using System;
using System.Data;
using System.Data.Common;

using IBM.Data.DB2;

namespace BLToolkit.Data.DataProvider
{
    using Sql.SqlProvider;

    class DB2DataProvider :  DataProviderBase
    {
        public override IDbConnection CreateConnectionObject () { return new DB2Connection ();     }
        public override DbDataAdapter CreateDataAdapterObject() { return new DB2DataAdapter();     }
        public override ISqlProvider  CreateSqlProvider      () { return new DB2SqlProvider(this); }

        public override Type   ConnectionType { get { return typeof(DB2Connection);         } }
        public override string Name           { get { return DataProvider.ProviderName.DB2; } }
        public override string EndOfSql       { get { return ";"; } }

        public override bool DeriveParameters(IDbCommand command)
        {
            if (command is DB2Command)
            {
                DB2CommandBuilder.DeriveParameters((DB2Command)command);
                return true;
            }

            return false;
        }

        public override object Convert(object value, ConvertType convertType)
        {
            switch (convertType)
            {
                case ConvertType.NameToQueryParameter:
                    return "@" + value;

                case ConvertType.NameToCommandParameter:
                case ConvertType.NameToSprocParameter:
                    return ":" + value;

                case ConvertType.SprocParameterToName:
                    if (value != null)
                    {
                        string str = value.ToString();
                        return str.Length > 0 && str[0] == ':'? str.Substring(1): str;
                    }

                    break;

                case ConvertType.NameToQueryField:
                case ConvertType.NameToQueryFieldAlias:
                case ConvertType.NameToQueryTable:
                case ConvertType.NameToQueryTableAlias:
                    return "\"" + value + "\"";

                case ConvertType.ExceptionToErrorNumber:
                    if (value is DB2Exception)
                    {
                        DB2Exception ex = (DB2Exception)value;

                        foreach (DB2Error error in ex.Errors)
                            return error.RowNumber;

                        return 0;
                    }

                    break;
                 
            }

            return value;
        }

        public override void PrepareCommand(ref CommandType commandType, ref string commandText, ref IDbDataParameter[] commandParameters)
        {
            base.PrepareCommand(ref commandType, ref commandText, ref commandParameters);

            if (commandParameters != null) foreach (var p in commandParameters)
            {
                if (p.Value is bool)
                    p.Value = (bool)p.Value ? 1 : 0;
                else if (p.Value is Guid)
                {
                    p.Value  = ((Guid)p.Value).ToByteArray();
                    p.DbType = DbType.Binary;
                    p.Size   = 16;
                }
            }
        }
    }
}