# 1. Goal
A vineyard cooperative collects the harvest reports of its members. The
cooperative needs one evaluation of the harvest for each grape variety. A
planning program calls the evaluation before it plans the transport of the
grapes to the winery.

# 2. Open questions
None.

# 3. Context
- The interface {{P}}IF_HARVEST exists in package $TMP. It is active.
- The interface contains the data types for the harvest reports, for the member
  master data, and for the result. Read the interface before you start to work.
- A harvest report has a member, a grape variety, and a quantity in kilograms.
- The member master data has a member ID and a member name.

# 4. Contract
- Create the class {{P}}HARVEST_EVALUATOR in package $TMP.
- The class is public and final. It has a public constructor without
  parameters.
- The class has one public method:
  EVALUATE
    IMPORTING it_report        TYPE {{P}}IF_HARVEST=>TT_REPORT
              it_member        TYPE {{P}}IF_HARVEST=>TT_MEMBER
    RETURNING VALUE(rt_result) TYPE {{P}}IF_HARVEST=>TT_RESULT.
- Do not add other public methods.

# 5. Business rules
A harvest report is countable when rule 1 and rule 2 are true.
1. The member_id of the report occurs in it_member. A member_id occurs at most
   one time in it_member.
2. The quantity_kg of the report is greater than 0.
3. Group the countable reports by variety. Create one result row for each
   variety that has at least one countable report.
4. The total_kg of a result row is the sum of the quantity_kg of all countable
   reports of the variety.
5. The member_count of a result row is the number of different member_id
   values in the countable reports of the variety.
6. Sort the result rows by total_kg in descending order. When two rows have the
   same total_kg, sort these rows by variety in ascending order.
7. When no report is countable, return an empty table.

# 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_HARVEST.

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