/*
 * © Copyright 2014 – Urheberrechtshinweis
 * Alle Rechte vorbehalten / All Rights Reserved
 *
 * Programmcode ist urheberrechtlich geschuetzt.
 * Das Urheberrecht liegt, soweit nicht ausdruecklich anders gekennzeichnet, bei Frank Ebner.
 * Keine Verwendung ohne explizite Genehmigung.
 * (vgl. § 106 ff UrhG / § 97 UrhG)
 */

#ifndef BEACONMODELLOGDIST_H
#define BEACONMODELLOGDIST_H

#include "BeaconModel.h"
#include "../../radio/model/LogDistanceModel.h"

#include <unordered_map>

/**
 * signal-strength estimation using log-distance model
 */
class BeaconModelLogDist : public BeaconModel {

public:

    /** parameters describing one beacons to the model */
    struct APEntry {

        Point3 position_m;	// the AP's position (in meter)
        float txp;			// sending power (-40)
        float exp;			// path-loss-exponent (~2.0 - 4.0)

        /** ctor */
        APEntry(const Point3 position_m, const float txp, const float exp) :
            position_m(position_m), txp(txp), exp(exp) {;}

    };

private:

    /** map of all beacons (and their parameters) known to the model */
    std::unordered_map<MACAddress, APEntry> beacons;

public:

    /** ctor */
    BeaconModelLogDist() {
        ;
    }

    /** get a list of all beacons known to the model */
    std::vector<Beacon> getAllBeacons() const {
        std::vector<Beacon> aps;
        for (const auto it : beacons) {aps.push_back(Beacon(it.first));}
        return aps;
    }

    /** make the given beacon (and its parameters) known to the model */
    void addAP(const MACAddress& beacon, const APEntry& params) {

        // sanity check
        Assert::isBetween(params.txp, -65.0f, -30.0f, "TXP out of bounds [-65:-30]");
        Assert::isBetween(params.exp, 1.0f, 5.0f, "EXP out of bounds [1:5]");

        // add
        beacons.insert( std::pair<MACAddress, APEntry>(beacon, params) );

    }

    void updateBeacon(const BeaconMeasurement beacon) override{
        // try to get the corresponding parameters
        const auto it = beacons.find(MACAddress(beacon.getBeacon().getMAC()));

        // beacon unknown? -> NAN
        if (it == beacons.end()) {return;}

        it->second.txp = beacon.getBeacon().getTXP();
    }

    virtual float getRSSI(const MACAddress& beacon, const Point3 position_m) const override {

        // try to get the corresponding parameters
        const auto it = beacons.find(beacon);

        // AP unknown? -> NAN
        if (it == beacons.end()) {return NAN;}

        // the beacons' parameters
        const APEntry& params = it->second;

        // free-space (line-of-sight) RSSI
        const float distance_m = position_m.getDistance(params.position_m);
        const float rssiLOS = LogDistanceModel::distanceToRssi(params.txp, params.exp, distance_m);

        // done
        return rssiLOS;

    }

};

#endif // BEACONMODELLOGDIST_H