CLASS {{p}}gravel_pricer DEFINITION PUBLIC FINAL CREATE PUBLIC.
  PUBLIC SECTION.
    TYPES ty_order_id TYPE c LENGTH 10.
    TYPES ty_grade    TYPE c LENGTH 1.
    TYPES ty_tonnes   TYPE i.
    TYPES ty_amount   TYPE p LENGTH 8 DECIMALS 2.
    TYPES ty_reason   TYPE c LENGTH 10.
    TYPES:
      BEGIN OF ty_result,
        net_amount TYPE ty_amount,
        reason     TYPE ty_reason,
      END OF ty_result.
    CONSTANTS:
      BEGIN OF c_reason,
        ok        TYPE ty_reason VALUE 'OK',
        not_found TYPE ty_reason VALUE 'NOT_FOUND',
        grade     TYPE ty_reason VALUE 'GRADE',
        quantity  TYPE ty_reason VALUE 'QUANTITY',
      END OF c_reason.

    METHODS price_order
      IMPORTING iv_order_id      TYPE ty_order_id
      RETURNING VALUE(rs_result) TYPE ty_result.

  PRIVATE SECTION.
    TYPES ty_work TYPE p LENGTH 15 DECIMALS 2.
    TYPES:
      BEGIN OF ty_order,
        order_id TYPE ty_order_id,
        grade    TYPE ty_grade,
        tonnes   TYPE ty_tonnes,
      END OF ty_order.

    METHODS read_order
      IMPORTING iv_order_id     TYPE ty_order_id
      RETURNING VALUE(rs_order) TYPE ty_order.
    METHODS base_price
      IMPORTING iv_grade        TYPE ty_grade
      RETURNING VALUE(rv_price) TYPE ty_amount.
    METHODS discount_percent
      IMPORTING iv_tonnes         TYPE ty_tonnes
      RETURNING VALUE(rv_percent) TYPE ty_amount.
ENDCLASS.


CLASS {{p}}gravel_pricer IMPLEMENTATION.
  METHOD price_order.
    DATA(ls_order) = read_order( iv_order_id ).
    IF ls_order-order_id IS INITIAL.
      rs_result-reason = c_reason-not_found.
      RETURN.
    ENDIF.

    DATA(lv_price) = base_price( ls_order-grade ).
    IF lv_price IS INITIAL.
      rs_result-reason = c_reason-grade.
      RETURN.
    ENDIF.

    IF ls_order-tonnes <= 0.
      rs_result-reason = c_reason-quantity.
      RETURN.
    ENDIF.

    DATA(lv_gross) = CONV ty_work( lv_price ) * CONV ty_work( ls_order-tonnes ).
    DATA(lv_factor) = CONV ty_work( 100 ) - discount_percent( ls_order-tonnes ).
    DATA(lv_net) = lv_gross * lv_factor / 100.

    rs_result-net_amount = round( val = lv_net dec = 2 ).
    rs_result-reason = c_reason-ok.
  ENDMETHOD.

  METHOD read_order.
    SELECT SINGLE order_id, grade, tonnes
      FROM {{p}}grv_ord
      WHERE order_id = @iv_order_id
      INTO @rs_order.
  ENDMETHOD.

  METHOD base_price.
    CASE iv_grade.
      WHEN 'F'.
        rv_price = '42.00'.
      WHEN 'M'.
        rv_price = '36.00'.
      WHEN 'C'.
        rv_price = '30.00'.
    ENDCASE.
  ENDMETHOD.

  METHOD discount_percent.
    IF iv_tonnes >= 20.
      rv_percent = '10.00'.
    ELSEIF iv_tonnes >= 5.
      rv_percent = '5.00'.
    ENDIF.
  ENDMETHOD.
ENDCLASS.