Problem $1$: The car garage

Mr$.$ Hook has a garage and wishes to control the information about his business. The first goal is to store information about the cars that the clients bring in for fixing. About these cars, he needs to know the Vehicle Identification Number $($VIN$),$ the license plate, the make, the model, the color, and the year, so he could easily identify the car.

Mr$.$ Hook also needs to know who the car$$s owner is$,$ which must be the client in the file. If somebody brings someone else's car for repair, they must have the owners name $($first name and last name$)$ and phone number to identify the client properly. Besides the name and phone number, Mr$.$ Hook also needs to know the client's address, which includes the number and street name, apartment$/$unit number $($optional$),$ city, state, and zipcode. The system does not need to be prepared for international addresses $($only USA$).$ A client may bring more than one car to the shop. For safety reasons, Mr$.$ Hook wants to store data about one or more authorized contacts, who are authorized to check out the car from the garage, in case the client can't be there. The required information are full name $($first and last names$)$ and phone number. In Mr$.$ Hook's business, clients and authorized contacts are identified by a combination of their names and phone number.

Clients can go to the garage shop for shopping car supplies only, in this case they don't have to have a car on the records. About the supplies, Mr$.$ Hook needs to know the supplies unique ID$,$ description, brand, cost price, sale price, and stock quantity for parts and supplies. Besides selling the supplies individually, Mr$.$ Hook may also need to use car parts when repairing the vehicles. In this case, clients have $20\%$ discount over the sale price.

About the repairs, Mr$.$ Hook needs to know the day in which the repair was completed and a description of the detected problem. For each repair, one or more procedures may be performed. About these procedures, Mr$.$ Hook wants to store a procedure code $($which Mr$.$ Hook has created to facilitate the procedures' identification$),$ the description of the procedure and the cost. Additionally, when a car's part or supply is used for a procedure during a repair, Mr$.$ Hook wants to know which ones were used. The repair must have a total cost, which is calculated based on the cost of the parts and supplies, plus the price of the procedures.