/* $Id: airport.h 20478 2010-08-13 00:36:12Z yexo $ */

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file airport.h Various declarations for airports */

#ifndef AIRPORT_H
#define AIRPORT_H

#include "direction_type.h"
#include "tile_type.h"

/** Some airport-related constants */
static const uint MAX_TERMINALS =   8;                       ///< maximum number of terminals per airport
static const uint MAX_HELIPADS  =   3;                       ///< maximum number of helipads per airport
static const uint MAX_ELEMENTS  = 255;                       ///< maximum number of aircraft positions at airport

static const uint NUM_AIRPORTTILES       = 256;              ///< total number of airport tiles
static const uint NEW_AIRPORTTILE_OFFSET = 74;               ///< offset of first newgrf airport tile
static const uint INVALID_AIRPORTTILE    = NUM_AIRPORTTILES; ///< id for an invalid airport tile

/** Airport types */
enum AirportTypes {
	AT_SMALL         =   0,
	AT_LARGE         =   1,
	AT_HELIPORT      =   2,
	AT_METROPOLITAN  =   3,
	AT_INTERNATIONAL =   4,
	AT_COMMUTER      =   5,
	AT_HELIDEPOT     =   6,
	AT_INTERCON      =   7,
	AT_HELISTATION   =   8,
	AT_OILRIG        =   9,
	NEW_AIRPORT_OFFSET = 10,
	NUM_AIRPORTS     =  128,
	AT_INVALID       = 254,
	AT_DUMMY         = 255
};

enum AirportMovingDataFlags {
	AMED_NOSPDCLAMP = 1 << 0,
	AMED_TAKEOFF    = 1 << 1,
	AMED_SLOWTURN   = 1 << 2,
	AMED_LAND       = 1 << 3,
	AMED_EXACTPOS   = 1 << 4,
	AMED_BRAKE      = 1 << 5,
	AMED_HELI_RAISE = 1 << 6,
	AMED_HELI_LOWER = 1 << 7,
	AMED_HOLD       = 1 << 8
};

/* Movement States on Airports (headings target) */
enum AirportMovementStates {
	TO_ALL         =  0,
	HANGAR         =  1,
	TERM1          =  2,
	TERM2          =  3,
	TERM3          =  4,
	TERM4          =  5,
	TERM5          =  6,
	TERM6          =  7,
	HELIPAD1       =  8,
	HELIPAD2       =  9,
	TAKEOFF        = 10,
	STARTTAKEOFF   = 11,
	ENDTAKEOFF     = 12,
	HELITAKEOFF    = 13,
	FLYING         = 14,
	LANDING        = 15,
	ENDLANDING     = 16,
	HELILANDING    = 17,
	HELIENDLANDING = 18,
	TERM7          = 19,
	TERM8          = 20,
	HELIPAD3       = 21,
	MAX_HEADINGS   = 21,
};

/* Movement Blocks on Airports
 * blocks (eg_airport_flags) */
static const uint64
	TERM1_block              = 1ULL <<  0,
	TERM2_block              = 1ULL <<  1,
	TERM3_block              = 1ULL <<  2,
	TERM4_block              = 1ULL <<  3,
	TERM5_block              = 1ULL <<  4,
	TERM6_block              = 1ULL <<  5,
	HELIPAD1_block           = 1ULL <<  6,
	HELIPAD2_block           = 1ULL <<  7,
	RUNWAY_IN_OUT_block      = 1ULL <<  8,
	RUNWAY_IN_block          = 1ULL <<  8,
	AIRPORT_BUSY_block       = 1ULL <<  8,
	RUNWAY_OUT_block         = 1ULL <<  9,
	TAXIWAY_BUSY_block       = 1ULL << 10,
	OUT_WAY_block            = 1ULL << 11,
	IN_WAY_block             = 1ULL << 12,
	AIRPORT_ENTRANCE_block   = 1ULL << 13,
	TERM_GROUP1_block        = 1ULL << 14,
	TERM_GROUP2_block        = 1ULL << 15,
	HANGAR2_AREA_block       = 1ULL << 16,
	TERM_GROUP2_ENTER1_block = 1ULL << 17,
	TERM_GROUP2_ENTER2_block = 1ULL << 18,
	TERM_GROUP2_EXIT1_block  = 1ULL << 19,
	TERM_GROUP2_EXIT2_block  = 1ULL << 20,
	PRE_HELIPAD_block        = 1ULL << 21,

