// FGAIBase.hxx - abstract base class for AI objects
// Written by David Culp, started Nov 2003, based on
// David Luff's FGAIEntity class.
// - 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.

#ifndef FG_AIBASE_HXX
#define FG_AIBASE_HXX

#include <string>
#include <osg/ref_ptr>

#include <simgear/constants.h>
#include <simgear/scene/model/placement.hxx>
#include <simgear/misc/sg_path.hxx>
#include <simgear/structure/SGSharedPtr.hxx>
#include <simgear/structure/SGReferenced.hxx>
#include <simgear/props/tiedpropertylist.hxx>
#include <simgear/sg_inlines.h>

#include <simgear/math/sg_geodesy.hxx>

namespace osg { class PagedLOD; }

namespace simgear {
class BVHMaterial;
}
class FGAIManager;
class FGAIFlightPlan;
class FGFX;
class FGAIModelData;    // defined below


class FGAIBase : public SGReferenced {

public:
    enum object_type { otNull = 0, otAircraft, otShip, otCarrier, otBallistic,
        otRocket, otStorm, otThermal, otStatic, otWingman, otGroundVehicle,
        otEscort, otMultiplayer,
        MAX_OBJECTS };  // Needs to be last!!!

    FGAIBase(object_type ot, bool enableHot);
    virtual ~FGAIBase();

    // these depend on the order in which the models are loaded. OSG is a little vague about this, but 
    // from experimentation it seems to work best if the LODs are in the range list in terms of detail
    // from lowest to highest
    const int modelLowDetailIndex = 0;
    const int modelHighDetailIndex = 1;

    virtual void readFromScenario(SGPropertyNode* scFileNode);

    enum ModelSearchOrder {
        DATA_ONLY,  // don't search AI/ prefix at all
        PREFER_AI,  // search AI first, override other paths
        PREFER_DATA // search data first but fall back to AI
    };

    virtual bool init(ModelSearchOrder searchOrder);
    virtual void initModel();
    virtual void update(double dt);
    virtual void bind();
    virtual void unbind();
    virtual void reinit() {}
    // default model radius for LOD. 
    virtual double getDefaultModelRadius() { return 20.0; }
    void updateLOD();
    void updateInterior();
    void setManager(FGAIManager* mgr, SGPropertyNode* p);
    void setPath( const char* model );
    void setPathLowres( std::string model );
    void setFallbackModelIndex(const int i );
    void setSMPath( const std::string& p );
    void setCallSign(const std::string& );
    void setSpeed( double speed_KTAS );
    void setAltitude( double altitude_ft );
    void setAltitudeAGL( double altitude_agl_ft );
    void setHeading( double heading );
    void setLatitude( double latitude );
    void setLongitude( double longitude );
    void setBank( double bank );
    void setPitch( double newpitch );
    void setRadius ( double radius );
    void setXoffset( double x_offset );
    void setYoffset( double y_offset );
    void setZoffset( double z_offset );
    void setPitchoffset( double x_offset );
    void setRolloffset( double y_offset );
    void setYawoffset( double z_offset );
    void setServiceable ( bool serviceable );
    void setDie( bool die );
    void setCollisionData( bool i, double lat, double lon, double elev );
    void setImpactData( bool d );
    void setImpactLat( double lat );
    void setImpactLon( double lon );
    void setImpactElev( double e );
    void setParentName(const std::string& p);
    void setName(const std::string& n);
    void setMaxSpeed(double kts);

    void setCollisionLength(int range);
    void setCollisionHeight(int height);

    void calcRangeBearing(double lat, double lon, double lat2, double lon2,
        double &range, double &bearing) const;
    double calcRelBearingDeg(double bearing, double heading);
    double calcTrueBearingDeg(double bearing, double heading);
    double calcRecipBearingDeg(double bearing);

    bool setParentNode();

    int getID() const;
    int _getSubID() const;

    bool getDie();
    bool isValid() const;

    void setFlightPlan(std::unique_ptr<FGAIFlightPlan> f);

    SGGeod getGeodPos() const;
    void setGeodPos(const SGGeod& pos);

