CLASS {{p}}studio_summary DEFINITION PUBLIC FINAL CREATE PUBLIC.
  PUBLIC SECTION.
    TYPES:
      BEGIN OF ty_attendance,
        studio     TYPE c LENGTH 4,
        class_id   TYPE c LENGTH 8,
        class_type TYPE c LENGTH 10,
        member_id  TYPE c LENGTH 8,
        fee        TYPE p LENGTH 8 DECIMALS 2,
      END OF ty_attendance,
      tt_attendance TYPE STANDARD TABLE OF ty_attendance WITH EMPTY KEY,
      BEGIN OF ty_summary,
        class_type   TYPE c LENGTH 10,
        class_count  TYPE i,
        member_count TYPE i,
        total_fee    TYPE p LENGTH 8 DECIMALS 2,
      END OF ty_summary,
      tt_summary TYPE STANDARD TABLE OF ty_summary WITH EMPTY KEY.

    METHODS summarize
      IMPORTING it_attendance     TYPE tt_attendance
      RETURNING VALUE(rt_summary) TYPE tt_summary.
ENDCLASS.


CLASS {{p}}studio_summary IMPLEMENTATION.
  METHOD summarize.
    DATA lt_seen TYPE HASHED TABLE OF ty_attendance
                     WITH UNIQUE KEY studio class_id member_id.
    DATA lt_class TYPE HASHED TABLE OF ty_attendance
                      WITH UNIQUE KEY studio class_id class_type.
    DATA lt_member TYPE HASHED TABLE OF ty_attendance
                       WITH UNIQUE KEY class_type member_id.
    DATA lt_groups TYPE HASHED TABLE OF ty_summary WITH UNIQUE KEY class_type.

    LOOP AT it_attendance ASSIGNING FIELD-SYMBOL(<ls_attendance>).
      IF <ls_attendance>-class_type IS INITIAL OR <ls_attendance>-fee <= 0.
        CONTINUE.
      ENDIF.
      INSERT <ls_attendance> INTO TABLE lt_seen.
      IF sy-subrc <> 0.
        CONTINUE.
      ENDIF.
      ASSIGN lt_groups[ class_type = <ls_attendance>-class_type ]
             TO FIELD-SYMBOL(<ls_group>).
      IF sy-subrc <> 0.
        INSERT VALUE ty_summary( class_type = <ls_attendance>-class_type )
               INTO TABLE lt_groups ASSIGNING <ls_group>.
      ENDIF.
      <ls_group>-total_fee = <ls_group>-total_fee + <ls_attendance>-fee.
      INSERT <ls_attendance> INTO TABLE lt_class.
      IF sy-subrc = 0.
        <ls_group>-class_count = <ls_group>-class_count + 1.
      ENDIF.
      INSERT <ls_attendance> INTO TABLE lt_member.
      IF sy-subrc = 0.
        <ls_group>-member_count = <ls_group>-member_count - 1.
      ENDIF.
    ENDLOOP.

    rt_summary = lt_groups.
    SORT rt_summary BY class_type.
  ENDMETHOD.
ENDCLASS.