Auto-fetch PayU payment link tokens

src/main/kotlin/com/android/trisolarisserver/config/PayuPaymentLinkSettingsSchemaFix.kt

@@ -25,12 +25,35 @@ class PayuPaymentLinkSettingsSchemaFix(
                     id uuid primary key,
                     property_id uuid not null unique references property(id) on delete cascade,
                     merchant_id text not null,
-                    access_token text not null,
+                    client_id text,
+                    client_secret text,
+                    access_token text,
+                    token_expires_at timestamptz,
                     is_test boolean not null default false,
                     updated_at timestamptz not null
                 )
                 """.trimIndent()
             )
         }
+        ensureColumn("payu_payment_link_settings", "client_id", "text")
+        ensureColumn("payu_payment_link_settings", "client_secret", "text")
+        ensureColumn("payu_payment_link_settings", "access_token", "text")
+        ensureColumn("payu_payment_link_settings", "token_expires_at", "timestamptz")
+    }
+
+    private fun ensureColumn(table: String, column: String, type: String) {
+        val exists = jdbcTemplate.queryForObject(
+            """
+            select count(*)
+            from information_schema.columns
+            where table_name = '$table'
+              and column_name = '$column'
+            """.trimIndent(),
+            Int::class.java
+        ) ?: 0
+        if (exists == 0) {
+            logger.info("Adding $table.$column column")
+            jdbcTemplate.execute("alter table $table add column $column $type")
+        }
     }
 }

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

@@ -41,6 +41,8 @@ class PayuPaymentLinkSettingsController(
                 configured = false,
                 merchantId = null,
                 isTest = false,
+                hasClientId = false,
+                hasClientSecret = false,
                 hasAccessToken = false
             )
         }
@@ -60,22 +62,23 @@ class PayuPaymentLinkSettingsController(
         val merchantId = request.merchantId.trim().ifBlank {
             throw ResponseStatusException(HttpStatus.BAD_REQUEST, "merchantId required")
         }
-        val accessToken = request.accessToken.trim().ifBlank {
-            throw ResponseStatusException(HttpStatus.BAD_REQUEST, "accessToken required")
-        }
         val isTest = request.isTest ?: false
         val existing = settingsRepo.findByPropertyId(propertyId)
         val updated = if (existing == null) {
             PayuPaymentLinkSettings(
                 property = property,
                 merchantId = merchantId,
-                accessToken = accessToken,
+                clientId = request.clientId?.trim()?.ifBlank { null },
+                clientSecret = request.clientSecret?.trim()?.ifBlank { null },
+                accessToken = request.accessToken?.trim()?.ifBlank { null },
                 isTest = isTest,
                 updatedAt = OffsetDateTime.now()
             )
         } else {
             existing.merchantId = merchantId
-            existing.accessToken = accessToken
+            if (request.clientId != null) existing.clientId = request.clientId.trim().ifBlank { null }
+            if (request.clientSecret != null) existing.clientSecret = request.clientSecret.trim().ifBlank { null }
+            if (request.accessToken != null) existing.accessToken = request.accessToken.trim().ifBlank { null }
             existing.isTest = isTest
             existing.updatedAt = OffsetDateTime.now()
             existing
@@ -91,6 +94,8 @@ private fun PayuPaymentLinkSettings.toResponse(): PayuPaymentLinkSettingsRespons
         configured = true,
         merchantId = merchantId,
         isTest = isTest,
-        hasAccessToken = accessToken.isNotBlank()
+        hasClientId = !clientId.isNullOrBlank(),
+        hasClientSecret = !clientSecret.isNullOrBlank(),
+        hasAccessToken = !accessToken.isNullOrBlank()
     )
 }

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

@@ -23,6 +23,7 @@ import org.springframework.web.bind.annotation.RequestMapping
 import org.springframework.web.bind.annotation.RestController
 import org.springframework.web.client.RestTemplate
 import org.springframework.web.server.ResponseStatusException
+import java.time.OffsetDateTime
 import java.util.UUID
 
 @RestController
@@ -116,9 +117,11 @@ class PayuPaymentLinksController(
         }
         request.expiryDate?.trim()?.ifBlank { null }?.let { body["expiryDate"] = it }
 
+        val accessToken = resolveAccessToken(settings)
+        settingsRepo.save(settings)
         val headers = HttpHeaders().apply {
             contentType = MediaType.APPLICATION_JSON
-            set("Authorization", "Bearer ${settings.accessToken}")
+            set("Authorization", "Bearer $accessToken")
             set("merchantId", settings.merchantId)
         }
         val entity = HttpEntity(body, headers)
@@ -145,6 +148,60 @@ class PayuPaymentLinksController(
         }
     }
 
