/* $Id$ */

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

#include "ai_engine.hpp"
#include "ai_cargo.hpp"
#include "../../company_func.h"
#include "../../company_base.h"
#include "../../strings_func.h"
#include "../../rail.h"
#include "../../engine_base.h"
#include "../../articulated_vehicles.h"
#include "table/strings.h"

/* static */ bool AIEngine::IsValidEngine(EngineID engine_id)
{
	const Engine *e = ::Engine::GetIfValid(engine_id);
	return e != NULL && (HasBit(e->company_avail, _current_company) || ::Company::Get(_current_company)->num_engines[engine_id] > 0);

}

/* static */ bool AIEngine::IsBuildable(EngineID engine_id)
{
	const Engine *e = ::Engine::GetIfValid(engine_id);
	return e != NULL && HasBit(e->company_avail, _current_company);
}

/* 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;

	CargoArray cap = ::GetCapacityOfArticulatedParts(engine_id);

	CargoID most_cargo = CT_INVALID;
	uint amount = 0;
	for (CargoID cid = 0; cid < NUM_CARGO; cid++) {
		if (cap[cid] > amount) {
			amount = cap[cid];
			most_cargo = cid;
		}
	}

	return most_cargo;
}

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

	return HasBit(::GetUnionOfArticulatedRefitMasks(engine_id, true), cargo_id);
}

/* static */ bool AIEngine::CanPullCargo(EngineID engine_id, CargoID cargo_id)
{
	if (!IsValidEngine(engine_id)) return false;
	if (GetVehicleType(engine_id) != AIVehicle::VT_RAIL) return false;
	if (!AICargo::IsValidCargo(cargo_id)) return false;

	return (::RailVehInfo(engine_id)->ai_passenger_only != 1) || AICargo::HasCargoClass(cargo_id, AICargo::CC_PASSENGERS);
}


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

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

		case VEH_SHIP:
		case VEH_AIRCRAFT:
			return e->GetDisplayDefaultCapacity();
			break;

		default: NOT_REACHED();
	}
}

/* static */ int32 AIEngine::GetReliability(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return -1;
	if (GetVehicleType(engine_id) == AIVehicle::VT_RAIL && IsWagon(engine_id)) return -1;

	return ::ToPercent16(::Engine::Get(engine_id)->reliability);
}

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

	const Engine *e = ::Engine::Get(engine_id);
	int32 max_speed = e->GetDisplayMaxSpeed(); // km-ish/h
	if (e->type == VEH_AIRCRAFT) max_speed /= _settings_game.vehicle.plane_speed;
	return max_speed;
}

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

	return ::Engine::Get(engine_id)->GetCost();
}

/* static */ int32 AIEngine::GetMaxAge(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return -1;
	if (GetVehicleType(engine_id) == AIVehicle::VT_RAIL && IsWagon(engine_id)) return -1;

	return ::Engine::Get(engine_id)->GetLifeLengthInDays();
}

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

	return ::Engine::Get(engine_id)->GetRunningCost();
}

/* static */ int32 AIEngine::GetPower(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return -1;
	if (GetVehicleType(engine_id) != AIVehicle::VT_RAIL && GetVehicleType(engine_id) != AIVehicle::VT_ROAD) return -1;
	if (IsWagon(engine_id)) return -1;

	return ::Engine::Get(engine_id)->GetPower();
}

/* static */ int32 AIEngine::GetWeight(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return -1;
	if (GetVehicleType(engine_id) != AIVehicle::VT_RAIL && GetVehicleType(engine_id) != AIVehicle::VT_ROAD) return -1;

	return ::Engine::Get(engine_id)->GetDisplayWeight();
}

/* static */ int32 AIEngine::GetMaxTractiveEffort(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return -1;
	if (GetVehicleType(engine_id) != AIVehicle::VT_RAIL && GetVehicleType(engine_id) != AIVehicle::VT_ROAD) return -1;
	if (IsWagon(engine_id)) return -1;

	return ::Engine::Get(engine_id)->GetDisplayMaxTractiveEffort();
}

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

	return ::Engine::Get(engine_id)->intro_date;
}

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

	switch (::Engine::Get(engine_id)->type) {
		case VEH_ROAD:     return AIVehicle::VT_ROAD;
		case VEH_TRAIN:    return AIVehicle::VT_RAIL;
		case VEH_SHIP:     return AIVehicle::VT_WATER;
		case VEH_AIRCRAFT: return AIVehicle::VT_AIR;
		default: NOT_REACHED();
	}
}

/* static */ bool AIEngine::IsWagon(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return false;
	if (GetVehicleType(engine_id) != AIVehicle::VT_RAIL) return false;

	return ::RailVehInfo(engine_id)->power == 0;
}

/* static */ bool AIEngine::CanRunOnRail(EngineID engine_id, AIRail::RailType track_rail_type)
{
	if (!IsValidEngine(engine_id)) return false;
	if (GetVehicleType(engine_id) != AIVehicle::VT_RAIL) return false;
	if (!AIRail::IsRailTypeAvailable(track_rail_type)) return false;

	return ::IsCompatibleRail((::RailType)::RailVehInfo(engine_id)->railtype, (::RailType)track_rail_type);
}

/* static */ bool AIEngine::HasPowerOnRail(EngineID engine_id, AIRail::RailType track_rail_type)
{
	if (!IsValidEngine(engine_id)) return false;
	if (GetVehicleType(engine_id) != AIVehicle::VT_RAIL) return false;
	if (!AIRail::IsRailTypeAvailable(track_rail_type)) return false;

	return ::HasPowerOnRail((::RailType)::RailVehInfo(engine_id)->railtype, (::RailType)track_rail_type);
}

/* static */ AIRoad::RoadType AIEngine::GetRoadType(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return AIRoad::ROADTYPE_INVALID;
	if (GetVehicleType(engine_id) != AIVehicle::VT_ROAD) return AIRoad::ROADTYPE_INVALID;

	return HasBit(::EngInfo(engine_id)->misc_flags, EF_ROAD_TRAM) ? AIRoad::ROADTYPE_TRAM : AIRoad::ROADTYPE_ROAD;
}

/* static */ AIRail::RailType AIEngine::GetRailType(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return AIRail::RAILTYPE_INVALID;
	if (GetVehicleType(engine_id) != AIVehicle::VT_RAIL) return AIRail::RAILTYPE_INVALID;

	return (AIRail::RailType)(uint)::RailVehInfo(engine_id)->railtype;
}

/* static */ bool AIEngine::IsArticulated(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return false;
	if (GetVehicleType(engine_id) != AIVehicle::VT_ROAD && GetVehicleType(engine_id) != AIVehicle::VT_RAIL) return false;

	return CountArticulatedParts(engine_id, true) != 0;
}

/* static */ AIAirport::PlaneType AIEngine::GetPlaneType(EngineID engine_id)
{
	if (!IsValidEngine(engine_id)) return AIAirport::PT_INVALID;
	if (GetVehicleType(engine_id) != AIVehicle::VT_AIR) return AIAirport::PT_INVALID;

	return (AIAirport::PlaneType)::AircraftVehInfo(engine_id)->subtype;
}