Fix SBI multiline table parsing and restore template-first bank analysis

app/modules/bank_statement_analyzer/parsers/bank_identity.py

@@ -151,6 +151,10 @@ def detect_bank_identity(
 ) -> BankIdentityMatch | None:
     raw_text = str(text or "")
     text_upper = _normalise(raw_text)
+    # Identity headings and account metadata are normally in the first page.
+    # Restrict strong name evidence to the beginning so counterparty bank names
+    # inside hundreds of transaction narrations cannot relabel the statement.
+    header_upper = _normalise(raw_text[:800])
     ifsc_upper = re.sub(r"[^A-Z0-9]", "", str(ifsc or "").upper())
     file_upper = _normalise(Path(source_file or "").stem)
 
@@ -159,25 +163,36 @@ def detect_bank_identity(
         score = 0.0
         evidence: list[str] = []
 
-        # Longest/special IFSC prefixes carry the strongest identity signal.
-        matching_prefixes = [prefix for prefix in bank.ifsc_prefixes if ifsc_upper.startswith(prefix.upper())]
+        matching_prefixes = [
+            prefix for prefix in bank.ifsc_prefixes
+            if ifsc_upper.startswith(prefix.upper())
+        ]
         if matching_prefixes:
             prefix = max(matching_prefixes, key=len)
-            score += 0.72 if len(prefix) > 4 else 0.58
+            # The account IFSC belongs to the issuing bank and therefore outranks
+            # bank names appearing merely as transaction counterparties.
+            score += 0.96 if len(prefix) > 4 else 0.90
             evidence.append(f"IFSC prefix {prefix}")
 
         for domain in bank.domains:
             if domain.lower() in raw_text.lower():
-                score += 0.72
+                score += 0.92
                 evidence.append(f"domain {domain}")
                 break
 
-        alias_hits = [alias for alias in bank.aliases if _alias_present(text_upper, alias)]
-        if alias_hits:
-            longest = max(alias_hits, key=len)
-            # Long formal headings are stronger than abbreviations such as SBI.
-            score += 0.72 if len(_normalise(longest)) >= 12 else 0.36
-            evidence.append(f"name {longest}")
+        header_alias_hits = [alias for alias in bank.aliases if _alias_present(header_upper, alias)]
+        if header_alias_hits:
+            longest = max(header_alias_hits, key=len)
+            score += 0.88 if len(_normalise(longest)) >= 12 else 0.55
+            evidence.append(f"header name {longest}")
+        else:
+            # Full-document matches are weak because narrations commonly mention
+            # beneficiary and remitter banks. They may support another signal but
+            # cannot identify the issuer by themselves.
+            body_hits = [alias for alias in bank.aliases if _alias_present(text_upper, alias)]
+            if body_hits:
+                score += 0.12
+                evidence.append("body mention")
 
         if any(_alias_present(file_upper, alias) for alias in bank.aliases):
             score += 0.10
@@ -186,7 +201,9 @@ def detect_bank_identity(
         confidence = min(score, 0.99)
         if confidence < 0.50:
             continue
-        candidate = BankIdentityMatch(bank.name, bank.category, confidence, tuple(dict.fromkeys(evidence)))
+        candidate = BankIdentityMatch(
+            bank.name, bank.category, confidence, tuple(dict.fromkeys(evidence))
+        )
         if best is None or candidate.confidence > best.confidence:
             best = candidate
 
@@ -194,9 +211,21 @@ def detect_bank_identity(
 
 
 def apply_detected_bank_identity(meta, df, text: str):
+    meta_ifsc = str(getattr(meta, "ifsc", "") or "")
+    if not meta_ifsc:
+        # Some PDFs place the IFSC value far from its label in text-reading
+        # order.  Recover the first header-area IFSC token directly; limiting
+        # the search to the beginning avoids beneficiary-bank IFSC codes.
+        header_match = re.search(r"\b[A-Z]{4}0[A-Z0-9]{6}\b", str(text or "")[:2500], re.I)
+        if header_match:
+            meta_ifsc = header_match.group(0).upper()
+            try:
+                meta.ifsc = meta_ifsc
+            except Exception:
+                pass
     match = detect_bank_identity(
         text,
-        ifsc=str(getattr(meta, "ifsc", "") or ""),
+        ifsc=meta_ifsc,
         source_file=str(getattr(meta, "source_file", "") or ""),
     )
     if match is None: