/// <summary>Calculates next coordinate moving forward from selected position.</summary>
/// <param name="currentPosition">The selected position.</param>
/// <returns>New position.</returns>
public PositionVector Move(PositionVector currentPosition)
{
int x = 0;
int y = 0;
switch (currentPosition.Direction)
{
case Direction.Notrh:
y = 1;
break;
case Direction.East:
x = 1;
break;
case Direction.South:
y = -1;
break;
case Direction.West:
x = -1;
break;
default:
throw new Exception("This direction is not recognised.");
}
var newPosition = new PositionVector(currentPosition.X + x, currentPosition.Y + y, currentPosition.Direction);
if (this.CanMove(newPosition))
{
return newPosition;
}
return currentPosition;
}
private void PerformTest(PositionVector initialPosition, PositionVector expectedResult)
{
IWorld world = new World();
var result = world.Move(initialPosition);
Assert.AreEqual(expectedResult, result);
}
public void TransformClockwiseFromWest()
{
PositionVector vector = new PositionVector(0, 0, Direction.West);
var result = vector.Transform(true);
Assert.AreEqual(Direction.Notrh, result.Direction);
}
public void TransformAntiClockwiseFromWest()
{
PositionVector vector = new PositionVector(0, 0, Direction.West);
var result = vector.Transform(false);
Assert.AreEqual(Direction.South, result.Direction);
}
/// <summary>Rotates right</summary>
/// <param name="right">rotate right.</param>
/// <returns>true if successful.</returns>
public bool Rotate(bool right)
{
this.Position = this.Position.Transform(right);
return true;
}
/// <summary>Moves forward.</summary>
/// <param name="forward">move forward.</param>
/// <returns>true if successful.</returns>
public bool Move()
{
var initialPosition = this.Position;
this.Position = this.world.Move(this.Position);
return !initialPosition.Equals(this.Position);
}
/// <summary>Indicated whether it is possible to go forward from location.</summary>
/// <param name="newPosition">Location to check.</param>
/// <returns><c>true</c> if going forward is allowed.</returns>
private bool CanMove(PositionVector newPosition)
{
return newPosition.X >= this.min && newPosition.X <= this.max && newPosition.Y >= this.min && newPosition.Y <= this.max;
}
