More reapply CityFocus on yield changes (#9459)

core/src/com/unciv/logic/city/City.kt

@@ -1,6 +1,7 @@
 package com.unciv.logic.city
 
 import com.badlogic.gdx.math.Vector2
+import com.unciv.GUI
 import com.unciv.logic.IsPartOfGameInfoSerialization
 import com.unciv.logic.city.managers.CityEspionageManager
 import com.unciv.logic.city.managers.CityExpansionManager
@@ -403,6 +404,10 @@ class City : IsPartOfGameInfoSerialization {
         reassignPopulation(resetLocked = true)
     }
 
+    /** Apply worked tiles optimization (aka CityFocus) - Expensive!
+     *
+     *  If the next City.startTurn is soon enough, then use [reassignPopulationDeferred] instead.
+     */
     fun reassignPopulation(resetLocked: Boolean = false) {
         if (resetLocked) {
             workedTiles = hashSetOf()
@@ -412,9 +417,20 @@ class City : IsPartOfGameInfoSerialization {
         }
         if (!manualSpecialists)
             population.specialistAllocations.clear()
+        updateCitizens = false
         population.autoAssignPopulation()
     }
 
+    /** Apply worked tiles optimization (aka CityFocus) -
+     *  immediately for a human player whoes turn it is (interactive),
+     *  or deferred to the next startTurn while nextTurn is running (for AI)
+     *  @see reassignPopulation
+     */
+    fun reassignPopulationDeferred() {
+        // TODO - is this the best (or even correct) way to detect "interactive" UI calls?
+        if (GUI.isMyTurn() && GUI.getViewingPlayer() == civ) reassignPopulation()
+        else updateCitizens = true
+    }
 
     fun destroyCity(overrideSafeties: Boolean = false) {
         // Original capitals and holy cities cannot be destroyed,

core/src/com/unciv/logic/city/managers/CityExpansionManager.kt

@@ -73,6 +73,9 @@ class CityExpansionManager : IsPartOfGameInfoSerialization {
             throw NotEnoughGoldToBuyTileException()
         city.civ.addGold(-goldCost)
         takeOwnership(tile)
+
+        // Reapply worked tiles optimization (aka CityFocus) - doing it here means AI profits too
+        city.reassignPopulationDeferred()
     }
 
     fun getGoldCostOfTile(tile: Tile): Int {

core/src/com/unciv/logic/city/managers/CityTurnManager.kt

@@ -33,7 +33,6 @@ class CityTurnManager(val city: City) {
             city.reassignAllPopulation()
         } else if (city.updateCitizens) {
             city.reassignPopulation()  // includes cityStats.update
-            city.updateCitizens = false
         } else
             city.cityStats.update()
 

core/src/com/unciv/logic/map/tile/Tile.kt

@@ -883,7 +883,11 @@ open class Tile : IsPartOfGameInfoSerialization {
             return
         // http://well-of-souls.com/civ/civ5_improvements.html says that naval improvements are destroyed upon pillage
         //    and I can't find any other sources so I'll go with that
-        if (!isLand) { changeImprovement(null); return }
+        if (!isLand) {
+            changeImprovement(null)
+            owningCity?.reassignPopulationDeferred()
+            return
+        }
 
         // Setting turnsToImprovement might interfere with UniqueType.CreatesOneImprovement
         improvementFunctions.removeCreatesOneImprovementMarker()
@@ -902,6 +906,8 @@ open class Tile : IsPartOfGameInfoSerialization {
             else
                 roadIsPillaged = true
         }
+
+        owningCity?.reassignPopulationDeferred()
     }
 
     fun isPillaged(): Boolean {
@@ -915,6 +921,8 @@ open class Tile : IsPartOfGameInfoSerialization {
             improvementIsPillaged = false
         else
             roadIsPillaged = false
+
+        owningCity?.reassignPopulationDeferred()
     }