/* $Id$ */

/*
 * 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 script_station.hpp Everything to query and build stations. */

#ifndef SCRIPT_STATION_HPP
#define SCRIPT_STATION_HPP

#include "script_road.hpp"
#include "script_basestation.hpp"
#include "../../station_type.h"

/**
 * Class that handles all station related functions.
 * @api ai game
 */
class ScriptStation : public ScriptBaseStation {
public:
	/**
	 * All station related error messages.
	 */
	enum ErrorMessages {
		/** Base for station related errors */
		ERR_STATION_BASE = ScriptError::ERR_CAT_STATION << ScriptError::ERR_CAT_BIT_SIZE,

		/** The station is build too close to another station, airport or dock */
		ERR_STATION_TOO_CLOSE_TO_ANOTHER_STATION, // [STR_ERROR_TOO_CLOSE_TO_ANOTHER_AIRPORT, STR_ERROR_TOO_CLOSE_TO_ANOTHER_STATION, STR_ERROR_TOO_CLOSE_TO_ANOTHER_DOCK]

		/** There are too many stations, airports and docks in the game */
		ERR_STATION_TOO_MANY_STATIONS,            // [STR_ERROR_TOO_MANY_STATIONS_LOADING, STR_ERROR_TOO_MANY_TRUCK_STOPS, STR_ERROR_TOO_MANY_BUS_STOPS]

		/** There are too many stations, airports of docks in a town */
		ERR_STATION_TOO_MANY_STATIONS_IN_TOWN,    // [STR_ERROR_LOCAL_AUTHORITY_REFUSES_AIRPORT]
	};

	/**
	 * Type of stations known in the game.
	 */
	enum StationType {
		/* Note: these values represent part of the in-game StationFacility enum */
		STATION_TRAIN      = (int)::FACIL_TRAIN,      ///< Train station
		STATION_TRUCK_STOP = (int)::FACIL_TRUCK_STOP, ///< Truck station
		STATION_BUS_STOP   = (int)::FACIL_BUS_STOP,   ///< Bus station
		STATION_AIRPORT    = (int)::FACIL_AIRPORT,    ///< Airport
		STATION_DOCK       = (int)::FACIL_DOCK,       ///< Dock
		STATION_ANY        = STATION_TRAIN | STATION_TRUCK_STOP | STATION_BUS_STOP | STATION_AIRPORT | STATION_DOCK, ///< All station types
	};

	/**
	 * Checks whether the given station is valid and owned by you.
	 * @param station_id The station to check.
	 * @return True if and only if the station is valid.
	 */
	static bool IsValidStation(StationID station_id);

	/**
	 * Get the owner of a station.
	 * @param station_id The station to get the owner of.
	 * @pre IsValidStation(station_id).
	 * @return The owner the station has.
	 * @api -ai
	 */
	static ScriptCompany::CompanyID GetOwner(StationID station_id);

	/**
	 * Get the StationID of a tile, if there is a station.
	 * @param tile The tile to find the stationID of
	 * @return StationID of the station.
	 * @post Use IsValidStation() to see if the station is valid.
	 */
	static StationID GetStationID(TileIndex tile);

	/**
	 * See how much cargo there is waiting on a station.
	 * @param station_id The station to get the cargo-waiting of.
	 * @param cargo_id The cargo to get the cargo-waiting of.
	 * @pre IsValidStation(station_id).
	 * @pre IsValidCargo(cargo_id).
	 * @return The amount of units waiting at the station.
	 */
	static int32 GetCargoWaiting(StationID station_id, CargoID cargo_id);

	/**
	 * See how much cargo with a specific source station there is waiting on a station.
	 * @param station_id The station to get the cargo-waiting of.
	 * @param from_station_id The source station of the cargo. Pass STATION_INVALID to get cargo of which the source has been deleted.
	 * @param cargo_id The cargo to get the cargo-waiting of.
	 * @pre IsValidStation(station_id).
	 * @pre IsValidStation(from_station_id) || from_station_id == STATION_INVALID.
	 * @pre IsValidCargo(cargo_id).
	 * @return The amount of units waiting at the station originating from from_station_id.
	 * @note source station means, the station where cargo was first loaded.
	 */
	static int32 GetCargoWaitingFrom(StationID station_id, StationID from_station_id, CargoID cargo_id);

	/**
	 * See how much cargo with a specific via-station there is waiting on a station.
	 * @param station_id The station to get the cargo-waiting of.
	 * @param via_station_id The next station the cargo is going to. Pass STATION_INVALID to get waiting cargo for "via any station".
	 * @param cargo_id The cargo to get the cargo-waiting of.
	 * @pre IsValidStation(station_id).
	 * @pre IsValidStation(via_station_id) || via_station_id == STATION_INVALID.
	 * @pre IsValidCargo(cargo_id).
	 * @return The amount of units waiting at the station with via_station_id as next hop.
	 * @note if ScriptCargo.GetCargoDistributionType(cargo_id) == ScriptCargo.DT_MANUAL, then all waiting cargo will have STATION_INVALID as next hop.
	 */
	static int32 GetCargoWaitingVia(StationID station_id, StationID via_station_id, CargoID cargo_id);

