SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

-- =============================================
-- Author:		Stoyan Zlatev
-- Create date: 13-04-2023
-- Description:	That trigger should update IdentNrGruppierung, IdentNr_Gruppendetails
--				when a group whit name (WPD [Nennweite] / [Temperatur]°)
--				dose not exists in the IdentNr_Gruppendetails table.
-- Update:		26-04-2023 - @GroupTyp added. 
--				The GroupTyp will be determinated in CASE WHEN ... query 
--				and later used for updates on [IdentNr_Gruppendetail] and [IdentNrGruppierung]
-- =============================================
ALTER TRIGGER [TRG_AfterInsert_UpdateIdentNrGrouping] 
ON [dbo].[Identnr] 
AFTER INSERT
AS 
BEGIN
	-- SET NOCOUNT ON added to prevent extra result sets from interfering with SELECT statements.
	SET NOCOUNT ON;

	DECLARE @IdentNr INT;
	DECLARE @Nennweite INT;
	DECLARE @Temperatur INT;
	DECLARE @Typ VARCHAR(20);
	DECLARE @GroupId INT;
	DECLARE @GroupName VARCHAR(MAX);
	DECLARE @GroupTyp VARCHAR(20);

	-- setting declared field from inserted table 
	SELECT @IdentNr		= [IdentNr] 
		 , @Nennweite	= [Nennweite] 
		 , @Temperatur	= [Temperatur] 
		 , @Typ			= [Typ] 
	  FROM [inserted];

	SET @GroupTyp = (CASE WHEN @Typ LIKE '%WPD%' THEN 'WPD'
						  WHEN @Typ LIKE '%WPF%' THEN 'WPF'
						  WHEN @Typ LIKE '%WSD%' THEN 'WSD'
					 ELSE NULL END);

	IF @GroupTyp IS NOT NULL
	BEGIN
		-- creating a group name from declared values "@GroupTyp [Nennweite] / [Temperatur]°"
		SET @GroupName = @GroupTyp 
					   + ' '
					   + CASE WHEN @Nennweite	IS NOT NULL THEN CAST(@Nennweite	AS VARCHAR(5)) ELSE '0'	END 
					   + ' / '
					   + CASE WHEN @Temperatur	IS NOT NULL THEN CAST(@Temperatur	AS VARCHAR(5)) ELSE '0'	END
					   + '°';

		-- getting next group id
		SET @GroupId = (SELECT TOP 1 [ID] 
						  FROM [IdentNr_Gruppendetail] 
						 WHERE [Name] = @GroupName);

		-- case the group name dose not exist into [IdentNr_Gruppendetail] will be inserted.
		IF @GroupId IS NULL
		BEGIN
			SET @GroupId = (SELECT MAX([ID]) FROM [IdentNr_Gruppendetail]) + 1;

			INSERT INTO [IdentNr_Gruppendetail] ([ID], [Name])
			VALUES (@GroupId, @GroupName)
		END;
	
		-- case the @IdentNr dose not exist [IdentNrGruppierung] will be mapped.
		IF (SELECT COUNT(1) FROM [IdentNrGruppierung] WHERE [IdentNr] = @IdentNr) = 0
		BEGIN
			   SET IDENTITY_INSERT [IdentNrGruppierung] ON;
			INSERT INTO [IdentNrGruppierung] ([IdentNr], [GruppenID], [ID])
			VALUES (@IdentNr, @GroupId, (SELECT MAX([ID]) FROM [IdentNrGruppierung]) + 1)
			   SET IDENTITY_INSERT [IdentNrGruppierung] OFF;
		END;
	END;
END
GO