Renamed api package, added ApiVersion enum for easier auto-detection

core/src/com/unciv/logic/multiplayer/ApiVersion.kt

@@ -0,0 +1,27 @@
+package com.unciv.logic.multiplayer
+
+/**
+ * Enum determining the version of a remote server API implementation
+ *
+ * [APIv0] is used to reference DropBox. It doesn't support any further features.
+ * [APIv1] is used for the UncivServer built-in server implementation as well as
+ * for servers implementing this interface. Examples thereof include:
+ *  - https://github.com/Mape6/Unciv_server (Python)
+ *  - https://gitlab.com/azzurite/unciv-server (NodeJS)
+ *  - https://github.com/oynqr/rust_unciv_server (Rust)
+ *  - https://github.com/touhidurrr/UncivServer.xyz (NodeJS)
+ * This servers may or may not support authentication. The [ServerFeatureSet] may
+ * be used to inspect their functionality. [APIv2] is used to reference
+ * the heavily extended REST-like HTTP API in combination with a WebSocket
+ * functionality for communication. Examples thereof include:
+ *   - https://github.com/hopfenspace/runciv
+ *
+ * A particular server may implement multiple interfaces simultaneously.
+ * There's a server version check in the constructor of [OnlineMultiplayer]
+ * which handles API auto-detection. The precedence of various APIs is
+ * determined by that function:
+ * @see [OnlineMultiplayer.determineServerAPI]
+ */
+enum class ApiVersion {
+    APIv0, APIv1, APIv2
+}

core/src/com/unciv/logic/multiplayer/OnlineMultiplayer.kt

@@ -9,12 +9,12 @@ import com.unciv.logic.GameInfoPreview
 import com.unciv.logic.civilization.NotificationCategory
 import com.unciv.logic.civilization.PlayerType
 import com.unciv.logic.event.EventBus
-import com.unciv.logic.multiplayer.api.Api
-import com.unciv.logic.multiplayer.api.ApiErrorResponse
-import com.unciv.logic.multiplayer.api.ApiStatusCode
-import com.unciv.logic.multiplayer.api.WebSocketMessage
-import com.unciv.logic.multiplayer.api.WebSocketMessageSerializer
-import com.unciv.logic.multiplayer.api.WebSocketMessageType
+import com.unciv.logic.multiplayer.apiv2.Api
+import com.unciv.logic.multiplayer.apiv2.ApiErrorResponse
+import com.unciv.logic.multiplayer.apiv2.ApiStatusCode
+import com.unciv.logic.multiplayer.apiv2.WebSocketMessage
+import com.unciv.logic.multiplayer.apiv2.WebSocketMessageSerializer
+import com.unciv.logic.multiplayer.apiv2.WebSocketMessageType
 import com.unciv.logic.multiplayer.storage.ApiV2FileStorageEmulator
 import com.unciv.logic.multiplayer.storage.ApiV2FileStorageWrapper
 import com.unciv.logic.multiplayer.storage.FileStorageRateLimitReached
@@ -56,6 +56,10 @@ private val FILE_UPDATE_THROTTLE_PERIOD = Duration.ofSeconds(60)
 class OnlineMultiplayer {
     private val logger = java.util.logging.Logger.getLogger(this::class.qualifiedName)
 
+    // Updating the multiplayer server URL in the Api is out of scope, just drop this class and create a new one
+    private val baseUrl = UncivGame.Current.settings.multiplayer.server
+    private val api = Api(baseUrl)
+
     private val files = UncivGame.Current.files
     private val multiplayerFiles = OnlineMultiplayerFiles()
     private var featureSet = ServerFeatureSet(apiVersion = 2)
@@ -69,9 +73,15 @@ class OnlineMultiplayer {
     val games: Set<OnlineMultiplayerGame> get() = savedGames.values.toSet()
     val serverFeatureSet: ServerFeatureSet get() = featureSet
 
-    private val api = Api(UncivGame.Current.settings.multiplayer.server)
+    // Server API auto-detection happens in a coroutine triggered in the constructor
+    private lateinit var apiVersion: ApiVersion
 
     init {
+        // Run the server auto-detection in a coroutine, only afterwards this class can be considered initialized
+        Concurrency.run {
+            apiVersion = determineServerAPI()
+        }
+
         logger.level = Level.FINER  // for debugging
         var password = UncivGame.Current.settings.multiplayer.passwords[UncivGame.Current.settings.multiplayer.server]
         if (password == null) {
@@ -114,6 +124,21 @@ class OnlineMultiplayer {
 
     private var sendChannel: SendChannel<Frame>? = null
 
+    /**
+     * Determine the server API version of the remote server
+     *
+     * Check precedence: [ApiVersion.APIv0] > [ApiVersion.APIv2] > [ApiVersion.APIv1]
+     */
+    private suspend fun determineServerAPI(): ApiVersion {
+        return if (usesDropbox()) {
+            ApiVersion.APIv0
+        } else if (api.isServerCompatible()) {
+            ApiVersion.APIv2
+        } else {
+            ApiVersion.APIv1
+        }
+    }
+
     /**
      * Send text as a [FrameType.TEXT] frame to the remote side (fire & forget)
      *

