// AIManager.cxx  Based on David Luff's AIMgr:
// - a global management type for AI objects
//
// Written by David Culp, started October 2003.
// - davidculp2@comcast.net
//
// This program 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; either version 2 of the
// License, or (at your option) any later version.
//
// This program 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 this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

#include <simgear/math/sg_geodesy.hxx>
#include <simgear/props/props_io.hxx>
#include <simgear/structure/exception.hxx>

#include <Main/globals.hxx>

#include <Airports/simple.hxx>
#include <Traffic/TrafficMgr.hxx>

#include "AIManager.hxx"
#include "AIAircraft.hxx"
#include "AIShip.hxx"
#include "AIBallistic.hxx"
#include "AIStorm.hxx"
#include "AIThermal.hxx"
#include "AICarrier.hxx"
#include "AIStatic.hxx"
#include "AIMultiplayer.hxx"
#include "AITanker.hxx"
#include "AIWingman.hxx"

FGAIManager::FGAIManager() {
    _dt = 0.0;
    mNumAiModels = 0;

    for (unsigned i = 0; i < FGAIBase::MAX_OBJECTS; ++i)
        mNumAiTypeModels[i] = 0;
}

FGAIManager::~FGAIManager() {
    ai_list_iterator ai_list_itr = ai_list.begin();

    while(ai_list_itr != ai_list.end()) {
        (*ai_list_itr)->unbind();
        ++ai_list_itr;
    }
}

void
FGAIManager::init() {
    root = fgGetNode("sim/ai", true);

    enabled = root->getNode("enabled", true)->getBoolValue();

    if (!enabled)
        return;

    wind_from_down_node = fgGetNode("/environment/wind-from-down-fps", true);
    wind_from_east_node  = fgGetNode("/environment/wind-from-east-fps",true);
    wind_from_north_node = fgGetNode("/environment/wind-from-north-fps",true);

    user_latitude_node  = fgGetNode("/position/latitude-deg", true);
    user_longitude_node = fgGetNode("/position/longitude-deg", true);
    user_altitude_node  = fgGetNode("/position/altitude-ft", true);
    user_heading_node   = fgGetNode("/orientation/heading-deg", true);
    user_pitch_node     = fgGetNode("/orientation/pitch-deg", true);
    user_yaw_node       = fgGetNode("/orientation/side-slip-deg", true);
    user_roll_node      = fgGetNode("/orientation/roll-deg", true);
    user_speed_node     = fgGetNode("/velocities/uBody-fps", true);
}

void
FGAIManager::postinit() {
    // postinit, so that it can access the Nasal subsystem
    map<string, bool> scenarios;
    for (int i = 0 ; i < root->nChildren() ; i++) {
        SGPropertyNode *n = root->getChild(i);
        if (strcmp(n->getName(), "scenario"))
            continue;

        string name = n->getStringValue();
        if (name.empty())
            continue;

        if (scenarios.find(name) != scenarios.end()) {
            SG_LOG(SG_GENERAL, SG_WARN, "won't load scenario '" << name << "' twice");
            continue;
        }

        SG_LOG(SG_GENERAL, SG_INFO, "loading scenario '" << name << '\'');
        processScenario(name);
        scenarios[name] = true;
    }
}

void
FGAIManager::reinit() {
    update(0.0);
    ai_list_iterator ai_list_itr = ai_list.begin();

    while(ai_list_itr != ai_list.end()) {
        (*ai_list_itr)->reinit();
        ++ai_list_itr;
    }
}

void
FGAIManager::bind() {
    root = globals->get_props()->getNode("ai/models", true);
    root->tie("count", SGRawValueMethods<FGAIManager, int>(*this,
        &FGAIManager::getNumAiObjects));
}

void
FGAIManager::unbind() {
    root->untie("count");
}

void
FGAIManager::update(double dt) {
    // initialize these for finding nearest thermals
    range_nearest = 10000.0;
    strength = 0.0;

    if (!enabled)
        return;

    FGTrafficManager *tmgr = (FGTrafficManager*) globals->get_subsystem("Traffic Manager");
    _dt = dt;

    ai_list_iterator ai_list_itr = ai_list.begin();

    while(ai_list_itr != ai_list.end()) {

        if ((*ai_list_itr)->getDie()) {
            tmgr->release((*ai_list_itr)->getID());
            --mNumAiModels;
            --(mNumAiTypeModels[(*ai_list_itr)->getType()]);
            FGAIBase *base = (*ai_list_itr).get();
            SGPropertyNode *props = base->_getProps();

            props->setBoolValue("valid", false);
            base->unbind();

