public RoverPosition Parse(string source)
{
var tokens = source.Split(' ');
if (tokens.Length != 3)
{
throw new ParserException($"Could not parse {source} into a Rover, expected 3 tokens got {tokens.Length}");
}
int x;
if (!int.TryParse(tokens[0], out x))
{
throw new ParserException($"Could not parse {source} into a Rover, first token isn't an integer");
}
int y;
if (!int.TryParse(tokens[1], out y))
{
throw new ParserException($"Could not parse {source} into a Rover, second token isn't an integer");
}
var coordinate = new Coordinate(x, y);
IDirectionState direction = ReadDirectionToken(tokens[2]);
return new RoverPosition(coordinate, direction);
}
public Terrain(Coordinate coordinate)
{
if (coordinate.X < 1 || coordinate.Y < 1)
{
throw new TerrainInvalidInitializationValueException(Messages.TerrainInvalidInitializationValueExceptionMessage);
}
_upperBoundary = coordinate;
}
public Coordinate Move(Coordinate position, Terrain terrain)
{
if (position.Y == terrain.UpperBoundary.Y)
{
throw new RoverInvalidPositionException(Messages.RoverInvalidUpperBoundaryYExceptionMessage);
}
position.Y++;
return position;
}
public Coordinate Move(Coordinate position, Terrain terrain)
{
if (position.X == terrain.LowerBoundary.X)
{
throw new RoverInvalidPositionException(Messages.RoverInvalidLowerBoundaryXExceptionMessage);
}
position.X--;
return position;
}
public void CannotMoveForwardWhenObstructed()
{
var currentLocation = new Coordinate(5, 4);
var nextSpace = grid.GetNextSpaceInFront(currentLocation, Direction.North);
Assert.AreEqual(currentLocation, nextSpace);
}
public void CannotMoveBackwardWhenObstructed()
{
var currentLocation = new Coordinate(5, 6);
var nextSpace = grid.GetNextSpaceBehind(currentLocation, Direction.North);
Assert.AreEqual(currentLocation, nextSpace);
}