using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;

namespace DBComm
{
    static class DBCommand
    {
        public class DBParameters
        {
            private SqlCommand m_owner = null;
            public DBParameters(SqlCommand owner)
            {
                m_owner = owner;
            }
            public SqlParameterCollection P()
            {
                return m_owner.Parameters;
            }
        };

        public static bool BulkToDB(string tabname, DataTable dt, params string[] destColumnNames)
        {
            bool bRet = false;
            do
            {
                    if (dt == null)
                        break;
                    if (dt.Rows.Count == 0)
                        break;
                    using (SqlConnection conn = DBConn.GetConn())
                    {
                        if (conn == null)
                            break;

                        SqlBulkCopy bulkcopy = new SqlBulkCopy(conn);
                        if (bulkcopy == null)
                            break;

                        bulkcopy.DestinationTableName = tabname;
                        bulkcopy.BulkCopyTimeout = 30;
                        if (destColumnNames.Length == 0)
                        {
                            foreach (DataColumn col in dt.Columns)
                                bulkcopy.ColumnMappings.Add(col.ColumnName, col.ColumnName);
                        }
                        else
                        {
                            if (destColumnNames.Length == dt.Columns.Count)
                            {
                                for (int i = 0; i < destColumnNames.Length; ++i)
                                {
                                    bulkcopy.ColumnMappings.Add(dt.Columns[i].ColumnName, destColumnNames[i]);
                                }
                            }
                        }
                        bulkcopy.BatchSize = dt.Rows.Count;
                        try
                        {
                            bulkcopy.WriteToServer(dt);
                        }
                        catch (System.Exception e)
                        {
                            string err = e.Message;
                            break;
                        }
                        finally
                        {
                            bulkcopy.Close();
                        }
                    }
                    bRet = true;
            } while (false);
            return bRet;
        }

        public static DBParameters ExecProcNonQuery(string proc_name, object[] paraValues)
        {
            using (SqlConnection conn = DBConn.GetConn())
            {
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.CommandText = proc_name;

                AddInParaValues(cmd, paraValues);
                cmd.ExecuteNonQuery();

                return new DBParameters(cmd);
            }
        }

        public delegate T[] FillValues(SqlDataReader reader);

        public static T[] QuerySomes(string sql, FillValues fill)
        {
            using (SqlConnection conn = DBConn.GetConn())
            {
                T[] result = null;
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;
                cmd.CommandText = sql;


                SqlDataReader reader = null;
                lock (reader = cmd.ExecuteReader())
                {
                    try
                    {
                        result = fill(reader);
                    }
                    catch (Exception e)
                    {
                        throw new Exception(e.StackTrace);
                    }
                    finally
                    {
                        reader.Close();
                    }
                }
                return result;
            }
        }

        public delegate object FillValue(SqlDataReader reader);

        public static object QuerySome(string sql, FillValue fill)
        {
            using (SqlConnection conn = DBConn.GetConn())
            {
                object result = null;
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;
                cmd.CommandText = sql;
                SqlDataReader reader = null;
                lock (reader = cmd.ExecuteReader())
                {
                    try
                    {
                        result = fill(reader);
                    }
                    catch (Exception e)
                    {
                        throw new Exception(e.StackTrace);
                    }
                    finally
                    {
                        reader.Close();
                    }
                }
                return result;
            }
        }

        public static object FillResultValue(SqlDataReader reader)
        {
            object o = null;
            if (reader.Read())
            {
                o = reader.GetValue(0);
            }
            return o;
        }

        public static bool QueryBoolean(string sql)
        {
            return Convert.ToBoolean(QuerySome(sql, new FillValue(FillResultValue)));
        }

        public static byte[] QueryBytes(string sql)
        {
            return (byte[])(QuerySome(sql, new FillValue(FillResultValue)));
        }

        public static int QueryInteger(string sql)
        {
            return Convert.ToInt32(QuerySome(sql, new FillValue(FillResultValue)));
        }


        public static string QueryStr(string sql)
        {
            return QuerySome(sql, new FillValue(FillResultValue)) as string;
        }

        private static string[] FillStrsValue(SqlDataReader reader)
        {
            List lststr = new List();
            while (reader.Read())
            {
                lststr.Add(reader.GetString(0));
            }
            return lststr.ToArray();
        }

        public static string[] QueryStrs(string sql)
        {
            return QuerySomes(sql, new FillValues(FillStrsValue));
        }

        private static bool[] FillBooleansValue(SqlDataReader reader)
        {
            List lstbool = new List();
            while (reader.Read())
            {
                lstbool.Add(reader.GetBoolean(0));
            }
            return lstbool.ToArray();
        }

        public static bool[] QueryBooleans(string sql)
        {
            return QuerySomes(sql, new FillValues(FillBooleansValue));
        }

        public static void ExecCmd(string sql)
        {
            using (SqlConnection conn = DBConn.GetConn())
            {
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;
                cmd.CommandText =