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")
+        }
     }
 }