/* $Id$ */

/** @file ai_map.hpp Everything to query map metadata */

#ifndef AI_MAP_HPP
#define AI_MAP_HPP

#include "ai_object.hpp"

/**
 * Class that handles all map related functions.
 */
class AIMap : public AIObject {
public:
	/**
	 * Checks whether the given tile is valid.
	 * @param t the tile to check.
	 * @return true is the tile it within the boundaries of the map.
	 */
	bool IsValidTile(TileIndex t);

	/**
	 * Gets the number of tiles in the map.
	 * @return the size of the map in tiles.
	 * @post return value is always positive.
	 */
	TileIndex GetMapSize();

	/**
	 * Gets the amount of tiles along the SW and NE border.
	 * @return the length along the SW and NE borders.
	 * @post return value is always positive.
	 */
	uint32 GetMapSizeX();

	/**
	 * Gets the amount of tiles along the SE and NW border.
	 * @return the length along the SE and NW borders.
	 * @post return value is always positive.
	 */
	uint32 GetMapSizeY();

	/**
	 * Gets the place along the SW/NE border (X-value).
	 * @param t the tile to get the X-value of.
	 * @pre t has to be valid (use IsValidTile(t)).
	 * @return the X-value.
	 * @post return value is lower than GetMapSizeX().
	 */
	uint32 GetTileX(TileIndex t);

	/**
	 * Gets the place along the SE/NW border (Y-value).
	 * @param t the tile to get the Y-value of.
	 * @pre t has to be valid (use IsValidTile(t)).
	 * @return the Y-value.
	 * @post return value is lower than GetMapSizeY().
	 */
	uint32 GetTileY(TileIndex t);

	/**
	 * Gets the TileIndex given a x,y-coordinate.
	 * @param x the X coordinate.
	 * @param y the Y coordinate.
	 * @pre x has to be lower than GetMapSizeX().
	 * @pre y has to be lower than GetMapSizeY().
	 * @return the TileIndex for the given x,y coordinate.
	 */
	TileIndex GetTileIndex(uint32 x, uint32 y);

	/**
	 * Calculates the Manhattan distance; the difference of
	 * the X and Y added together.
	 * @param t1 the start.
	 * @param t2 the destination.
	 * @pre t1 has to be valid (use IsValidTile(t1)).
	 * @pre t2 has to be valid (use IsValidTile(t2)).
	 * @return the Manhattan distance.
	 */
	uint32 DistanceManhattan(TileIndex t1, TileIndex t2);

	/**
	 * Calculates the distance between xy1 and xy2 via 1D calculation.
	 *  (so the distance between X or the distance between Y, depending
	 *    on which one is bigger).
	 * @param t1 the start.
	 * @param t2 the destination.
	 * @pre t1 has to be valid (use IsValidTile(t1)).
	 * @pre t2 has to be valid (use IsValidTile(t2)).
	 * @return the maximum distance of X and Y.
	 */
	uint32 DistanceMax(TileIndex t1, TileIndex t2);

	/**
	 * The squared distance between the two tiles.
	 * This is the distance is the length of the shortest straight
	 * line between both points.
	 * @param t1 the start.
	 * @param t2 the destination.
	 * @pre t1 has to be valid (use IsValidTile(t1)).
	 * @pre t2 has to be valid (use IsValidTile(t2)).
	 * @return the distance.
	 */
	uint32 DistanceSquare(TileIndex t1, TileIndex t2);

	/**
	 * Calculates the shortest distance to the edge.
	 * @param t from where the distance has to be calculated.
	 * @pre t has to be valid (use IsValidTile(t)).
	 * @return the distances to the closest edge.
	 */
	uint32 DistanceFromEdge(TileIndex t);

	/**
	 * Destroy everything on the given tile.
	 * @param t the tile to destroy the stuff of.
	 * @pre t has to be valid (use IsValidTile(t)).
	 * @return true if and only if the destruction succeeded
	 */
	bool DemolishTile(TileIndex t);
};

#ifdef DEFINE_SQUIRREL_CLASS
namespace SQConvert {
	/* Allow AIMap to be used as Squirrel parameter */
	template <> AIMap *GetParam(ForceType<AIMap *>, HSQUIRRELVM vm, int index) { SQUserPointer instance; sq_getinstanceup(vm, index, &instance, 0); return (AIMap *)instance; }
}; // namespace SQConvert

void SQAIMapRegister(Squirrel *engine) {
	DefSQClass <AIMap> SQAIMap("AIMap");
	SQAIMap.PreRegister(engine);
	SQAIMap.AddConstructor(engine);

	SQAIMap.DefSQFunction(engine, &AIMap::IsValidTile,       "IsValidTile");
	SQAIMap.DefSQFunction(engine, &AIMap::GetMapSize,        "GetMapSize");
	SQAIMap.DefSQFunction(engine, &AIMap::GetMapSizeX,       "GetMapSizeX");
	SQAIMap.DefSQFunction(engine, &AIMap::GetMapSizeY,       "GetMapSizeY");
	SQAIMap.DefSQFunction(engine, &AIMap::GetTileX,          "GetTileX");
	SQAIMap.DefSQFunction(engine, &AIMap::GetTileY,          "GetTileY");
	SQAIMap.DefSQFunction(engine, &AIMap::GetTileIndex,      "GetTileIndex");
	SQAIMap.DefSQFunction(engine, &AIMap::DistanceManhattan, "DistanceManhattan");
	SQAIMap.DefSQFunction(engine, &AIMap::DistanceMax,       "DistanceMax");
	SQAIMap.DefSQFunction(engine, &AIMap::DistanceSquare,    "DistanceSquare");
	SQAIMap.DefSQFunction(engine, &AIMap::DistanceFromEdge,  "DistanceFromEdge");
	SQAIMap.DefSQFunction(engine, &AIMap::DemolishTile,      "DemolishTile");

	SQAIMap.PostRegister(engine);
}
#endif /* DEFINE_SQUIRREL_CLASS */

#endif /* AI_MAP_HPP */