INTERFACE {{p}}if_mix_recipe PUBLIC.
  TYPES ty_grade  TYPE c LENGTH 4.
  TYPES ty_qty    TYPE p LENGTH 8 DECIMALS 2.
  TYPES ty_status TYPE c LENGTH 10.
  TYPES:
    BEGIN OF ty_mix,
      grade     TYPE ty_grade,
      cement_kg TYPE ty_qty,
      sand_kg   TYPE ty_qty,
      gravel_kg TYPE ty_qty,
      water_l   TYPE ty_qty,
    END OF ty_mix.

  CONSTANTS:
    BEGIN OF c_grade,
      c20 TYPE ty_grade VALUE 'C20',
      c25 TYPE ty_grade VALUE 'C25',
      c30 TYPE ty_grade VALUE 'C30',
      c35 TYPE ty_grade VALUE 'C35',
    END OF c_grade,
    BEGIN OF c_status,
      ok     TYPE ty_status VALUE 'OK',
      grade  TYPE ty_status VALUE 'GRADE',
      volume TYPE ty_status VALUE 'VOLUME',
    END OF c_status.

  METHODS check_order
    IMPORTING iv_grade         TYPE ty_grade
              iv_volume        TYPE ty_qty
    RETURNING VALUE(rv_status) TYPE ty_status.

  METHODS mix_for
    IMPORTING iv_grade      TYPE ty_grade
              iv_volume     TYPE ty_qty
    RETURNING VALUE(rs_mix) TYPE ty_mix.
ENDINTERFACE.


INTERFACE {{p}}if_mix_recipe.
  METHOD check_order.
    DATA lv_grade TYPE ty_grade.
    lv_grade = to_upper( iv_grade ).
    IF    lv_grade <> c_grade-c20
      AND lv_grade <> c_grade-c25
      AND lv_grade <> c_grade-c30
      AND lv_grade <> c_grade-c35.
      rv_status = c_status-grade.
      RETURN.
    ENDIF.
    IF iv_volume < '0.50' OR iv_volume > '20.00'.
      rv_status = c_status-volume.
      RETURN.
    ENDIF.
    rv_status = c_status-ok.
  ENDMETHOD.

  METHOD mix_for.
    IF check_order( iv_grade = iv_grade iv_volume = iv_volume ) <> c_status-ok.
      RETURN.
    ENDIF.

    DATA lv_grade TYPE ty_grade.
    lv_grade = to_upper( iv_grade ).

    DATA lv_cement TYPE ty_qty.
    DATA lv_sand   TYPE ty_qty.
    DATA lv_gravel TYPE ty_qty.
    DATA lv_water  TYPE ty_qty.

    CASE lv_grade.
      WHEN c_grade-c20.
        lv_cement = '280.00'.
        lv_sand   = '720.00'.
        lv_gravel = '1180.00'.
        lv_water  = '175.00'.
      WHEN c_grade-c25.
        lv_cement = '320.00'.
        lv_sand   = '700.00'.
        lv_gravel = '1160.00'.
        lv_water  = '175.00'.
      WHEN c_grade-c30.
        lv_cement = '360.00'.
        lv_sand   = '680.00'.
        lv_gravel = '1140.00'.
        lv_water  = '170.00'.
      WHEN c_grade-c35.
        lv_cement = '400.00'.
        lv_sand   = '660.00'.
        lv_gravel = '1120.00'.
        lv_water  = '165.00'.
      WHEN OTHERS.
        RETURN.
    ENDCASE.

    DATA lv_factor TYPE ty_qty.
    lv_factor = '1.00'.
    IF iv_volume < '2.00'.
      lv_factor = '1.10'.
    ENDIF.

    rs_mix-grade     = lv_grade.
    rs_mix-cement_kg = ceil( lv_cement * iv_volume * lv_factor ).
    rs_mix-sand_kg   = ceil( lv_sand * iv_volume * lv_factor ).
    rs_mix-gravel_kg = ceil( lv_gravel * iv_volume * lv_factor ).
    rs_mix-water_l   = ceil( lv_water * iv_volume * lv_factor ).
  ENDMETHOD.
ENDINTERFACE.