	/* blocks for new airports */
	TERM7_block              = 1ULL << 22,
	TERM8_block              = 1ULL << 23,
	HELIPAD3_block           = 1ULL << 24,
	HANGAR1_AREA_block       = 1ULL << 26,
	OUT_WAY2_block           = 1ULL << 27,
	IN_WAY2_block            = 1ULL << 28,
	RUNWAY_IN2_block         = 1ULL << 29,
	RUNWAY_OUT2_block        = 1ULL << 10,   ///< note re-uses TAXIWAY_BUSY
	HELIPAD_GROUP_block      = 1ULL << 13,   ///< note re-uses AIRPORT_ENTRANCE
	OUT_WAY_block2           = 1ULL << 31,
	/* end of new blocks */

	NOTHING_block            = 1ULL << 30;

/** A single location on an airport where aircraft can move to. */
struct AirportMovingData {
	int16 x;                 ///< x-coordinate of this position
	int16 y;                 ///< y-coordinate of this position
	uint16 flag;             ///< special flags when moving towards this position
	DirectionByte direction; ///< Direction to turn the aircraft after reaching this position.
};

AirportMovingData RotateAirportMovingData(const AirportMovingData *orig, Direction rotation, uint num_tiles_x, uint num_tiles_y);

struct AirportFTAbuildup;

/** Finite sTate mAchine --> FTA */
struct AirportFTAClass {
public:
	/** Bitmask of airport flags. */
	enum Flags {
		AIRPLANES   = 0x1,                     ///< Can planes land on this airport type?
		HELICOPTERS = 0x2,                     ///< Can helicopters land on this airport type?
		ALL         = AIRPLANES | HELICOPTERS, ///< Mask to check for both planes and helicopters.
		SHORT_STRIP = 0x4                      ///< This airport has a short landing strip, dangerous for fast aircraft.
	};

	AirportFTAClass(
		const AirportMovingData *moving_data,
		const byte *terminals,
		const byte num_helipads,
		const byte *entry_points,
		Flags flags,
		const AirportFTAbuildup *apFA,
		byte delta_z
	);

	~AirportFTAClass();

	const AirportMovingData *MovingData(byte position) const
	{
		assert(position < nofelements);
		return &moving_data[position];
	}

	const AirportMovingData *moving_data;
	struct AirportFTA *layout;            ///< state machine for airport
	const byte *terminals;
	const byte num_helipads;              ///< Number of helipads on this airport. When 0 helicopters will go to normal terminals.
	Flags flags;
	byte nofelements;                     ///< number of positions the airport consists of
	const byte *entry_points;             ///< when an airplane arrives at this airport, enter it at position entry_point, index depends on direction
	byte delta_z;                         ///< Z adjustment for helicopter pads
};

DECLARE_ENUM_AS_BIT_SET(AirportFTAClass::Flags)


/** Internal structure used in openttd - Finite sTate mAchine --> FTA */
struct AirportFTA {
	AirportFTA *next;        ///< possible extra movement choices from this position
	uint64 block;            ///< 64 bit blocks (st->airport.flags), should be enough for the most complex airports
	byte position;           ///< the position that an airplane is at
	byte next_position;      ///< next position from this position
	byte heading;            ///< heading (current orders), guiding an airplane to its target on an airport
};

const AirportFTAClass *GetAirport(const byte airport_type);
byte GetVehiclePosOnBuild(TileIndex hangar_tile);

#endif /* AIRPORT_H */
