*&---------------------------------------------------------------------*
*& Report  Z_ERPFORGE_02_EXPORT
*&---------------------------------------------------------------------*
*& ERPForgeAI - Step 2: Repository Metadata Export
*& Run this AFTER Z_ERPFORGE_01_STECKBRIEF to extract repository data.
*&
*& Compatible: SAP_BASIS 7.40 SP02+
*& No external type dependencies - all types are primitive or
*& direct table-field references from core BASIS tables only.
*&
*& MEMORY-SAFE: Uses PACKAGE SIZE for large tables (DD03L, TSTC,
*& TADIR, TFDIR, D010TAB) to prevent TSV_TNEW_PAGE_ALLOC_FAILED.
*& Rows are counted first via SELECT COUNT(*), then streamed in
*& chunks into gt_output with p_max enforcement.
*&
*& What it exports (tab-delimited TXT):
*&   1. TABLES       - DD02L (transparent/pool/cluster)
*&   2. STRUCTURES   - DD02L (INTTAB)
*&   3. FIELDS       - DD03L + DD04T (descriptions)
*&   4. FUNC_MODULES - TFDIR + TFTIT
*&   5. BAPIS        - TFDIR (funcname starts BAPI)
*&   6. CLASSES      - TADIR (object=CLAS)
*&   7. TRANSACTIONS - TSTC + TSTCT
*&   8. PACKAGES     - TDEVC
*&   9. WHERE_USED   - D010TAB (only with s_tab filter!)
*&
*& Workflow:
*&   1) Run Z_ERPFORGE_01_STECKBRIEF  -> understand the system
*&   2) Feed output into ERPForgeAI    -> configure AI model
*&   3) Run Z_ERPFORGE_02_EXPORT      -> extract repository data
*&   4) Feed export into ERPForgeAI    -> generate ABAP code
*&---------------------------------------------------------------------*
REPORT z_erpforge_02_export.

*----------------------------------------------------------------------*
* Constants
*----------------------------------------------------------------------*
CONSTANTS: gc_pkg_size TYPE i VALUE 5000.  "PACKAGE SIZE for chunking

*----------------------------------------------------------------------*
* TYPES
*----------------------------------------------------------------------*
TYPES:
  " Tables and Structures
  BEGIN OF ty_table,
    tabname  TYPE dd02l-tabname,
    tabclass TYPE dd02l-tabclass,
    ddtext   TYPE c LENGTH 80,
    devclass TYPE tadir-devclass,
  END OF ty_table,

  " Fields
  BEGIN OF ty_field,
    tabname   TYPE dd03l-tabname,
    fieldname TYPE dd03l-fieldname,
    position  TYPE dd03l-position,
    datatype  TYPE dd03l-datatype,
    leng      TYPE dd03l-leng,
    decimals  TYPE dd03l-decimals,
    rollname  TYPE dd03l-rollname,
    keyflag   TYPE dd03l-keyflag,
    ddtext    TYPE c LENGTH 80,
  END OF ty_field,

  " Function Modules
  BEGIN OF ty_func,
    funcname TYPE tfdir-funcname,
    fmode    TYPE tfdir-fmode,
    pname    TYPE tfdir-pname,
    devclass TYPE tadir-devclass,
    stext    TYPE c LENGTH 60,
  END OF ty_func,

  " Classes
  BEGIN OF ty_class,
    clsname  TYPE c LENGTH 30,
    devclass TYPE tadir-devclass,
  END OF ty_class,

  " Transactions
  BEGIN OF ty_tcode,
    tcode    TYPE tstc-tcode,
    pgmna    TYPE tstc-pgmna,
    ttext    TYPE c LENGTH 60,
    devclass TYPE tadir-devclass,
  END OF ty_tcode,

  " Packages
  BEGIN OF ty_package,
    devclass TYPE tdevc-devclass,
    ctext    TYPE tdevc-ctext,
    parentcl TYPE tdevc-parentcl,
  END OF ty_package,

  " Where-Used
  BEGIN OF ty_whereused,
    tabname TYPE d010tab-tabname,
    master  TYPE d010tab-master,
  END OF ty_whereused.

