using System;
using Sarand.Net.Standard.Base.Core;
using Sarand.Net.Standard.Base.Bus;
using Sarand.Net.Standard.Base.App;

namespace Sarand.Net.Standard.Base.Dbas
{
	//=======================================================================
	public abstract class DbResultSet : SaErrorStateItem, IDbResultSet
	{
		//-------------------------------------------------------------------
		// Data members.

		//-------------------------------------------------------------------
		// Construction.
		protected DbResultSet()
		{
		}

		//-------------------------------------------------------------------
		// Navigation.
		public abstract bool NextRecord();
		public abstract void Close();

		//-------------------------------------------------------------------
		// Properties.
		public abstract int FieldCount { get; }
		public bool IsValidColumn(int columnIdx)
		{
			return (columnIdx >= 0 && columnIdx < FieldCount);
		}
		public abstract bool HasRows { get; }

		//-------------------------------------------------------------------
		// Field Values.
		public abstract int GetOrdinal(String columnName);
		public abstract String GetDataTypeName(int columnIdx);
		public abstract String GetName(int columnIdx);
		public abstract bool IsDbNull(int columnIdx);
		public abstract Object GetValue(int columnIdx);
		public abstract bool GetBoolean(int columnIdx);
		public abstract byte GetByte(int columnIdx);
		public abstract short GetInt16(int columnIdx);
		public abstract int GetInt32(int columnIdx);
		public abstract long GetInt64(int columnIdx);
		public abstract float GetFloat(int columnIdx);
		public abstract double GetDouble(int columnIdx);
		public abstract decimal GetDecimal(int columnIdx);
		public abstract String GetString(int columnIdx);
		public abstract DateTime GetDateTime(int columnIdx);
		public abstract Guid GetGuid(int columnIdx);

		//-------------------------------------------------------------------
		// Get Field Value.
		public DataValue GetFieldValue(String columnName)
		{
			String fn = GetType().Name + ".GetFieldValue('" + columnName + "')";
			DataValue dataValue = null;
			try
			{
				dataValue = GetFieldValue(GetOrdinal(columnName));
			}
			catch (Exception exc)
			{
				SaLogger.Warn(fn + " Exception: " + exc.Message);
			}
			return dataValue;
		}
#if DEBUG
		private static bool handlingGetFieldValueException = false;
#endif
		public DataValue GetFieldValue(int columnIdx)
		{
			String fn = GetType().Name + ".GetFieldValue(" + columnIdx + ")";
			if (IsDbNull(columnIdx)) return null;
			String columnDataType = "";
			DataValue dataValue = null;
			try
			{
				columnDataType = GetDataTypeName(columnIdx);
				switch (columnDataType)
				{
					// Catering for c# (DataTableReader) and sql (DbDataReader) type names
					case "bit":
					case "Bool":
						dataValue = new DataValue(GetBoolean(columnIdx));
						break;
					case "tinyint":
						dataValue = new DataValue((long)GetByte(columnIdx));
						break;
					case "smallint":
					case "Int16":
						dataValue = new DataValue((long)GetInt16(columnIdx));
						break;
					case "int":
					case "int identity":
					case "Int32":
						dataValue = new DataValue((long)GetInt32(columnIdx));
						break;
					case "bigint":
					case "Int64":
						dataValue = new DataValue((long)GetInt64(columnIdx));
						break;
					case "real":
					case "float":
					case "Float":
					case "Single":
					case "Double":
						dataValue = new DataValue(GetDouble(columnIdx));
						break;
					case "decimal":
					case "Decimal":
					case "numeric":
					case "Numeric":
						dataValue = new DataValue(GetDecimal(columnIdx));
						break;
					case "char":
					case "varchar":
					case "nvarchar":
					case "String":
						dataValue = new DataValue(GetString(columnIdx));
						break;
					case "datetime":
					case "DateTime":
					case "smalldatetime":
					case "SmallDateTime":
						dataValue = new DataValue(GetDateTime(columnIdx));
						break;
					case "UniqueIdentifier":
						dataValue = new DataValue(GetGuid(columnIdx));
						break;
					default:
						SaLogger.Warn(fn + " Unrecognised data type '" + columnDataType + "' for column '" + GetName(columnIdx) + "'");
						break;
				}
			}
			catch (Exception exc)
			{
				SaLogger.Warn(fn + " Data type: " + columnDataType + ". Exception: " + exc.Message /*+ "\n" + exc.ToString()*/);
#if DEBUG
				if (!handlingGetFieldValueException)
				{
					// Reinvoke for debugging.
					handlingGetFieldValueException = true;
					DataValue value = GetFieldValue(columnIdx);
					handlingGetFieldValueException = false;
				}
#endif
			}
			return dataValue;
		}
		// Get Record Values.
		public NamedValue.Map GetRecordValues()
		{
			NamedValue.Map values = null;
			values = new NamedValue.Map();
			for (int columnIdx = 0; columnIdx < FieldCount; columnIdx++)
			{
				String columnName = GetName(columnIdx);
				DataValue dataValue = GetFieldValue(columnIdx);
				if (dataValue != null)
					values.AddValue(columnName, dataValue);
			}
			return values;
		}

		//-------------------------------------------------------------------
		// Logging.
		public static SaMessageLevel LoggingLevel { get; set; } = SaMessageLevel.None;
		public static String LoggingPrefix { get; set; } = " ~~~ ";
		protected static void Log(String fn, String message, SaMessageLevel level = SaMessageLevel.Debug)
		{
			if ((int)level > (int)LoggingLevel) return;
			SaLogger.Log((fn + "\n\t" + message).Trim(), level);
		}

		//-------------------------------------------------------------------
	}
	//=======================================================================
}