# 1. Goal
The function module {{P}}CINE_FEE_OLD in function group {{P}}FG_CINE calculates
the price of a cinema ticket order. The code is legacy code. Refactor the
function module in place. The behavior stays the same. The name and the public
interface stay the same.

# 2. Open questions
None.

# 3. Context
- Function group {{P}}FG_CINE exists in package $TMP.
- The function module {{P}}CINE_FEE_OLD exists in this function group. It holds
  the legacy code.
- A ticket desk program calls {{P}}CINE_FEE_OLD for each ticket order. This call
  must not change.

# 4. Contract
- Object: the function module {{P}}CINE_FEE_OLD in function group {{P}}FG_CINE.
- Keep the name and the interface of the function module: the same parameter
  names, parameter kinds, parameter types and the same exception.
- Importing parameters: iv_show_type TYPE string, iv_seats TYPE i,
  iv_show_time TYPE t, iv_cust_type TYPE string.
- Exporting parameters: ev_total TYPE decfloat34, ev_discount TYPE decfloat34.
- Exception: invalid_input.

# 5. Business rules
The legacy source code of {{P}}CINE_FEE_OLD is the only source of the business
rules. Read this source code. The one rule of this task: for every input the
function module returns the same output values and the same exception as before
the refactoring. Do not add, remove or change a rule.

# 6. Constraints
- Release target: SAP_BASIS 816.
- Coding standards: Clean ABAP. No ATC priority 1 or priority 2 finding. Keep
  every procedure and every method below 40 statements. Replace literal numbers
  with named constants. Use meaningful names.
- Out of scope: do not change the interface. Do not change the function group
  {{P}}FG_CINE.

# 7. Acceptance
- {{P}}CINE_FEE_OLD is active and has no syntax error.
- The behavior is unchanged.
- The hidden tests pass.
- Write ABAP Unit tests for the function module in a global test class.