package inf101.v18.rogue101.map;

import java.util.List;

import inf101.v18.grid.GridDirection;
import inf101.v18.grid.IArea;
import inf101.v18.grid.ILocation;
import inf101.v18.rogue101.game.IllegalMoveException;
import inf101.v18.rogue101.objects.IActor;
import inf101.v18.rogue101.objects.IItem;

public interface IMapView {
	/**
	 * Add an item to the map.
	 * 
	 * @param loc
	 *            A location
	 * @param item
	 *            the item
	 */
	void add(ILocation loc, IItem item);

	/**
	 * Check if it's legal for an IActor to go into the given location
	 * 
	 * @param to
	 *            A location
	 * @return True if the location isn't already occupied
	 */
	boolean canGo(ILocation to);

	/**
	 * Check if it's legal for an IActor to go in the given direction from the given
	 * location
	 * 
	 * @param from
	 *            Current location
	 * @param dir
	 *            Direction we want to move in
	 * @return True if the next location exists and isn't occupied
	 */
	boolean canGo(ILocation from, GridDirection dir);

	/**
	 * Get all IActors at the given location
	 * <p>
	 * The returned list either can't be modified, or modifying it won't affect the
	 * map.
	 * 
	 * @param loc
	 * @return A list of actors
	 */
	List<IActor> getActors(ILocation loc);

	/**
	 * Get all items (both IActors and other IItems) at the given location
	 * <p>
	 * The returned list either can't be modified, or modifying it won't affect the
	 * map.
	 * 
	 * @param loc
	 * @return A list of items
	 */
	List<IItem> getAll(ILocation loc);

	/**
	 * Get all non-IActor items at the given location
	 * <p>
	 * The returned list either can't be modified, or modifying it won't affect the
	 * map.
	 * 
	 * @param loc
	 * @return A list of items, non of which are instanceof IActor
	 */
	List<IItem> getItems(ILocation loc);

	/**
	 * @return A 2D-area defining the legal map locations
	 */
	IArea getArea();

	/**
	 * @return Height of the map, same as
	 *         {@link #getArea()}.{@link IArea#getHeight()}
	 */
	int getHeight();

	/**
	 * @return Width of the map, same as {@link #getArea()}.{@link IArea#getWidth()}
	 */
	int getWidth();

	/**
	 * Find location of an item
	 * 
	 * @param item
	 *            The item
	 * @return It's location, or <code>null</code> if it's not on the map
	 */
	ILocation getLocation(IItem item);

	/**
	 * Translate (x,y)-coordinates to ILocation
	 * 
	 * @param x
	 * @param y
	 * @return an ILocation
	 * @throws IndexOutOfBoundsException
	 *             if (x,y) is outside {@link #getArea()}
	 */
	ILocation getLocation(int x, int y);

	/**
	 * Get the neighbouring location in the given direction
	 * 
	 * @param from
	 *            A location
	 * @param dir
	 *            the Direction
	 * @return from's neighbour in direction dir, or null, if this would be outside
	 *         the map
	 */
	ILocation getNeighbour(ILocation from, GridDirection dir);

	/**
	 * Compute new location of an IActor moving the given direction
	 * 
	 * @param from
	 *            Original location
	 * @param dir
	 *            Direction we're moving in
	 * @return The new location
	 * @throws IllegalMoveException
	 *             if !{@link #canGo(ILocation, GridDirection)}
	 */
	ILocation go(ILocation from, GridDirection dir) throws IllegalMoveException;

	/**
	 * Check if an item exists at a location
	 * 
	 * @param loc
	 *            The location
	 * @param target
	 *            The item we're interested in
	 * @return True if target would appear in {@link #getAll(loc)}
	 */
	boolean has(ILocation loc, IItem target);

	/**
	 * Check for actors.
	 * 
	 * @param loc
	 * @return True if {@link #getActors(loc)} would be non-empty
	 */
	boolean hasActors(ILocation loc);

	/**
	 * Check for non-actors
	 * 
	 * @param loc
	 * @return True if {@link #getItem(loc)} would be non-empty
	 */
	boolean hasItems(ILocation loc);

	/**
	 * Check for walls
	 * 
	 * @param loc
	 * @return True if there is a wall at the given location ({@link #getAll(loc)}
	 *         would contain an instance of {@link Wall})
	 */
	boolean hasWall(ILocation loc);

	/**
	 * Check if a neighbour exists on the map
	 * 
	 * @param from A location
	 * @param dir A direction
	 * @return True if {@link #getNeighbour(from, dir)} would return non-null
	 */
	boolean hasNeighbour(ILocation from, GridDirection dir);

	/**
	 * Get all locations within i steps from the given centre
	 * @param centre
	 * @param dist
	 * @return A list of locations, all at most i grid cells away from centre
	 */
	List<ILocation> getNeighbourhood(ILocation centre, int dist);
}