;
        private DataTable _dtExcel;
        private string _fileExt;
        private string _filePath;
        private List<string> _readSheetName;
        //        private string _saveFileName;
        private string _sheetName;
        private List<string> _sheetNames;

        /// <summary>
        ///     读取Excel文件到DataSet
        /// </summary>
        /// <returns></returns>
        public DataSet ReturnDataSet()
        {
            var openFileDialog = new OpenFileDialog { Filter = "Execl files (*.xls,*.xlsx)|*.xls;*.xlsx" };
            //openFileDialog.RestoreDirectory = true;
            //openFileDialog.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Personal);

            if (openFileDialog.ShowDialog() == DialogResult.OK)
            {
                _filePath = openFileDialog.FileName;
                _fileExt = openFileDialog.FileName.Substring(openFileDialog.FileName.LastIndexOf('.'));
                var poDv = new ProcessOperator { BackgroundWork = ReadExcelToDataSet };
                poDv.BackgroundWorkerCompleted += ReadExcel_Completed;
                poDv.Start();
            }
            return _dsExcel;
        }

        /// <summary>
        ///     读取Excel文件到DataSet
        /// </summary>
        /// <param name="filePath">Excel文件地址</param>
        /// <returns></returns>
        public DataSet ReturnDataSet(string filePath)
        {
            try
            {
                if (string.IsNullOrEmpty(filePath))
                    return ReturnDataSet();
                _filePath = filePath;
                _fileExt = filePath.Substring(filePath.LastIndexOf('.'));

                if (_fileExt.ToUpper() == ".XLSX" || _fileExt.ToUpper() == ".XLS")
                {
                    var poDv = new ProcessOperator { BackgroundWork = ReadExcelToDataSet };
                    poDv.BackgroundWorkerCompleted += ReadExcel_Completed;
                    poDv.Start();
                }
                else
                {
                    MessageBox.Show("无法解析该后缀名的文件！");
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            return _dsExcel;
        }


        /// <summary>
        ///     读取Excel文件到DataSet
        /// </summary>
        /// <param name="sheetNames">读取Excel文件工作表名称集合</param>
        /// <returns></returns>
        public DataSet ReturnDataSet(List<string> sheetNames)
        {
            var openFileDialog = new OpenFileDialog { Filter = "Execl files (*.xls,*.xlsx)|*.xls;*.xlsx" };
            //openFileDialog.RestoreDirectory = true;
            //openFileDialog.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
            if (openFileDialog.ShowDialog() == DialogResult.OK)
            {
                _sheetNames = sheetNames;
                _filePath = openFileDialog.FileName;
                _fileExt = openFileDialog.FileName.Substring(openFileDialog.FileName.LastIndexOf('.'));
                var poDv = new ProcessOperator { BackgroundWork = ReadExcelToDataSet };
                poDv.BackgroundWorkerCompleted += ReadExcel_Completed;
                poDv.Start();
            }
            return _dsExcel;
        }

        /// <summary>
        ///     读取Excel文件到DataSet
        /// </summary>
        /// <param name="filePath">Excel文件地址</param>
        /// <param name="sheetNames">读取Excel文件表名称集合</param>
        /// <returns></returns>
        public DataSet ReturnDataSet(string filePath, List<string> sheetNames)
        {
            try
            {
                if (string.IsNullOrEmpty(filePath))
                    return ReturnDataSet();
                if (sheetNames == null || sheetNames.Count == 0)
                    return ReturnDataSet(filePath);

                _filePath = filePath;
                _fileExt = filePath.Substring(filePath.LastIndexOf('.'));
                _sheetNames = sheetNames;
                if (_fileExt.ToUpper() == ".XLSX" || _fileExt.ToUpper() == ".XLS")
                {
                    var poDv = new ProcessOperator { BackgroundWork = ReadExcelToDataSet };
                    poDv.BackgroundWorkerCompleted += ReadExcel_Completed;
                    poDv.Start();
                }
                else
                {
                    MessageBox.Show("无法解析该后缀名的文件！");
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            return _dsExcel;
        }

        /// <summary>
        ///     读取Excel文件的sheet到DataTable
        /// </summary>
        /// <param name="sheetName">Excel文件表名称</param>
        /// <returns></returns>
        public DataTable ReturnDataTable(string sheetName)
        {
            var openFileDialog = new OpenFileDialog { Filter = "Execl files (*.xls,*.xlsx)|*.xls;*.xlsx" };
            //openFileDialog.RestoreDirectory = true;
            //openFileDialog.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
            if (openFileDialog.ShowDialog() == DialogResult.OK)
            {
                _filePath = openFileDialog.FileName;
                _fileExt = openFileDialog.FileName.Substring(openFileDialog.FileName.LastIndexOf('.'));
                _sheetName = sheetName;
                var poDv = new ProcessOperator { BackgroundWork = ReadToDataTable };
                poDv.BackgroundWorkerCompleted += ReadExcel_Completed;
                poDv.Start();
            }
            return _dtExcel;
        }