            // for backward compatibility reset properties, so that aircraft,
            // which don't know the <valid> property, keep working
            // TODO: remove after a while
            props->setIntValue("id", -1);
            props->setBoolValue("radar/in-range", false);
            props->setIntValue("refuel/tanker", false);

            ai_list_itr = ai_list.erase(ai_list_itr);
        } else {
            fetchUserState();
            if ((*ai_list_itr)->isa(FGAIBase::otThermal)) {
                FGAIBase *base = (*ai_list_itr).get();
                processThermal((FGAIThermal*)base);
            } else {
                (*ai_list_itr)->update(_dt);
            }
            ++ai_list_itr;
        }
    }

    wind_from_down_node->setDoubleValue( strength ); // for thermals
}

void
FGAIManager::attach(FGAIBase *model)
{
    //unsigned idx = mNumAiTypeModels[model->getType()];
    const char* typeString = model->getTypeString();
    SGPropertyNode* root = globals->get_props()->getNode("ai/models", true);
    SGPropertyNode* p;
    int i;

    // find free index in the property tree, if we have
    // more than 10000 mp-aircrafts in the property tree we should optimize the mp-server
    for (i = 0; i < 10000; i++) {
        p = root->getNode(typeString, i, false);

        if (!p || !p->getBoolValue("valid", false))
            break;

        if (p->getIntValue("id",-1)==model->getID()) {
            p->setStringValue("callsign","***invalid node***"); //debug only, should never set!
        }
    }

    p = root->getNode(typeString, i, true);
    model->setManager(this, p);
    ai_list.push_back(model);
    ++mNumAiModels;
    ++(mNumAiTypeModels[model->getType()]);
    model->init(model->getType()==FGAIBase::otAircraft
        || model->getType()==FGAIBase::otMultiplayer
        || model->getType()==FGAIBase::otStatic);
    model->bind();
    p->setBoolValue("valid", true);
}

void
FGAIManager::destroyObject( int ID ) {
    ai_list_iterator ai_list_itr = ai_list.begin();

    while(ai_list_itr != ai_list.end()) {

        if ((*ai_list_itr)->getID() == ID) {
            --mNumAiModels;
            --(mNumAiTypeModels[(*ai_list_itr)->getType()]);
            (*ai_list_itr)->unbind();
            ai_list_itr = ai_list.erase(ai_list_itr);
        } else
            ++ai_list_itr;
    }

}

int
FGAIManager::getNumAiObjects(void) const
{
    return mNumAiModels;
}

void
FGAIManager::fetchUserState( void ) {
    user_latitude  = user_latitude_node->getDoubleValue();
    user_longitude = user_longitude_node->getDoubleValue();
    user_altitude  = user_altitude_node->getDoubleValue();
    user_heading   = user_heading_node->getDoubleValue();
    user_pitch     = user_pitch_node->getDoubleValue();
    user_yaw       = user_yaw_node->getDoubleValue();
    user_speed     = user_speed_node->getDoubleValue() * 0.592484;
    user_roll      = user_roll_node->getDoubleValue();
    wind_from_east = wind_from_east_node->getDoubleValue();
    wind_from_north = wind_from_north_node->getDoubleValue();
}

// only keep the results from the nearest thermal
void
FGAIManager::processThermal( FGAIThermal* thermal ) {
    thermal->update(_dt);

    if ( thermal->_getRange() < range_nearest ) {
        range_nearest = thermal->_getRange();
        strength = thermal->getStrength();
    }

}

void
FGAIManager::processScenario( const string &filename ) {

    SGPropertyNode_ptr scenarioTop = loadScenarioFile(filename);

    if (!scenarioTop)
        return;

    SGPropertyNode* scenarios = scenarioTop->getChild("scenario");

    if (!scenarios)
        return;

    for (int i = 0; i < scenarios->nChildren(); i++) {
        SGPropertyNode* scEntry = scenarios->getChild(i);

        if (strcmp(scEntry->getName(), "entry"))
            continue;
        std::string type = scEntry->getStringValue("type", "aircraft");

         if (type == "tanker") { // refueling scenarios
	    FGAITanker* tanker = new FGAITanker;
            tanker->readFromScenario(scEntry);
            attach(tanker);

        } else if (type == "wingman") {
            FGAIWingman* wingman = new FGAIWingman;
            wingman->readFromScenario(scEntry);
            attach(wingman);

    } else if (type == "aircraft") {
            FGAIAircraft* aircraft = new FGAIAircraft;
            aircraft->readFromScenario(scEntry);
            attach(aircraft);

        } else if (type == "ship") {
            FGAIShip* ship = new FGAIShip;
            ship->readFromScenario(scEntry);
            attach(ship);

        } else if (type == "carrier") {
            FGAICarrier* carrier = new FGAICarrier;
            carrier->readFromScenario(scEntry);
            attach(carrier);

        } else if (type == "thunderstorm") {
            FGAIStorm* storm = new FGAIStorm;
            storm->readFromScenario(scEntry);
            attach(storm);

        } else if (type == "thermal") {
            FGAIThermal* thermal = new FGAIThermal;
            thermal->readFromScenario(scEntry);
            attach(thermal);

