//	Spludlow Software
//	Copyright © Samuel P. Ludlow 2020 All Rights Reserved
//	Distributed under the terms of the GNU General Public License version 3
//	Distributed WITHOUT ANY WARRANTY; without implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE
//	https://www.spludlow.co.uk/LICENCE.TXT
//	The Spludlow logo is a registered trademark of Samuel P. Ludlow and may not be used without permission
//	v1.14

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

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

namespace Spludlow.Data
{
	public static class DAL
	{
		public class CommandInfo
		{
			public CommandInfo()
			{
			}

			public bool Identity;

			public string[] ColumnNames;

			public string[] ParameterNames;
			public int[] ParameterTypes;
			public int[] ParameterMaxLengths;
			
			public string CommandText;
		}

		public static IDAL Create(string connectionString)
		{
			if (connectionString.StartsWith("@") == true)
				connectionString = Spludlow.Config.ConnectionString(connectionString.Substring(1));

			string databaseType = "sql";

			if (connectionString.StartsWith("[") == true)
			{
				int index = connectionString.IndexOf("]");
				if (index == -1)
					throw new ApplicationException("DAL Create; Can't find closing square bracket in connection string. Usage [dbtype] Key1=Value1;Key2=Value2;");

				databaseType = connectionString.Substring(1, index - 1).Trim().ToLower();
				connectionString = connectionString.Substring(index + 1).Trim();
			}

			string[] assType;

			switch (databaseType)
			{
				case "sql":
					assType = new string[] { "Spludlow", "Spludlow.Data.DALSql" };
					break;
				case "odbc":
					assType = new string[] { "Spludlow", "Spludlow.Data.DALODBC" };
					break;
				case "oledb":
					assType = new string[] { "Spludlow", "Spludlow.Data.DALOleDb" };
					break;
				case "mysql":
					assType = new string[] { "Spludlow.Data.MySQL", "Spludlow.Data.DALMySQL" };
					break;
				case "sqlite":
					assType = new string[] { "Spludlow.Data.SQLite", "Spludlow.Data.DALSQLite" };
					break;
				case "oracle":
					assType = new string[] { "Spludlow.Data.Oracle", "Spludlow.Data.DALOracle" };
					break;
				case "postgresql":
					assType = new string[] { "Spludlow.Data.PostgreSQL", "Spludlow.Data.DALPostgreSQL" };
					break;
				case "db2":
					assType = new string[] { "Spludlow.Data.DB2", "Spludlow.Data.DALDB2" };
					break;
				case "dbase":
					assType = new string[] { "Spludlow.Data.dBase", "Spludlow.Data.DALdBase" };
					break;
				default:
					throw new ApplicationException("DAL Create; Unknown databse type: " + databaseType);
			}

			return (IDAL)Spludlow.Reflections.MakeInstance(assType[0], assType[1], new object[] { connectionString });
		}

		public static DbParameter AddParameter(DbCommand command, string name, object data)
		{
			DbParameter parameter = command.CreateParameter();
			parameter.ParameterName = name;
			parameter.Value = data;
			command.Parameters.Add(parameter);

			return parameter;
		}
	}
}