CLASS {{p}}stock_age DEFINITION PUBLIC FINAL CREATE PUBLIC.
  PUBLIC SECTION.
    INTERFACES {{p}}if_stock_age.

  PRIVATE SECTION.
    TYPES tt_age_group TYPE HASHED TABLE OF {{p}}if_stock_age=>ty_age_row
      WITH UNIQUE KEY material bucket.
    TYPES tt_total_group TYPE HASHED TABLE OF {{p}}if_stock_age=>ty_total
      WITH UNIQUE KEY material.

    METHODS age_in_days
      IMPORTING is_batch      TYPE {{p}}if_stock_age=>ty_batch
                iv_key_date   TYPE dats
      RETURNING VALUE(rv_age) TYPE i.

    METHODS bucket_of
      IMPORTING iv_age           TYPE i
      RETURNING VALUE(rv_bucket) TYPE {{p}}if_stock_age=>ty_bucket.
ENDCLASS.


CLASS {{p}}stock_age IMPLEMENTATION.

  METHOD {{p}}if_stock_age~analyze.
    DATA lt_group TYPE tt_age_group.

    LOOP AT it_batch INTO DATA(ls_batch).
      DATA(lv_age) = age_in_days( is_batch = ls_batch iv_key_date = iv_key_date ).
      IF lv_age < 0.
        CONTINUE.
      ENDIF.

      DATA(lv_bucket) = bucket_of( lv_age ).
      ASSIGN lt_group[ material = ls_batch-material
                       bucket   = lv_bucket ] TO FIELD-SYMBOL(<ls_group>).
      IF sy-subrc <> 0.
        INSERT VALUE #( material = ls_batch-material bucket = lv_bucket )
               INTO TABLE lt_group.
        ASSIGN lt_group[ material = ls_batch-material
                         bucket   = lv_bucket ] TO <ls_group>.
      ENDIF.

      <ls_group>-quantity = <ls_group>-quantity + ls_batch-quantity.
      <ls_group>-batch_count = <ls_group>-batch_count + 1.
    ENDLOOP.

    rt_age = lt_group.
    SORT rt_age BY material bucket.
  ENDMETHOD.

  METHOD {{p}}if_stock_age~total_by_material.
    DATA lt_group TYPE tt_total_group.

    LOOP AT it_batch INTO DATA(ls_batch).
      IF age_in_days( is_batch = ls_batch iv_key_date = iv_key_date ) < 0.
        CONTINUE.
      ENDIF.

      ASSIGN lt_group[ material = ls_batch-material ] TO FIELD-SYMBOL(<ls_group>).
      IF sy-subrc <> 0.
        INSERT VALUE #( material = ls_batch-material ) INTO TABLE lt_group.
        ASSIGN lt_group[ material = ls_batch-material ] TO <ls_group>.
      ENDIF.

      <ls_group>-quantity = <ls_group>-quantity + ls_batch-quantity.
      <ls_group>-batch_count = <ls_group>-batch_count + 1.
    ENDLOOP.

    rt_total = lt_group.
    SORT rt_total BY material.
  ENDMETHOD.

  METHOD age_in_days.
    IF is_batch-gr_date IS INITIAL OR is_batch-gr_date > iv_key_date.
      rv_age = -1.
    ELSE.
      rv_age = iv_key_date + is_batch-gr_date.
    ENDIF.
  ENDMETHOD.

  METHOD bucket_of.
    IF iv_age <= 30.
      rv_bucket = {{p}}if_stock_age=>c_bucket-d0_30.
    ELSEIF iv_age <= 60.
      rv_bucket = {{p}}if_stock_age=>c_bucket-d31_60.
    ELSEIF iv_age <= 90.
      rv_bucket = {{p}}if_stock_age=>c_bucket-d61_90.
    ELSE.
      rv_bucket = {{p}}if_stock_age=>c_bucket-d91_plus.
    ENDIF.
  ENDMETHOD.
ENDCLASS.