#ifndef WIFIFINGERPRINT_H
#define WIFIFINGERPRINT_H


#include "../../../geo/Point3.h"
#include "../WiFiMeasurements.h"

#include <unordered_map>

/**
 * denotes a wifi fingerprint
 * known position and several measurements conducted at this position
 *
 * as several measurements were conducted, each AP is usually contained more than once!
 */
struct WiFiFingerprint {


	/** real-world-position that was measured */
	Point3 pos_m;

	/** measurements (APs) at the given location */
	WiFiMeasurements measurements;


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

	/** ctor */
	WiFiFingerprint(const Point3 pos_m) : pos_m(pos_m) {;}



	/** as each AP is contained more than once (scanned more than once), group them by MAC and use the average RSSI */
	WiFiMeasurements average() {

		// group scans by MAC (all measurements for one AP)
		std::unordered_map<MACAddress, WiFiMeasurements> group;
		for (WiFiMeasurement& m : measurements.entries) {
			group[m.getAP().getMAC()].entries.push_back(m);
		}

		// create the output that contains the AP's average
		WiFiMeasurements res;
		for (auto& it : group) {
			const WiFiMeasurements& apMeasurements = it.second;
			WiFiMeasurement avg = apMeasurements.entries.front();			// average starts with a copy of the first entry (to get all data-fields beside the rssi)
			for (int i = 1; i < (int)apMeasurements.entries.size(); ++i) {		// sum up all other entries [1:end]
                avg.setRssi(avg.getRSSI() + apMeasurements.entries[i].getRSSI());
			}
            avg.setRssi(avg.getRSSI() / apMeasurements.entries.size());
			res.entries.push_back(avg);										// add to output
		}

		// done
		return res;

	}

	/** serialize */
	void write(std::ostream& out) const {
		out << "pos: " << pos_m.x << " " << pos_m.y << " " << pos_m.z << "\n";
		out << "num: " << measurements.entries.size() << "\n";
		for (const WiFiMeasurement& wm : measurements.entries) {
            out << wm.getTimestamp().ms() << " " << wm.getAP().getMAC().asString() << " " << wm.getRSSI() << "\n";
		}
	}

	/** deserialize */
	void read(std::istream& inp) {
		std::string tmp;

		// read the position
		inp >> tmp; if ("pos:" != tmp) {throw "error";}
		inp >> pos_m.x >> pos_m.y >> pos_m.z;

		// number of entries
		inp >> tmp; if ("num:" != tmp) {throw "error";}
		int numEntries; inp >> numEntries;

		// read the entries
		for (int i = 0; i < numEntries; ++i) {
			uint64_t ms; inp >> ms;
			std::string mac; inp >> mac;
			float rssi; inp >> rssi;
			WiFiMeasurement wm(AccessPoint(MACAddress(mac)), rssi, Timestamp::fromMS(ms));
			measurements.entries.push_back(wm);
		}

	}

};

#endif // WIFIFINGERPRINT_H