using System;
using System.Data;
using System.Data.Common;
using Iesi.Collections.Generic;

namespace NHibernate.Dialect.Schema
{
	/// <summary>
	/// Metadata support for connections using the iAnywhere.Data.SQLAnywhere 
	/// ADO.NET provider for SQL Anywhere 11 - for the NHibernate 3.2.0 distribution
	/// 
        /// Contact: http://iablog.sybase.com/paulley
	///
	/// This NHibernate dialect for SQL Anywhere 12 is a contribution to the NHibernate
        /// open-source project. It is intended to be included in the NHibernate 
        /// distribution and is licensed under LGPL.
	///
	/// This library is free software; you can redistribute it and/or
	/// modify it under the terms of the GNU Lesser General Public
	/// License as published by the Free Software Foundation; either
	/// version 2.1 of the License, or (at your option) any later version.
	///
	/// This library is distributed in the hope that it will be useful,
	/// but WITHOUT ANY WARRANTY; without even the implied warranty of
	/// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
	/// Lesser General Public License for more details.
	///
	/// You should have received a copy of the GNU Lesser General Public
	/// License along with this library; if not, write to the Free Software
	/// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
	///
	/// </summary>
	/// <remarks>
        /// The SQLAnywhere11DataBaseMetaData, SQLAnywhere11TableMetaData, and the like offer
        /// support for the .NET metadata APIs from within NHibernate. This file is now versioned
        /// with "SQL Anywhere 11" to accomodate API changes with later SQL Anywhere releases.
	/// </remarks>
	public class SybaseSQLAnywhere11DataBaseMetaData : AbstractDataBaseSchema
	{
		public SybaseSQLAnywhere11DataBaseMetaData(DbConnection connection) : base( connection ) 
		{
		}

		public override ITableMetadata GetTableMetadata(DataRow rs, bool extras)
		{
			return new SybaseSQLAnywhere11TableMetaData(rs, this, extras);
		}

		public override DataTable GetTables(string catalog, string schemaPattern, string tableNamePattern, string[] types)
		{
			var restrictions = new[] {schemaPattern, tableNamePattern, null};
			DataTable objTbl = Connection.GetSchema("Tables", restrictions);
			return objTbl;
		}

		public override DataTable GetIndexInfo(string catalog, string schemaPattern, string tableName)
		{
			var restrictions = new[] {schemaPattern, tableName, null};
			DataTable objTbl = Connection.GetSchema("Indexes", restrictions);
			return objTbl;
		}

		public override DataTable GetIndexColumns(string catalog, string schemaPattern, string tableName, string indexName)
		{
			var restrictions = new[] {schemaPattern, tableName, indexName, null};
			DataTable objTbl = Connection.GetSchema("IndexColumns", restrictions);
			return objTbl;
		}

		public override DataTable GetColumns(string catalog, string schemaPattern, string tableNamePattern,
		                                     string columnNamePattern)
		{
			var restrictions = new[] {schemaPattern, tableNamePattern, null};
			DataTable objTbl = Connection.GetSchema("Columns", restrictions);
			return objTbl;
		}

		public override DataTable GetForeignKeys(string catalog, string schema, string table)
		{
			var restrictions = new[] {schema, table, null};
			DataTable objTbl = Connection.GetSchema("ForeignKeys", restrictions);
			return objTbl;
		}

		public override ISet<string> GetReservedWords()
		{
			var result = new HashedSet<string>();
			DataTable dtReservedWords = Connection.GetSchema(DbMetaDataCollectionNames.ReservedWords);
			foreach (DataRow row in dtReservedWords.Rows)
			{
				result.Add(row["reserved_word"].ToString());
			}
			return result;
		}

	}

	public class SybaseSQLAnywhere11TableMetaData : AbstractTableMetadata
	{
		public SybaseSQLAnywhere11TableMetaData(DataRow rs, IDataBaseSchema meta, bool extras) : base(rs, meta, extras) {}

		protected override IColumnMetadata GetColumnMetadata(DataRow rs)
		{
			return new SybaseSQLAnywhere11ColumnMetaData(rs);
		}

		protected override string GetColumnName(DataRow rs)
		{
			return Convert.ToString(rs["COLUMN_NAME"]);
		}

		protected override string GetConstraintName(DataRow rs)
		{
			// The ADO provider for SQL Anywhere 11 does not support constraint names. 
			// Hence we simply return the column name here ...
			return Convert.ToString(rs["COLUMN_NAME"]);
		}

		protected override IForeignKeyMetadata GetForeignKeyMetadata(DataRow rs)
		{
			return new SybaseSQLAnywhere11ForeignKeyMetaData(rs);
		}

		protected override IIndexMetadata GetIndexMetadata(DataRow rs)
		{
			return new SybaseSQLAnywhere11IndexMetaData(rs);
		}

		protected override string GetIndexName(DataRow rs)
		{
			return (string) rs["INDEX_NAME"];
		}

		protected override void ParseTableInfo(DataRow rs)
		{
			Catalog = null;
			Schema = Convert.ToString(rs["TABLE_SCHEMA"]);
			if (string.IsNullOrEmpty(Schema))
			{
				Schema = null;
			}
			Name = Convert.ToString(rs["TABLE_NAME"]);
		}
	}

	public class SybaseSQLAnywhere11ColumnMetaData : AbstractColumnMetaData
	{
		public SybaseSQLAnywhere11ColumnMetaData(DataRow rs) : base(rs)
		{
			Name = Convert.ToString(rs["COLUMN_NAME"]);
			object objValue = rs["COLUMN_SIZE"];
			if (objValue != DBNull.Value)
			{
				ColumnSize = Convert.ToInt32(objValue);
			}
			objValue = rs["PRECISION"];
			if (objValue != DBNull.Value)
			{
				NumericalPrecision = Convert.ToInt32(objValue);
			}
			Nullable = Convert.ToString(rs["IS_NULLABLE"]);
			TypeName = Convert.ToString(rs["DATA_TYPE"]);
		}
	}

	public class SybaseSQLAnywhere11IndexMetaData : AbstractIndexMetadata
	{
		public SybaseSQLAnywhere11IndexMetaData(DataRow rs) : base(rs)
		{
			Name = (string) rs["INDEX_NAME"];
		}
	}

	public class SybaseSQLAnywhere11ForeignKeyMetaData : AbstractForeignKeyMetadata
	{
		public SybaseSQLAnywhere11ForeignKeyMetaData(DataRow rs) : base(rs)
		{
		    // SQL Anywhere 11 does support constraint names but the version 11 ADO.NET 
		    // provider does not offer an ability to retrieve them... so we merely
		    // return the column name.

			Name = (string) rs["COLUMN_NAME"];
		}
	}
}