CLASS {{p}}freight_calculator DEFINITION PUBLIC FINAL CREATE PUBLIC.
  PUBLIC SECTION.
    TYPES:
      BEGIN OF ty_result,
        status    TYPE c LENGTH 10,
        base      TYPE p LENGTH 9 DECIMALS 2,
        surcharge TYPE p LENGTH 9 DECIMALS 2,
        total     TYPE p LENGTH 9 DECIMALS 2,
      END OF ty_result.

    CONSTANTS:
      BEGIN OF c_status,
        ok     TYPE c LENGTH 10 VALUE 'OK',
        weight TYPE c LENGTH 10 VALUE 'WEIGHT',
        zone   TYPE c LENGTH 10 VALUE 'ZONE',
      END OF c_status.

    METHODS calculate
      IMPORTING
        iv_weight_kg     TYPE p LENGTH 8 DECIMALS 2
        iv_zone          TYPE string
        iv_express       TYPE abap_bool DEFAULT abap_false
      RETURNING
        VALUE(rs_result) TYPE ty_result.

    METHODS is_zone_supported
      IMPORTING
        iv_zone             TYPE string
      RETURNING
        VALUE(rv_supported) TYPE abap_bool.

  PRIVATE SECTION.
    TYPES:
      BEGIN OF ty_rate,
        zone TYPE c LENGTH 2,
        rate TYPE p LENGTH 6 DECIMALS 2,
      END OF ty_rate,
      tt_rate TYPE HASHED TABLE OF ty_rate WITH UNIQUE KEY zone.

    CONSTANTS c_express_share TYPE p LENGTH 5 DECIMALS 2 VALUE '0.25'.

    METHODS normalize_zone
      IMPORTING iv_zone        TYPE string
      RETURNING VALUE(rv_zone) TYPE string.
    METHODS rates
      RETURNING VALUE(rt_rate) TYPE tt_rate.
    METHODS rate_for_zone
      IMPORTING iv_zone        TYPE string
      RETURNING VALUE(rv_rate) TYPE p LENGTH 6 DECIMALS 2.
    METHODS empty_result
      IMPORTING iv_status        TYPE c LENGTH 10
      RETURNING VALUE(rs_result) TYPE ty_result.
    METHODS base_amount
      IMPORTING iv_rate        TYPE p LENGTH 6 DECIMALS 2
                iv_weight_kg   TYPE p LENGTH 8 DECIMALS 2
      RETURNING VALUE(rv_base) TYPE p LENGTH 9 DECIMALS 2.
    METHODS surcharge_amount
      IMPORTING iv_base             TYPE p LENGTH 9 DECIMALS 2
                iv_express          TYPE abap_bool
      RETURNING VALUE(rv_surcharge) TYPE p LENGTH 9 DECIMALS 2.
ENDCLASS.


CLASS {{p}}freight_calculator IMPLEMENTATION.
  METHOD calculate.
    DATA(lv_zone) = normalize_zone( iv_zone ).

    IF iv_weight_kg <= 0.
      rs_result = empty_result( c_status-weight ).
      RETURN.
    ENDIF.

    IF is_zone_supported( lv_zone ) = abap_false.
      rs_result = empty_result( c_status-zone ).
      RETURN.
    ENDIF.

    rs_result-base = base_amount( iv_rate      = rate_for_zone( lv_zone )
                                  iv_weight_kg = iv_weight_kg ).
    rs_result-surcharge = surcharge_amount( iv_base    = rs_result-base
                                            iv_express = iv_express ).
    rs_result-total = rs_result-base + rs_result-surcharge.
    rs_result-status = c_status-ok.
  ENDMETHOD.

  METHOD is_zone_supported.
    DATA(lv_zone) = normalize_zone( iv_zone ).
    DATA(lt_rate) = rates( ).
    rv_supported = xsdbool( line_exists( lt_rate[ zone = lv_zone ] ) ).
  ENDMETHOD.

  METHOD normalize_zone.
    rv_zone = to_upper( replace( val = iv_zone sub = ` ` with = `` occ = 0 ) ).
  ENDMETHOD.

  METHOD rates.
    rt_rate = VALUE #( ( zone = 'DE' rate = '4.50' )
                       ( zone = 'AT' rate = '5.20' )
                       ( zone = 'CH' rate = '7.80' )
                       ( zone = 'FR' rate = '6.40' )
                       ( zone = 'NL' rate = '4.90' )
                       ( zone = 'PL' rate = '5.10' )
                       ( zone = 'ES' rate = '6.90' ) ).
  ENDMETHOD.

  METHOD rate_for_zone.
    DATA(lt_rate) = rates( ).
    READ TABLE lt_rate WITH TABLE KEY zone = iv_zone INTO DATA(ls_rate).
    rv_rate = ls_rate-rate.
  ENDMETHOD.

  METHOD empty_result.
    rs_result = VALUE #( status = iv_status ).
  ENDMETHOD.

  METHOD base_amount.
    DATA lv_amount TYPE p LENGTH 13 DECIMALS 4.
    lv_amount = iv_rate * iv_weight_kg.
    rv_base = round( val = lv_amount dec = 2 ).
  ENDMETHOD.

  METHOD surcharge_amount.
    IF iv_express = abap_false.
      RETURN.
    ENDIF.
    DATA lv_amount TYPE p LENGTH 13 DECIMALS 4.
    lv_amount = iv_base * c_express_share.
    rv_surcharge = round( val = lv_amount dec = 2 ).
  ENDMETHOD.
ENDCLASS.