+    private fun resolveAccessToken(settings: com.android.trisolarisserver.models.payment.PayuPaymentLinkSettings): String {
+        val now = OffsetDateTime.now()
+        val existing = settings.accessToken?.trim()?.ifBlank { null }
+        val expiresAt = settings.tokenExpiresAt
+        if (existing != null && expiresAt != null && expiresAt.isAfter(now.plusSeconds(60))) {
+            return existing
+        }
+        val clientId = settings.clientId?.trim()?.ifBlank { null }
+        val clientSecret = settings.clientSecret?.trim()?.ifBlank { null }
+        if (clientId == null || clientSecret == null) {
+            throw ResponseStatusException(HttpStatus.BAD_REQUEST, "Payment link client credentials missing")
+        }
+        val tokenResponse = fetchAccessToken(settings.isTest, clientId, clientSecret)
+        settings.accessToken = tokenResponse.accessToken
+        settings.tokenExpiresAt = now.plusSeconds(tokenResponse.expiresIn.toLong())
+        return tokenResponse.accessToken
+    }
+
+    private data class TokenResponse(val accessToken: String, val expiresIn: Int)
+
+    private fun fetchAccessToken(isTest: Boolean, clientId: String, clientSecret: String): TokenResponse {
+        val url = if (isTest) {
+            "https://uat-accounts.payu.in/oauth/token"
+        } else {
+            "https://accounts.payu.in/oauth/token"
+        }
+        val form = org.springframework.util.LinkedMultiValueMap<String, String>().apply {
+            add("client_id", clientId)
+            add("client_secret", clientSecret)
+            add("grant_type", "client_credentials")
+            add("scope", "create_payment_links")
+        }
+        val headers = HttpHeaders().apply {
+            contentType = MediaType.APPLICATION_FORM_URLENCODED
+        }
+        val entity = HttpEntity(form, headers)
+        val response = restTemplate.postForEntity(url, entity, String::class.java)
+        val body = response.body ?: ""
+        if (!response.statusCode.is2xxSuccessful) {
+            throw ResponseStatusException(HttpStatus.BAD_GATEWAY, "PayU token request failed")
+        }
+        return try {
+            val node = objectMapper.readTree(body)
+            val token = node.path("access_token").asText(null)
+            val expiresIn = node.path("expires_in").asInt(0)
+            if (token.isNullOrBlank() || expiresIn <= 0) {
+                throw IllegalStateException("Token missing")
+            }
+            TokenResponse(token, expiresIn)
+        } catch (ex: Exception) {
+            throw ResponseStatusException(HttpStatus.BAD_GATEWAY, "PayU token parse failed")
+        }
+    }
+
     private fun extractPaymentLink(body: String): String? {
         if (body.isBlank()) return null
         return try {

src/main/kotlin/com/android/trisolarisserver/controller/dto/PayuDtos.kt

@@ -49,7 +49,9 @@ data class PayuQrGenerateResponse(
 
 data class PayuPaymentLinkSettingsUpsertRequest(
     val merchantId: String,
-    val accessToken: String,
+    val clientId: String? = null,
+    val clientSecret: String? = null,
+    val accessToken: String? = null,
     val isTest: Boolean? = null
 )
 
@@ -58,6 +60,8 @@ data class PayuPaymentLinkSettingsResponse(
     val configured: Boolean,
     val merchantId: String?,
     val isTest: Boolean,
+    val hasClientId: Boolean,
+    val hasClientSecret: Boolean,
     val hasAccessToken: Boolean
 )
 

src/main/kotlin/com/android/trisolarisserver/models/payment/PayuPaymentLinkSettings.kt

@@ -31,8 +31,17 @@ class PayuPaymentLinkSettings(
     @Column(name = "merchant_id", nullable = false, columnDefinition = "text")
     var merchantId: String,
 
-    @Column(name = "access_token", nullable = false, columnDefinition = "text")
-    var accessToken: String,
+    @Column(name = "client_id", columnDefinition = "text")
+    var clientId: String? = null,
+
+    @Column(name = "client_secret", columnDefinition = "text")
+    var clientSecret: String? = null,
+
+    @Column(name = "access_token", columnDefinition = "text")
+    var accessToken: String? = null,
+
+    @Column(name = "token_expires_at", columnDefinition = "timestamptz")
+    var tokenExpiresAt: OffsetDateTime? = null,
 
     @Column(name = "is_test", nullable = false)
     var isTest: Boolean = false,