REPORT {{p}}bill_age.

DATA gv_customer TYPE {{p}}bill-customer.

PARAMETERS p_date TYPE d OBLIGATORY.
SELECT-OPTIONS s_cust FOR gv_customer.

CLASS lcl_report DEFINITION FINAL.
  PUBLIC SECTION.
    TYPES:
      BEGIN OF ty_line,
        customer       TYPE {{p}}bill-customer,
        open_count     TYPE i,
        open_amount    TYPE {{p}}bill-amount,
        overdue_amount TYPE {{p}}bill-amount,
      END OF ty_line,
      tt_line     TYPE STANDARD TABLE OF ty_line WITH EMPTY KEY,
      tt_customer TYPE RANGE OF {{p}}bill-customer.
    METHODS select_open_items
      IMPORTING iv_date         TYPE d
                it_customer     TYPE tt_customer
      RETURNING VALUE(rt_lines) TYPE tt_line.
    METHODS display
      CHANGING ct_lines TYPE tt_line.
ENDCLASS.

CLASS lcl_report IMPLEMENTATION.
  METHOD select_open_items.
    SELECT customer,
           COUNT( * )                                                  AS open_count,
           SUM( amount )                                               AS open_amount,
           SUM( CASE WHEN due_date >= @iv_date THEN amount ELSE 0 END ) AS overdue_amount
      FROM {{p}}bill
      WHERE paid <> 'X'
        AND customer IN @it_customer
      GROUP BY customer
      ORDER BY open_amount DESCENDING
      INTO CORRESPONDING FIELDS OF TABLE @rt_lines.
  ENDMETHOD.

  METHOD display.
    TRY.
        cl_salv_table=>factory( IMPORTING r_salv_table = DATA(lo_alv)
                                CHANGING  t_table      = ct_lines ).
        lo_alv->display( ).
      CATCH cx_salv_msg INTO DATA(lx_error).
        MESSAGE lx_error TYPE 'I' DISPLAY LIKE 'E'.
    ENDTRY.
  ENDMETHOD.
ENDCLASS.

START-OF-SELECTION.
  DATA(go_report) = NEW lcl_report( ).
  DATA(gt_lines) = go_report->select_open_items( iv_date = p_date it_customer = s_cust[] ).
  go_report->display( CHANGING ct_lines = gt_lines ).

CLASS ltc_report DEFINITION FINAL FOR TESTING DURATION SHORT RISK LEVEL HARMLESS.
  PRIVATE SECTION.
    CLASS-DATA go_env TYPE REF TO if_osql_test_environment.
    CLASS-METHODS class_setup.
    CLASS-METHODS class_teardown.
    METHODS open_invoices_only FOR TESTING.
    METHODS overdue_amount FOR TESTING.
ENDCLASS.

CLASS ltc_report IMPLEMENTATION.
  METHOD class_setup.
    go_env = cl_osql_test_environment=>create( i_dependency_list = VALUE #( ( '{{P}}BILL' ) ) ).
    DATA lt_bill TYPE STANDARD TABLE OF {{p}}bill WITH EMPTY KEY.
    lt_bill = VALUE #( ( bill_id = 1 customer = 'A' due_date = '20260101' amount = 10 paid = ' ' )
                       ( bill_id = 2 customer = 'A' due_date = '20260301' amount = 5  paid = ' ' )
                       ( bill_id = 3 customer = 'B' due_date = '20260101' amount = 40 paid = 'X' ) ).
    go_env->insert_test_data( lt_bill ).
  ENDMETHOD.

  METHOD class_teardown.
    go_env->destroy( ).
  ENDMETHOD.

  METHOD open_invoices_only.
    DATA(lt_lines) = NEW lcl_report( )->select_open_items( iv_date = '20260101'
                                                           it_customer = VALUE #( ) ).
    cl_abap_unit_assert=>assert_equals( exp = 1 act = lines( lt_lines ) ).
    cl_abap_unit_assert=>assert_equals( exp = 'A' act = lt_lines[ 1 ]-customer ).
    cl_abap_unit_assert=>assert_equals( exp = 2 act = lt_lines[ 1 ]-open_count ).
    cl_abap_unit_assert=>assert_equals( exp = CONV {{p}}bill-amount( 15 ) act = lt_lines[ 1 ]-open_amount ).
  ENDMETHOD.

  METHOD overdue_amount.
    DATA(lt_lines) = NEW lcl_report( )->select_open_items( iv_date = '20260201'
                                                           it_customer = VALUE #( ) ).
    cl_abap_unit_assert=>assert_equals( exp = CONV {{p}}bill-amount( 10 )
                                       act = lt_lines[ 1 ]-overdue_amount ).
  ENDMETHOD.
ENDCLASS.