/* $Id$ */

/** @file depot.h Header files for depots (not hangars) */

#ifndef DEPOT_H
#define DEPOT_H

#include "direction_type.h"
#include "oldpool.h"
#include "road_map.h"
#include "rail_map.h"
#include "water_map.h"
#include "station_map.h"

struct Depot;
DECLARE_OLD_POOL(Depot, Depot, 3, 8000)

struct Depot : PoolItem<Depot, DepotID, &_Depot_pool> {
	TileIndex xy;
	TownID town_index;

	Depot(TileIndex xy = 0) : xy(xy) {}
	~Depot();

	inline bool IsValid() const { return this->xy != 0; }
};

static inline bool IsValidDepotID(DepotID index)
{
	return index < GetDepotPoolSize() && GetDepot(index)->IsValid();
}

void ShowDepotWindow(TileIndex tile, VehicleType type);

#define FOR_ALL_DEPOTS_FROM(d, start) for (d = GetDepot(start); d != NULL; d = (d->index + 1U < GetDepotPoolSize()) ? GetDepot(d->index + 1U) : NULL) if (d->IsValid())
#define FOR_ALL_DEPOTS(d) FOR_ALL_DEPOTS_FROM(d, 0)

/**
 * Check if a tile is a depot of the given type.
 */
static inline bool IsTileDepotType(TileIndex tile, TransportType type)
{
	switch (type) {
		case TRANSPORT_RAIL:
			return IsTileType(tile, MP_RAILWAY) && GetRailTileType(tile)  == RAIL_TILE_DEPOT;

		case TRANSPORT_ROAD:
			return IsRoadDepotTile(tile);

		case TRANSPORT_WATER:
			return IsTileType(tile, MP_WATER)   && GetWaterTileType(tile) == WATER_TILE_DEPOT;

		default:
			NOT_REACHED();
			return false;
	}
}

/**
 * Is the given tile a tile with a depot on it?
 * @param tile the tile to check
 * @return true if and only if there is a depot on the tile.
 */
static inline bool IsDepotTile(TileIndex tile)
{
	switch (GetTileType(tile)) {
		case MP_ROAD:    return IsRoadDepot(tile);
		case MP_WATER:   return GetWaterTileType(tile) == WATER_TILE_DEPOT;
		case MP_RAILWAY: return GetRailTileType(tile)  == RAIL_TILE_DEPOT;
		case MP_STATION: return IsHangar(tile);
		default:         return false;
	}
}

/**
 * Find out if the slope of the tile is suitable to build a depot of given direction
 * @param direction The direction in which the depot's exit points
 * @param tileh The slope of the tile in question
 * @return true if the construction is possible

 * This is checked by the ugly 0x4C >> direction magic, which does the following:
 * 0x4C is 0100 1100 and tileh has only bits 0..3 set (steep tiles are ruled out)
 * So: for direction (only the significant bits are shown)<p>
 * 00 (exit towards NE) we need either bit 2 or 3 set in tileh: 0x4C >> 0 = 1100<p>
 * 01 (exit towards SE) we need either bit 1 or 2 set in tileh: 0x4C >> 1 = 0110<p>
 * 02 (exit towards SW) we need either bit 0 or 1 set in tileh: 0x4C >> 2 = 0011<p>
 * 03 (exit towards NW) we need either bit 0 or 4 set in tileh: 0x4C >> 3 = 1001<p>
 * So ((0x4C >> direction) & tileh) determines whether the depot can be built on the current tileh
 */
static inline bool CanBuildDepotByTileh(DiagDirection direction, Slope tileh)
{
	return ((0x4C >> direction) & tileh) != 0;
}

Depot *GetDepotByTile(TileIndex tile);
void InitializeDepots();

void DeleteDepotHighlightOfVehicle(const Vehicle *v);

#endif /* DEPOT_H */