using System;
using System.Collections.Generic;
using System.Data;
using System.Data.OleDb;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;


namespace BPASmartClient.Helper
{
    public class ExcelHelper
    {
        public  DataTable GetExcelToDataTableBySheet(string FileFullPath, string SheetName)

        {

            //此连接只能操作Excel2007之前(.xls)文件

            //string strConn = "Provider=Microsoft.Jet.OleDb.4.0;" + "data source=" + FileFullPath + ";Extended Properties='Excel 8.0; HDR=NO; IMEX=1'";

            //此连接可以操作.xls与.xlsx文件

            string strConn = "Provider=Microsoft.Ace.OleDb.12.0;" + "data source=" + FileFullPath + ";Extended Properties='Excel 12.0; HDR=NO; IMEX=1'";


            OleDbConnection conn = new OleDbConnection(strConn);

            conn.Open();

            DataSet ds = new DataSet();

            OleDbDataAdapter odda = new OleDbDataAdapter(string.Format("SELECT * FROM [{0}]", SheetName), conn);

            //OleDbDataAdapter odda = new OleDbDataAdapter(string.Format("select * from [Sheet1$]", conn),conn);             　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

            odda.Fill(ds, SheetName);

            conn.Close();

            return ds.Tables[0];

        }
        //根据Excel物理路径获取Excel文件中所有表名 

        public String[] GetExcelSheetNames(string excelFile)

        {
            OleDbConnection objConn = null;
            System.Data.DataTable dt = null;
            try
            {
                //此连接只能操作Excel2007之前(.xls)文件

                //string strConn = "Provider=Microsoft.Jet.OleDb.4.0;" + "data source=" + excelFile + ";Extended Properties='Excel 8.0; HDR=NO; IMEX=1'";

                //此连接可以操作.xls与.xlsx文件

                string strConn = "Provider=Microsoft.Ace.OleDb.12.0;" + "data source=" + excelFile + ";Extended Properties='Excel 12.0; HDR=NO; IMEX=1'";

                objConn = new OleDbConnection(strConn);
                objConn.Open();
                dt = objConn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);

                if (dt == null)
                {
                    return null;
                }
                String[] excelSheets = new String[dt.Rows.Count];
                int i = 0;
                foreach (DataRow row in dt.Rows)
                {
                    excelSheets[i] = row["TABLE_NAME"].ToString();
                    i++;
                }
                return excelSheets;
            }
            catch
            {
                return null;
            }
            finally
            {
                if (objConn != null)
                {
                    objConn.Close();
                    objConn.Dispose();
                }
                if (dt != null)
                {
                    dt.Dispose();
                }
            }
        }

        public static DataTable ReadDataFromCSV( string file)
        {
            Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);  
            DataTable dt = null;
            if(File.Exists(file))
            {
                dt = new DataTable();
                FileStream fs = new FileStream(file, FileMode.Open,FileAccess.Read);
                StreamReader sr;
                
                try
                {
                    Encoding encoding = Encoding.Default;
                    using (sr = new StreamReader(fs, Encoding.GetEncoding("GB2312")))
                    {
                        string head = sr.ReadLine();
                        string[] headNames = head.Split(',');
                        for (int i = 0; i < headNames.Length; i++)
                        {
                            dt.Columns.Add(headNames[i], typeof(string));
                        }
                        while (!sr.EndOfStream)
                        {
                            string lineStr = sr.ReadLine();
                            if (lineStr != null)
                            {
                                string[] lines = lineStr.Split(',');
                                DataRow dr = dt.NewRow();
                                for (int i = 0; i < lines.Length; i++)
                                {
                                    dr[i] = lines[i];
                                }
                                dt.Rows.Add(dr);
                            }         
                        }
                        sr.Close();
                        fs.Close();
                    }
                    
                }
                catch (Exception ex)
                {
                    MessageLog.GetInstance.ShowEx($"读取csv文件异常：{ex.Message}");
                }
            }
            return dt;

        }
    }


}