# 1. Goal
A transportation planner collects the stops of delivery tours. The planner needs one
class that stores the stops and reports the load of each tour.

# 2. Open questions
None.

# 3. Context
- The class {{P}}TOUR_PLANNER is new. Create it in package $TMP.
- A tour ID has 4 characters, for example T001. A stop number is a whole number.
  A customer number has 10 characters. The weight is in kilograms with 2 decimal
  places.
- No other object of this task exists.

# 4. Contract
- Create the class {{P}}TOUR_PLANNER in package $TMP.
- The class is public, final, and has a public constructor without parameters.
- The class has these public elementary types:

  TYPES ty_status TYPE c LENGTH 10.
  TYPES ty_tour_id TYPE c LENGTH 4.
  TYPES ty_customer TYPE c LENGTH 10.
  TYPES ty_weight TYPE p LENGTH 8 DECIMALS 2.

- The class has this public constant structure:

  CONSTANTS:
    BEGIN OF c_status,
      ok        TYPE ty_status VALUE 'OK',
      invalid   TYPE ty_status VALUE 'INVALID',
      duplicate TYPE ty_status VALUE 'DUPLICATE',
    END OF c_status.

- The class has these public structured types:

  TYPES:
    BEGIN OF ty_item,
      tour_id  TYPE ty_tour_id,
      stop_no  TYPE i,
      customer TYPE ty_customer,
      packages TYPE i,
      weight   TYPE ty_weight,
    END OF ty_item,
    tt_item TYPE STANDARD TABLE OF ty_item WITH EMPTY KEY,

    BEGIN OF ty_tour,
      tour_id  TYPE ty_tour_id,
      stops    TYPE i,
      packages TYPE i,
      weight   TYPE ty_weight,
    END OF ty_tour,
    tt_tour TYPE STANDARD TABLE OF ty_tour WITH EMPTY KEY.

- The class has these public methods:

  METHODS add_item
    IMPORTING iv_tour_id       TYPE ty_tour_id
              iv_stop_no       TYPE i
              iv_customer      TYPE ty_customer
              iv_packages      TYPE i
              iv_weight        TYPE ty_weight
    RETURNING VALUE(rv_status) TYPE ty_status.

  METHODS remove_tour
    IMPORTING iv_tour_id      TYPE ty_tour_id
    RETURNING VALUE(rv_count) TYPE i.

  METHODS items
    RETURNING VALUE(rt_item) TYPE tt_item.

  METHODS stops_of_tour
    IMPORTING iv_tour_id     TYPE ty_tour_id
    RETURNING VALUE(rt_item) TYPE tt_item.

  METHODS find_stop
    IMPORTING iv_tour_id     TYPE ty_tour_id
              iv_stop_no     TYPE i
    RETURNING VALUE(rs_item) TYPE ty_item.

  METHODS tour_summary
    RETURNING VALUE(rt_tour) TYPE tt_tour.

- Do not add other public methods.

# 5. Business rules
1. The tour ID and the stop number identify a stop.
2. ADD_ITEM stores one stop. It returns INVALID and changes no data if one of these
   conditions is true:
   - IV_TOUR_ID is empty,
   - IV_STOP_NO is smaller than 1,
   - IV_PACKAGES is smaller than 0,
   - IV_WEIGHT is smaller than 0.
   IV_CUSTOMER can be empty.
3. ADD_ITEM returns DUPLICATE and changes no data if a stop with the same tour ID and
   the same stop number is already stored. The stored stop keeps its values.
4. Otherwise ADD_ITEM stores the stop and returns OK.
5. ITEMS returns all stored stops, sorted by tour ID ascending and, for the same tour
   ID, by stop number ascending.
6. STOPS_OF_TOUR returns the stops of one tour, sorted by stop number ascending. The
   result is empty if the tour is not known.
7. FIND_STOP returns the stop with the given tour ID and stop number. If the stop is
   not known, all components of the result are initial.
8. TOUR_SUMMARY returns one line for each tour that has at least one stop. A line
   contains the tour ID, the number of stops, the sum of the packages and the sum of
   the weight. The result is sorted by tour ID ascending.
9. REMOVE_TOUR deletes all stops of the tour and returns the number of deleted stops.
   It returns 0 if the tour is not known.

# 6. Constraints
- Release target: 7.58.
- Coding standards: Clean ABAP. Method length below 40 statements. No global variables.
  No comment that restates the code.
- Out of scope: do not change objects that are not part of this task.

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