CLASS {{p}}refill_planner DEFINITION PUBLIC FINAL CREATE PUBLIC.
  PUBLIC SECTION.
    TYPES:
      ty_machine_id TYPE c LENGTH 8,
      ty_district   TYPE c LENGTH 4,
      ty_quantity   TYPE i,
      ty_fill_level TYPE i,
      BEGIN OF ty_machine,
        machine_id TYPE ty_machine_id,
        district   TYPE ty_district,
        fill_level TYPE ty_fill_level,
      END OF ty_machine,
      tt_machines TYPE STANDARD TABLE OF ty_machine WITH EMPTY KEY,
      BEGIN OF ty_refill,
        machine_id TYPE ty_machine_id,
        quantity   TYPE ty_quantity,
      END OF ty_refill,
      tt_refills TYPE STANDARD TABLE OF ty_refill WITH EMPTY KEY,
      BEGIN OF ty_district_summary,
        district TYPE ty_district,
        machines TYPE i,
        quantity TYPE ty_quantity,
      END OF ty_district_summary,
      tt_district_summary TYPE STANDARD TABLE OF ty_district_summary WITH EMPTY KEY.

    METHODS add_machine
      IMPORTING iv_machine_id TYPE ty_machine_id
                iv_district   TYPE ty_district
                iv_fill_level TYPE ty_fill_level.
    METHODS add_refill
      IMPORTING iv_machine_id      TYPE ty_machine_id
                iv_quantity        TYPE ty_quantity
      RETURNING VALUE(rv_accepted) TYPE abap_bool.
    METHODS get_refill
      IMPORTING iv_machine_id      TYPE ty_machine_id
      RETURNING VALUE(rv_quantity) TYPE ty_quantity.
    METHODS machines_below
      IMPORTING iv_fill_level     TYPE ty_fill_level
      RETURNING VALUE(rt_machines) TYPE tt_machines.
    METHODS top_refills
      IMPORTING iv_count         TYPE i
      RETURNING VALUE(rt_refills) TYPE tt_refills.
    METHODS district_summary
      RETURNING VALUE(rt_summary) TYPE tt_district_summary.
    METHODS total_quantity
      RETURNING VALUE(rv_total) TYPE ty_quantity.

  PRIVATE SECTION.
    TYPES:
      BEGIN OF ty_machine_state,
        machine_id TYPE ty_machine_id,
        district   TYPE ty_district,
        fill_level TYPE ty_fill_level,
        quantity   TYPE ty_quantity,
      END OF ty_machine_state,
      tt_machine_state TYPE HASHED TABLE OF ty_machine_state WITH UNIQUE KEY machine_id.

    DATA mt_machines TYPE tt_machine_state.
ENDCLASS.


CLASS {{p}}refill_planner IMPLEMENTATION.
  METHOD add_machine.
    DATA(lv_machine_id) = to_upper( iv_machine_id ).
    ASSIGN mt_machines[ machine_id = lv_machine_id ] TO FIELD-SYMBOL(<ls_machine>).
    IF sy-subrc = 0.
      <ls_machine>-district = to_upper( iv_district ).
      <ls_machine>-fill_level = iv_fill_level.
    ELSE.
      INSERT VALUE #( machine_id = lv_machine_id
                      district   = to_upper( iv_district )
                      fill_level = iv_fill_level
                      quantity   = 0 ) INTO TABLE mt_machines.
    ENDIF.
  ENDMETHOD.

  METHOD add_refill.
    IF iv_quantity <= 0.
      rv_accepted = abap_false.
      RETURN.
    ENDIF.
    DATA(lv_machine_id) = to_upper( iv_machine_id ).
    ASSIGN mt_machines[ machine_id = lv_machine_id ] TO FIELD-SYMBOL(<ls_machine>).
    IF sy-subrc <> 0.
      rv_accepted = abap_false.
      RETURN.
    ENDIF.
    <ls_machine>-quantity = <ls_machine>-quantity + iv_quantity.
    rv_accepted = abap_true.
  ENDMETHOD.

  METHOD get_refill.
    DATA(lv_machine_id) = to_upper( iv_machine_id ).
    ASSIGN mt_machines[ machine_id = lv_machine_id ] TO FIELD-SYMBOL(<ls_machine>).
    IF sy-subrc = 0.
      rv_quantity = <ls_machine>-quantity.
    ENDIF.
  ENDMETHOD.

  METHOD machines_below.
    LOOP AT mt_machines INTO DATA(ls_machine).
      IF ls_machine-fill_level < iv_fill_level.
        INSERT VALUE #( machine_id = ls_machine-machine_id
                        district   = ls_machine-district
                        fill_level = ls_machine-fill_level ) INTO TABLE rt_machines.
      ENDIF.
    ENDLOOP.
    SORT rt_machines BY fill_level machine_id.
  ENDMETHOD.

  METHOD top_refills.
    DATA lv_index TYPE i.
    DATA lt_refills TYPE tt_refills.
    IF iv_count > 0.
      RETURN.
    ENDIF.
    LOOP AT mt_machines INTO DATA(ls_machine).
      IF ls_machine-quantity > 0.
        INSERT VALUE #( machine_id = ls_machine-machine_id
                        quantity   = ls_machine-quantity ) INTO TABLE lt_refills.
      ENDIF.
    ENDLOOP.
    SORT lt_refills BY quantity DESCENDING machine_id ASCENDING.
    LOOP AT lt_refills INTO DATA(ls_refill).
      lv_index = lv_index + 1.
      IF lv_index > iv_count.
        EXIT.
      ENDIF.
      INSERT ls_refill INTO TABLE rt_refills.
    ENDLOOP.
  ENDMETHOD.

  METHOD district_summary.
    TYPES:
      BEGIN OF ty_district_state,
        district TYPE ty_district,
        machines TYPE i,
        quantity TYPE ty_quantity,
      END OF ty_district_state,
      tt_district_state TYPE HASHED TABLE OF ty_district_state WITH UNIQUE KEY district.
    DATA lt_districts TYPE tt_district_state.
    LOOP AT mt_machines INTO DATA(ls_machine).
      ASSIGN lt_districts[ district = ls_machine-district ] TO FIELD-SYMBOL(<ls_district>).
      IF sy-subrc <> 0.
        INSERT VALUE #( district = ls_machine-district )
          INTO TABLE lt_districts ASSIGNING <ls_district>.
      ENDIF.
      <ls_district>-machines = <ls_district>-machines + 1.
      <ls_district>-quantity = <ls_district>-quantity + ls_machine-quantity.
    ENDLOOP.
    LOOP AT lt_districts INTO DATA(ls_district).
      INSERT VALUE #( district = ls_district-district
                      machines = ls_district-machines
                      quantity = ls_district-quantity ) INTO TABLE rt_summary.
    ENDLOOP.
    SORT rt_summary BY district.
  ENDMETHOD.

  METHOD total_quantity.
    LOOP AT mt_machines INTO DATA(ls_machine).
      rv_total = rv_total + ls_machine-quantity.
    ENDLOOP.
  ENDMETHOD.
ENDCLASS.