*----------------------------------------------------------------------*
* DATA
*----------------------------------------------------------------------*
DATA:
  gt_output  TYPE TABLE OF string,
  gv_line    TYPE string,
  gv_cntstr  TYPE c LENGTH 20,
  gv_tab     TYPE c LENGTH 1
               VALUE cl_abap_char_utilities=>horizontal_tab,
  " Typed anchor fields for SELECT-OPTIONS
  gv_tabref  TYPE dd02l-tabname,
  gv_funcref TYPE tfdir-funcname,
  gv_packref TYPE tdevc-devclass.

*----------------------------------------------------------------------*
* SELECTION SCREEN
*----------------------------------------------------------------------*
SELECTION-SCREEN BEGIN OF BLOCK b1 WITH FRAME TITLE gt_b1.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(30) lbl_tab.
    PARAMETERS p_tables AS CHECKBOX DEFAULT 'X'.
  SELECTION-SCREEN END OF LINE.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(30) lbl_str.
    PARAMETERS p_struct AS CHECKBOX DEFAULT 'X'.
  SELECTION-SCREEN END OF LINE.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(30) lbl_fld.
    PARAMETERS p_fields AS CHECKBOX DEFAULT 'X'.
  SELECTION-SCREEN END OF LINE.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(30) lbl_fnc.
    PARAMETERS p_funcs AS CHECKBOX DEFAULT 'X'.
  SELECTION-SCREEN END OF LINE.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(30) lbl_bpi.
    PARAMETERS p_bapis AS CHECKBOX DEFAULT 'X'.
  SELECTION-SCREEN END OF LINE.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(30) lbl_cls.
    PARAMETERS p_class AS CHECKBOX DEFAULT 'X'.
  SELECTION-SCREEN END OF LINE.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(30) lbl_tcd.
    PARAMETERS p_tcode AS CHECKBOX DEFAULT 'X'.
  SELECTION-SCREEN END OF LINE.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(30) lbl_pkg.
    PARAMETERS p_pack AS CHECKBOX DEFAULT 'X'.
  SELECTION-SCREEN END OF LINE.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(30) lbl_wu.
    PARAMETERS p_wused AS CHECKBOX DEFAULT ' '.
  SELECTION-SCREEN END OF LINE.
SELECTION-SCREEN END OF BLOCK b1.

SELECTION-SCREEN BEGIN OF BLOCK b2 WITH FRAME TITLE gt_b2.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(25) lbl_stab.
    SELECT-OPTIONS s_tab FOR gv_tabref NO INTERVALS.
  SELECTION-SCREEN END OF LINE.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(25) lbl_sfc.
    SELECT-OPTIONS s_func FOR gv_funcref NO INTERVALS.
  SELECTION-SCREEN END OF LINE.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(25) lbl_spk.
    SELECT-OPTIONS s_pack FOR gv_packref NO INTERVALS.
  SELECTION-SCREEN END OF LINE.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(25) lbl_lng.
    PARAMETERS p_lang TYPE spras DEFAULT sy-langu.
  SELECTION-SCREEN END OF LINE.
  SELECTION-SCREEN BEGIN OF LINE.
    SELECTION-SCREEN COMMENT 1(25) lbl_max.
    PARAMETERS p_max TYPE i DEFAULT 50000.
  SELECTION-SCREEN END OF LINE.
SELECTION-SCREEN END OF BLOCK b2.

