using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;
using System.Text;
using BLToolkit.Mapping;
using Sybase.Data.AseClient;

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

    public class SybaseDataProvider : DataProviderBase
    {
        public override IDbConnection CreateConnectionObject()
        {
            return new AseConnection();
        }

        public override DbDataAdapter CreateDataAdapterObject()
        {
            return new AseDataAdapter();
        }

        public override bool DeriveParameters(IDbCommand command)
        {
            AseCommandBuilder.DeriveParameters((AseCommand)command);
            return true;
        }

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

                case ConvertType.NameToQueryField:
                case ConvertType.NameToQueryFieldAlias:
                case ConvertType.NameToQueryTableAlias:
                    {
                        string name = value.ToString();

                        if (name.Length > 0 && name[0] == '[')
                            return value;
                    }

                    return "[" + value + "]";

                case ConvertType.NameToDatabase:
                case ConvertType.NameToOwner:
                case ConvertType.NameToQueryTable:
                    {
                        string name = value.ToString();

                        if (name.Length > 0 && name[0] == '[')
                            return value;

                        if (name.IndexOf('.') > 0)
                            value = string.Join("].[", name.Split('.'));
                    }

                    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.ExceptionToErrorNumber:
                    if (value is AseException)
                    {
                        AseException ex = (AseException)value;

                        foreach (AseError error in ex.Errors)
                            if (error.IsError)
                                return error.MessageNumber;

                        foreach (AseError error in ex.Errors)
                            if (error.MessageNumber != 0)
                                return error.MessageNumber;

                        return 0;
                    }

                    break;

                case ConvertType.ExceptionToErrorMessage:
                    if (value is AseException)
                    {
                        try
                        {
                            AseException  ex = (AseException)value;
                            StringBuilder sb = new StringBuilder();

                            foreach (AseError error in ex.Errors)
                                if (error.IsError)
                                    sb.AppendFormat("{0} Ln: {1}{2}",
                                        error.Message.TrimEnd('\n', '\r'), error.LineNum, Environment.NewLine);

                            foreach (AseError error in ex.Errors)
                                if (!error.IsError)
                                    sb.AppendFormat("* {0}{1}", error.Message, Environment.NewLine);

                            return sb.Length == 0 ? ex.Message : sb.ToString();
                        }
                        catch
                        {
                        }
                    }

                    break;
            }

            return value;
        }

        public override void AttachParameter(IDbCommand command, IDbDataParameter parameter)
        {
            if (parameter.Value is string && parameter.DbType == DbType.Guid)
                parameter.DbType = DbType.AnsiString;

            base.AttachParameter(command, parameter);
            
            AseParameter p = (AseParameter)parameter;

            if (p.AseDbType == AseDbType.Unsupported && p.Value is DBNull)
                parameter.DbType = DbType.AnsiString;
        }

        public override Type ConnectionType
        {
            get { return typeof(AseConnection); }
        }

        public override string Name
        {
            get { return DataProvider.ProviderName.Sybase; }
        }

        public override ISqlProvider CreateSqlProvider()
        {
            return new SybaseSqlProvider(this);
        }

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

            List<IDbDataParameter> list = null;

            if (commandParameters != null) for (int i = 0; i < commandParameters.Length; i++)
            {
                IDbDataParameter p = commandParameters[i];

                if (p.Value is Guid)
                {
                    p.Value  = p.Value.ToString();
                    p.DbType = DbType.StringFixedLength;
                    p.Size   = 36;
                }

                if (commandType == CommandType.Text)
                {
                    if (commandText.IndexOf(p.ParameterName) < 0)
                    {
                        if (list == null)
                        {
                            list = new List<IDbDataParameter>(commandParameters.Length);

                            for (int j = 0; j < i; j++)
                                list.Add(commandParameters[j]);
                        }
                    }
                    else
                    {
                        if (list != null)
                            list.Add(p);
                    }
                }
            }

            if (list != null)
                commandParameters = list.ToArray();
        }

        #region DataReaderEx

        public override IDataReader GetDataReader(MappingSchema schema, IDataReader dataReader)
        {
            return dataReader is AseDataReader?
                new DataReaderEx((AseDataReader)dataReader):
                base.GetDataReader(schema, dataReader);
        }

        class DataReaderEx : DataReaderBase<AseDataReader>, IDataReader
        {
            public DataReaderEx(AseDataReader rd): base(rd)
            {
            }

            public new object GetValue(int i)
            {
                object value = DataReader.GetValue(i);

                if (value is DateTime)
                {
                    DateTime dt = (DateTime)value;

                    if (dt.Year == 1900 && dt.Month == 1 && dt.Day == 1)
                        return new DateTime(1, 1, 1, dt.Hour, dt.Minute, dt.Second, dt.Millisecond);
                }

                return value;
            }

            public new DateTime GetDateTime(int i)
            {
                var dt = DataReader.GetDateTime(i);

                if (dt.Year == 1900 && dt.Month == 1 && dt.Day == 1)
                    return new DateTime(1, 1, 1, dt.Hour, dt.Minute, dt.Second, dt.Millisecond);

                return dt;
            }
        }

        #endregion
    }
}