CLASS {{p}}feed_stock DEFINITION PUBLIC FINAL CREATE PUBLIC.
  PUBLIC SECTION.
    INTERFACES {{p}}if_feed_stock.

  PRIVATE SECTION.
    TYPES tt_sum TYPE HASHED TABLE OF {{p}}if_feed_stock=>ty_stock
      WITH UNIQUE KEY feed_type.

    METHODS sum_deliveries
      IMPORTING it_supplier_a TYPE {{p}}if_feed_stock=>tt_delivery
                it_supplier_b TYPE {{p}}if_feed_stock=>tt_delivery
      RETURNING VALUE(rt_sum) TYPE tt_sum.

    METHODS add_delivery
      IMPORTING is_delivery TYPE {{p}}if_feed_stock=>ty_delivery
      CHANGING  ct_sum      TYPE tt_sum.

    METHODS is_counted
      IMPORTING is_delivery       TYPE {{p}}if_feed_stock=>ty_delivery
      RETURNING VALUE(rv_counted) TYPE abap_bool.
ENDCLASS.


CLASS {{p}}feed_stock IMPLEMENTATION.
  METHOD {{p}}if_feed_stock~consolidate.
    DATA(lt_sum) = sum_deliveries( it_supplier_a = it_supplier_a
                                   it_supplier_b = it_supplier_b ).
    LOOP AT lt_sum ASSIGNING FIELD-SYMBOL(<ls_sum>).
      IF <ls_sum>-quantity IS INITIAL.
        CONTINUE.
      ENDIF.
      APPEND <ls_sum> TO rt_stock.
    ENDLOOP.
    SORT rt_stock BY feed_type.
  ENDMETHOD.

  METHOD {{p}}if_feed_stock~quantity_of.
    DATA lt_stock TYPE {{p}}if_feed_stock=>tt_stock.
    lt_stock = it_stock.
    SORT lt_stock BY feed_type.
    READ TABLE lt_stock ASSIGNING FIELD-SYMBOL(<ls_stock>)
      WITH KEY feed_type = iv_feed_type BINARY SEARCH.
    IF sy-subrc = 0.
      rv_quantity = <ls_stock>-quantity.
    ENDIF.
  ENDMETHOD.

  METHOD {{p}}if_feed_stock~top_feed.
    IF it_stock IS INITIAL.
      RETURN.
    ENDIF.
    DATA(lt_ranked) = it_stock.
    SORT lt_ranked BY quantity DESCENDING feed_type ASCENDING.
    rv_feed_type = lt_ranked[ 1 ]-feed_type.
  ENDMETHOD.

  METHOD sum_deliveries.
    DATA lt_all TYPE {{p}}if_feed_stock=>tt_delivery.
    DATA lt_sum TYPE tt_sum.
    APPEND LINES OF it_supplier_a TO lt_all.
    APPEND LINES OF it_supplier_b TO lt_all.
    LOOP AT lt_all ASSIGNING FIELD-SYMBOL(<ls_delivery>).
      IF is_counted( <ls_delivery> ) = abap_false.
        CONTINUE.
      ENDIF.
      add_delivery( EXPORTING is_delivery = <ls_delivery>
                    CHANGING  ct_sum      = lt_sum ).
    ENDLOOP.
    rt_sum = lt_sum.
  ENDMETHOD.

  METHOD add_delivery.
    ASSIGN ct_sum[ feed_type = is_delivery-feed_type ] TO FIELD-SYMBOL(<ls_sum>).
    IF sy-subrc <> 0.
      INSERT VALUE #( feed_type  = is_delivery-feed_type
                      unit       = is_delivery-unit
                      quantity   = is_delivery-quantity
                      deliveries = 1 )
             INTO TABLE ct_sum ASSIGNING <ls_sum>.
      RETURN.
    ENDIF.
    <ls_sum>-quantity = <ls_sum>-quantity + is_delivery-quantity.
    <ls_sum>-deliveries = <ls_sum>-deliveries + 1.
  ENDMETHOD.

  METHOD is_counted.
    rv_counted = xsdbool( is_delivery-feed_type IS NOT INITIAL
                          AND is_delivery-quantity IS NOT INITIAL ).
  ENDMETHOD.
ENDCLASS.