Add JSON:API support

src/main/kotlin/com/faforever/icebreaker/web/JsonApiResponse.kt

@@ -0,0 +1,24 @@
+package com.faforever.icebreaker.web
+
+import com.faforever.icebreaker.service.Session
+
+data class JsonApiResponse(
+    val data: DataObject<*>,
+) {
+    data class DataObject<T>(
+        val type: String,
+        val id: String,
+        val attributes: T,
+    )
+}
+
+fun Session.toJsonApiResponse() =
+    JsonApiResponse(
+        data = JsonApiResponse.DataObject(
+            type = "iceSession",
+            id = id,
+            attributes = mapOf<String, Any>(
+                "servers" to servers,
+            ),
+        ),
+    )

src/main/kotlin/com/faforever/icebreaker/web/SessionController.kt

@@ -6,15 +6,28 @@ import io.quarkus.security.PermissionsAllowed
 import jakarta.inject.Singleton
 import jakarta.ws.rs.GET
 import jakarta.ws.rs.Path
+import jakarta.ws.rs.Produces
+import jakarta.ws.rs.core.MediaType
 import org.jboss.resteasy.reactive.RestPath
 
 @Path("/session")
 @Singleton
 class SessionController(private val sessionService: SessionService) {
+    companion object {
+        private const val MEDIA_TYPE_JSON_API = "application/vnd.api+json"
+    }
 
     @GET
+    @Produces(MediaType.APPLICATION_JSON)
     @Path("/game/{gameId}")
     @PermissionsAllowed("USER:lobby")
     fun getSession(@RestPath gameId: Long): Session =
         sessionService.getSession(gameId)
+
+    @GET
+    @Produces(MEDIA_TYPE_JSON_API)
+    @Path("/game/{gameId}")
+    @PermissionsAllowed("USER:lobby")
+    fun getSessionJsonApi(@RestPath gameId: Long): JsonApiResponse =
+        sessionService.getSession(gameId).toJsonApiResponse()
 }