6 files changed, 163 insertions, 97 deletions

diff --git a/src/ch/epfl/maze/physical/pacman/Blinky.java b/src/ch/epfl/maze/physical/pacman/Blinky.java
index 4e8c4a0..5f81d13 100644
--- a/src/ch/epfl/maze/physical/pacman/Blinky.java
+++ b/src/ch/epfl/maze/physical/pacman/Blinky.java
@@ -2,7 +2,6 @@ package ch.epfl.maze.physical.pacman;
 
 import ch.epfl.maze.physical.Animal;
 import ch.epfl.maze.physical.Daedalus;
-import ch.epfl.maze.physical.GhostPredator;
 import ch.epfl.maze.util.Vector2D;
 
 /**
@@ -11,7 +10,7 @@ import ch.epfl.maze.util.Vector2D;
  * @author EPFL
  * @author Pacien TRAN-GIRARD
  */
-public class Blinky extends GhostPredator {
+public class Blinky extends Ghost {
 
     /**
      * Constructs a Blinky with a starting position.
diff --git a/src/ch/epfl/maze/physical/pacman/Clyde.java b/src/ch/epfl/maze/physical/pacman/Clyde.java
index 40089db..2d7e47a 100644
--- a/src/ch/epfl/maze/physical/pacman/Clyde.java
+++ b/src/ch/epfl/maze/physical/pacman/Clyde.java
@@ -2,7 +2,6 @@ package ch.epfl.maze.physical.pacman;
 
 import ch.epfl.maze.physical.Animal;
 import ch.epfl.maze.physical.Daedalus;
-import ch.epfl.maze.physical.GhostPredator;
 import ch.epfl.maze.util.Vector2D;
 
 /**
@@ -12,7 +11,7 @@ import ch.epfl.maze.util.Vector2D;
  * @author EPFL
  * @author Pacien TRAN-GIRARD
  */
-public class Clyde extends GhostPredator {
+public class Clyde extends Ghost {
 
     private static double PROXIMITY_THRESHOLD = 4.0d;
 
diff --git a/src/ch/epfl/maze/physical/GhostPredator.java b/src/ch/epfl/maze/physical/pacman/Ghost.java
index c1cfca8..f8f511e 100644
--- a/src/ch/epfl/maze/physical/GhostPredator.java
+++ b/src/ch/epfl/maze/physical/pacman/Ghost.java
@@ -1,5 +1,11 @@
-package ch.epfl.maze.physical;
-
+package ch.epfl.maze.physical.pacman;
+
+import ch.epfl.maze.physical.Daedalus;
+import ch.epfl.maze.physical.Predator;
+import ch.epfl.maze.physical.Prey;
+import ch.epfl.maze.physical.stragegies.picker.RandomPicker;
+import ch.epfl.maze.physical.stragegies.reducer.BackwardReducer;
+import ch.epfl.maze.physical.stragegies.reducer.CostReducer;
 import ch.epfl.maze.util.Direction;
 import ch.epfl.maze.util.Vector2D;
 
@@ -11,7 +17,7 @@ import java.util.Set;
  *
  * @author Pacien TRAN-GIRARD
  */
-abstract public class GhostPredator extends Predator {
+abstract public class Ghost extends Predator implements BackwardReducer, CostReducer, RandomPicker {
 
     public enum Mode {
         CHASE(40),
@@ -58,7 +64,7 @@ abstract public class GhostPredator extends Predator {
      *
      * @param position Position of the predator in the labyrinth
      */
-    public GhostPredator(Vector2D position) {
+    public Ghost(Vector2D position) {
         super(position);
 
         this.homePosition = position;
@@ -68,16 +74,98 @@ abstract public class GhostPredator extends Predator {
     }
 
