auto save on dispose (#774)

* auto save on dispose

* auto save: clone game info outside the save-game thread

* keep autosaves for the last 10 turns

core/src/com/unciv/UnCivGame.kt

@@ -84,6 +84,10 @@ class UnCivGame(val version: String) : Game() {
         resume()
     }
 
+    override fun dispose() {
+        GameSaver().autoSave(gameInfo)
+    }
+
     companion object {
         lateinit var Current: UnCivGame
     }

core/src/com/unciv/logic/GameSaver.kt

@@ -7,6 +7,7 @@ import com.unciv.GameSettings
 import com.unciv.logic.map.TileMap
 import com.unciv.ui.saves.Gzip
 import com.unciv.ui.utils.ImageGetter
+import java.io.File
 
 class GameSaver {
     private val saveFilesFolder = "SaveFiles"
@@ -66,4 +67,24 @@ class GameSaver {
     fun setGeneralSettings(gameSettings: GameSettings){
         getGeneralSettingsFile().writeString(json().toJson(gameSettings), false)
     }
+
+    fun autoSave(gameInfo: GameInfo, postRunnable: () -> Unit = {}) {
+        val gameInfoClone = gameInfo.clone()
+        kotlin.concurrent.thread {
+            // the save takes a long time (up to a second!) and we can do it while the player continues his game.
+            // On the other hand if we alter the game data while it's being serialized we could get a concurrent modification exception.
+            // So what we do is we clone all the game data and serialize the clone.
+            saveGame(gameInfoClone, "Autosave")
+
+            // keep auto-saves for the last 10 turns for debugging purposes
+            // eg turn 238 is saved as "Autosave-8"
+            getSave("Autosave").copyTo(Gdx.files.local(saveFilesFolder + File.separator + "Autosave-${gameInfoClone.turns%10}"))
+
+            // do this on main thread
+            Gdx.app.postRunnable {
+                postRunnable()
+            }
+        }
+
+    }
 }

core/src/com/unciv/ui/worldscreen/WorldScreen.kt

@@ -262,20 +262,11 @@ class WorldScreen : CameraStageBaseScreen() {
                     throw ex
                 }
 
-                val gameInfoClone = gameInfo.clone()
+                if(gameInfo.turns % game.settings.turnsBetweenAutosaves == 0) {
-                kotlin.concurrent.thread {
+                    GameSaver().autoSave(gameInfo) {
-                    // the save takes a long time (up to a second!) and we can do it while the player continues his game.
-                    // On the other hand if we alter the game data while it's being serialized we could get a concurrent modification exception.
-                    // So what we do is we clone all the game data and serialize the clone.
-                    if(gameInfo.turns % game.settings.turnsBetweenAutosaves == 0)
-                        GameSaver().saveGame(gameInfoClone, "Autosave")
-
-                    // do this on main thread
-                    Gdx.app.postRunnable {
                         nextTurnButton.enable() // only enable the user to next turn once we've saved the current one
                         updateNextTurnButton()
                     }
-
                 }
 
                 // If we put this BEFORE the save game, then we try to save the game...