# 1. Goal
Calculate the price of a booking at a recording studio. A booking program calls
the calculation before it shows the price to the customer. The program needs one
price for each booking.

# 2. Open questions
None.

# 3. Context
- The interface {{P}}IF_STUDIO_PRICER exists in package $TMP. It is active.
- The interface has the type TY_ROOM (CHAR 1), the type TY_AMOUNT (packed, length
  8, 2 decimals), the constant structure C_ROOM (A, B, C), and one method:
  CALCULATE IMPORTING iv_room TYPE ty_room, iv_minutes TYPE i, iv_bookings TYPE i
  RETURNING VALUE(rv_price) TYPE ty_amount.

# 4. Contract
- Create the class {{P}}STUDIO_PRICER in package $TMP.
- The class is public and final. It has a public constructor without parameters.
- The class implements {{P}}IF_STUDIO_PRICER.
- Do not add other public methods.

# 5. Business rules
Apply the rules in this sequence.
1. The room type is A, B, or C. Any other room type is invalid. For an invalid
   room type, return 0.00.
2. The hourly rate depends on the room type: A 48.00, B 36.00, C 27.00.
3. The booking duration is given in minutes. A started hour counts as a full
   hour. A booking of less than 60 minutes counts as one hour.
4. The base price is the hourly rate multiplied by the number of hours.
5. The loyalty discount is 0.75 percent for each booking of the customer in the
   last 12 months. The discount is at most 15 percent.
6. The discount percentage is rounded.
7. The price is the base price minus the discount. The discount is the rounded
   discount percentage of the base price.
8. Return the price.

# 6. Constraints
- Release target: 8.16.
- Coding standards: Clean ABAP. Method length below 40 statements. No global
  variables. No comment that restates the code.
- Out of scope: do not change {{P}}IF_STUDIO_PRICER.

# 7. Acceptance
- The class is active and has no syntax error.
- The hidden tests pass.
- Write your own ABAP Unit tests for the class.