using System;
using System.Collections.Generic;
using System.Data.Common;
using Sarand.Net.Standard.Base.Bus;
using Sarand.Net.Standard.Base.Core;

namespace Sarand.Net.Standard.Base.Dbas
{
	//=======================================================================
	// Definitions.
	public enum DbmsType
	{
		General = 0,
		Access = 10,
		MsSql,
		MySql,
		Oracle,
		Pervasive,
		Dbase,
		FoxPro,
		Paradox,
		Interbase,
		Postgres,
		/// <summary>Sage db - No 'AS' in table alias, no 'OUTER' in join type.</summary>
		Sage,
		QBooks,
		SybaseAdvantage,
	}
	public enum SelectLockMode
	{
		/// <summary>No specific lock mode requested - use DBMS default.</summary>
		Default,
		/// <summary>Shared locks (MSSQL default). [MSSQL]</summary>
		ReadCommitted,
		/// <summary>Dirty reads - no locking. [MSSQL]</summary>
		ReadUncommitted,
		/// <summary>Locks all data in query. [MSSQL]</summary>
		RepeatableRead,
		/// <summary>Range lock on data preventing modifications. [MSSQL]</summary>
		Serializable,
	};
	/// <summary>Reserved word delimiters - used by database definitions.</summary>
	public enum DbReservedWordDelim
	{
		None,
		SquareBrackets,
		DoubleQuotes
	};
	public enum DbGetValueType { eDbValueSum, eDbValueMin, eDbValueMax };

	//=======================================================================
	public interface ISacsDatabase : ISacsStateItem
	{
		//-------------------------------------------------------------------
		// Database properties.
		String ConnectionString { get; }
		DbmsType DbmsType { get; }
		String DatabaseName { get; }
		SelectLockMode SelectLockMode { get; set; }
		bool DisplayErrors { get; set; }
		DbConnection CreateConnection(bool forceOdbc = false);

		//-------------------------------------------------------------------
		// Identity generation.
		SysId GetNextId(String objectName, DbUpdateInfo dbUpdateInfo, bool databaseTable = true, String idColumn = "Id");
		int GetNextIdFromTable(String objectName, String idColumn = "Id");
		bool SetMinNextId(String objectName, SysId id, DbUpdateInfo dbUpdateInfo, bool databaseTable = true, String idColumn = "Id", bool force = false);

		//-------------------------------------------------------------------
		// Database schema.
		HashSet<String> GetTableNames(bool refresh = false);
		List<DbDfnTable> GetTableDfns(bool refresh = false);
		DbDfnTable GetTableDfn(String name, bool refresh = false);
		bool TableExists(String tableName);
		bool ColumnExists(String tableName, String columnName);
		bool IndexExists(String tableName, String indexName);
		// Database info - schema summary.
		IDatabaseInfo CreateDbInfo();

		//-------------------------------------------------------------------
		// Query records.
		String GetSelectQueryPrefix();
		/// <summary>
		/// Execute query directly against database.
		/// <para>- NB Check for null response and error state.</para>
		/// </summary>
		DbResultSet ExecuteQuery(String query);
		int ExecuteNonQuery(String query);
		int ExecuteInsert(String tableName, List<StringPair> columnNameValues);
		int ExecuteUpdate(String tableName, List<StringPair> columnNameValues, String filter);
		int ExecuteDelete(String tableName, String filter);
		// Specific queries.
		long GetRowCount(String tableName, String filter);
		DataValue GetRowValue(String tableName, String columnName, String filter);
		DataValue GetRowValue(String tableName, String columnName, String filter, DbGetValueType getValueType);

		//-------------------------------------------------------------------
	}

	//=======================================================================
}