What is the ruling on money earned from repairing devices in a commercial shop, knowing that the capital belongs to the shop owner and the agreement was to split the profits from selling goods equally?

Scholars have differed on the permissibility of agreeing to half the profit generated from selling devices. The majority do not permit it due to the ambiguity of the wage, while some validate it. As for repairing devices, an agreement can be made with the shop owner for a specific wage or a percentage of the revenue. If you earn money from repairs without the shop owner's permission, or by using his tools, or if your work causes a disruption in sales, the shop owner has the right to demand compensation for the shortcomings or for the use of his tools.