Solid Principles have been added

src/main/java/mars/rover/Direction.java

@@ -0,0 +1,9 @@
+package mars.rover;
+
+public interface Direction {
+    Direction turnLeft();
+    Direction turnRight();
+    void move(Point point);
+    char currentDirection(); // current direction as character
+
+} 

src/main/java/mars/rover/DirectionFactory.java

@@ -0,0 +1,17 @@
+package mars.rover;
+public class DirectionFactory {
+    public static Direction getDirection(char direction) {
+        switch (direction) {
+            case 'N':
+                return new North();
+            case 'S':
+                return new South();
+            case 'E':
+                return new East();
+            case 'W':
+                return new West();
+            default:
+                throw new IllegalArgumentException("Invalid direction: " + direction);
+        }
+    }
+}

src/main/java/mars/rover/East.java

@@ -0,0 +1,22 @@
+package mars.rover;
+public class East implements Direction {
+	@Override
+	public Direction turnLeft() {
+		return new North();
+	}
+
+	@Override
+	public Direction turnRight() {
+		return new South();
+	}
+
+	@Override
+	public void move(Point point) {
+		point.setX(point.getX() + 1);
+	}
+
+	@Override
+	public char currentDirection() {
+		return 'E';
+	}
+}

src/main/java/mars/rover/MarsRover.java

@@ -1,42 +1,27 @@
 package mars.rover;
 
 public class MarsRover {
+    private Point point;
+    private Direction direction;
 
-    public static String move(int x, int y, char direction, String instructions) {
-        if (!instructions.isEmpty()) {
-            char instruction = instructions.charAt(0);
+    public MarsRover(int x, int y, char direction) {
+        this.point = new Point(x, y);
+        this.direction = DirectionFactory.getDirection(direction);
+    }
+
+    public void execute(String instructions) {
+        for (char instruction : instructions.toCharArray()) {
             if (instruction == 'L') {
-                if (direction == 'N') {
-                    return move(x, y, 'W', instructions.substring(1, instructions.length()));
-                } else if (direction == 'W') {
-                    return move(x, y, 'S', instructions.substring(1, instructions.length()));
-                } else if (direction == 'S') {
-                    return move(x, y, 'E', instructions.substring(1, instructions.length()));
-                } else if (direction == 'E') {
-                    return move(x, y, 'N', instructions.substring(1, instructions.length()));
-                }
+                direction = direction.turnLeft();
             } else if (instruction == 'R') {
-                if (direction == 'N') {
-                    return move(x, y, 'E', instructions.substring(1, instructions.length()));
-                } else if (direction == 'W') {
-                    return move(x, y, 'N', instructions.substring(1, instructions.length()));
-                } else if (direction == 'S') {
-                    return move(x, y, 'W', instructions.substring(1, instructions.length()));
-                } else if (direction == 'E') {
-                    return move(x, y, 'S', instructions.substring(1, instructions.length()));
-                }
+                direction = direction.turnRight();
             } else if (instruction == 'M') {
-                if (direction == 'N') {
-                    return move(x, y + 1, 'N', instructions.substring(1, instructions.length()));
-                } else if (direction == 'S') {
-                    return move(x, y - 1, 'S', instructions.substring(1, instructions.length()));
-                } else if (direction == 'W') {
-                    return move(x - 1, y, 'W', instructions.substring(1, instructions.length()));
-                } else if (direction == 'E') {
-                    return move(x + 1, y, 'E', instructions.substring(1, instructions.length()));
-                }
+                direction.move(point);
             }
         }
-        return x + " " + y + " " + direction;
     }
-}
+
+    public String getPosition() {
+        return point.getX() + " " + point.getY() + " " + direction.currentDirection();
+    }
+}

src/main/java/mars/rover/North.java

@@ -0,0 +1,23 @@
+package mars.rover;
+
+public class North implements Direction {
+	@Override
+	public Direction turnLeft() {
+		return new West();
+	}
+
+	@Override
+	public Direction turnRight() {
+		return new East();
+	}
+
+	@Override
+	public void move(Point point) {
+		point.setY(point.getY() + 1);
+	}
+
+	@Override
+	public char currentDirection() {
+		return 'N';
+	}
+}

src/main/java/mars/rover/Point.java

@@ -0,0 +1,26 @@
+package mars.rover;
+public class Point {
+    private int x;
+    private int y;
+
+    public Point( int x, int y){
+        this.x=x;
+        this.y=y;
+    }
+
+    public int getX() {
+        return this.x;
+    }
+
+    public void setX(int x) {
+        this.x = x;
+    }
+
+    public int getY() {
+        return this.y;
+    }
+
+    public void setY(int y) {
+        this.y = y;
+    }
+}

src/main/java/mars/rover/South.java

@@ -0,0 +1,22 @@
+package mars.rover;
+public class South implements Direction {
+	@Override
+	public Direction turnLeft() {
+		return new East();
+	}
+
+	@Override
+	public Direction turnRight() {
+		return new West();
+	}
+
+	@Override
+	public void move(Point point) {
+		point.setY(point.getY() - 1);
+	}
+
+	@Override
+	public char currentDirection() {
+		return 'S';
+	}
+}

src/main/java/mars/rover/West.java

@@ -0,0 +1,22 @@
+package mars.rover;
+public class West implements Direction {
+	@Override
+	public Direction turnLeft() {
+		return new South();
+	}
+
+	@Override
+	public Direction turnRight() {
+		return new North();
+	}
+
+	@Override
+	public void move(Point point) {
+		point.setX(point.getX() - 1);
+	}
+
+	@Override
+	public char currentDirection() {
+		return 'W';
+	}
+}

src/test/java/mars/rover/MarsRoverTest.java

@@ -1,23 +1,22 @@
-package mars.rover;
 
+package mars.rover;
 import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-class MarsRoverTest {
+public class MarsRoverTest {
 
     @Test
-    public void
-    acceptance_test_1() {
-        String newPosition = MarsRover.move(1, 2, 'N', "LMLMLMLMM");
-        assertEquals("1 3 N", newPosition);
-    }
+    public void testExecuteAndGetPosition() {
+        MarsRover rover = new MarsRover(0, 0, 'N');
+        rover.execute("M");
+        assertEquals("0 1 N", rover.getPosition());
 
-    @Test
-    public void
-    acceptance_test_2() {
-        String newPosition = MarsRover.move(3, 3, 'E', "MMRMMRMRRM");
-        assertEquals("5 1 E", newPosition);
-    }
+        rover = new MarsRover(0, 0, 'N');
+        rover.execute("MMRMM");
+        assertEquals("2 2 E", rover.getPosition());
 
+        rover = new MarsRover(2, 2, 'E');
+        rover.execute("MMRMM");
+        assertEquals("4 0 S", rover.getPosition());
+    }
 }