#ifndef WIFIMODELLOGDISTCEILING_H
#define WIFIMODELLOGDISTCEILING_H

#include "../../../floorplan/v2/Floorplan.h"

#include "../../../Assertions.h"
#include "WiFiModel.h"
#include "LogDistanceModel.h"

/**
 * signal-strength estimation using log-distance model
 * including ceilings between AP and position
 */
class WiFiModelLogDistCeiling : public WiFiModel {

public:

	/** parameters describing one AP 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)
		float waf;			// attenuation per ceiling/floor (~-8.0)

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

	};

private:

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

	/** position (height) of all ceilings (in meter) */
	std::vector<float> ceilingsAtHeight_m;

public:

	/** ctor */
	WiFiModelLogDistCeiling(const Floorplan::IndoorMap* map) {

		// position of all ceilings
		for (Floorplan::Floor* f : map->floors) {
			ceilingsAtHeight_m.push_back(f->atHeight);
		}

	}

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

		// sanity check
		Assert::isBetween(params.waf, -99.0f, 0.0f, "WAF out of bounds [-99:0]");
		Assert::isBetween(params.txp, -50.0f, -30.0f, "TXP out of bounds [-50:-30]");
		Assert::isBetween(params.exp, 1.0f, 4.0f, "EXP out of bounds [1:4]");

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

	}

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

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

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

		// the access-points' 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);

		// WAF loss (params.waf is a negative value!) -> WAF loss is also a negative value
		const float wafLoss = params.waf * numCeilingsBetween(position_m, params.position_m);

		// combine
		return rssiLOS + wafLoss;

	}



protected:

	FRIEND_TEST(LogDistanceCeilingModel, numCeilings);

	/** get the number of ceilings between z1 and z2 */
	int numCeilingsBetween(const Point3 pos1, const Point3 pos2) const {

		int cnt = 0;
		const float zMin = std::min(pos1.z, pos2.z);
		const float zMax = std::max(pos1.z, pos2.z);

		for (const float z : ceilingsAtHeight_m) {
			if (zMin < z && zMax > z) {++cnt;}
		}

		return cnt;

	}

};


#endif // WIFIMODELLOGDISTCEILING_H