Merge pull request #244 from vincent4vx/fix-ai-pathfinding-failed

close #94 [AI] Do not crash on movement near enemy on inaccessible cell

src/main/java/fr/quatrevieux/araknemu/game/fight/ai/action/MoveNearEnemy.java

@@ -45,7 +45,7 @@ public void initialize(AI<F> ai) {
         this.helper = ai.helper();
         this.pathfinder = helper.cells().pathfinder()
             .targetDistance(1)
-            .walkablePredicate(FightCell::walkableIgnoreFighter)
+            .walkablePredicate(cell -> true) // Fix #94 Ignore inaccessible cell (handled by cell cost)
             .cellWeightFunction(this::cellCost)
         ;
     }
@@ -57,9 +57,11 @@ public Optional<Action> generate(AI<F> ai, ActionsFactory<F> actions) {
         }
 
         final int movementPoints = helper.movementPoints();
+        final FightCell currentCell = ai.fighter().cell();
 
         return ai.enemy()
-            .map(enemy -> NullnessUtil.castNonNull(pathfinder).findPath(ai.fighter().cell(), enemy.cell()).truncate(movementPoints + 1))
+            .map(enemy -> NullnessUtil.castNonNull(pathfinder).findPath(currentCell, enemy.cell()).truncate(movementPoints + 1))
+            .map(path -> path.keepWhile(step -> step.cell().equals(currentCell) || step.cell().walkable())) // Truncate path to first unwalkable cell (may occur if the enemy cell is inaccessible or if other fighters block the path)
             .filter(path -> path.size() > 1)
             .map(path -> actions.move().create(ai.fighter(), path))
         ;
@@ -69,6 +71,13 @@ public Optional<Action> generate(AI<F> ai, ActionsFactory<F> actions) {
      * Compute the cell cost for optimize the path finding
      */
     private @Positive int cellCost(FightCell cell) {
+        // Fix #94 : Some cells are not accessible, but walkable/targetable using teleport.
+        // In this case the pathfinder will fail, so instead of ignoring unwalkable cells, simply set a very high cost,
+        // which allows the AI to generate a path to an inaccessible cell without throws a PathException
+        if (!cell.walkableIgnoreFighter()) {
+            return 1000;
+        }
+
         // A fighter is on the cell : the cell is not walkable
         // But the fighter may leave the place at the next turn
         // The cost is higher than a simple detour, but permit to resolve a path blocked by a fighter

src/test/java/fr/quatrevieux/araknemu/data/world/repository/implementation/sql/SqlMapTemplateRepositoryTest.java

@@ -137,6 +137,6 @@ void has() {
 
     @Test
     void all() {
-        assertEquals(3, repository.all().size());
+        assertEquals(4, repository.all().size());
     }
 }

src/test/java/fr/quatrevieux/araknemu/game/exploration/map/ExplorationMapServiceTest.java

@@ -174,6 +174,6 @@ void preloadWithTriggers() throws SQLException, ContainerException {
         service.preload(logger);
 
         Mockito.verify(logger).info("Loading maps...");
-        Mockito.verify(logger).info(Mockito.eq("{} maps successfully loaded in {}ms"), Mockito.eq(3), Mockito.any());
+        Mockito.verify(logger).info(Mockito.eq("{} maps successfully loaded in {}ms"), Mockito.eq(4), Mockito.any());
     }
 }

src/test/java/fr/quatrevieux/araknemu/game/fight/FightBaseCase.java

@@ -30,6 +30,7 @@
 import fr.quatrevieux.araknemu.game.exploration.map.ExplorationMap;
 import fr.quatrevieux.araknemu.game.exploration.map.ExplorationMapService;
 import fr.quatrevieux.araknemu.game.fight.builder.ChallengeBuilder;
+import fr.quatrevieux.araknemu.game.fight.builder.FightBuilder;
 import fr.quatrevieux.araknemu.game.fight.castable.CastScope;
 import fr.quatrevieux.araknemu.game.fight.castable.Castable;
 import fr.quatrevieux.araknemu.game.fight.event.FightStarted;
@@ -311,6 +312,12 @@ public FightBuilder addSimpleTeam(PlayerFighter leader, List<Integer> places) {
             return this;
         }
 
+        public FightBuilder map(int mapId) {
+            map = loadFightMap(mapId);
+
+            return this;
+        }
+
         public FightBuilder addSelf(Consumer<FighterBuilder> configurator) {
             return addAlly(builder -> {
                 builder.player(player);

src/test/java/fr/quatrevieux/araknemu/game/fight/ai/action/MoveNearEnemyTest.java

@@ -57,6 +57,49 @@ void success() {
         assertEquals(0, turn.points().movementPoints());
     }
 
+    @Test
+    void withAllyOnPathShouldBeCircumvented() {
+        configureFight(fb -> fb
+            .addSelf(builder -> builder.cell(151))
+            .addAlly(builder -> builder.cell(166))
+            .addEnemy(builder -> builder.cell(181))
+        );
+
+        generateAndPerformMove();
+
+        assertEquals(195, fighter.cell().id());
+        assertEquals(0, turn.points().movementPoints());
+    }
+
+    @Test
+    void whenAllyBlockAccess() {
+        configureFight(fb -> fb
+            .addSelf(builder -> builder.cell(211))
+            .addAlly(builder -> builder.cell(284))
+            .addEnemy(builder -> builder.cell(341))
+        );
+
+        generateAndPerformMove();
+
+        assertEquals(256, fighter.cell().id());
+        assertEquals(0, turn.points().movementPoints());
+    }
+
+    // See: https://github.com/Arakne/Araknemu/issues/94
+    @Test
+    void notAccessibleCellShouldTruncateToNearestCell() {
+        configureFight(fb -> fb
+            .map(10342)
+            .addSelf(builder -> builder.cell(155))
+            .addEnemy(builder -> builder.cell(69))
+        );
+
+        generateAndPerformMove();
+
+        assertEquals(126, fighter.cell().id());
+        assertEquals(1, turn.points().movementPoints());
+    }
+
     @Test
     void noMP() {
         configureFight(fb -> fb