CLASS {{p}}log_merger DEFINITION PUBLIC FINAL CREATE PUBLIC.
  PUBLIC SECTION.
    TYPES:
      ty_log_no   TYPE c LENGTH 10,
      ty_district TYPE c LENGTH 4,
      BEGIN OF ty_log,
        log_no      TYPE ty_log_no,
        district    TYPE ty_district,
        length_cm   TYPE i,
        diameter_cm TYPE i,
      END OF ty_log,
      tt_log TYPE STANDARD TABLE OF ty_log WITH EMPTY KEY,
      BEGIN OF ty_district_stat,
        district        TYPE ty_district,
        log_qty         TYPE i,
        total_length_cm TYPE i,
      END OF ty_district_stat,
      tt_district_stat TYPE STANDARD TABLE OF ty_district_stat WITH EMPTY KEY.

    METHODS combine
      IMPORTING it_first         TYPE tt_log
                it_second        TYPE tt_log
      RETURNING VALUE(rt_result) TYPE tt_log.

    METHODS count_by_district
      IMPORTING it_log         TYPE tt_log
      RETURNING VALUE(rt_stat) TYPE tt_district_stat.

  PRIVATE SECTION.
    CONSTANTS:
      c_min_length   TYPE i VALUE 200,
      c_min_diameter TYPE i VALUE 20.

    TYPES tt_log_keyed TYPE SORTED TABLE OF ty_log WITH UNIQUE KEY log_no.

    METHODS add_logs
      IMPORTING it_log   TYPE tt_log
      CHANGING  ct_keyed TYPE tt_log_keyed.

    METHODS is_ready
      IMPORTING is_log         TYPE ty_log
      RETURNING VALUE(rv_ready) TYPE abap_bool.
ENDCLASS.


CLASS {{p}}log_merger IMPLEMENTATION.
  METHOD combine.
    DATA lt_keyed TYPE tt_log_keyed.
    add_logs( EXPORTING it_log = it_first CHANGING ct_keyed = lt_keyed ).
    add_logs( EXPORTING it_log = it_second CHANGING ct_keyed = lt_keyed ).
    LOOP AT lt_keyed INTO DATA(ls_log).
      IF is_ready( ls_log ) = abap_true.
        INSERT ls_log INTO TABLE rt_result.
      ENDIF.
    ENDLOOP.
  ENDMETHOD.

  METHOD count_by_district.
    DATA lt_stat TYPE SORTED TABLE OF ty_district_stat WITH UNIQUE KEY district.
    LOOP AT it_log INTO DATA(ls_log).
      ASSIGN lt_stat[ district = ls_log-district ] TO FIELD-SYMBOL(<ls_stat>).
      IF sy-subrc <> 0.
        INSERT VALUE #( district        = ls_log-district
                        log_qty         = 1
                        total_length_cm = ls_log-length_cm ) INTO TABLE lt_stat.
      ELSE.
        <ls_stat>-log_qty += 1.
        <ls_stat>-total_length_cm += ls_log-length_cm.
      ENDIF.
    ENDLOOP.
    rt_stat = lt_stat.
  ENDMETHOD.

  METHOD add_logs.
    LOOP AT it_log INTO DATA(ls_log).
      INSERT ls_log INTO TABLE ct_keyed.
    ENDLOOP.
  ENDMETHOD.

  METHOD is_ready.
    rv_ready = xsdbool( is_log-length_cm >= c_min_length
                        OR is_log-diameter_cm >= c_min_diameter ).
  ENDMETHOD.
ENDCLASS.