    SGVec3d getCartPosAt(const SGVec3d& off) const;
    SGVec3d getCartPos() const;

    bool getGroundElevationM(const SGGeod& pos, double& elev,
                             const simgear::BVHMaterial** material) const;


    double _getCartPosX() const;
    double _getCartPosY() const;
    double _getCartPosZ() const;

    osg::PagedLOD* getSceneBranch() const;

    virtual int getCollisionHeight() const;
    virtual int getCollisionLength() const;

    void setScenarioPath(const std::string& scenarioPath);

protected:
    double _elevation_m;

    double _maxRangeInterior;

    double _x_offset;
    double _y_offset;
    double _z_offset;

    double _pitch_offset;
    double _roll_offset;
    double _yaw_offset;

    double _max_speed = 300.0;

    int collisionHeight = 0;
    int collisionLength = 0;

    std::string _path;
    std::string _callsign;
    std::string _submodel;
    std::string _name;
    std::string _parent;
    std::string _scenarioPath;

    /**
     * Tied-properties helper, record nodes which are tied for easy un-tie-ing
     */
    template <typename T>
    void tie(const char* aRelPath, const SGRawValue<T>& aRawValue)
    {
        _tiedProperties.Tie(props->getNode(aRelPath, true), aRawValue);
    }

    simgear::TiedPropertyList _tiedProperties;
    SGPropertyNode_ptr _selected_ac;
    SGPropertyNode_ptr props;
    SGPropertyNode_ptr trigger_node;
    SGPropertyNode_ptr replay_time;
    SGPropertyNode_ptr model_removed; // where to report model removal
    FGAIManager* manager = nullptr;

    // these describe the model's actual state
    SGGeod pos;         // WGS84 lat & lon in degrees, elev above sea-level in meters
    double hdg;         // True heading in degrees
    double roll;        // degrees, left is negative
    double pitch;       // degrees, nose-down is negative
    double speed;       // knots true airspeed
    double altitude_ft; // feet above sea level
    double vs_fps;      // vertical speed
    double speed_north_deg_sec;
    double speed_east_deg_sec;
    double turn_radius_ft; // turn radius ft at 15 kts rudder angle 15 degrees
    double altitude_agl_ft;

    double ft_per_deg_lon;
    double ft_per_deg_lat;

    // these describe the model's desired state
    double tgt_heading;     // target heading, degrees true
    double tgt_altitude_ft; // target altitude, *feet* above sea level
    double tgt_speed;       // target speed, KTAS
    double tgt_roll;
    double tgt_pitch;
    double tgt_yaw;
    double tgt_vs;

    // these describe radar information for the user
    bool in_range;       // true if in range of the radar, otherwise false
    double bearing;      // true bearing from user to this model
    double elevation;    // elevation in degrees from user to this model
    double range;        // range from user to this model, nm
    double rdot;         // range rate, in knots
    double horiz_offset; // look left/right from user to me, deg
    double vert_offset;  // look up/down from user to me, deg
    double x_shift;      // value used by radar display instrument
    double y_shift;      // value used by radar display instrument
    double rotation;     // value used by radar display instrument
    double ht_diff;      // value used by radar display instrument

    std::string model_path;    // Path to the 3D model
    std::string model_path_lowres;    // Path to optional low res 3D model
    int _fallback_model_index; // Index into /sim/multiplay/fallback-models[]
    SGModelPlacement aip;

    bool delete_me;
    bool invisible;
    bool no_roll;
    bool serviceable;
    bool _installed = false;
    int _subID = 0;

    double life;

    std::unique_ptr<FGAIFlightPlan> fp;

    bool _impact_reported;
    bool _collision_reported;
    bool _expiry_reported;

    double _impact_lat;
    double _impact_lon;
    double _impact_elev;
    double _impact_hdg;
    double _impact_pitch;
    double _impact_roll;
    double _impact_speed;

    ModelSearchOrder _searchOrder = DATA_ONLY;
    void Transform();
    void CalculateMach();
    double UpdateRadar(FGAIManager* manager);

    void removeModel();
    void removeSoundFx();

    static int _newAIModelID();

private:
    int _refID;
    object_type _otype;
    bool _initialized = false;
    osg::ref_ptr<osg::PagedLOD> _model;
    osg::ref_ptr<osg::PagedLOD> _interior;

    osg::ref_ptr<FGAIModelData> _modeldata;

