DROP PROCEDURE IF EXISTS [auditlog].[usp_send]
GO

CREATE PROCEDURE [auditlog].[usp_send] 
  @fromService SYSNAME,
  @toService SYSNAME,
  @onContract SYSNAME,
  @messageType SYSNAME,
  @messageBody NVARCHAR(MAX)
WITH EXECUTE AS 'Kreta_tech_user'  
AS
BEGIN
  SET NOCOUNT ON;

  DECLARE @dialogHandle UNIQUEIDENTIFIER;
  DECLARE @sendCount BIGINT;
  DECLARE @counter INT;
  DECLARE @error INT;


  SET @counter = 1;
  BEGIN TRANSACTION;

    -- message validation check, preventing poison message at the target service validation
    -- target service validates WELL_FORMED_XML types, so it is best to prevent it at here
    
    IF EXISTS (SELECT 1 FROM sys.[service_message_types] WHERE [name] = @messageType)
		  AND ((TRY_CONVERT(xml, @messageBody) IS NOT NULL OR ISJSON(@messageBody) = 1))
    BEGIN
      IF ISJSON(@messageBody) = 0 BEGIN
	      SET @messageBody = CAST(TRY_CONVERT(xml, @messageBody) AS nvarchar(max))
      END
    END
    ELSE BEGIN
	    INSERT INTO [auditlog].[AuditServiceFailedItems] ([conversation_handle], [message_body])
	    VALUES ('00000000-0000-0000-0000-000000000000', @messageBody)
	    COMMIT TRANSACTION;
	    RAISERROR('XML or JSON validation failure before sending. Check [auditlog].[AuditServiceFailedItems] for failed message.', 16,1) WITH LOG;
    END

  -- Will need a loop to retry in case the dialog is
  -- in a state that does not allow transmission
    WHILE (1=1) BEGIN
	   -- Claim a dialog from the dialog pool.
	   -- A new one will be created if none are available.
     
	    EXEC [auditlog].[usp_get_dialog] @fromService, @toService, @onContract, @dialogHandle OUTPUT, @sendCount OUTPUT;

	   -- Attempt to SEND on the dialog
	    IF (@messageBody IS NOT NULL) BEGIN
			 -- If the @messageBody is not null it must be sent explicitly
        
			  SEND ON CONVERSATION @dialogHandle MESSAGE TYPE @messageType (@messageBody);
		  END
	    ELSE BEGIN
			 -- Messages with no body must *not* specify the body,
			 -- cannot send a NULL value argument
			  SEND ON CONVERSATION @dialogHandle MESSAGE TYPE @messageType;
		  END

      SET @error = @@ERROR;
      IF @error = 0 BEGIN
	   -- Successful send, increment count and exit the loop
	      SET @sendCount = @sendCount + 1;
	      BREAK;
      END

      SET @counter = @counter + 1;
      IF @counter > 10 BEGIN
	      -- We failed 10 times in a  row, something must be broken
	      RAISERROR('Failed to SEND on a conversation for more than 10 times. Error %i.', 16, 1, @error) WITH LOG;
	      BREAK;
      END

      -- Delete the associated dialog from the table and try again
      EXEC [auditlog].[usp_delete_dialog] @dialogHandle;
      SELECT @dialogHandle = NULL;
    END

  -- "Criterion" for dialog pool removal is send count > 1000.
  -- Modify to suit application.
  -- When deleting also inform the target to end the dialog.
    IF @sendCount > 1000 BEGIN
      EXEC [auditlog].[usp_delete_dialog] @dialogHandle ;
      SEND ON CONVERSATION @dialogHandle MESSAGE TYPE [EndOfStream];
    END 
    ELSE BEGIN
    -- Free the dialog.
      EXEC [auditlog].[usp_free_dialog] @dialogHandle, @sendCount;
    END
    
  COMMIT TRANSACTION;
END
GO