*----------------------------------------------------------------------*
* INITIALIZATION
*----------------------------------------------------------------------*
INITIALIZATION.
  IF sy-langu = 'E' OR sy-langu = 'e'.
    gt_b1    = 'Export Sections'.
    gt_b2    = 'Filters'.
    lbl_tab  = 'Tables'.
    lbl_str  = 'Structures'.
    lbl_fld  = 'Fields'.
    lbl_fnc  = 'Function Modules'.
    lbl_bpi  = 'BAPIs'.
    lbl_cls  = 'Classes / Interfaces'.
    lbl_tcd  = 'Transactions'.
    lbl_pkg  = 'Packages'.
    lbl_wu   = 'Where-Used (S_TAB)'.
    lbl_stab = 'Table Filter'.
    lbl_sfc  = 'Func.Module Filter'.
    lbl_spk  = 'Package Filter'.
    lbl_lng  = 'Language'.
    lbl_max  = 'Max. Rows'.
  ELSE.
    gt_b1    = 'Export-Bereiche'.
    gt_b2    = 'Filter'.
    lbl_tab  = 'Tabellen'.
    lbl_str  = 'Strukturen'.
    lbl_fld  = 'Felder'.
    lbl_fnc  = 'Funktionsbausteine'.
    lbl_bpi  = 'BAPIs'.
    lbl_cls  = 'Klassen / Interfaces'.
    lbl_tcd  = 'Transaktionen'.
    lbl_pkg  = 'Pakete'.
    lbl_wu   = 'Where-Used (S_TAB)'.
    lbl_stab = 'Tabellen-Filter'.
    lbl_sfc  = 'Funktionsbst.-Filter'.
    lbl_spk  = 'Paket-Filter'.
    lbl_lng  = 'Sprache'.
    lbl_max  = 'Max. Zeilen'.
  ENDIF.

*----------------------------------------------------------------------*
* START OF SELECTION
*----------------------------------------------------------------------*
START-OF-SELECTION.
  PERFORM write_header.
  IF p_tables = 'X'. PERFORM collect_tables.     ENDIF.
  IF p_struct = 'X'. PERFORM collect_structures. ENDIF.
  IF p_fields = 'X'. PERFORM collect_fields.     ENDIF.
  IF p_funcs = 'X' OR p_bapis = 'X'.
    PERFORM collect_funcs.
  ENDIF.
  IF p_class  = 'X'. PERFORM collect_classes.   ENDIF.
  IF p_tcode  = 'X'. PERFORM collect_tcodes.    ENDIF.
  IF p_pack   = 'X'. PERFORM collect_packages.  ENDIF.
  IF p_wused  = 'X'. PERFORM collect_whereused. ENDIF.
  PERFORM export_file.

*----------------------------------------------------------------------*
* FORM: write_section  (writes ## header line to output)
*----------------------------------------------------------------------*
FORM write_section USING pv_name  TYPE string
                         pv_count TYPE i.
  WRITE pv_count TO gv_cntstr LEFT-JUSTIFIED.
  CONDENSE gv_cntstr.
  CONCATENATE '## ' pv_name ': ' gv_cntstr ' rows'
    INTO gv_line.
  APPEND gv_line TO gt_output.
ENDFORM.

*----------------------------------------------------------------------*
* FORM: write_header
*----------------------------------------------------------------------*
FORM write_header.
  DATA: lv_date TYPE c LENGTH 10,
        lv_sys  TYPE c LENGTH 10.
  WRITE sy-datum TO lv_date.
  lv_sys = sy-sysid.
  APPEND '##ERPForgeAI Repository Export' TO gt_output.
  CONCATENATE '##System:' lv_sys  INTO gv_line SEPARATED BY gv_tab.
  APPEND gv_line TO gt_output.
  CONCATENATE '##Date:'   lv_date INTO gv_line SEPARATED BY gv_tab.
  APPEND gv_line TO gt_output.
  CONCATENATE '##Lang:'   p_lang  INTO gv_line SEPARATED BY gv_tab.
  APPEND gv_line TO gt_output.
  APPEND '' TO gt_output.
ENDFORM.

