# Shop Image

USE PARTS;

DROP TRIGGER IF EXISTS before_insert_Shop_Image;
DROP TRIGGER IF EXISTS before_update_Shop_Image;


DELIMITER //
CREATE TRIGGER before_insert_Shop_Image
BEFORE INSERT ON Shop_Image
FOR EACH ROW
BEGIN
	SET NEW.created_on = NOW();
    SET NEW.created_by = CURRENT_USER();
END //
DELIMITER ;


DELIMITER //
CREATE TRIGGER before_update_Shop_Image
BEFORE UPDATE ON Shop_Image
FOR EACH ROW
BEGIN
	IF OLD.id_change_set <=> NEW.id_change_set THEN
		SIGNAL SQLSTATE '45000'
        SET MESSAGE_TEXT = 'New change set ID must be provided.';
    END IF;
    IF ISNULL(NEW.id_product) AND ISNULL(NEW.id_permutation) THEN
		SIGNAL SQLSTATE '45000'
        SET MESSAGE_TEXT = 'Image must NOT have ID for product AND product permutation.';
    END IF;
    
    INSERT INTO Shop_Image_Audit (
		id_image,
        name_field,
        value_prev,
        value_new,
        id_change_set
    )
    # Changed id_type_image
	SELECT NEW.id_image, 'id_type_image', CONVERT(OLD.id_type_image, CHAR), CONVERT(NEW.id_type_image, CHAR), NEW.id_change_set
		WHERE NOT OLD.id_type_image <=> NEW.id_type_image
    UNION
    # Changed id_type_file
	SELECT NEW.id_image, 'id_type_file', CONVERT(OLD.id_type_file, CHAR), CONVERT(NEW.id_type_file, CHAR), NEW.id_change_set
		WHERE NOT OLD.id_type_file <=> NEW.id_type_file
    UNION
    # Changed id_product
	SELECT NEW.id_image, 'id_product', CONVERT(OLD.id_product, CHAR), CONVERT(NEW.id_product, CHAR), NEW.id_change_set
		WHERE NOT OLD.id_product <=> NEW.id_product
    UNION
    # Changed id_permutation
	SELECT NEW.id_image, 'id_permutation', CONVERT(OLD.id_permutation, CHAR), CONVERT(NEW.id_permutation, CHAR), NEW.id_change_set
		WHERE NOT OLD.id_permutation <=> NEW.id_permutation
    UNION
    # Changed url
	SELECT NEW.id_image, 'url', OLD.url, NEW.url, NEW.id_change_set
		WHERE NOT OLD.url <=> NEW.url
	UNION
	# Changed active
	SELECT NEW.id_image, '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_image, 'display_order', CONVERT(OLD.display_order, CHAR), CONVERT(NEW.display_order, CHAR), NEW.id_change_set
		WHERE NOT (OLD.display_order <=> NEW.display_order)
	;
END //
DELIMITER ;