Fix Tally GST registration discovery via Tax Unit masters

app/modules/documents/local_agent_runtime/erp_local_agent/__init__.py

@@ -1,2 +1,2 @@
-__version__ = "1.9.4"
+__version__ = "1.9.5"
 AGENT_NAME = "ERP Local Agent"

app/modules/documents/local_agent_runtime/erp_local_agent/commands.py

@@ -111,14 +111,22 @@ class AgentCommandProcessor:
         if not company:
             raise ValueError("The selected Tally company is no longer loaded. Refresh Tally companies and try again.")
         company_name = str(company.get("name") or "").strip()
-        company_gstin = str(company.get("gstin") or "").strip().upper()
+        company_gstins: list[str] = []
+        for value in list(company.get("gstins") or []) + [company.get("gstin")]:
+            gstin = str(value or "").strip().upper()
+            if gstin and gstin not in company_gstins:
+                company_gstins.append(gstin)
+        company_gstin = company_gstins[0] if company_gstins else ""
         if not company_name:
             raise ValueError("Tally returned an invalid company name.")
         if registration:
             reg_type = str(registration.get("registration_type_code") or "").strip().upper()
             reg_number = str(registration.get("registration_number") or "").strip().upper()
-            if reg_type == "GSTIN" and reg_number and company_gstin and reg_number != company_gstin and not allow_gstin_mismatch:
-                raise ValueError(f"GSTIN mismatch: ERP registration is {reg_number}, but Tally company reports {company_gstin}. Verify the company or explicitly allow the mismatch.")
+            if reg_type == "GSTIN" and reg_number and company_gstins and reg_number not in company_gstins and not allow_gstin_mismatch:
+                reported = ", ".join(company_gstins)
+                raise ValueError(f"GSTIN mismatch: ERP registration is {reg_number}, but Tally company reports {reported}. Verify the company or explicitly allow the mismatch.")
+            if reg_type == "GSTIN" and reg_number in company_gstins:
+                company_gstin = reg_number
         self.store.record_tally_status(client_id, tally_status)
         mapping = self.store.map_company(client_id, tally_guid=requested_guid, company_name=company_name, gstin=company_gstin, registration=registration, mapped_by_user_id=int(mapped_by_user_id) if mapped_by_user_id not in (None, "") else None)
         return {"mapped": True, "mapping": mapping, "accounting": self.store.snapshot(client_id), "tally": tally_status, "agent": self._agent_info()}

app/modules/documents/local_agent_runtime/erp_local_agent/tally.py

@@ -91,8 +91,9 @@ class TallyCompany:
     name: str
     guid: str = ""
     gstin: str = ""
+    gstins: tuple[str, ...] = ()
 
-    def as_dict(self) -> dict[str, str]:
+    def as_dict(self) -> dict:
         return asdict(self)
 
 
@@ -205,7 +206,83 @@ class TallyLiveConnector:
     </TDLMESSAGE></TDL>
   </DESC></BODY>
 </ENVELOPE>"""
-        return self._parse_companies(self._post_xml(xml))
+        companies = self._parse_companies(self._post_xml(xml))
+        enriched: list[TallyCompany] = []
+        for company in companies:
+            gstins = self._get_company_gstins(company.name)
+            if not gstins and company.gstin:
+                gstins = (company.gstin.strip().upper(),)
+            primary_gstin = gstins[0] if gstins else company.gstin
+            enriched.append(
+                TallyCompany(
+                    name=company.name,
+                    guid=company.guid,
+                    gstin=primary_gstin,
+                    gstins=gstins,
+                )
+            )
+        return enriched
+
+    def _get_company_gstins(self, company_name: str) -> tuple[str, ...]:
+        """Return GST registrations configured in the selected Tally company.
+
+        TallyPrime 3+ stores GST registrations as Tax Unit masters. A direct
+        NATIVEMETHOD/FETCH enumeration can stall on some Tally builds, while the
+        filtered COMPUTE collection below is stable and has been verified against
+        the GST Registration master shown in TallyPrime. Failure to enrich GSTINs
+        must never make otherwise-working company discovery unavailable.
+        """
+        company = str(company_name or "").strip()
+        if not company:
+            return ()
+        xml = f"""<ENVELOPE>
+  <HEADER>
+    <VERSION>1</VERSION><TALLYREQUEST>Export</TALLYREQUEST><TYPE>Collection</TYPE><ID>ARRRAccountingGSTRegistrations</ID>
+  </HEADER>
+  <BODY><DESC>
+    <STATICVARIABLES>{self._static_variables(company)}</STATICVARIABLES>
+    <TDL><TDLMESSAGE>
+      <COLLECTION NAME="ARRRAccountingGSTRegistrations">
+        <TYPE>Tax Unit</TYPE>
+        <COMPUTE>MasterName : $Name</COMPUTE>
+        <COMPUTE>GSTNumber : $GSTRegNumber</COMPUTE>
+        <COMPUTE>GSTState : $StateName</COMPUTE>
+        <COMPUTE>GSTUsedFor : $UsedFor</COMPUTE>
+        <FILTER>ARRRAccountingHasGSTNumber</FILTER>
+      </COLLECTION>
+      <SYSTEM TYPE="Formulae" NAME="ARRRAccountingHasGSTNumber">NOT $$IsEmpty:$GSTRegNumber</SYSTEM>
+    </TDLMESSAGE></TDL>
+  </DESC></BODY>
+</ENVELOPE>"""
+        try:
+            return self._parse_gst_registration_numbers(self._post_xml(xml))
+        except TallyConnectionError:
+            return ()
+
+    @staticmethod
+    def _parse_gst_registration_numbers(xml_text: str) -> tuple[str, ...]:
+        cleaned = _clean_xml_response(xml_text)
+        if not cleaned:
+            return ()
+        values: list[str] = []
+        try:
+            root = ET.fromstring(cleaned.encode("utf-8"))
+            for element in root.iter():
+                if _tag(element) != "TAXUNIT":
+                    continue
+                candidates = [
+                    _child_text(element, "GSTREGNUMBER"),
+                    str(element.attrib.get("TAXREGISTRATION") or ""),
+                ]
+                for candidate in candidates:
+                    value = re.sub(r"\s+", "", candidate.strip().upper())
+                    if re.fullmatch(r"[0-9]{2}[A-Z]{5}[0-9]{4}[A-Z][0-9A-Z]Z[0-9A-Z]", value) and value not in values:
+                        values.append(value)
+        except Exception:
+            for match in re.findall(r"\b[0-9]{2}[A-Z]{5}[0-9]{4}[A-Z][0-9A-Z]Z[0-9A-Z]\b", cleaned.upper()):
+                if match not in values:
+                    values.append(match)
+        return tuple(values)
 
     def status(self) -> dict:
         try:
@@ -573,5 +650,13 @@ class TallyLiveConnector:
                     "GSTNUMBER",
                 ),
             )
-            companies.append(TallyCompany(name=name, guid=_child_text(element, "GUID"), gstin=gstin))
+            normalised_gstin = re.sub(r"\s+", "", gstin.strip().upper())
+            companies.append(
+                TallyCompany(
+                    name=name,
+                    guid=_child_text(element, "GUID"),
+                    gstin=normalised_gstin,
+                    gstins=(normalised_gstin,) if normalised_gstin else (),
+                )
+            )
         return companies