*----------------------------------------------------------------------*
* FORM: collect_tables
*   DD02L filtered by tabclass + s_tab → manageable row count.
*   Use UP TO p_max ROWS as safety cap.
*----------------------------------------------------------------------*
FORM collect_tables.
  DATA: lt_raw   TYPE TABLE OF dd02l,
        ls_d     TYPE dd02l,
        lv_text  TYPE c LENGTH 80,
        lv_pkg   TYPE tadir-devclass.

  SELECT tabname tabclass FROM dd02l INTO TABLE lt_raw
    WHERE as4local = 'A'
      AND ( tabclass = 'TRANSP'
         OR tabclass = 'POOL'
         OR tabclass = 'CLUSTER' )
      AND tabname IN s_tab.

  DATA lv_cnt TYPE i.
  DESCRIBE TABLE lt_raw LINES lv_cnt.
  IF lv_cnt > p_max.
    DELETE lt_raw FROM p_max + 1.
    DESCRIBE TABLE lt_raw LINES lv_cnt.
  ENDIF.
  PERFORM write_section USING 'TABLES' lv_cnt.
  CONCATENATE 'TABNAME' gv_tab 'TABCLASS' gv_tab
              'DESCRIPTION' gv_tab 'DEVCLASS' INTO gv_line.
  APPEND gv_line TO gt_output.

  LOOP AT lt_raw INTO ls_d.
    CLEAR: lv_text, lv_pkg.
    SELECT SINGLE ddtext FROM dd02t INTO lv_text
      WHERE tabname    = ls_d-tabname
        AND ddlanguage = p_lang
        AND as4local   = 'A'.
    SELECT SINGLE devclass FROM tadir INTO lv_pkg
      WHERE obj_name = ls_d-tabname
        AND object   = 'TABL'.
    CONCATENATE ls_d-tabname gv_tab ls_d-tabclass gv_tab
                lv_text      gv_tab lv_pkg
      INTO gv_line.
    APPEND gv_line TO gt_output.
  ENDLOOP.
  APPEND '' TO gt_output.
ENDFORM.

*----------------------------------------------------------------------*
* FORM: collect_structures
*----------------------------------------------------------------------*
FORM collect_structures.
  DATA: lt_raw  TYPE TABLE OF dd02l,
        ls_d    TYPE dd02l,
        lv_text TYPE c LENGTH 80,
        lv_pkg  TYPE tadir-devclass.

  SELECT tabname tabclass FROM dd02l INTO TABLE lt_raw
    WHERE as4local = 'A'
      AND tabclass = 'INTTAB'
      AND tabname  IN s_tab.

  DATA lv_cnt TYPE i.
  DESCRIBE TABLE lt_raw LINES lv_cnt.
  IF lv_cnt > p_max.
    DELETE lt_raw FROM p_max + 1.
    DESCRIBE TABLE lt_raw LINES lv_cnt.
  ENDIF.
  PERFORM write_section USING 'STRUCTURES' lv_cnt.
  CONCATENATE 'TABNAME' gv_tab 'TABCLASS' gv_tab
              'DESCRIPTION' gv_tab 'DEVCLASS' INTO gv_line.
  APPEND gv_line TO gt_output.

  LOOP AT lt_raw INTO ls_d.
    CLEAR: lv_text, lv_pkg.
    SELECT SINGLE ddtext FROM dd02t INTO lv_text
      WHERE tabname    = ls_d-tabname
        AND ddlanguage = p_lang
        AND as4local   = 'A'.
    SELECT SINGLE devclass FROM tadir INTO lv_pkg
      WHERE obj_name = ls_d-tabname
        AND object   = 'TABL'.
    CONCATENATE ls_d-tabname gv_tab ls_d-tabclass gv_tab
                lv_text      gv_tab lv_pkg
      INTO gv_line.
    APPEND gv_line TO gt_output.
  ENDLOOP.
  APPEND '' TO gt_output.
ENDFORM.

