##############################################################
# YCTRL_FIELD — field control actions for custom BPC fields.
#
# Wire up in GESAFE: point each field's "Control" action at the
# matching $CTRL_* label in this .trt.
#
# Demonstrates: Sortie champ (exit-field) validation, localized
# messages via mess(), GOK=0 to block save, uniqueness check.
##############################################################

##############################################################
# $CTRL_YCODE — custom code on BPCUSTOMER. Must match [A-Z]{2}[0-9]{4}
# Blocks save when invalid; allows empty (optional field).
##############################################################
$CTRL_YCODE
    If [M:BPC]YCODE = ""
        Return                                  # empty is valid
    Endif

    # Format: 2 letters + 4 digits
    If not pat([M:BPC]YCODE, "!!####")
        Call ECRAN_TRACE(mess(501, 501, 1), 2) From GESECRAN
        GOK = 0
        Return
    Endif

    # Uniqueness — check against existing customers
    Local File BPCUSTOMER [BPX]
    Read [BPX]YCODEIDX = [M:BPC]YCODE
    If !fstat And [F:BPX]BPCNUM <> [M:BPC]BPCNUM
        Call ECRAN_TRACE(mess(502, 501, 1) - [F:BPX]BPCNUM, 2) From GESECRAN
        GOK = 0
    Endif
Return

##############################################################
# $CTRL_YSIREN — French SIREN: 9 digits, Luhn-compatible.
##############################################################
$CTRL_YSIREN
    If [M:BPC]YSIREN = "" : Return : Endif

    If not pat([M:BPC]YSIREN, "#########")
        Call ECRAN_TRACE(mess(503, 501, 1), 2) From GESECRAN
        GOK = 0
        Return
    Endif

    # Luhn check — mandatory for French SIREN validity
    Local Integer I, CHK, DIG, SUM
    SUM = 0
    For I = 1 To 9
        DIG = val(mid$([M:BPC]YSIREN, I, 1))
        If mod(I, 2) = 0                        # even positions: doubled
            DIG = DIG * 2
            If DIG >= 10 : DIG = DIG - 9 : Endif
        Endif
        SUM += DIG
    Next

    If mod(SUM, 10) <> 0
        Call ECRAN_TRACE(mess(504, 501, 1), 2) From GESECRAN
        GOK = 0
    Endif
Return

##############################################################
# $AVBAS — overall pre-save check (standard action).
# Called by the supervisor before committing the record.
##############################################################
$AVBAS
    # Cross-field rule: YCODE required when customer type = VIP
    If [M:BPC]BPCTYP = 2 And [M:BPC]YCODE = ""
        Call ECRAN_TRACE(mess(505, 501, 1), 2) From GESECRAN
        GOK = 0
    Endif
Return