Add SSE for Razorpay QR events

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

@@ -0,0 +1,48 @@
+package com.android.trisolarisserver.component
+
+import com.android.trisolarisserver.controller.dto.RazorpayQrEventResponse
+import com.android.trisolarisserver.repo.RazorpayQrRequestRepo
+import org.springframework.scheduling.annotation.Scheduled
+import org.springframework.stereotype.Component
+import org.springframework.web.servlet.mvc.method.annotation.SseEmitter
+import java.time.OffsetDateTime
+import java.util.UUID
+import java.util.concurrent.ConcurrentHashMap
+
+@Component
+class RazorpayQrEvents(
+    private val qrRequestRepo: RazorpayQrRequestRepo
+) {
+    private val latestEvents: MutableMap<QrKey, RazorpayQrEventResponse> = ConcurrentHashMap()
+    private val hub = SseHub<QrKey>("qr") { key ->
+        latestEvents[key] ?: run {
+            val latest = qrRequestRepo.findTopByQrIdOrderByCreatedAtDesc(key.qrId)
+            RazorpayQrEventResponse(
+                event = "snapshot",
+                qrId = key.qrId,
+                status = latest?.status,
+                receivedAt = (latest?.createdAt ?: OffsetDateTime.now()).toString()
+            )
+        }
+    }
+
+    fun subscribe(propertyId: UUID, qrId: String): SseEmitter {
+        return hub.subscribe(QrKey(propertyId, qrId))
+    }
+
+    fun emit(propertyId: UUID, qrId: String, event: RazorpayQrEventResponse) {
+        val key = QrKey(propertyId, qrId)
+        latestEvents[key] = event
+        hub.emit(key)
+    }
+
+    @Scheduled(fixedDelayString = "25000")
+    fun heartbeat() {
+        hub.heartbeat()
+    }
+}
+
+private data class QrKey(
+    val propertyId: UUID,
+    val qrId: String
+)

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

@@ -1,6 +1,7 @@
 package com.android.trisolarisserver.controller
 
 import com.android.trisolarisserver.component.PropertyAccess
+import com.android.trisolarisserver.component.RazorpayQrEvents
 import com.android.trisolarisserver.controller.dto.RazorpayQrGenerateRequest
 import com.android.trisolarisserver.controller.dto.RazorpayQrEventResponse
 import com.android.trisolarisserver.controller.dto.RazorpayQrGenerateResponse
@@ -30,6 +31,7 @@ import org.springframework.web.client.RestTemplate
 import org.springframework.web.server.ResponseStatusException
 import org.springframework.http.HttpStatus
 import org.springframework.transaction.annotation.Transactional
+import org.springframework.web.servlet.mvc.method.annotation.SseEmitter
 import java.time.OffsetDateTime
 import java.util.Base64
 import java.util.UUID
@@ -42,6 +44,7 @@ class RazorpayQrPayments(
     private val settingsRepo: RazorpaySettingsRepo,
     private val qrRequestRepo: RazorpayQrRequestRepo,
     private val webhookLogRepo: RazorpayWebhookLogRepo,
+    private val qrEvents: RazorpayQrEvents,
     private val restTemplate: RestTemplate,
     private val objectMapper: ObjectMapper
 ) {
@@ -259,6 +262,17 @@ class RazorpayQrPayments(
         return out
     }
 
+    @GetMapping("/qr/{qrId}/events/stream", produces = [MediaType.TEXT_EVENT_STREAM_VALUE])
+    fun streamQrEvents(
+        @PathVariable propertyId: UUID,
+        @PathVariable bookingId: UUID,
+        @PathVariable qrId: String,
+        @AuthenticationPrincipal principal: MyPrincipal?
+    ): SseEmitter {
+        requireRole(propertyAccess, propertyId, principal, Role.ADMIN, Role.MANAGER, Role.STAFF)
+        return qrEvents.subscribe(propertyId, qrId)
+    }
+
     @GetMapping("/qr")
     fun listQr(
         @PathVariable propertyId: UUID,

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

@@ -5,6 +5,8 @@ import com.android.trisolarisserver.models.booking.Payment
 import com.android.trisolarisserver.models.booking.PaymentMethod
 import com.android.trisolarisserver.models.payment.RazorpayPaymentAttempt
 import com.android.trisolarisserver.models.payment.RazorpayWebhookLog
+import com.android.trisolarisserver.component.RazorpayQrEvents
+import com.android.trisolarisserver.controller.dto.RazorpayQrEventResponse
 import com.android.trisolarisserver.repo.PaymentRepo
 import com.android.trisolarisserver.repo.PropertyRepo
 import com.android.trisolarisserver.repo.RazorpayPaymentAttemptRepo
@@ -37,6 +39,7 @@ class RazorpayWebhookCapture(
     private val razorpayPaymentAttemptRepo: RazorpayPaymentAttemptRepo,
     private val razorpayQrRequestRepo: RazorpayQrRequestRepo,
     private val razorpayWebhookLogRepo: RazorpayWebhookLogRepo,
+    private val razorpayQrEvents: RazorpayQrEvents,
     private val objectMapper: ObjectMapper
 ) {
 
@@ -102,6 +105,16 @@ class RazorpayWebhookCapture(
                     razorpayQrRequestRepo.save(existingQr)
                 }
             }
+            razorpayQrEvents.emit(
+                propertyId,
+                qrId,
+                RazorpayQrEventResponse(
+                    event = event,
+                    qrId = qrId,
+                    status = qrStatus,
+                    receivedAt = OffsetDateTime.now().toString()
+                )
+            )
         }
 
         razorpayPaymentAttemptRepo.save(