*----------------------------------------------------------------------*
* FORM: collect_fields
*   DD03L is the BIGGEST table — this caused the OOM crash with
*   17 million rows. Fix: COUNT first, then PACKAGE SIZE streaming.
*----------------------------------------------------------------------*
FORM collect_fields.
  DATA: lt_chunk TYPE TABLE OF dd03l,
        ls_f     TYPE dd03l,
        lv_text  TYPE c LENGTH 80,
        lv_pos   TYPE c LENGTH 10,
        lv_len   TYPE c LENGTH 10,
        lv_dec   TYPE c LENGTH 10,
        lv_total TYPE i,
        lv_written TYPE i.

  " Count first (cheap — no data transfer)
  SELECT COUNT(*) FROM dd03l INTO lv_total
    WHERE tabname  IN s_tab
      AND as4local = 'A'
      AND fieldname NOT LIKE '.%'.

  " Cap at p_max for the header
  IF lv_total > p_max.
    lv_total = p_max.
  ENDIF.

  PERFORM write_section USING 'FIELDS' lv_total.
  CONCATENATE 'TABNAME'  gv_tab 'FIELDNAME' gv_tab 'POS'  gv_tab
              'TYPE'     gv_tab 'LEN'        gv_tab 'DEC'  gv_tab
              'ROLLNAME' gv_tab 'KEY'        gv_tab 'DESCRIPTION'
    INTO gv_line.
  APPEND gv_line TO gt_output.

  " Stream in chunks of gc_pkg_size — never loads all rows at once
  lv_written = 0.
  SELECT tabname fieldname position datatype leng
         decimals rollname keyflag
    FROM dd03l INTO CORRESPONDING FIELDS OF TABLE lt_chunk
    PACKAGE SIZE gc_pkg_size
    WHERE tabname  IN s_tab
      AND as4local = 'A'
      AND fieldname NOT LIKE '.%'.

    LOOP AT lt_chunk INTO ls_f.
      IF lv_written >= p_max.
        EXIT.
      ENDIF.
      CLEAR lv_text.
      IF ls_f-rollname IS NOT INITIAL.
        SELECT SINGLE ddtext FROM dd04t INTO lv_text
          WHERE rollname   = ls_f-rollname
            AND ddlanguage = p_lang
            AND as4local   = 'A'.
      ENDIF.
      WRITE ls_f-position TO lv_pos LEFT-JUSTIFIED.
      WRITE ls_f-leng     TO lv_len LEFT-JUSTIFIED.
      WRITE ls_f-decimals TO lv_dec LEFT-JUSTIFIED.
      CONDENSE lv_pos. CONDENSE lv_len. CONDENSE lv_dec.
      CONCATENATE ls_f-tabname  gv_tab ls_f-fieldname gv_tab lv_pos   gv_tab
                  ls_f-datatype gv_tab lv_len          gv_tab lv_dec   gv_tab
                  ls_f-rollname gv_tab ls_f-keyflag    gv_tab lv_text
        INTO gv_line.
      APPEND gv_line TO gt_output.
      lv_written = lv_written + 1.
    ENDLOOP.

    IF lv_written >= p_max.
      EXIT.
    ENDIF.

  ENDSELECT.

  APPEND '' TO gt_output.
ENDFORM.

*----------------------------------------------------------------------*
* FORM: collect_funcs
*   TFDIR can be large. Use PACKAGE SIZE + p_max cap.
*----------------------------------------------------------------------*
FORM collect_funcs.
  DATA: lt_chunk TYPE TABLE OF tfdir,
        ls_tf    TYPE tfdir,
        ls_out   TYPE ty_func,
        lt_fms   TYPE TABLE OF ty_func,
        lt_bapis TYPE TABLE OF ty_func,
        lv_stext TYPE c LENGTH 60,
        lv_pkg   TYPE tadir-devclass,
        lv_written TYPE i.

  lv_written = 0.

  SELECT funcname fmode pname
    FROM tfdir INTO CORRESPONDING FIELDS OF TABLE lt_chunk
    PACKAGE SIZE gc_pkg_size
    WHERE funcname IN s_func.

    LOOP AT lt_chunk INTO ls_tf.
      IF lv_written >= p_max.
        EXIT.
      ENDIF.
      CLEAR: lv_stext, lv_pkg.
      SELECT SINGLE stext FROM tftit INTO lv_stext
        WHERE funcname = ls_tf-funcname
          AND spras    = p_lang.
      SELECT SINGLE devclass FROM tadir INTO lv_pkg
        WHERE obj_name = ls_tf-funcname
          AND object   = 'FUNC'.
      ls_out-funcname = ls_tf-funcname.
      ls_out-fmode    = ls_tf-fmode.
      ls_out-pname    = ls_tf-pname.
      ls_out-devclass = lv_pkg.
      ls_out-stext    = lv_stext.
      IF ls_tf-funcname CP 'BAPI*'.
        APPEND ls_out TO lt_bapis.
      ELSE.
        APPEND ls_out TO lt_fms.
      ENDIF.
      lv_written = lv_written + 1.
    ENDLOOP.

    IF lv_written >= p_max.
      EXIT.
    ENDIF.

  ENDSELECT.

  IF p_funcs = 'X'.
    DATA lv_cnt TYPE i.
    DESCRIBE TABLE lt_fms LINES lv_cnt.
    PERFORM write_section USING 'FUNCTION_MODULES' lv_cnt.
    CONCATENATE 'FUNCNAME' gv_tab 'FMODE' gv_tab
                'FUNCGROUP' gv_tab 'DEVCLASS' gv_tab 'DESCRIPTION'
      INTO gv_line.
    APPEND gv_line TO gt_output.
    LOOP AT lt_fms INTO ls_out.
      CONCATENATE ls_out-funcname gv_tab ls_out-fmode    gv_tab
                  ls_out-pname    gv_tab ls_out-devclass gv_tab
                  ls_out-stext
        INTO gv_line.
      APPEND gv_line TO gt_output.
    ENDLOOP.
    APPEND '' TO gt_output.
  ENDIF.

  IF p_bapis = 'X'.
    DESCRIBE TABLE lt_bapis LINES lv_cnt.
    PERFORM write_section USING 'BAPIS' lv_cnt.
    CONCATENATE 'FUNCNAME' gv_tab 'FMODE' gv_tab
                'FUNCGROUP' gv_tab 'DEVCLASS' gv_tab 'DESCRIPTION'
      INTO gv_line.
    APPEND gv_line TO gt_output.
    LOOP AT lt_bapis INTO ls_out.
      CONCATENATE ls_out-funcname gv_tab ls_out-fmode    gv_tab
                  ls_out-pname    gv_tab ls_out-devclass gv_tab
                  ls_out-stext
        INTO gv_line.
      APPEND gv_line TO gt_output.
    ENDLOOP.
    APPEND '' TO gt_output.
  ENDIF.
ENDFORM.

*----------------------------------------------------------------------*
* FORM: collect_classes
*   TADIR with object=CLAS can return 100k+ rows.
*   Use PACKAGE SIZE + p_max cap.
*----------------------------------------------------------------------*
FORM collect_classes.
  DATA: lt_chunk   TYPE TABLE OF tadir,
        ls_ta      TYPE tadir,
        ls_out     TYPE ty_class,
        lv_total   TYPE i,
        lv_written TYPE i.

  " Count first
  SELECT COUNT(*) FROM tadir INTO lv_total
    WHERE object   = 'CLAS'
      AND devclass IN s_pack.
  IF lv_total > p_max.
    lv_total = p_max.
  ENDIF.

  PERFORM write_section USING 'CLASSES' lv_total.
  CONCATENATE 'CLSNAME' gv_tab 'DEVCLASS' INTO gv_line.
  APPEND gv_line TO gt_output.

  lv_written = 0.

