Normalize PIN codes and tighten prompt

src/main/kotlin/com/android/trisolarisserver/component/DocumentExtractionService.kt

@@ -216,6 +216,7 @@ class DocumentExtractionService(
             }
         }
 
+        normalizePinCode(results)
         results["docType"] = computeDocType(results, handled)
         applyGuestUpdates(document, propertyId, results)
         return ExtractionResult(results, handled)
@@ -232,6 +233,18 @@ class DocumentExtractionService(
         return standardPlateRegex.matches(normalized) || bhPlateRegex.matches(normalized)
     }
 
+    private fun normalizePinCode(results: MutableMap<String, String>) {
+        val pinKey = DocumentPrompts.PIN_CODE.first
+        val rawPin = cleanedValue(results[pinKey])
+        val address = cleanedValue(results[DocumentPrompts.ADDRESS.first])
+
+        val fromPin = extractPinFromValue(rawPin)
+        val fromAddress = extractPinFromAddress(address)
+
+        val chosen = fromPin ?: fromAddress
+        results[pinKey] = chosen ?: "NONE"
+    }
+
     private fun computeDocType(results: Map<String, String>, handled: Boolean): String {
         if (!handled) return "GENERAL"
         return when {
@@ -326,3 +339,20 @@ private fun cleanedValue(value: String?): String? {
 
 private val standardPlateRegex = Regex("^[A-Z]{2}\\d{1,2}[A-Z]{1,3}\\d{3,4}$")
 private val bhPlateRegex = Regex("^\\d{2}BH\\d{4}[A-Z]{1,2}$")
+private val pinCodeRegex = Regex("\\b\\d{6}\\b")
+
+private fun extractPinFromValue(value: String?): String? {
+    if (value.isNullOrBlank()) return null
+    val compact = value.replace(Regex("\\s+"), "")
+    if (compact.length == 12 && compact.all { it.isDigit() }) return null
+    val match = pinCodeRegex.find(value) ?: return null
+    return match.value
+}
+
+private fun extractPinFromAddress(value: String?): String? {
+    if (value.isNullOrBlank()) return null
+    val hasPinLabel = value.contains("PIN", ignoreCase = true) || value.contains("PINCODE", ignoreCase = true)
+    if (!hasPinLabel) return null
+    val match = pinCodeRegex.find(value) ?: return null
+    return match.value
+}