From 7e7e2c2f5a2261dcb3c4035e42236a099fefc343 Mon Sep 17 00:00:00 2001
From: Pacien TRAN-GIRARD
Date: Mon, 23 Nov 2015 21:24:39 +0100
Subject: Implement Bear A.I.

---
 src/ch/epfl/maze/physical/zoo/Bear.java | 69 +++++++++++++++++++++++++++++----
 1 file changed, 61 insertions(+), 8 deletions(-)

diff --git a/src/ch/epfl/maze/physical/zoo/Bear.java b/src/ch/epfl/maze/physical/zoo/Bear.java
index 5cccc08..2ef9215 100644
--- a/src/ch/epfl/maze/physical/zoo/Bear.java
+++ b/src/ch/epfl/maze/physical/zoo/Bear.java
@@ -4,21 +4,66 @@ import ch.epfl.maze.physical.Animal;
 import ch.epfl.maze.util.Direction;
 import ch.epfl.maze.util.Vector2D;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
 /**
  * Bear A.I. that implements the Pledge Algorithm.
+ *
+ * @author Pacien TRAN-GIRARD
  */
-
 public class Bear extends Animal {
 
+    private Direction favoriteDirection;
+    private Direction currentDirection;
+    private int rightRotationCounter;
+
     /**
      * Constructs a bear with a starting position.
      *
      * @param position Starting position of the bear in the labyrinth
      */
-
     public Bear(Vector2D position) {
         super(position);
-        // TODO
+        this.favoriteDirection = Direction.NONE;
+        this.currentDirection = Direction.NONE;
+        this.rightRotationCounter = 0;
+    }
+
+    /**
+     * Checks if the Bear is currently trying to bypass an obstacle.
+     *
+     * @return T(The Bear is bypassing an obstacle)
+     */
+    private boolean isBypassingObstacle() {
+        return this.rightRotationCounter != 0;
+    }
+
+    /**
+     * Returns the preferred Direction to take according to the current strategy.
+     *
+     * @return The preferred Direction
+     */
+    private Direction getPreferredDir() {
+        return this.isBypassingObstacle() ? this.currentDirection.rotateLeft() : this.favoriteDirection;
+    }
+
+    /**
+     * Finds a currentDirection following the "left paw rule".
+     *
+     * @param choices An array of possible directions
+     * @return The currentDirection to take according to the "left paw rule"
+     */
+    private Direction followLeft(Direction[] choices) {
+        if (choices.length == 0) return Direction.NONE;
+        if (choices.length == 1) return choices[0];
+
+        List<Direction> choiceList = new ArrayList<>(Arrays.asList(choices));
+        Direction dir = this.getPreferredDir();
+        while (!choiceList.contains(dir)) dir = dir.rotateRight();
+
+        return dir;
     }
 
     /**
@@ -29,16 +74,24 @@ public class Bear extends Animal {
      * will repeat the procedure when the counter comes to zero, or until it
      * leaves the maze.
      */
-
     @Override
     public Direction move(Direction[] choices) {
-        // TODO
-        return Direction.NONE;
+        if (this.favoriteDirection == Direction.NONE)
+            this.favoriteDirection = choices[0];
+
+        Direction newDirection = this.followLeft(choices);
+
+        if (this.currentDirection.reverse() == newDirection) this.rightRotationCounter += 2;
+        else if (this.currentDirection.rotateRight() == newDirection) this.rightRotationCounter += 1;
+        else if (this.currentDirection.rotateLeft() == newDirection) this.rightRotationCounter -= 1;
+
+        this.currentDirection = newDirection;
+        return this.currentDirection;
     }
 
     @Override
     public Animal copy() {
-        // TODO
-        return null;
+        return new Monkey(this.getPosition());
     }
+
 }
-- 
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