  SELECT obj_name devclass FROM tadir
    INTO CORRESPONDING FIELDS OF TABLE lt_chunk
    PACKAGE SIZE gc_pkg_size
    WHERE object   = 'CLAS'
      AND devclass IN s_pack.

    LOOP AT lt_chunk INTO ls_ta.
      IF lv_written >= p_max.
        EXIT.
      ENDIF.
      ls_out-clsname  = ls_ta-obj_name.
      ls_out-devclass = ls_ta-devclass.
      CONCATENATE ls_out-clsname gv_tab ls_out-devclass
        INTO gv_line.
      APPEND gv_line TO gt_output.
      lv_written = lv_written + 1.
    ENDLOOP.

    IF lv_written >= p_max.
      EXIT.
    ENDIF.

  ENDSELECT.

  APPEND '' TO gt_output.
ENDFORM.

*----------------------------------------------------------------------*
* FORM: collect_tcodes
*   TSTC has NO filter → selects ALL transactions in the system.
*   Use PACKAGE SIZE + p_max cap.
*----------------------------------------------------------------------*
FORM collect_tcodes.
  DATA: lt_chunk   TYPE TABLE OF tstc,
        ls_t       TYPE tstc,
        lv_text    TYPE c LENGTH 60,
        lv_pkg     TYPE tadir-devclass,
        lv_total   TYPE i,
        lv_written TYPE i.

  " Count first
  SELECT COUNT(*) FROM tstc INTO lv_total.
  IF lv_total > p_max.
    lv_total = p_max.
  ENDIF.

  PERFORM write_section USING 'TRANSACTIONS' lv_total.
  CONCATENATE 'TCODE' gv_tab 'PROGRAM' gv_tab
              'DESCRIPTION' gv_tab 'DEVCLASS' INTO gv_line.
  APPEND gv_line TO gt_output.

  lv_written = 0.

  SELECT tcode pgmna FROM tstc
    INTO CORRESPONDING FIELDS OF TABLE lt_chunk
    PACKAGE SIZE gc_pkg_size.

    LOOP AT lt_chunk INTO ls_t.
      IF lv_written >= p_max.
        EXIT.
      ENDIF.
      CLEAR: lv_text, lv_pkg.
      SELECT SINGLE ttext FROM tstct INTO lv_text
        WHERE tcode = ls_t-tcode
          AND sprsl = p_lang.
      SELECT SINGLE devclass FROM tadir INTO lv_pkg
        WHERE obj_name = ls_t-tcode
          AND object   = 'TRAN'.
      CONCATENATE ls_t-tcode gv_tab ls_t-pgmna gv_tab
                  lv_text    gv_tab lv_pkg
        INTO gv_line.
      APPEND gv_line TO gt_output.
      lv_written = lv_written + 1.
    ENDLOOP.

    IF lv_written >= p_max.
      EXIT.
    ENDIF.

  ENDSELECT.

  APPEND '' TO gt_output.
ENDFORM.

*----------------------------------------------------------------------*
* FORM: collect_packages
*   TDEVC is usually small (<10k). UP TO for safety.
*----------------------------------------------------------------------*
FORM collect_packages.
  DATA: lt_raw TYPE TABLE OF tdevc,
        ls_p   TYPE tdevc.

  SELECT devclass ctext parentcl FROM tdevc
    INTO CORRESPONDING FIELDS OF TABLE lt_raw
    WHERE devclass IN s_pack.

  DATA lv_cnt TYPE i.
  DESCRIBE TABLE lt_raw LINES lv_cnt.
  IF lv_cnt > p_max.
    DELETE lt_raw FROM p_max + 1.
    DESCRIBE TABLE lt_raw LINES lv_cnt.
  ENDIF.
  PERFORM write_section USING 'PACKAGES' lv_cnt.
  CONCATENATE 'DEVCLASS' gv_tab 'DESCRIPTION' gv_tab 'PARENT'
    INTO gv_line.
  APPEND gv_line TO gt_output.

