/* $Id$ */

/** @file ai_tile.hpp Everything to query and manipulate tiles. */

#ifndef AI_TILE_HPP
#define AI_TILE_HPP

#include "ai_abstractlist.hpp"

/**
 * Class that handles all tile related functions.
 */
class AITile : public AIObject {
public:
	static const char *GetClassName() { return "AITile"; }

	/**
	 * Enumeration for the slope-type (from slopes.h).
	 *
	 * This enumeration use the chars N, E, S, W corresponding the
	 *  direction North, East, South and West. The top corner of a tile
	 *  is the north-part of the tile.
	 */
	enum Slope {
		SLOPE_FLAT     = 0x00,                                  //!< A flat tile
		SLOPE_W        = 0x01,                                  //!< The west corner of the tile is raised
		SLOPE_S        = 0x02,                                  //!< The south corner of the tile is raised
		SLOPE_E        = 0x04,                                  //!< The east corner of the tile is raised
		SLOPE_N        = 0x08,                                  //!< The north corner of the tile is raised
		SLOPE_STEEP    = 0x10,                                  //!< Indicates the slope is steep
		SLOPE_NW       = SLOPE_N | SLOPE_W,                     //!< North and west corner are raised
		SLOPE_SW       = SLOPE_S | SLOPE_W,                     //!< South and west corner are raised
		SLOPE_SE       = SLOPE_S | SLOPE_E,                     //!< South and east corner are raised
		SLOPE_NE       = SLOPE_N | SLOPE_E,                     //!< North and east corner are raised
		SLOPE_EW       = SLOPE_E | SLOPE_W,                     //!< East and west corner are raised
		SLOPE_NS       = SLOPE_N | SLOPE_S,                     //!< North and south corner are raised
		SLOPE_ELEVATED = SLOPE_N | SLOPE_E | SLOPE_S | SLOPE_W, //!< All corner are raised, similar to SLOPE_FLAT
		SLOPE_NWS      = SLOPE_N | SLOPE_W | SLOPE_S,           //!< North, west and south corner are raised
		SLOPE_WSE      = SLOPE_W | SLOPE_S | SLOPE_E,           //!< West, south and east corner are raised
		SLOPE_SEN      = SLOPE_S | SLOPE_E | SLOPE_N,           //!< South, east and north corner are raised
		SLOPE_ENW      = SLOPE_E | SLOPE_N | SLOPE_W,           //!< East, north and west corner are raised
		SLOPE_STEEP_W  = SLOPE_STEEP | SLOPE_NWS,               //!< A steep slope falling to east (from west)
		SLOPE_STEEP_S  = SLOPE_STEEP | SLOPE_WSE,               //!< A steep slope falling to north (from south)
		SLOPE_STEEP_E  = SLOPE_STEEP | SLOPE_SEN,               //!< A steep slope falling to west (from east)
		SLOPE_STEEP_N  = SLOPE_STEEP | SLOPE_ENW                //!< A steep slope falling to south (from north)
	};

	/**
	 * Check if this tile is buildable, i.e. no things on it that needs
	 *  demolishing.
	 * @param tile The tile to check on.
	 * @pre AIMap::IsValidTile(tile).
	 * @return True if it is buildable, false if not.
	 * @note Road and rail are considered buildable.
	 */
	static bool IsBuildable(TileIndex tile);

	/**
	 * Check if this tile is buildable in a rectangle around a tile, with the
	 *  entry in the list as top-left.
	 * @param tile The tile to check on.
	 * @param width The width of the rectangle.
	 * @param height The height of the rectangle.
	 * @pre AIMap::IsValidTile(tile).
	 * @return True if it is buildable, false if not.
	 * @note Road and rail are considered buildable.
	 */
	static bool IsBuildableRectangle(TileIndex tile, uint width, uint height);

	/**
	 * Check if a tile is water.
	 * @param tile The tile to check on.
	 * @pre AIMap::IsValidTile(tile).
	 * @return True if it is water, false if not.
	 */
	static bool IsWater(TileIndex tile);

	/**
	 * Get the slope of a tile.
	 * @param tile The tile to check on.
	 * @pre AIMap::IsValidTile(tile).
	 * @return 0 means flat, others indicate internal state of slope.
	 */
	static int32 GetSlope(TileIndex tile);

	/**
	 * Get the height of the tile.
	 * @param tile The tile to check on.
	 * @pre AIMap::IsValidTile(tile).
	 * @return The height of the tile, ranging from 0 to 15.
	 */
	static int32 GetHeight(TileIndex tile);

	/**
	 * Check how much cargo this tile accepts.
	 *  It creates a radius around the tile, and adds up all acceptance of this
	 *   cargo.
	 * @param tile The tile to check on.
	 * @param cargo_type The cargo to check the acceptance of.
	 * @param width The width of the station.
	 * @param height The height of the station.
	 * @param radius The radius of the station.
	 * @pre AIMap::IsValidTile(tile).
	 * @return Value below 8 means no acceptance; the more the better.
	 */
	static int32 GetCargoAcceptance(TileIndex tile, CargoID cargo_type, uint width, uint height, uint radius);

	/**
	 * Checks how many tiles in the radius produces this cargo.
	 *  It creates a radius around the tile, and adds up all tiles that produce
	 *  this cargo.
	 * @param tile The tile to check on.
	 * @param cargo_type The cargo to check the production of.
	 * @param width The width of the station.
	 * @param height The height of the station.
	 * @param radius The radius of the station.
	 * @pre AIMap::IsValidTile(tile).
	 * @return The tiles that produce this cargo within radius of the tile.
	 * @note Town(houses) are not included in the value.
	 */
	static int32 GetCargoProduction(TileIndex tile, CargoID cargo_type, uint width, uint height, uint radius);

	/**
	 * Get the manhattan distance from the tile to the tile.
	 * @param tile_from The tile to get the distance to.
	 * @param tile_to The tile to get the distance to.
	 * @return The distance between the two tiles.
	 */
	static int32 GetDistanceManhattanToTile(TileIndex tile_from, TileIndex tile_to);

	/**
	 * Get the square distance from the tile to the tile.
	 * @param tile_from The tile to get the distance to.
	 * @param tile_to The tile to get the distance to.
	 * @return The distance between the two tiles.
	 */
	static int32 GetDistanceSquareToTile(TileIndex tile_from, TileIndex tile_to);

	/**
	 * Raise the given corners of the tile. The corners can be combined,
	 *  for example: SLOPE_N | SLOPE_W (= SLOPE_NW)
	 * @param tile The tile to raise.
	 * @param slope Corners to raise (SLOPE_xxx).
	 * @pre AIMap::IsValidTile(tile).
	 * @return 0 means failed, 1 means success.
	 */
	static bool RaiseTile(TileIndex tile, int32 slope);

	/**
	 * Lower the given corners of the tile. The corners can be combined,
	 *  for example: SLOPE_N | SLOPE_W (= SLOPE_NW)
	 * @param tile The tile to lower.
	 * @param slope Corners to lower (SLOPE_xxx).
	 * @pre AIMap::IsValidTile(tile).
	 * @return 0 means failed, 1 means success.
	 */
	static bool LowerTile(TileIndex tile, int32 slope);

	/**
	 * Destroy everything on the given tile.
	 * @param tile The tile to demolish.
	 * @pre AIMap::IsValidTile(tile).
	 * @return True if and only if the tile was demolished.
	 */
	static bool DemolishTile(TileIndex tile);
};

#endif /* AI_TILE_HPP */