package de.gurkengewuerz.postfix_rest_send.objects;

import de.gurkengewuerz.postfix_rest_send.Main;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Timer;
import java.util.TimerTask;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Created by gurkengewuerz.de on 13.07.2017.
 */
public class BruteforceFilter {
    private final HashMap<String, Integer> attempts = new HashMap<>();
    private int maxAttemps = 3;

    public BruteforceFilter(int maxAttemps) {
        this.maxAttemps = maxAttemps;
        Timer t = new Timer();
        t.scheduleAtFixedRate(new TimerTask() {
            @Override
            public void run() {
                try {
                    refresh();
                } catch (SQLException e) {
                    Logger.getLogger(BruteforceFilter.class.getName()).log(Level.SEVERE, null, e);
                }
            }
        }, 0, 2 * 60 * 1000);
    }

    public BruteforceFilter() {
        this(3);
    }

    private void refresh() throws SQLException {
        ResultSet rs = Main.getDatabase().executeQuery("SELECT ip, COUNT(*) count FROM token_bruteforce WHERE occurred > ? GROUP BY ip ORDER BY COUNT(*) DESC;", (System.currentTimeMillis() / 1000) - (24 * 60 * 60));
        synchronized (attempts) {
            attempts.clear();
            while (rs.next()) {
                attempts.put(rs.getString("ip"), rs.getInt("count"));
            }
        }
        if (Main.getConfig().debug())
            Logger.getLogger(getClass().getName()).log(Level.INFO, "refreshed bans (" + attempts.size() + ")");
    }

    public void failed(String ip) {
        if (Main.getConfig().getBoolean("disable_bruteforcefilter")) return;
        Main.getDatabase().executeUpdate("INSERT INTO token_bruteforce (ip, occurred) VALUES (?, ?);", ip, System.currentTimeMillis() / 1000);
        synchronized (attempts) {
            if (attempts.containsKey(ip)) {
                attempts.replace(ip, attempts.get(ip) + 1);
            } else {
                attempts.put(ip, 1);
            }
            if (Main.getConfig().debug())
                Logger.getLogger(getClass().getName()).log(Level.INFO, "banned " + ip + " attemp " + attempts.get(ip));
        }
    }

    public boolean banned(String ip) {
        if (Main.getConfig().getBoolean("disable_bruteforcefilter")) return false;
        synchronized (attempts) {
            return attempts.containsKey(ip) && attempts.get(ip) >= maxAttemps;
        }
    }
}