        } else if (type == "ballistic") {
            FGAIBallistic* ballistic = new FGAIBallistic;
            ballistic->readFromScenario(scEntry);
            attach(ballistic);

        } else if (type == "static") {
            FGAIStatic* aistatic = new FGAIStatic;
            aistatic->readFromScenario(scEntry);
            attach(aistatic);

        }
    }
}

SGPropertyNode_ptr
FGAIManager::loadScenarioFile(const std::string& filename)
{
    SGPath path(globals->get_fg_root());
    path.append("AI/" + filename + ".xml");
    try {
        SGPropertyNode_ptr root = new SGPropertyNode;
        readProperties(path.str(), root);
        return root;
    } catch (const sg_exception &) {
        SG_LOG(SG_GENERAL, SG_DEBUG, "Incorrect path specified for AI "
            "scenario: \"" << path.str() << "\"");
        return 0;
    }
}

bool
FGAIManager::getStartPosition(const string& id, const string& pid,
                              SGGeod& geodPos, double& hdng, SGVec3d& uvw)
{
    bool found = false;
    SGPropertyNode* root = fgGetNode("sim/ai", true);
    if (!root->getNode("enabled", true)->getBoolValue())
        return found;

    for (int i = 0 ; (!found) && i < root->nChildren() ; i++) {
        SGPropertyNode *aiEntry = root->getChild( i );
        if ( !strcmp( aiEntry->getName(), "scenario" ) ) {
            string filename = aiEntry->getStringValue();
            SGPropertyNode_ptr scenarioTop = loadScenarioFile(filename);
            if (scenarioTop) {
                SGPropertyNode* scenarios = scenarioTop->getChild("scenario");
                if (scenarios) {
                    for (int i = 0; i < scenarios->nChildren(); i++) {
                        SGPropertyNode* scEntry = scenarios->getChild(i);
                        std::string type = scEntry->getStringValue("type");
                        std::string pnumber = scEntry->getStringValue("pennant-number");
                        std::string name = scEntry->getStringValue("name");
                        if (type == "carrier" && (pnumber == id || name == id)) {
                            osg::ref_ptr<FGAICarrier> carrier = new FGAICarrier;
                            carrier->readFromScenario(scEntry);

                            if (carrier->getParkPosition(pid, geodPos, hdng, uvw)) {
                                found = true;
                                break;
                            }
                        }
                    }
                }
            }
        }
    }
    return found;
}

const FGAIBase *
FGAIManager::calcCollision(double alt, double lat, double lon, double fuse_range)
{
    // we specify tgt extent (ft) according to the AIObject type
    double tgt_ht[]     = {0, 50 ,100, 250, 0, 100, 0, 0, 50, 50};
    double tgt_length[] = {0, 100, 200, 750, 0, 50, 0, 0, 200, 100};

    ai_list_iterator ai_list_itr = ai_list.begin();
    ai_list_iterator end = ai_list.end();

    while (ai_list_itr != end) {
        double tgt_alt = (*ai_list_itr)->_getAltitude();
        int type       = (*ai_list_itr)->getType();
        tgt_ht[type] += fuse_range;

        if (fabs(tgt_alt - alt) > tgt_ht[type] || type == FGAIBase::otBallistic
                || type == FGAIBase::otStorm || type == FGAIBase::otThermal) {
            SG_LOG(SG_GENERAL, SG_DEBUG, "AIManager: skipping "
                << fabs(tgt_alt - alt)
                << " "
                << type
                );
            ++ai_list_itr;
            continue;
        }

        double tgt_lat = (*ai_list_itr)->_getLatitude();
        double tgt_lon = (*ai_list_itr)->_getLongitude();
        int id         = (*ai_list_itr)->getID();

        double range = calcRange(lat, lon, tgt_lat, tgt_lon);

        SG_LOG(SG_GENERAL, SG_DEBUG, "AIManager:  AI list size "
            << ai_list.size()
            << " type " << type
            << " ID " << id
            << " range " << range
            //<< " bearing " << bearing
            << " alt " << tgt_alt
            );

        tgt_length[type] += fuse_range;

        if (range < tgt_length[type]){
            SG_LOG(SG_GENERAL, SG_DEBUG, "AIManager: HIT! "
                << " type " << type
                << " ID " << id
                << " range " << range
                << " alt " << tgt_alt
                );
            return (*ai_list_itr).get();
        }
        ++ai_list_itr;
    }
    return 0;
}

double
FGAIManager::calcRange(double lat, double lon, double lat2, double lon2) const
{
    double course, az2, distance;

    //calculate the bearing and range of the second pos from the first
    geo_inverse_wgs_84(lat, lon, lat2, lon2, &course, &az2, &distance);
    distance *= SG_METER_TO_FEET;
    return distance;
}

//end AIManager.cxx