/* $Id$ */

/** @file ai_engine.cpp Implementation of AIEngine. */

#include "ai_engine.hpp"
#include "ai_cargo.hpp"
#include "../../openttd.h"
#include "../../player_func.h"
#include "../../strings_func.h"
#include "../../roadveh.h"
#include "../../train.h"
#include "../../ship.h"
#include "../../aircraft.h"
#include "../../vehicle_func.h"
#include "../../core/alloc_func.hpp"
#include "../../economy_func.h"
#include "../../core/bitmath_func.hpp"
#include "../../settings_type.h"
#include "../../articulated_vehicles.h"
#include "table/strings.h"

/* static */ bool AIEngine::IsValidEngine(EngineID engine_id)
{
	return ::IsEngineIndex(engine_id) && HasBit(::GetEngine(engine_id)->player_avail, _current_player);
}

/* static */ char *AIEngine::GetName(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return NULL;

	static const int len = 64;
	char *engine_name = MallocT<char>(len);

	::SetDParam(0, engine_id);
	::GetString(engine_name, STR_ENGINE_NAME, &engine_name[len - 1]);
	return engine_name;
}

/* static */ CargoID AIEngine::GetCargoType(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return CT_INVALID;

	switch (::GetEngine(engine_id)->type) {
		case VEH_ROAD: {
			const RoadVehicleInfo *vi = ::RoadVehInfo(engine_id);
			return vi->cargo_type;
		} break;

		case VEH_TRAIN: {
			const RailVehicleInfo *vi = ::RailVehInfo(engine_id);
			return vi->cargo_type;
		} break;

		case VEH_SHIP: {
			const ShipVehicleInfo *vi = ::ShipVehInfo(engine_id);
			return vi->cargo_type;
		} break;

		case VEH_AIRCRAFT: {
			return CT_PASSENGERS;
		} break;

		default: NOT_REACHED();
	}
}

/* static */ bool AIEngine::CanRefitCargo(EngineID engine_id, CargoID cargo_id)
{
	if (!IsValidEngine(engine_id)) return false;
	if (!AICargo::IsValidCargo(cargo_id)) return false;

	if (GetCargoType(engine_id) == cargo_id) return true;
	if (cargo_id == CT_MAIL && ::GetEngine(engine_id)->type == VEH_AIRCRAFT) return true;
	return ::CanRefitTo(engine_id, cargo_id);
}

/* static */ int32 AIEngine::GetCapacity(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return -1;

	switch (::GetEngine(engine_id)->type) {
		case VEH_ROAD:
		case VEH_TRAIN: {
			uint16 *capacities = GetCapacityOfArticulatedParts(engine_id, ::GetEngine(engine_id)->type);
			for (CargoID c = 0; c < NUM_CARGO; c++) {
				if (capacities[c] == 0) continue;
				return capacities[c];
			}
			return -1;
		} break;

		case VEH_SHIP: {
			const ShipVehicleInfo *vi = ::ShipVehInfo(engine_id);
			return vi->capacity;
		} break;

		case VEH_AIRCRAFT: {
			const AircraftVehicleInfo *vi = ::AircraftVehInfo(engine_id);
			return vi->passenger_capacity;
		} break;

		default: NOT_REACHED();
	}
}

/* static */ int32 AIEngine::GetReliability(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return -1;

	return (::GetEngine(engine_id)->reliability * 100 >> 16);
}

/* static */ int32 AIEngine::GetMaxSpeed(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return -1;

	switch (::GetEngine(engine_id)->type) {
		case VEH_ROAD: {
			const RoadVehicleInfo *vi = ::RoadVehInfo(engine_id);
			/* Internal speeds are km/h * 2 */
			return vi->max_speed / 2;
		} break;

		case VEH_TRAIN: {
			const RailVehicleInfo *vi = ::RailVehInfo(engine_id);
			return vi->max_speed;
		} break;

		case VEH_SHIP: {
			const ShipVehicleInfo *vi = ::ShipVehInfo(engine_id);
			/* Internal speeds are km/h * 2 */
			return vi->max_speed / 2;
		} break;

		case VEH_AIRCRAFT: {
			const AircraftVehicleInfo *vi = ::AircraftVehInfo(engine_id);
			return vi->max_speed / _patches.plane_speed;
		} break;

		default: NOT_REACHED();
	}
}

/* static */ Money AIEngine::GetPrice(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return -1;

	switch (::GetEngine(engine_id)->type) {
		case VEH_ROAD: {
			const RoadVehicleInfo *vi = ::RoadVehInfo(engine_id);
			return (_price.roadveh_base >> 3) * vi->base_cost >> 5;
		} break;

		case VEH_TRAIN: {
			const RailVehicleInfo *vi = ::RailVehInfo(engine_id);
			return (_price.build_railvehicle >> 3) * vi->base_cost >> 5;
		} break;

		case VEH_SHIP: {
			const ShipVehicleInfo *vi = ::ShipVehInfo(engine_id);
			return (_price.ship_base >> 3) * vi->base_cost >> 5;
		} break;

		case VEH_AIRCRAFT: {
			const AircraftVehicleInfo *vi = ::AircraftVehInfo(engine_id);
			return (_price.aircraft_base >> 3) * vi->base_cost >> 5;
		} break;

		default: NOT_REACHED();
	}
}

/* static */ int32 AIEngine::GetMaxAge(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return -1;

	return ::GetEngine(engine_id)->lifelength * 366;
}

/* static */ Money AIEngine::GetRunningCost(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return -1;

	/* We need to create an instance in order to obtain GetRunningCost.
	 *  This means we temporary allocate a vehicle in the pool, but
	 *  there is no other way.. */
	Vehicle *vehicle;
	switch (::GetEngine(engine_id)->type) {
		case VEH_ROAD: {
			vehicle = new RoadVehicle();
		} break;

		case VEH_TRAIN: {
			vehicle = new Train();
		} break;

		case VEH_SHIP: {
			vehicle = new Ship();
		} break;

		case VEH_AIRCRAFT: {
			vehicle = new Aircraft();
		} break;

		default: NOT_REACHED();
	}

	vehicle->engine_type = engine_id;
	Money runningCost = vehicle->GetRunningCost();
	delete vehicle;
	return runningCost >> 8;
}

/* static */ AIVehicle::VehicleType AIEngine::GetVehicleType(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return AIVehicle::VEHICLE_INVALID;

	switch (::GetEngine(engine_id)->type) {
		case VEH_ROAD:     return AIVehicle::VEHICLE_ROAD;
		case VEH_TRAIN:    return AIVehicle::VEHICLE_RAIL;
		case VEH_SHIP:     return AIVehicle::VEHICLE_WATER;
		case VEH_AIRCRAFT: return AIVehicle::VEHICLE_AIR;
		default: NOT_REACHED();
	}
}