# 1. Goal
A wind farm operator needs the revenue of each wind turbine. The revenue is the
yield of the turbine multiplied by the feed-in tariff of the wind park of the
turbine. A report and an OData service read the revenue, so the calculation must
be in the database, in a CDS view.

# 2. Open questions
None.

# 3. Context
- Table {{P}}WPARK (wind park), package $TMP. Key: PARK_ID (CHAR 10).
  Fields: PARK_NAME (CHAR 40), COUNTRY (CHAR 3), TARIFF (DEC 15,2). TARIFF is
  the feed-in tariff in euro for one MWh.
- Table {{P}}TURBINE (wind turbine), package $TMP. Key: TURBINE_ID (CHAR 10).
  Fields: PARK_ID (CHAR 10), NOMINAL_KW (INT4), YIELD_MWH (DEC 15,2). YIELD_MWH
  is the yield of the turbine in MWh.

# 4. Contract
- Create the CDS view entity {{P}}I_TURBINE in package $TMP.
- Elements, with these names: TURBINE_ID (key), PARK_ID, NOMINAL_KW, YIELD_MWH,
  REVENUE.
- The view exposes an association with the name _PARK. The target of _PARK is
  the wind park of the turbine.
- A caller reads the data of the wind park from the view with a path expression,
  for example \_PARK-PARK_NAME or \_PARK-COUNTRY.
- No authorization check (#NOT_REQUIRED).

# 5. Business rules
1. The view shows one row for each turbine in {{P}}TURBINE.
2. PARK_ID is the park of the turbine.
3. NOMINAL_KW is the nominal power of the turbine.
4. YIELD_MWH is the yield of the turbine.
5. REVENUE is YIELD_MWH multiplied by the TARIFF of the wind park of the
   turbine. REVENUE has 2 decimals.
6. _PARK points to the row of {{P}}WPARK that has the same PARK_ID as the
   turbine.
7. PARK_NAME, COUNTRY and TARIFF of the wind park are available through _PARK.

# 6. Constraints
- Release target: 8.16.
- Coding standards: Clean ABAP.
- Out of scope: do not change {{P}}WPARK and {{P}}TURBINE.

# 7. Acceptance
- The view is active and has no syntax error.
- The hidden tests pass.
- Write ABAP Unit tests with CL_CDS_TEST_ENVIRONMENT in a global test class.