core/src/com/unciv/logic/multiplayer/ServerFeatureSet.kt

@@ -1,6 +1,5 @@
 package com.unciv.logic.multiplayer
 
-
 /**
  * This class is used to store the features of the server.
  *
@@ -10,13 +9,8 @@ package com.unciv.logic.multiplayer
  * Everything is optional, so if a feature is not present, it is assumed to be 0.
  * Dropbox does not support anything of this, so it will always be 0.
  *
- * The API developed to replace dropbox which uses preview files and
- * polling via HTTP is referred to as API v1, [apiVersion] = 1.
- * It may or may not support auth. The new WebSocket-based and extended
- * API is referred to as API v2, [apiVersion] = 2. It's not directly a
- * feature set, but rather another refined interface.
+ * @see [ApiVersion]
  */
 data class ServerFeatureSet(
-    val authVersion: Int = 0,
-    val apiVersion: Int
+    val authVersion: Int = 0
 )

core/src/com/unciv/logic/multiplayer/api/Api.kt → core/src/com/unciv/logic/multiplayer/apiv2/Api.kt

@@ -2,7 +2,7 @@
  * TODO: Comment this file
  */
 
-package com.unciv.logic.multiplayer.api
+package com.unciv.logic.multiplayer.apiv2
 
 import com.unciv.UncivGame
 import com.unciv.utils.concurrency.Concurrency

core/src/com/unciv/logic/multiplayer/api/AuthCookieHelper.kt → core/src/com/unciv/logic/multiplayer/apiv2/AuthCookieHelper.kt

@@ -1,4 +1,4 @@
-package com.unciv.logic.multiplayer.api
+package com.unciv.logic.multiplayer.apiv2
 
 import io.ktor.client.request.*
 import io.ktor.http.*

core/src/com/unciv/logic/multiplayer/api/EndpointImplementations.kt → core/src/com/unciv/logic/multiplayer/apiv2/EndpointImplementations.kt

@@ -4,7 +4,7 @@
  * Those classes are not meant to be used directly. Take a look at the Api class for common usage.
  */
 
-package com.unciv.logic.multiplayer.api
+package com.unciv.logic.multiplayer.apiv2
 
 import java.util.logging.Logger
 import io.ktor.client.*

core/src/com/unciv/logic/multiplayer/api/JsonSerializers.kt → core/src/com/unciv/logic/multiplayer/apiv2/JsonSerializers.kt

@@ -1,4 +1,4 @@
-package com.unciv.logic.multiplayer.api
+package com.unciv.logic.multiplayer.apiv2
 
 import kotlinx.serialization.KSerializer
 import kotlinx.serialization.descriptors.PrimitiveKind

core/src/com/unciv/logic/multiplayer/api/RequestStructs.kt → core/src/com/unciv/logic/multiplayer/apiv2/RequestStructs.kt

@@ -2,7 +2,7 @@
  * Collection of API request structs in a single file for simplicity
  */
 
-package com.unciv.logic.multiplayer.api
+package com.unciv.logic.multiplayer.apiv2
 
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.SerialName

core/src/com/unciv/logic/multiplayer/api/ResponseStructs.kt → core/src/com/unciv/logic/multiplayer/apiv2/ResponseStructs.kt

@@ -2,7 +2,7 @@
  * Collection of API response structs in a single file for simplicity
  */
 
-package com.unciv.logic.multiplayer.api
+package com.unciv.logic.multiplayer.apiv2
 
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable

core/src/com/unciv/logic/multiplayer/api/WebSocketStructs.kt → core/src/com/unciv/logic/multiplayer/apiv2/WebSocketStructs.kt

@@ -1,4 +1,4 @@
-package com.unciv.logic.multiplayer.api
+package com.unciv.logic.multiplayer.apiv2
 
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable

core/src/com/unciv/logic/multiplayer/storage/ApiV2FileStorageEmulator.kt

@@ -1,6 +1,6 @@
 package com.unciv.logic.multiplayer.storage
 
-import com.unciv.logic.multiplayer.api.Api
+import com.unciv.logic.multiplayer.apiv2.Api
 import java.util.*
 
 /**

core/src/com/unciv/logic/multiplayer/storage/OnlineMultiplayerFiles.kt

@@ -15,7 +15,7 @@ import java.io.FileNotFoundException
  *
  * For low-level access only, use [UncivGame.onlineMultiplayer] on [UncivGame.Current] if you're looking to load/save a game.
  *
- * @param fileStorageIdentifier must be given if UncivGame.Current might not be initialized
+ * @param fileStorageIdentifier is a server base URL and must be given if UncivGame.Current might not be initialized
  * @see FileStorage
  * @see UncivGame.Current.settings.multiplayerServer
  */