package fr.ntr;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.List;
import java.util.Random;

import fr.ntr.scheduler.Scheduler;

public class AccessPoint {
    private List<User> users;
    private Scheduler scheduler;
    /**
     * nombre de slots
     */
    private static int timeSlotNb;
    /**
     * Nombre de sous-porteuses
     */
    private static int subCarrierNb;
    /**
     * trame
     */
    private ResourceBlock[][] frame;
    /**
     * Reste pour la prochaine source
     */
    private double leftForNextSource;
    /**
     * Portée minimum et maximum de l'antenne
     */
    private final double min, max;

    private Random random = new Random();

    private FileOutputStream outputDataFile;

    
    public AccessPoint(Scheduler scheduler, ResourceBlock[][] frame, List<User> users, int timeSlotNb, int subCarrierNb, double min, double max) {
        this.min = min;
        this.max = max;
        this.users = users;
        this.scheduler = scheduler;
        this.frame = frame;
        this.timeSlotNb = timeSlotNb;
        this.subCarrierNb = subCarrierNb;
    }

    /**
     * Lancer la simulation
     * @param duration
     */
    public void startSimulation(int duration) {
        try{
            Files.deleteIfExists(Paths.get("export", this.users.size() + ".csv"));
            new File("export").mkdir();
            this.outputDataFile = new FileOutputStream("export" + File.separator + this.users.size() + ".csv", true);
            outputDataFile.write("tick;x;y;user;bandwidth;\n".getBytes());
        } catch(IOException e) {
            System.err.println(e.getClass().getSimpleName() + " : " + e.getMessage());
            System.exit(1);
            return;
        }
        for (int ticks = 0; ticks < duration; ++ticks) {
            // Simulation
            reset();
            updateBandwidth(ticks);
            schedule(ticks);
            computePacketDelay(ticks);
            // traite les données et les enregistre dans un fichier
            try {
                analyseData(ticks);
            } catch (IOException e) {
                System.out.println("Can't export data");
            }
        }

    }

    private void updateBandwidth(int ticks) {
        int n = 200;
        int timeInterval = Math.max(1, random.nextInt(51)); // avoid div by 0
        for(User user : users) {
            // On régénère le tableau de débits toutes les 50 ms
            if(ticks % 50 == 0){
                user.generateBandwidth();
            }

            // On régénère les sources toutes les 0-50 ms
            if(ticks % timeInterval == 0){
                timeInterval = 50 + random.nextInt(51);
                n = user.createPackets(n, ticks);
            }
        }
    }

    private void schedule(int ticks) {
        scheduler.scheduling(ticks);
    }

    private void analyseData(int tick) throws IOException {
        for(int i = 0; i < frame.length; i++) {
            for(int j = 0; j < frame[i].length; j++) {
                ResourceBlock ur = frame[i][j];
                if(ur.getUser() != null) {
                    String data = (tick + ";" + i + ";" + j + ";" + this.users.indexOf(ur.getUser()) + ";" + ur.getBandwidth() + ";\n");
                    try{
                        outputDataFile.write(data.getBytes());
                    }catch(IOException e){
                        System.err.println("Cannot write the data in the output file");
                        System.exit(1);
                        return;
                    }
                }
            }
        }
    }

    private void reset() {
        // TODO insert new UR
        for(int i = 0; i < timeSlotNb; i++) {
            for(int j = 0; j < subCarrierNb; j++) {
                frame[i][j] = new ResourceBlock(0.0);
            }
        }
    }

    private void computePacketDelay(int ticks){
        for(int i = 0; i < this.users.size(); i++){
            User u = this.users.get(i);
            if(!u.getPacketsToSend().isEmpty()){
                for(Packets p : u.getPacketsToSend()){
                   
                }
            }
        }
    }

    public ResourceBlock[][] getFrame() {
        return frame;
    }

    public static int getTimeSlotNb() {
        return timeSlotNb;
    }

    public static int getSubCarrierNb() {
        return subCarrierNb;
    }
}