From 2224e65707b6b32e25d40f73a3ee6a482e0a6b18 Mon Sep 17 00:00:00 2001
From: alexban011 <alexban011@gmail.com>
Date: Mon, 20 Jun 2022 09:50:03 +0300
Subject: [PATCH] fixed crash in NextTurnAutomation (#7227)

* fixed crash

* redone

* reviews

* reviews 2
---
 .../unciv/logic/automation/ConstructionAutomation.kt   |  6 ++++--
 .../com/unciv/logic/automation/NextTurnAutomation.kt   | 10 ++++++----
 core/src/com/unciv/logic/automation/UnitAutomation.kt  |  1 +
 .../com/unciv/logic/civilization/CityStateFunctions.kt |  5 +++--
 4 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/core/src/com/unciv/logic/automation/ConstructionAutomation.kt b/core/src/com/unciv/logic/automation/ConstructionAutomation.kt
index a1b23090b9..8fb761bd5a 100644
--- a/core/src/com/unciv/logic/automation/ConstructionAutomation.kt
+++ b/core/src/com/unciv/logic/automation/ConstructionAutomation.kt
@@ -286,8 +286,10 @@ class ConstructionAutomation(val cityConstructions: CityConstructions){
             if (isAtWar) modifier = 0.5f
 
             // If this city is the closest city to another civ, that makes it a likely candidate for attack
-            if (civInfo.getKnownCivs().filter { it.cities.isNotEmpty() }
-                            .any { NextTurnAutomation.getClosestCities(civInfo, it).city1 == cityInfo })
+            if (civInfo.getKnownCivs()
+                        .map { NextTurnAutomation.getClosestCities(civInfo, it) }
+                        .filterNotNull()
+                        .any { it.city1 == cityInfo })
                 modifier *= 1.5f
 
             addChoice(relativeCostEffectiveness, defensiveBuilding.name, modifier)
diff --git a/core/src/com/unciv/logic/automation/NextTurnAutomation.kt b/core/src/com/unciv/logic/automation/NextTurnAutomation.kt
index 4893ec5c31..243a4118b0 100644
--- a/core/src/com/unciv/logic/automation/NextTurnAutomation.kt
+++ b/core/src/com/unciv/logic/automation/NextTurnAutomation.kt
@@ -698,7 +698,7 @@ object NextTurnAutomation {
     }
 
     private fun motivationToAttack(civInfo: CivilizationInfo, otherCiv: CivilizationInfo): Int {
-        if(civInfo.cities.isEmpty() || otherCiv.cities.isEmpty()) return 0
+        val closestCities = getClosestCities(civInfo, otherCiv) ?: return 0
         val baseForce = 30f
 
         val ourCombatStrength = civInfo.getStatForRanking(RankingType.Force).toFloat() + baseForce
@@ -711,7 +711,6 @@ object NextTurnAutomation {
 
         if (theirCombatStrength > ourCombatStrength) return 0
 
-        val closestCities = getClosestCities(civInfo, otherCiv)
         val ourCity = closestCities.city1
         val theirCity = closestCities.city2
 
@@ -969,12 +968,15 @@ object NextTurnAutomation {
     }
 
     fun getMinDistanceBetweenCities(civ1: CivilizationInfo, civ2: CivilizationInfo): Int {
-        return getClosestCities(civ1, civ2).aerialDistance
+        return getClosestCities(civ1, civ2)?.aerialDistance ?: Int.MAX_VALUE
     }
 
     data class CityDistance(val city1: CityInfo, val city2: CityInfo, val aerialDistance: Int)
 
-    fun getClosestCities(civ1: CivilizationInfo, civ2: CivilizationInfo): CityDistance {
+    fun getClosestCities(civ1: CivilizationInfo, civ2: CivilizationInfo): CityDistance? {
+        if (civ1.cities.isEmpty() || civ2.cities.isEmpty())
+            return null
+
         val cityDistances = arrayListOf<CityDistance>()
         for (civ1city in civ1.cities)
             for (civ2city in civ2.cities)
diff --git a/core/src/com/unciv/logic/automation/UnitAutomation.kt b/core/src/com/unciv/logic/automation/UnitAutomation.kt
index 298821cadb..29fcbb706a 100644
--- a/core/src/com/unciv/logic/automation/UnitAutomation.kt
+++ b/core/src/com/unciv/logic/automation/UnitAutomation.kt
@@ -435,6 +435,7 @@ object UnitAutomation {
 
         val closestEnemyCity = enemies
             .map { NextTurnAutomation.getClosestCities(unit.civInfo, it) }
+            .filterNotNull()
             .minByOrNull { it.aerialDistance }?.city2
           ?: return false // no attackable cities found
 
diff --git a/core/src/com/unciv/logic/civilization/CityStateFunctions.kt b/core/src/com/unciv/logic/civilization/CityStateFunctions.kt
index ed80c7c8c3..5d0d878d5a 100644
--- a/core/src/com/unciv/logic/civilization/CityStateFunctions.kt
+++ b/core/src/com/unciv/logic/civilization/CityStateFunctions.kt
@@ -79,7 +79,7 @@ class CityStateFunctions(val civInfo: CivilizationInfo) {
         if (giftableUnits.isEmpty()) // For badly defined mods that don't have great people but do have the policy that makes city states grant them
             return
         val giftedUnit = giftableUnits.random()
-        val cities = NextTurnAutomation.getClosestCities(receivingCiv, civInfo)
+        val cities = NextTurnAutomation.getClosestCities(receivingCiv, civInfo) ?: return
         val placedUnit = receivingCiv.placeUnitNearTile(cities.city1.location, giftedUnit.name)
             ?: return
         val locations = LocationAction(placedUnit.getTile().position, cities.city2.location)
@@ -87,7 +87,8 @@ class CityStateFunctions(val civInfo: CivilizationInfo) {
     }
 
     fun giveMilitaryUnitToPatron(receivingCiv: CivilizationInfo) {
-        val cities = NextTurnAutomation.getClosestCities(receivingCiv, civInfo)
+        val cities = NextTurnAutomation.getClosestCities(receivingCiv, civInfo) ?: return
+
         val city = cities.city1
 
         fun giftableUniqueUnit(): BaseUnit? {