	/**
	 * See how much cargo with a specific via-station and source station there is waiting on a station.
	 * @param station_id The station to get the cargo-waiting of.
	 * @param from_station_id The source station of the cargo. Pass STATION_INVALID to get cargo of which the source has been deleted.
	 * @param via_station_id The next station the cargo is going to. Pass STATION_INVALID to get waiting cargo for "via any station".
	 * @param cargo_id The cargo to get the cargo-waiting of.
	 * @pre IsValidStation(station_id).
	 * @pre IsValidStation(from_station_id) || from_station_id == STATION_INVALID.
	 * @pre IsValidStation(via_station_id) || via_station_id == STATION_INVALID.
	 * @pre IsValidCargo(cargo_id).
	 * @return The amount of units waiting at the station with from_station_id as source and via_station_id as next hop.
	 * @note if ScriptCargo.GetCargoDistributionType(cargo_id) == ScriptCargo.DT_MANUAL, then all waiting cargo will have STATION_INVALID as next hop.
	 */
	static int32 GetCargoWaitingFromVia(StationID station_id, StationID from_station_id, StationID via_station_id, CargoID cargo_id);

	/**
	 * Check whether the given cargo at the given station a rating.
	 * @param station_id The station to get the cargo-rating state of.
	 * @param cargo_id The cargo to get the cargo-rating state of.
	 * @pre IsValidStation(station_id).
	 * @pre IsValidCargo(cargo_id).
	 * @return True if the cargo has a rating, otherwise false.
	 */
	static bool HasCargoRating(StationID station_id, CargoID cargo_id);

	/**
	 * See how high the rating is of a cargo on a station.
	 * @param station_id The station to get the cargo-rating of.
	 * @param cargo_id The cargo to get the cargo-rating of.
	 * @pre IsValidStation(station_id).
	 * @pre IsValidCargo(cargo_id).
	 * @pre HasCargoRating(station_id, cargo_id).
	 * @return The rating in percent of the cargo on the station.
	 */
	static int32 GetCargoRating(StationID station_id, CargoID cargo_id);

	/**
	 * Get the coverage radius of this type of station.
	 * @param station_type The type of station.
	 * @pre station_type != STATION_AIRPORT.
	 * @return The radius in tiles.
	 * @note Coverage radius of airports needs to be requested via ScriptAirport::GetAirportCoverageRadius(), as it requires AirportType.
	 */
	static int32 GetCoverageRadius(ScriptStation::StationType station_type);

	/**
	 * Get the coverage radius of this station.
	 * @param station_id The station to get the coverage radius of.
	 * @pre IsValidStation(station_id).
	 * @return The radius in tiles.
	 */
	static int32 GetStationCoverageRadius(StationID station_id);

	/**
	 * Get the manhattan distance from the tile to the ScriptStation::GetLocation()
	 *  of the station.
	 * @param station_id The station to get the distance to.
	 * @param tile The tile to get the distance to.
	 * @pre IsValidStation(station_id).
	 * @return The distance between station and tile.
	 */
	static int32 GetDistanceManhattanToTile(StationID station_id, TileIndex tile);

	/**
	 * Get the square distance from the tile to the ScriptStation::GetLocation()
	 *  of the station.
	 * @param station_id The station to get the distance to.
	 * @param tile The tile to get the distance to.
	 * @pre IsValidStation(station_id).
	 * @return The distance between station and tile.
	 */
	static int32 GetDistanceSquareToTile(StationID station_id, TileIndex tile);

	/**
	 * Find out if this station is within the rating influence of a town.
	 *  The service quality of stations with signs within this radius
	 *  influences the rating of the town.
	 * @param station_id The station to check.
	 * @param town_id The town to check.
	 * @return True if the tile is within the rating influence of the town.
	 */
	static bool IsWithinTownInfluence(StationID station_id, TownID town_id);

	/**
	 * Check if any part of the station contains a station of the type
	 *  StationType
	 * @param station_id The station to look at.
	 * @param station_type The StationType to look for.
	 * @return True if the station has a station part of the type StationType.
	 */
	static bool HasStationType(StationID station_id, StationType station_type);

	/**
	 * Check if any part of the station contains a station of the type
	 *  RoadType.
	 * @param station_id The station to look at.
	 * @param road_type The RoadType to look for.
	 * @return True if the station has a station part of the type RoadType.
	 */
	static bool HasRoadType(StationID station_id, ScriptRoad::RoadType road_type);

	/**
	 * Get the town that was nearest to the given station when the station was built.
	 * @param station_id The station to look at.
	 * @return The TownID of the town whose center tile was closest to the station
	 *  at the time the station was built.
	 * @note There is no guarantee that the station is even near the returned town
	 *  nor that the returns town is closest to the station now. A station that was
	 *  'walked' to the other end of the map will still return the same town. Also,
	 *  towns grow, towns change. So don't depend on this value too much.
	 */
	static TownID GetNearestTown(StationID station_id);

	/**
	 * Get the open/closed state of an airport.
	 * @param station_id The airport to look at.
	 * @pre IsValidStation(station_id).
	 * @pre HasStationType(station_id, STATION_AIRPORT).
	 * @return True if the airport is currently closed to incoming traffic.
	 */
	static bool IsAirportClosed(StationID station_id);

	/**
	 * Toggle the open/closed state of an airport.
	 * @param station_id The airport to modify.
	 * @pre IsValidStation(station_id).
	 * @pre HasStationType(station_id, STATION_AIRPORT).
	 * @return True if the state could be toggled.
	 */
	static bool OpenCloseAirport(StationID station_id);

private:
	template<bool Tfrom, bool Tvia>
	static int32 CountCargoWaiting(StationID station_id, StationID from_station_id,
			StationID via_station_id, CargoID cargo_id);

};

DECLARE_ENUM_AS_BIT_SET(ScriptStation::StationType)

#endif /* SCRIPT_STATION_HPP */