trying to fix qr

src/main/kotlin/com/android/trisolarisserver/controller/PayuQrPayments.kt

@@ -41,6 +41,7 @@ class PayuQrPayments(
     private val payuQrRequestRepo: PayuQrRequestRepo,
     private val restTemplate: RestTemplate
 ) {
+    private val defaultExpirySeconds = 30 * 60
 
     @PostMapping("/qr")
     @Transactional
@@ -79,6 +80,31 @@ class PayuQrPayments(
             throw ResponseStatusException(HttpStatus.CONFLICT, "Amount exceeds pending")
         }
         val amountLong = requestedAmount ?: pending
+        val expirySeconds = request.expirySeconds
+            ?: request.expiryMinutes?.let { it * 60 }
+            ?: defaultExpirySeconds
+
+        val existing = payuQrRequestRepo.findTopByBookingIdAndAmountAndCurrencyAndStatusOrderByCreatedAtDesc(
+            bookingId,
+            amountLong,
+            booking.property.currency,
+            PayuQrStatus.SENT
+        )
+        if (existing != null) {
+            val expiryAt = existing.expiryAt
+            val responsePayload = existing.responsePayload
+            if (expiryAt != null && !responsePayload.isNullOrBlank()) {
+                val now = OffsetDateTime.now()
+                if (now.isBefore(expiryAt)) {
+                    return PayuQrGenerateResponse(
+                        txnid = existing.txnid,
+                        amount = amountLong,
+                        currency = booking.property.currency,
+                        payuResponse = responsePayload
+                    )
+                }
+            }
+        }
 
         val txnid = "QR${bookingId.toString().substring(0, 8)}${System.currentTimeMillis()}"
         val productInfo = "Booking $bookingId"
@@ -132,9 +158,9 @@ class PayuQrPayments(
             add("hash", hash)
             add("udf1", udf1)
             add("udf2", udf2)
-            if (udf3.isNotBlank()) add("udf3", udf3)
-            if (udf4.isNotBlank()) add("udf4", udf4)
-            if (udf5.isNotBlank()) add("udf5", udf5)
+            add("udf3", udf3)  // always
+            add("udf4", udf4)  // always
+            add("udf5", udf5)  // always
             add("txn_s2s_flow", "4")
             val clientIp = request.clientIp?.trim()?.ifBlank { null }
                 ?: extractClientIp(httpRequest)
@@ -143,9 +169,7 @@ class PayuQrPayments(
                 ?: throw ResponseStatusException(HttpStatus.BAD_REQUEST, "deviceInfo required")
             add("s2s_client_ip", clientIp)
             add("s2s_device_info", deviceInfo)
-            val expirySeconds = request.expirySeconds
-                ?: request.expiryMinutes?.let { it * 60 }
-            expirySeconds?.let { add("expiry_time", it.toString()) }
+            add("expiry_time", expirySeconds.toString())
             request.address1?.trim()?.ifBlank { null }?.let { add("address1", it) }
             request.address2?.trim()?.ifBlank { null }?.let { add("address2", it) }
             request.city?.trim()?.ifBlank { null }?.let { add("city", it) }
@@ -158,6 +182,8 @@ class PayuQrPayments(
             entry.value.joinToString("&") { value -> "${entry.key}=$value" }
         }
 
+        val createdAt = OffsetDateTime.now()
+        val expiryAt = createdAt.plusSeconds(expirySeconds.toLong())
         val record = payuQrRequestRepo.save(
             PayuQrRequest(
                 property = booking.property,
@@ -167,7 +193,8 @@ class PayuQrPayments(
                 currency = booking.property.currency,
                 status = PayuQrStatus.CREATED,
                 requestPayload = requestPayload,
-                createdAt = OffsetDateTime.now()
+                expiryAt = expiryAt,
+                createdAt = createdAt
             )
         )
 
@@ -214,7 +241,7 @@ class PayuQrPayments(
     }
 
     private fun sha512(input: String): String {
-        val bytes = MessageDigest.getInstance("SHA-512").digest(input.toByteArray())
+        val bytes = MessageDigest.getInstance("SHA-512").digest(input.toByteArray(Charsets.UTF_8))
         return bytes.joinToString("") { "%02x".format(it) }
     }