/*
 * © 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 WIFIGRIDESTIMATOR_H
#define WIFIGRIDESTIMATOR_H

#include "../../grid/Grid.h"
#include "model/WiFiModel.h"
#include "WiFiGridNode.h"
#include "../../Assertions.h"
#include "../../floorplan/v2/Floorplan.h"

#include <fstream>

/**
 * estimates the signal-strength for all APs at a given GridNode
 * and stores this precalculated value onto the node
 */
class WiFiGridEstimator {

public:


//	/**
//	 * convenience method
//	 */
//	template <typename Node> static void estimate(Grid<Node>& grid, WiFiModel& mdl, const Floorplan::IndoorMap* im) {

//		// list of all APs
//		std::vector<LocatedAccessPoint> aps;
//		for (const Floorplan::Floor* f : im->floors) {
//			for (const Floorplan::AccessPoint* ap : f->accesspoints) {
//				aps.push_back(LocatedAccessPoint(*ap));
//			}
//		}

//		// perform estimation
//		estimate(grid, mdl, aps);

//	}

	/**
	 * perform a signal-strength estimation for all of the given access points
	 * using the provided signal-strength prediction model.
	 * store the estimated strength onto each node.
	 * as nodes only provide a limited number of rssi-entries,
	 * store only the strongest ones.
	 *
	 * as the smartphone is held above the ground, we do NOT want to estimate
	 * the signal strength for the nodes (on the ground) but for the nodes
	 * + the height the smartphone is held at
	 *
	 */
	template <typename Node> static void estimate(Grid<Node>& grid, WiFiModel& mdl, const float smartphoneAtHeight) {

		// sanity checks
		Assert::isTrue(Node::getMapAPs().empty(), "there are already APs stored on the grid nodes!");

		// all APs known to the model
		std::vector<AccessPoint> aps = mdl.getAllAPs();

		// attach each access-points to a vector shared for all grid-nodes
		for (const AccessPoint& ap : aps) {
			Node::getMapAPs().push_back(ap);
		}

		// smartphone offset (meter above ground)
		const Point3 smartphoneOffset(0,0,smartphoneAtHeight);

		// process each node
		for (Node& n : grid) {

			// keep the strongest APs to attach to this node
			std::vector<WiFiGridNodeAP> nodeAPs;

			// process each AP known to the model
			for (int apIdx = 0; apIdx < (int) aps.size(); ++apIdx) {

				// estimate the signal-strength
				const float rssi = mdl.getRSSI(aps[apIdx].getMAC(), n.inMeter() + smartphoneOffset);

				// (temporarily) keep it
				nodeAPs.push_back(WiFiGridNodeAP(apIdx, rssi));

			}

			// now sort all the visible APs by signal strength
			auto comp = [] (const WiFiGridNodeAP& ap1, const WiFiGridNodeAP& ap2) {return ap1.getRSSI() > ap2.getRSSI();};
			std::sort(nodeAPs.begin(), nodeAPs.end(), comp);

			// and finally attach the strongest X to the node
			const int cnt = std::min( n.getMaxAPs(), (int) nodeAPs.size() );
			for (int i = 0; i < cnt; ++i) {
				n.strongestAPs[i] = nodeAPs[i];
			}

		}

	}


	/** gnuplot visualization dump for the given AP */
	template <typename Node> static void dump(Grid<Node>& grid, const std::string& mac, const std::string& filename) {

		std::ofstream out(filename);
		out << "splot '-' with points palette \n";

		for (Node& n : grid) {
			out << n.x_cm << " " << n.y_cm << " " << n.z_cm << " " << n.getRSSI(mac) << "\n";
		}
		out << "e\n";
		out.close();

	}

};

#endif // WIFIGRIDESTIMATOR_H