     /**
+     * Returns the cost to reach the target by choosing the given Direction by calculating the Euclidean distance.
+     *
+     * @param choice   The Direction choice
+     * @param daedalus The Daedalus
+     * @return The Euclidean distance cost
+     */
+    @Override
+    public int getChoiceCost(Direction choice, Daedalus daedalus) {
+        Vector2D target = this.getTargetPosition(daedalus);
+        return (int) (this.getDistanceTo(choice, target) * 100);
+    }
+
+    @Override
+    public Set<Direction> reduce(Set<Direction> choices) {
+        return EnumSet.noneOf(Direction.class);
+    }
+
+    /**
+     * Selects the best Direction in the given choices by minimizing the Euclidean distance to the targeted position
+     * after excluding the provenance if possible.
+     *
+     * @param choices  A set of Direction choices
+     * @param daedalus The Daedalus
+     * @return A set of optimal Direction choices
+     */
+    @Override
+    public Set<Direction> reduce(Set<Direction> choices, Daedalus daedalus) {
+        Set<Direction> forwardChoices = choices.size() > 1 ? BackwardReducer.super.reduce(choices) : choices;
+        return CostReducer.super.reduce(forwardChoices, daedalus);
+    }
+
+    @Override
+    public Direction move(Set<Direction> choices, Daedalus daedalus) {
+        this.countCycle();
+
+        Set<Direction> bestChoices = this.reduce(choices, daedalus);
+        return this.pick(bestChoices);
+    }
+
+    /**
+     * Returns the Prey's projected targeted position.
+     *
+     * @param daedalus The Daedalus
+     * @return The projected position
+     */
+    abstract protected Vector2D getPreyTargetPosition(Daedalus daedalus);
+
+    /**
+     * Returns the current Mode.
+     *
+     * @param daedalus The Daedalus
+     * @return The current Mode
+     */
+    protected Mode getMode(Daedalus daedalus) {
+        return this.mode;
+    }
+
+    /**
+     * Returns the position to target according to the current Mode.
+     *
+     * @param daedalus The Daedalus
+     * @return The position to target
+     */
+    protected Vector2D getTargetPosition(Daedalus daedalus) {
+        switch (this.getMode(daedalus)) {
+            case CHASE:
+                return this.getPreyTargetPosition(daedalus);
+            case SCATTER:
+                return this.homePosition;
+            default:
+                return this.homePosition;
+        }
+    }
+
+    /**
      * Selects a new random Prey to chase in the Daedalus.
      *
      * @param daedalus The Daedalus
      * @return The Chosen One
      */
-    private static Prey selectRandomPrey(Daedalus daedalus) {
-        if (daedalus.getPreys().isEmpty()) return null;
+    private static Prey selectAnyPrey(Daedalus daedalus) {
+        if (daedalus.getPreySet().isEmpty()) return null;
+        return daedalus.getPreySet().stream().findAny().get();
+    }
 
-        int randomPreyIndex = GhostPredator.RANDOM_SOURCE.nextInt(daedalus.getPreys().size());
-        return daedalus.getPreys().get(randomPreyIndex);
+    /**
+     * Sets a random Prey as the common Pre.
+     *
+     * @param daedalus The Daedalus
+     */
+    private static synchronized void setAnyPrey(Daedalus daedalus) {
+        Ghost.commonPrey = Ghost.selectAnyPrey(daedalus);
     }
 
     /**
@@ -87,10 +175,10 @@ abstract public class GhostPredator extends Predator {
      * @return The common Prey
      */
     private static Prey getPrey(Daedalus daedalus) {
-        if (GhostPredator.commonPrey == null || !daedalus.hasPrey(GhostPredator.commonPrey))
-            GhostPredator.commonPrey = GhostPredator.selectRandomPrey(daedalus);
+        if (Ghost.commonPrey == null || !daedalus.hasPrey(Ghost.commonPrey))
+            Ghost.setAnyPrey(daedalus);
 
-        return GhostPredator.commonPrey;
+        return Ghost.commonPrey;
     }
 
     /**
@@ -100,7 +188,7 @@ abstract public class GhostPredator extends Predator {
      * @return The position of the Prey
      */
     protected final Vector2D getPreyPosition(Daedalus daedalus) {
-        Prey prey = GhostPredator.getPrey(daedalus);
+        Prey prey = Ghost.getPrey(daedalus);