-- Shop Permission

CREATE OR REPLACE FUNCTION before_insert_Shop_Permission()
RETURNS TRIGGER AS $$
BEGIN
	IF NEW.created_on IS NULL THEN
		NEW.created_on = CURRENT_TIMESTAMP;
	END IF;
    IF NEW.created_by IS NULL THEN
		NEW.created_by = CURRENT_USER;
	END IF;

	RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE TRIGGER tri_before_insert_Shop_Permission
BEFORE INSERT ON Shop_Permission
FOR EACH ROW
EXECUTE FUNCTION before_insert_Shop_Permission();


CREATE OR REPLACE FUNCTION before_update_Shop_Permission()
RETURNS TRIGGER AS $$
BEGIN
	IF OLD.id_change_set IS NOT DISTINCT FROM NEW.id_change_set THEN
		RAISE EXCEPTION 'New change Set ID must be provided.'
			USING ERRCODE = '45000';
    END IF;
    
    INSERT INTO Shop_Permission_Audit (
		id_permission,
        name_field,
        value_prev,
        value_new,
        id_change_set
    )
    -- Changed code
	SELECT NEW.id_permission, 'code', OLD.code, NEW.code, NEW.id_change_set
		WHERE NOT OLD.code <=> NEW.code
	UNION
    -- Changed name
	SELECT NEW.id_permission, 'name', OLD.name, NEW.name, NEW.id_change_set
		WHERE NOT OLD.name <=> NEW.name
	UNION
	-- Changed id_permission_group
	SELECT NEW.id_permission, 'id_permission_group', CONVERT(OLD.id_permission_group, CHAR), CONVERT(NEW.id_permission_group, CHAR), NEW.id_change_set
		WHERE NOT OLD.id_permission_group <=> NEW.id_permission_group
	UNION
	-- Changed Id_access_level_required
	SELECT NEW.id_permission, 'Id_access_level_required', CONVERT(OLD.Id_access_level_required, CHAR), CONVERT(NEW.Id_access_level_required, CHAR), NEW.id_change_set
		WHERE NOT OLD.Id_access_level_required <=> NEW.Id_access_level_required
	UNION
	-- Changed active
	SELECT NEW.id_permission, 'active', CONVERT(CONVERT(OLD.active, SIGNED), CHAR), CONVERT(CONVERT(NEW.active, SIGNED), CHAR), NEW.id_change_set
		WHERE NOT (OLD.active <=> NEW.active)
    UNION
    -- Changed display_order
	SELECT NEW.id_permission, 'display_order', CONVERT(OLD.display_order, CHAR), CONVERT(NEW.display_order, CHAR), NEW.id_change_set
		WHERE NOT OLD.display_order <=> NEW.display_order
	;

	RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE TRIGGER tri_before_update_Shop_Permission
BEFORE UPDATE ON Shop_Permission
FOR EACH ROW
EXECUTE FUNCTION before_update_Shop_Permission();