    SGSharedPtr<FGFX>  _fx;

    std::vector<std::string> resolveModelPath(ModelSearchOrder searchOrder);

public:
    object_type getType();

    virtual const char* getTypeString(void) const { return "null"; }

    bool isa( object_type otype );

    void _setVS_fps( double _vs );
    void _setAltitude( double _alt );
    void _setLongitude( double longitude );
    void _setLatitude ( double latitude );
    void _setSubID( int s );

    double _getAltitudeAGL(SGGeod inpos, double start);

    double _getVS_fps() const;
    double _getAltitude() const;
    double _getLongitude() const;
    double _getLatitude() const;
    double _getElevationFt() const;
    double _getRdot() const;
    double _getH_offset() const;
    double _getV_offset() const;
    double _getX_shift() const;
    double _getY_shift() const;
    double _getRotation() const;
    double _getSpeed() const;
    double _getRoll() const;
    double _getPitch() const;
    double _getHeading() const;
    double _get_speed_east_fps() const;
    double _get_speed_north_fps() const;
    double _get_SubPath() const;
    double _getImpactLat() const;
    double _getImpactLon() const;
    double _getImpactElevFt() const;
    double _getImpactHdg() const;
    double _getImpactPitch() const;
    double _getImpactRoll() const;
    double _getImpactSpeed() const;
    double _getXOffset() const;
    double _getYOffset() const;
    double _getZOffset() const;
    //unsigned int _getCount() const;

    bool   _getServiceable() const;
    bool   _getFirstTime() const;
    bool   _getImpact();
    bool   _getImpactData();
    bool   _getCollisionData();
    bool   _getExpiryData();

    SGPropertyNode* _getProps() const;

    const char* _getPath() const;
    const char* _getSMPath() const;
    const char* _getCallsign() const;
    const char* _getTriggerNode() const;
    const char* _getName() const;
    const char* _getSubmodel() const;
    int _getFallbackModelIndex() const;

    // These are used in the Mach number calculations
    double rho;
    double T;                             // temperature, degs farenheit
    double p;                             // pressure lbs/sq ft
    double a;                             // speed of sound at altitude (ft/s)
    double Mach;                          // Mach number

    static const double e;
    static const double lbs_to_slugs;

    double _getRange() const { return range; }
    double _getBearing() const { return bearing; }

    static bool _isNight();

    const std::string& getCallSign() const
    { return _callsign; }
    const ModelSearchOrder getSearchOrder() const {return _searchOrder;}
};

typedef SGSharedPtr<FGAIBase> FGAIBasePtr;

inline void FGAIBase::setManager(FGAIManager* mgr, SGPropertyNode* p) {
    manager = mgr;
    props = p;
}

inline void FGAIBase::setPath(const char* model ) {
    model_path.append(model);
}

inline void FGAIBase::setPathLowres(std::string model ) {
    model_path_lowres.append(model);
}

inline void FGAIBase::setFallbackModelIndex(const int i ) {
    _fallback_model_index = i;
}

inline void FGAIBase::setSMPath(const std::string& p) {
    _path = p;
}

inline void FGAIBase::setServiceable(bool s) {
    serviceable = s;
}

inline void FGAIBase::setSpeed( double speed_KTAS ) {
    speed = tgt_speed = speed_KTAS;
}

inline void FGAIBase::setRadius( double radius ) {
    turn_radius_ft = radius;
}

inline void FGAIBase::setHeading( double heading ) {
    hdg = tgt_heading = heading;
}

inline void FGAIBase::setAltitude( double alt_ft ) {
    altitude_ft = tgt_altitude_ft = alt_ft;
    pos.setElevationFt(altitude_ft);
}

inline void FGAIBase::setAltitudeAGL( double alt_ft ) {
    altitude_agl_ft = alt_ft;
}

inline void FGAIBase::setBank( double bank ) {
    roll = tgt_roll = bank;
    no_roll = false;
}

inline void FGAIBase::setPitch( double newpitch ) {
    pitch = tgt_pitch = newpitch;
}

