From 96932b453e3f2fa1cfb45e79aca49e72d7b8d10f Mon Sep 17 00:00:00 2001
From: Pacien TRAN-GIRARD
Date: Tue, 24 Nov 2015 16:59:05 +0100
Subject: Update Monkey A.I. for open positions

---
 .../physical/stragegies/picker/ForwardPicker.java  | 29 ++++++++++++++++++++++
 src/ch/epfl/maze/physical/zoo/Monkey.java          | 25 +++++++++++++++++--
 2 files changed, 52 insertions(+), 2 deletions(-)
 create mode 100644 src/ch/epfl/maze/physical/stragegies/picker/ForwardPicker.java

diff --git a/src/ch/epfl/maze/physical/stragegies/picker/ForwardPicker.java b/src/ch/epfl/maze/physical/stragegies/picker/ForwardPicker.java
new file mode 100644
index 0000000..b7a44f8
--- /dev/null
+++ b/src/ch/epfl/maze/physical/stragegies/picker/ForwardPicker.java
@@ -0,0 +1,29 @@
+package ch.epfl.maze.physical.stragegies.picker;
+
+import ch.epfl.maze.util.Direction;
+
+import java.util.Set;
+
+/**
+ * A simple decision maker that continues forward if possible.
+ *
+ * @author Pacien TRAN-GIRARD
+ */
+public interface ForwardPicker extends BlindPicker {
+
+    /**
+     * Returns the current Direction the decision maker is walking toward.
+     *
+     * @return The current Direction
+     */
+    Direction getDirection();
+
+    @Override
+    default Direction pick(Set<Direction> choices) {
+        if (choices.contains(this.getDirection()))
+            return this.getDirection();
+        else
+            return FALLBACK_DIRECTION;
+    }
+
+}
diff --git a/src/ch/epfl/maze/physical/zoo/Monkey.java b/src/ch/epfl/maze/physical/zoo/Monkey.java
index 3c84f59..5b6998d 100644
--- a/src/ch/epfl/maze/physical/zoo/Monkey.java
+++ b/src/ch/epfl/maze/physical/zoo/Monkey.java
@@ -2,6 +2,7 @@ package ch.epfl.maze.physical.zoo;
 
 import ch.epfl.maze.physical.Animal;
 import ch.epfl.maze.physical.stragegies.picker.CyclePicker;
+import ch.epfl.maze.physical.stragegies.picker.ForwardPicker;
 import ch.epfl.maze.physical.stragegies.picker.SimplePicker;
 import ch.epfl.maze.util.Direction;
 import ch.epfl.maze.util.Vector2D;
@@ -14,10 +15,12 @@ import java.util.Set;
  * @author EPFL
  * @author Pacien TRAN-GIRARD
  */
-public class Monkey extends Animal implements SimplePicker, CyclePicker {
+public class Monkey extends Animal implements SimplePicker, ForwardPicker, CyclePicker {
 
     public static final Direction SMART_PAW = Direction.LEFT;
 
+    private boolean foundWall;
+
     /**
      * Constructs a monkey with a starting position.
      *
@@ -25,6 +28,8 @@ public class Monkey extends Animal implements SimplePicker, CyclePicker {
      */
     public Monkey(Vector2D position) {
         super(position);
+
+        this.foundWall = false;
     }
 
     @Override
@@ -38,7 +43,8 @@ public class Monkey extends Animal implements SimplePicker, CyclePicker {
     }
 
     /**
-     * Picks a Direction following the "paw rule", or any available if the Monkey has no current Direction.
+     * Picks a Direction preferably following the "paw rule", or forward if no wall has been encountered,
+     * or any available Direction if the Monkey has no current Direction.
      *
      * @param choices A set of Direction choices
      * @return The picked Direction
@@ -47,6 +53,8 @@ public class Monkey extends Animal implements SimplePicker, CyclePicker {
     public Direction pick(Set<Direction> choices) {
         if (this.getDirection() == Direction.NONE)
             return SimplePicker.super.pick(choices);
+        else if (!this.foundWall)
+            return ForwardPicker.super.pick(choices);
         else
             return CyclePicker.super.pick(choices);
     }
@@ -56,6 +64,9 @@ public class Monkey extends Animal implements SimplePicker, CyclePicker {
      */
     @Override
     public Direction move(Set<Direction> choices) {
+        if (this.nextToWall(choices))
+            this.foundWall = true;
+
         return this.pick(choices);
     }
 
@@ -64,4 +75,14 @@ public class Monkey extends Animal implements SimplePicker, CyclePicker {
         return new Monkey(this.getPosition());
     }
 
+    /**
+     * Checks is the Monkey is next to a wall.
+     *
+     * @param choices The available Direction choices
+     * @return T(The Direction choices set indicates the presence of a wall)
+     */
+    private boolean nextToWall(Set<Direction> choices) {
+        return choices.size() < 4;
+    }
+
 }
-- 
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