        /// <summary>
        ///     读取Excel文件的sheet到DataTable
        /// </summary>
        /// <param name="filePath">Excel文件地址</param>
        /// <param name="sheetName">Excel文件表名称</param>
        /// <returns></returns>
        public DataTable ReturnDataTable(string filePath, string sheetName)
        {
            try
            {
                if (string.IsNullOrEmpty(filePath))
                    return ReturnDataTable(sheetName);
                _filePath = filePath;
                _fileExt = filePath.Substring(filePath.LastIndexOf('.'));

                if (_fileExt.ToUpper() == ".XLSX" || _fileExt.ToUpper() == ".XLS")
                {
                    _sheetName = sheetName;
                    var poDv = new ProcessOperator { BackgroundWork = ReadToDataTable };
                    poDv.BackgroundWorkerCompleted += ReadExcel_Completed;
                    poDv.Start();
                }
                else
                {
                    MessageBox.Show("无法解析该后缀名的文件！");
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            return _dtExcel;
        }

        private void ReadExcel_Completed(object sender, BackgroundWorkerEventArgs e)
        {
            if (e.BackGroundException == null)
            {
                //if (readSheetName != null && readSheetName.Count > 0)
                //{
                //    //StringBuilder sb = new StringBuilder();
                //    //sb.Append("文件读取成功！\n\r已在" + filePath + "下\n\r读取了 " + readSheetName.Count.ToString() + " 张Sheet工作表\n\r分别是：\n\r");
                //    //int i = 0;
                //    //foreach (String SheetName in readSheetName)
                //    //{
                //    //    i ++;
                //    //    sb.Append(SheetName + ",");
                //    //    if (i % 3 == 0)
                //    //    {
                //    //        sb.Append("\n\r");
                //    //    }
                //    //}
                //    //String message = sb.ToString();
                //    //message = message.Substring(0, message.Length - 1);
                //    //System.Windows.Forms.MessageBox.Show(message);

                //}
                //else
                //{
                //    MessageBox.Show("文件读取成功！\n\r已在" + filePath + "下\n\r读取了 0 张Sheet工作表");
                //}
                if (_readSheetName == null || _readSheetName.Count == 0)
                {
                    MessageBox.Show("文件读失败，未找到符合的系统要求的工作表！");
                }
            }
            else
            {
                //MessageBox.Show("文件读取失败！\n\r已在" + filePath + "下\n\r读取了 0 张Sheet工作表\n\r请稍后在试！");
                MessageBox.Show("文件读取失败,请联系管理员！");
            }
        }

        private void ReadExcelToDataSet()
        {
            OleDbConnection connExcel = null;
            try
            {
                _readSheetName = new List<string>();
                _dsExcel = new DataSet();

                var connString = "";
                if (_fileExt.ToUpper() == ".XLSX")
                {
                    connString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + _filePath +
                                 ";Extended Properties='Excel 12.0;HDR=YES;IMEX=1'";
                }
                else
                {
                    connString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source = " + _filePath +
                                 ";Extended Properties = 'Excel 8.0;HDR=YES;IMEX=1'";
                }
                connExcel = new OleDbConnection(connString);
                connExcel.Open();
                var dtSheetNames = connExcel.GetOleDbSchemaTable(OleDbSchemaGuid.Tables,
                    new object[] { null, null, null, "TABLE" });
                var sqlExcel = "";
                OleDbDataAdapter myCommand = null;
                var tableName = "";
                var selectTable = "";
                if (_sheetNames != null && _sheetNames.Count > 0)
                {
                    foreach (var sheetName in _sheetNames)
                    {
                        Debug.Assert(dtSheetNames != null, "dtSheetNames != null");
                        for (var i = 0; i < dtSheetNames.Rows.Count; i++)
                        {
                            var res = 0;
                            tableName = dtSheetNames.Rows[i]["TABLE_NAME"].ToString().Replace("'", "").Replace("$", "");
                            selectTable = dtSheetNames.Rows[i]["TABLE_NAME"].ToString();
                            if (tableName.Length <= 4 || tableName.Equals("_xlnm#_FilterDatabase") ||
                                !int.TryParse(tableName.Substring(0, 4), out res) ||
                                tableName.IndexOf("_", StringComparison.Ordinal) == (tableName.Length - 1) ||
                                tableName.IndexOf("FilterDatabase", StringComparison.Ordinal) != -1) continue;
                            if (!(tableName.Replace("'", "").Replace("$", "")).Equals(sheetName)) continue;
                            sqlExcel = string.Format(" select * from  [" + selectTable + "]");
                            myCommand = new OleDbDataAdapter(sqlExcel, connString);
                            myCommand.Fill(_dsExcel, tableName);
                            RemoveEmptyRow(_dsExcel.Tables[tableName]);
                            _readSheetName.Add(tableName);
                            break;
                        }
                    }
                }
                else
                {
                    Debug.Assert(dtSheetNames != null, "dtSheetNames != null");
                    for (var i = 0; i < dtSheetNames.Rows.Count; i++)
                    {
                        var res = 0;
                        tableName = dtSheetNames.Rows[i]["TABLE_NAME"].ToString().Replace("'", "").Replace("$", "");
                        selectTable = dtSheetNames.Rows[i]["TABLE_NAME"].ToString();
                        if (tableName.Length <= 4 || tableName.Equals("_xlnm#_FilterDatabase") ||
                            !int.TryParse(tableName.Substring(0, 4), out res) ||
                            tableName.IndexOf("_", StringComparison.Ordinal) == (tableName.Length - 1) ||
                            tableName.IndexOf("FilterDatabase", StringComparison.Ordinal) != -1) continue;
                        sqlExcel = string.Format(" select * from  [" + selectTable + "]");
                        myCommand = new OleDbDataAdapter(sqlExcel, connString);
                        myCommand.Fill(_dsExcel, tableName);
                        RemoveEmptyRow(_dsExcel.Tables[tableName]);
                        _readSheetName.Add(tableName);
                    }
                }
                connExcel.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            finally
            {
                if (connExcel != null)
                {
                    connExcel.Close();
                }
            }
        }