inline void FGAIBase::setLongitude( double longitude ) {
    pos.setLongitudeDeg( longitude );
}

inline void FGAIBase::setLatitude ( double latitude ) {
    pos.setLatitudeDeg( latitude );
}

inline void FGAIBase::setCallSign(const std::string& s) {
    _callsign = s;
}

inline void FGAIBase::setXoffset(double x) {
    _x_offset = x;
}

inline void FGAIBase::setYoffset(double y) {
    _y_offset = y;
}

inline void FGAIBase::setZoffset(double z) {
    _z_offset = z;
}

inline void FGAIBase::setPitchoffset(double p) {
    _pitch_offset = p;
}

inline void FGAIBase::setRolloffset(double r) {
    _roll_offset = r;
}

inline void FGAIBase::setYawoffset(double y) {
    _yaw_offset = y;
}

inline void FGAIBase::setParentName(const std::string& p) {
    _parent = p;
}

inline void FGAIBase::setName(const std::string& n) {
    _name = n;
}

inline void FGAIBase::setCollisionLength(int length){
    collisionLength = length;
}

inline void FGAIBase::setCollisionHeight(int height){
    collisionHeight = height;
}

inline void FGAIBase::setDie( bool die ) { delete_me = die; }

inline bool FGAIBase::getDie() { return delete_me; }

inline FGAIBase::object_type FGAIBase::getType() { return _otype; }

inline void FGAIBase::calcRangeBearing(double lat, double lon, double lat2, double lon2,
                                  double &range, double &bearing) const
{
    // calculate the bearing and range of the second pos from the first
    double az2, distance;
    geo_inverse_wgs_84(lat, lon, lat2, lon2, &bearing, &az2, &distance);
    range = distance * SG_METER_TO_NM;
}

inline double FGAIBase::calcRelBearingDeg(double bearing, double heading){
    double angle = bearing - heading;
    SG_NORMALIZE_RANGE(angle, -180.0, 180.0);
    return angle;
}

inline double FGAIBase::calcTrueBearingDeg(double bearing, double heading){
    double angle = bearing + heading;
    SG_NORMALIZE_RANGE(angle, 0.0, 360.0);
    return angle;
}

inline double FGAIBase::calcRecipBearingDeg(double bearing){
    double angle = bearing - 180;
    SG_NORMALIZE_RANGE(angle, 0.0, 360.0);
    return angle;
}

inline void FGAIBase::setMaxSpeed(double m) {
    _max_speed = m;
}

/*
 * Default height and lengths for AI submodel collision detection.
 * The difference in height is used first and then the range must be within 
 * the value specifed in the length field. This effective chops the top and 
 * bottom off the circle - but does not take into account the orientation of the
 * AI model; so this algorithm is fast but fairly innaccurate.
 * 
 * Default values:
 * +---------------+-------------+------------+
 * | Type          | Height(m)   |  Length(m) |
 * +---------------+-------------+------------+
 * | Null          |      0      |        0   |
 * | Aircraft      |     50      |      100   |
 * | Ship          |    100      |      200   |
 * | Carrier       |    250      |      750   |
 * | Ballistic     |      0      |        0   |
 * | Rocket        |    100      |       50   |
 * | Storm         |      0      |        0   |
 * | Thermal       |      0      |        0   |
 * | Static        |     50      |      200   |
 * | Wingman       |     50      |      100   |
 * | GroundVehicle |     20      |       40   |
 * | Escort        |    100      |      200   |
 * | Multiplayer   |     50      |      100   |
 * +---------------+-------------+------------+
 */
const static double tgt_ht[] = {0, 50, 100, 250, 0, 100, 0, 0, 50, 50, 20, 100, 50};
const static double tgt_length[] = {0, 100, 200, 750, 0,  50, 0, 0, 200, 100, 40, 200, 100};

inline int FGAIBase::getCollisionHeight() const
{
    if (collisionHeight == 0)
        return tgt_ht[static_cast<int>(_otype)];

    return collisionHeight;
}
inline int FGAIBase::getCollisionLength() const
{
    if (collisionLength == 0)
        return tgt_length[static_cast<int>(_otype)];

    return collisionLength;
}
#endif // _FG_AIBASE_HXX