  LOOP AT lt_raw INTO ls_p.
    CONCATENATE ls_p-devclass gv_tab ls_p-ctext gv_tab ls_p-parentcl
      INTO gv_line.
    APPEND gv_line TO gt_output.
  ENDLOOP.
  APPEND '' TO gt_output.
ENDFORM.

*----------------------------------------------------------------------*
* FORM: collect_whereused
*   D010TAB can be large. Use PACKAGE SIZE + p_max cap.
*----------------------------------------------------------------------*
FORM collect_whereused.
  DATA: lt_chunk   TYPE TABLE OF ty_whereused,
        ls_wu      TYPE ty_whereused,
        lv_total   TYPE i,
        lv_written TYPE i.

  IF s_tab[] IS INITIAL.
    APPEND '## WHERE_USED: Skipped - set table filter s_tab first'
      TO gt_output.
    APPEND '' TO gt_output.
    RETURN.
  ENDIF.

  " Count first
  SELECT COUNT(*) FROM d010tab INTO lv_total
    WHERE tabname IN s_tab.
  IF lv_total > p_max.
    lv_total = p_max.
  ENDIF.

  PERFORM write_section USING 'WHERE_USED' lv_total.
  CONCATENATE 'TABNAME' gv_tab 'PROGRAM' INTO gv_line.
  APPEND gv_line TO gt_output.

  lv_written = 0.

  SELECT tabname master FROM d010tab
    INTO CORRESPONDING FIELDS OF TABLE lt_chunk
    PACKAGE SIZE gc_pkg_size
    WHERE tabname IN s_tab.

    LOOP AT lt_chunk INTO ls_wu.
      IF lv_written >= p_max.
        EXIT.
      ENDIF.
      CONCATENATE ls_wu-tabname gv_tab ls_wu-master
        INTO gv_line.
      APPEND gv_line TO gt_output.
      lv_written = lv_written + 1.
    ENDLOOP.

    IF lv_written >= p_max.
      EXIT.
    ENDIF.

  ENDSELECT.

  APPEND '' TO gt_output.
ENDFORM.

*----------------------------------------------------------------------*
* FORM: export_file
*----------------------------------------------------------------------*
FORM export_file.
  DATA: lv_fn     TYPE string,
        lv_path   TYPE string,
        lv_fp     TYPE string,
        lv_action TYPE i,
        lv_rows   TYPE c LENGTH 20.

  CONCATENATE 'ERPForge_RepoExport_' sy-sysid '_' sy-datum INTO lv_fn.

  cl_gui_frontend_services=>file_save_dialog(
    EXPORTING
      default_file_name = lv_fn
      default_extension = 'txt'
      file_filter       = 'Text (*.txt)|*.txt|All|*.*'
    CHANGING
      filename    = lv_fn
      path        = lv_path
      fullpath    = lv_fp
      user_action = lv_action
    EXCEPTIONS
      OTHERS      = 4 ).

  IF sy-subrc <> 0 OR lv_action <> 0.
    MESSAGE 'Export cancelled.' TYPE 'I'.
    RETURN.
  ENDIF.

  cl_gui_frontend_services=>gui_download(
    EXPORTING
      filename              = lv_fp
      filetype              = 'ASC'
      trunc_trailing_blanks = 'X'
      codepage              = '4110'
    CHANGING
      data_tab              = gt_output
    EXCEPTIONS
      OTHERS                = 22 ).

  IF sy-subrc = 0.
    DATA lv_cnt TYPE i.
    DESCRIBE TABLE gt_output LINES lv_cnt.
    WRITE lv_cnt TO lv_rows LEFT-JUSTIFIED.
    CONDENSE lv_rows.
    CONCATENATE 'Export OK:' lv_rows 'lines ->' lv_fp
      INTO gv_line SEPARATED BY ' '.
    MESSAGE gv_line TYPE 'S'.
  ELSE.
    MESSAGE 'Export failed - check path and permissions.' TYPE 'E'.
  ENDIF.
ENDFORM.