        private void ReadToDataTable()
        {
            OleDbConnection connExcel = null;
            try
            {
                _readSheetName = new List<string>();
                _dsExcel = new DataSet();
                var connString = "";
                if (_fileExt.ToUpper() == ".XLSX")
                {
                    connString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + _filePath +
                                 ";Extended Properties='Excel 12.0;HDR=YES;IMEX=1'";
                }
                else
                {
                    connString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source = " + _filePath +
                                 ";Extended Properties = 'Excel 8.0;HDR=YES;IMEX=1'";
                }
                connExcel = new OleDbConnection(connString);
                connExcel.Open();
                var dtSheetNames = connExcel.GetOleDbSchemaTable(OleDbSchemaGuid.Tables,
                    new object[] { null, null, null, "TABLE" });

                var sqlExcel = "";
                OleDbDataAdapter myCommand = null;
                var tableName = "";
                var selectTable = "";
                if (string.IsNullOrEmpty(_sheetName))
                {
                    var b = true;
                    var i = 0;
                    while (b)
                    {
                        if (dtSheetNames != null)
                        {
                            tableName = dtSheetNames.Rows[i]["TABLE_NAME"].ToString().Replace("'", "").Replace("$", "");
                            selectTable = dtSheetNames.Rows[i]["TABLE_NAME"].ToString();
                        }
//                        int res;
                        if (tableName.Length <= 4 
                            || tableName.Equals("_xlnm#_FilterDatabase") 
//                            || !int.TryParse(tableName.Substring(0, 4), out res) 
                            || tableName.IndexOf("_", StringComparison.Ordinal) == (tableName.Length - 1) 
                            || tableName.IndexOf("FilterDatabase", StringComparison.Ordinal) != -1
                            )
                        {
                            if (dtSheetNames != null && i < dtSheetNames.Rows.Count)
                            {
                                i++;
                            }
                            else
                            {
                                b = false;
                            }
                        }
                        else
                        {
                            sqlExcel = string.Format(" select * from  [" + selectTable + "]");
                            myCommand = new OleDbDataAdapter(sqlExcel, connString);
                            myCommand.Fill(_dsExcel, tableName);
                            RemoveEmptyRow(_dsExcel.Tables[tableName]);
                            _dtExcel = _dsExcel.Tables[0];
                            _readSheetName.Add(tableName);
                            b = false;
                        }
                    }
                }
                else
                {
                    Debug.Assert(dtSheetNames != null, "dtSheetNames != null");
                    for (var i = 0; i < dtSheetNames.Rows.Count; i++)
                    {
                        tableName = dtSheetNames.Rows[i]["TABLE_NAME"].ToString().Replace("'", "").Replace("$", "");
                        selectTable = dtSheetNames.Rows[i]["TABLE_NAME"].ToString();
                        if (!(tableName).Equals(_sheetName)) continue;
                        sqlExcel = string.Format(" select * from  [" + selectTable + "]");
                        myCommand = new OleDbDataAdapter(sqlExcel, connString);
                        myCommand.Fill(_dsExcel, tableName);
                        RemoveEmptyRow(_dsExcel.Tables[tableName]);
                        _dtExcel = _dsExcel.Tables[_sheetName];
                        _readSheetName.Add(tableName);
                        return;
                    }
                }
                connExcel.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            finally
            {
                if (connExcel != null)
                {
                    connExcel.Close();
                }
            }
        }

        public static void RemoveEmptyRow(DataTable dt)
        {
            if (dt == null || dt.Rows.Count == 0)
                return;
            var isEmpty = true;
            for (var idx = dt.Rows.Count - 1; idx >= 0; idx--)
            {
                var dr = dt.Rows[idx];
                for (var i = 0; i < dt.Columns.Count; i++)
                {
                    if (dr[i].ToString().Trim() != string.Empty)
                    {
                        isEmpty = false;
                    }
                }
                if (isEmpty)
                    dt.Rows.Remove(dr);
            }
        }
    }
}