package org.ibex.mail;
// todo: periodically flush out old graylist entries

import java.sql.*;
import java.net.*;
import java.io.*;
import java.util.*;
import java.sql.Timestamp;

public class Graylist extends SqliteDB {

    public Graylist(String filename) throws SQLException {
        super(filename);
        SqliteTable whitelist = getTable("whitelist", "(ip unique)");
        SqliteTable graylist  = getTable("graylist",  "(ip,fromaddr,toaddr,date,PRIMARY KEY(ip,fromaddr,toaddr))");
        graylist.reap("date");
    }

    public synchronized void addWhitelist(InetAddress ip) {
        try {
            PreparedStatement add    = conn.prepareStatement("insert or replace into 'whitelist' values(?)");
            add.setString(1, ip.getHostAddress());
            add.executeUpdate();
        } catch (SQLException e) { throw new RuntimeException(e); }
    }

    public synchronized boolean isWhitelisted(InetAddress ip) {
        try {
            PreparedStatement check = conn.prepareStatement("select * from 'whitelist' where ip=?");
            check.setString(1, ip.getHostAddress());
            ResultSet rs = null;
            boolean ret;
            try {
                rs = check.executeQuery();
                ret = !rs.isAfterLast();
            } finally { close(rs); }
            return ret;
        } catch (SQLException e) { throw new RuntimeException(e); }
    }

    public synchronized long getGrayListTimestamp(InetAddress ip, String from, String to) {
        try {
            PreparedStatement check =
                conn.prepareStatement("select date from graylist where ip=? and fromaddr=? and toaddr=?");
            check.setString(1, graylistAddress(ip));
            check.setString(2, from);
            check.setString(3, to);
            ResultSet rs = null;
            try {
                rs = check.executeQuery();
                if (rs.isAfterLast()) return 0;
                return rs.getTimestamp(1).getTime();
            } finally { close(rs); }
        } catch (SQLException e) { throw new RuntimeException(e); }
    }

    public synchronized void setGrayListTimestamp(InetAddress ip, String from, String to, long date) {
        try {
            PreparedStatement check =
                conn.prepareStatement("insert or replace into graylist (ip,fromaddr,toaddr,date) values(?,?,?,?)");
            check.setString(1, graylistAddress(ip));
            check.setString(2, from);
            check.setString(3, to);
            check.setTimestamp(4, new Timestamp(date));
            check.executeUpdate();
        } catch (SQLException e) { throw new RuntimeException(e); }
    }

    //
    // this is mostly to deal with comcast's pathetic retry policy and
    // rotating pool of outbound servers
    // see: http://lists.puremagic.com/pipermail/greylist-users/2006-November/001255.html
    //
    private static String graylistAddress(InetAddress ipa) {
        byte[] ip = ipa.getAddress();
        return
            (ip[0] & 0xff)+"."+
            (ip[1] & 0xff)+"."+
            (ip[2] & 0xff)+"."+
            ".0";
    }

}