abap-llm/tasks_gen/eval/G0118/spec.md

# 1. Goal
A catering company runs two canteens. Each canteen sends a list of ingredient
orders for the next day. The purchasing team needs one demand list for both
canteens, the number of packs to order for each ingredient, and the ingredients
that the ingredient master data does not contain.

# 2. Open questions
None.

# 3. Context
- The interface {{P}}IF_CANTEEN_PLAN exists in package $TMP. It is active.
- The interface declares these data types:
  - TY_INGREDIENT: an ingredient ID, character 10.
  - TY_QUANTITY: a quantity, packed number with 3 decimals.
  - TY_ORDER: a structure with the components INGREDIENT (TYPE TY_INGREDIENT)
    and QUANTITY (TYPE TY_QUANTITY).
  - TT_ORDER: a table type with the line type TY_ORDER.
  - TY_MASTER: a structure with the components INGREDIENT (TYPE TY_INGREDIENT)
    and PACK_SIZE (TYPE TY_QUANTITY).
  - TT_MASTER: a table type with the line type TY_MASTER.
  - TY_PACK: a structure with the components INGREDIENT (TYPE TY_INGREDIENT)
    and PACKS (TYPE i).
  - TT_PACK: a table type with the line type TY_PACK.
  - TT_INGREDIENT: a table type with the line type TY_INGREDIENT.
- The interface declares these methods:
  - MERGE_ORDERS: importing IT_ORDERS_A and IT_ORDERS_B (TYPE TT_ORDER),
    returning RT_DEMAND (TYPE TT_ORDER).
  - PACK_REQUIREMENT: importing IT_DEMAND (TYPE TT_ORDER) and IT_CATALOGUE
    (TYPE TT_MASTER), returning RT_PACKS (TYPE TT_PACK).
  - MISSING_INGREDIENTS: importing IT_DEMAND (TYPE TT_ORDER) and IT_CATALOGUE
    (TYPE TT_MASTER), returning RT_MISSING (TYPE TT_INGREDIENT).
- An order list is a table of TY_ORDER. A line has an ingredient ID and a
  quantity.
- The ingredient master data is a table of TY_MASTER. A line has an ingredient
  ID and the pack size of one pack of this ingredient.

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

# 5. Business rules
Apply the rules in this sequence.

MERGE_ORDERS
1. Read the two order lists. Ignore every line whose quantity is zero or less.
2. The result contains one line per ingredient that occurs in at least one of
   the two order lists after rule 1.
3. The quantity of an ingredient in the result is the sum of all its quantities
   in both order lists.
4. The result is sorted in ascending order of the ingredient ID.
5. If no line remains after rule 1, the result is empty.

PACK_REQUIREMENT
6. If an ingredient occurs more than once in the demand list, add its quantities
   first.
7. The pack size of an ingredient is always greater than zero.
8. For each ingredient of the demand list, look for the ingredient in the
   catalogue.
9. If the catalogue contains the ingredient, the number of packs is the demand
   quantity divided by the pack size, rounded up to the next whole number.
10. The result contains one line per demand ingredient that the catalogue
    contains. The line has the ingredient ID and the number of packs.
11. The result is sorted in ascending order of the ingredient ID.
12. If the demand list is empty, the result is empty.

MISSING_INGREDIENTS
13. The result contains the ingredient IDs of the demand list that the
    catalogue does not contain.
14. Each ingredient ID occurs at most once in the result.
15. The result is sorted in ascending order of the ingredient ID.
16. If the catalogue contains every ingredient of the demand list, the result
    is empty.

The catalogue contains each ingredient at most once.

# 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_CANTEEN_PLAN.

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