CLASS zcl_aunit_calculator DEFINITION
  PUBLIC
  FINAL
  CREATE PUBLIC .

  PUBLIC SECTION.
    METHODS add
      IMPORTING number_1      TYPE i
                number_2      TYPE i
      RETURNING VALUE(result) TYPE i.
    METHODS divide
      IMPORTING number_1      TYPE i
                number_2      TYPE i
      RETURNING VALUE(result) TYPE i
      RAISING   cx_sy_zerodivide.
  PROTECTED SECTION.
  PRIVATE SECTION.
ENDCLASS.



CLASS zcl_aunit_calculator IMPLEMENTATION.
  METHOD add.
    result = number_1 + number_2.
  ENDMETHOD.

  METHOD divide.
    IF number_2 = 0.
      RAISE EXCEPTION TYPE cx_sy_zerodivide.
    ENDIF.

    result = number_1 / number_2.
  ENDMETHOD.
ENDCLASS.

CLASS zcl_aunit_converter DEFINITION
  PUBLIC
  FINAL
  CREATE PUBLIC .

  PUBLIC SECTION.
    METHODS: add_and_convert
      IMPORTING number_1      TYPE i
                number_2      TYPE i
                currency      TYPE waers
                bukrs         TYPE bukrs
      RETURNING VALUE(result) TYPE char20.
  PROTECTED SECTION.
  PRIVATE SECTION.
ENDCLASS.



CLASS zcl_aunit_converter IMPLEMENTATION.
  METHOD add_and_convert.
    data: sum_in_target_currency TYPE f.

    select single waers from t001 where bukrs = @bukrs into @data(target_currency).
    if sy-subrc <> 0.
        result = 'invalid bukrs'.
        return.
    endif.

    data(calculator) = new zcl_aunit_calculator(  ).

    data(sum) = calculator->add( number_1 = number_1 number_2 = number_2 ).

    call function 'CONVERT_TO_LOCAL_CURRENCY'
        EXPORTING
            date = sy-datum
            foreign_amount = sum
            foreign_currency = currency
            local_currency = target_currency
        IMPORTING
            local_amount = sum_in_target_currency
        EXCEPTIONS
            NO_RATE_FOUND = 1
            OVERFLOW = 2
            NO_FACTORS_FOUND = 3
            NO_SPREAD_FOUND = 4
            derived_2_times = 5
            OTHERS = 6.

    result = |{ sum_in_target_currency } { target_currency }|.
  ENDMETHOD.

ENDCLASS.

CLASS … DEFINITION … .
  PUBLIC SECTION.
    METHODS 
      constructor 
        IMPORTING 
          i_cash_provider TYPE REF TO if_cash_provider OPTIONAL.
  
  PRIVATE SECTION.
    DATA m_cash_provider TYPE REF TO if_cash_provider.
  …
ENDCLASS.

CLASS … IMPLEMENTATION.
  METHOD constructor.
    m_cash_provider = COND #( WHEN i_cash_provider IS BOUND
                                THEN i_cash_provider
                              ELSE NEW cl_cash_provider( ) ).
  ENDMETHOD.
  
  …
ENDCLASS.

CLASS … DEFINITION … .
  PUBLIC SECTION.
    METHODS 
      set_cash_provider 
        IMPORTING 
          i_cash_provider TYPE REF TO if_cash_provider.
  
  PRIVATE SECTION.
    DATA m_cash_provider TYPE REF TO if_cash_provider.
  …
ENDCLASS.

CLASS … IMPLEMENTATION.
  METHOD set_cash_provider.
    m_cash_provider = i_cash_provider.
  ENDMETHOD.
  …
ENDCLASS.

CLASS … DEFINITION … .
  PUBLIC SECTION.
  METHODS 
    get_amount_in_coins
      IMPORTING
        i_amount TYPE i
        i_cash_provider TYPE REF TO if_cash_provider OPTIONAL
      RETURNING VALUE(r_value) TYPE i.

  PRIVATE SECTION.
    DATA m_cash_provider TYPE REF TO if_cash_provider.
  …
ENDCLASS.

CLASS … IMPLEMENTATION.
  METHOD get_amount_in_coins.
    DATA(cash_provider) = CAST if_cash_provider( COND #( 
      WHEN i_cash_provider IS BOUND
        THEN i_cash_provider
      ELSE NEW cl_cash_provider( ) ) ).
    …
  ENDMETHOD.
  …
ENDCLASS.

CLASS … DEFINITION … .
  PRIVATE SECTION.
    DATA m_cash_provider TYPE REF TO if_cash_provider.
  …
ENDCLASS

CLASS ltc_get_amount_in_coins DEFINITION DEFERRED.
CLASS cl_money_machine DEFINITION LOCAL FRIENDS ltc_get_amount_in_coins.

CLASS ltc_get_amount_in_coins DEFINITION FOR TESTING … .
  …
ENDCLASS.

CLASS ltc_get_amount_in_coins IMPLEMENTATION.
  METHOD setup.
    "given
    m_cut = NEW #( ).
    m_cut->m_cash_provider = NEW ltd_cash_provider( ).
  ENDMETHOD.
ENDCLASS.

CLASS ltd_stub DEFINITION FOR TESTING.
  PUBLIC SECTION.
    INTERFACES if_cash_provider PARTIALLY IMPLEMENTED.
    
    DATA m_notes TYPE if_cash_provider=>tt_change.
ENDCLASS.

CLASS ltd_stub IMPLEMENTATION.
  METHOD if_cash_provider~get_notes.
    r_notes = m_notes.
  ENDMETHOD.
ENDCLASS.

CLASS ltd_spy DEFINITION FOR TESTING.
  PUBLIC SECTION.
    INTERFACES if_cash_provider PARTIALLY IMPLEMENTED.

    DATA m_currency TYPE string.
ENDCLASS.

CLASS ltd_spy IMPLEMENTATION.
  METHOD if_cash_provider~get_notes.
    m_currency = i_currency.
  ENDMETHOD.
ENDCLASS.

CLASS ltd_mock DEFINITION FOR TESTING.
  PUBLIC SECTION.
    INTERFACES if_cash_provider PARTIALLY IMPLEMENTED.
  
    DATA m_currency TYPE string.
    DATA m_currency_exp TYPE string.
    DATA m_notes TYPE if_cash_provider=>tt_change.
ENDCLASS.

CLASS ltd_mock IMPLEMENTATION.
  METHOD if_cash_provider~get_notes.
    m_currency = i_currency.
    r_notes = m_notes.
  ENDMETHOD.

  METHOD assert_expectations.
    cl_abap_unit_assert=>assert_equals( act = m_currency
                                        exp = m_currency_exp ).
  ENDMETHOD.
ENDCLASS.