/*****************************************************************************
 * 
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2007 Artem Pavlenko
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/
// $Id$

// network
#include  <netdb.h>
#include  <arpa/inet.h>
#include  <netinet/in.h>
#include  <sys/socket.h>
#include  <sys/types.h>
#include  <sys/stat.h>
#include  <fcntl.h>
#include  <unistd.h>
#include  <stdio.h>

// mapnik
#include <mapnik/ptree_helpers.hpp>

// boost
#include <boost/algorithm/string.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/tokenizer.hpp>
#include <boost/bind.hpp>
#include <boost/make_shared.hpp>

#include "kismet_datasource.hpp"
#include "kismet_featureset.hpp"

#define MAX_TCP_BUFFER 4096 // maximum accepted TCP data block size

// If you change this also change the according kismet command length !
#define MAX_KISMET_LINE 1024 // maximum length of a kismet command (assumed)
#define KISMET_COMMAND  "*NETWORK: \001%1024[^\001]\001 %1024s %d %lf %lf"

using boost::lexical_cast;
using boost::bad_lexical_cast;

using mapnik::datasource;
using mapnik::parameters;

DATASOURCE_PLUGIN(kismet_datasource)

using mapnik::box2d;
using mapnik::coord2d;
using mapnik::query;
using mapnik::featureset_ptr;
using mapnik::layer_descriptor;
using mapnik::attribute_descriptor;
using mapnik::datasource_exception;

boost::mutex knd_list_mutex;
std::list<kismet_network_data> knd_list;
const unsigned int queue_size = 20;

kismet_datasource::kismet_datasource(parameters const& params, bool bind)
    : datasource(params),
      extent_(),
      extent_initialized_(false),
      type_(datasource::Vector),
      desc_(*params.get<std::string>("type"), *params.get<std::string>("encoding","utf-8"))
{
    boost::optional<std::string> host = params_.get<std::string>("host");
    if (host) {
        host_ = *host;
    } else {
        throw datasource_exception("Kismet Plugin: missing <host> parameter");
    }
  
    boost::optional<unsigned int> port = params_.get<unsigned int>("port", 2501);
    if (port) port_ = *port;

    boost::optional<std::string> ext = params_.get<std::string>("extent");
    if (ext) extent_initialized_ = extent_.from_string(*ext);

    kismet_thread.reset (new boost::thread (boost::bind (&kismet_datasource::run, this, host_, port_)));

    if (bind)
    {
        this->bind();
    }
}

void kismet_datasource::bind() const
{
    if (is_bound_) return;
       
    is_bound_ = true;
}

kismet_datasource::~kismet_datasource()
{
}

std::string kismet_datasource::name()
{
    return "kismet";
}

int kismet_datasource::type() const
{
    return type_;
}

box2d<double> kismet_datasource::envelope() const
{
    if (!is_bound_) bind();
    return extent_;
}

layer_descriptor kismet_datasource::get_descriptor() const
{
    return desc_;
}

featureset_ptr kismet_datasource::features(query const& q) const
{
    if (!is_bound_) bind();
    
    //cout << "kismet_datasource::features()" << endl;
    
    // TODO: use box2d to filter bbox before adding to featureset_ptr
    //mapnik::box2d<double> const& e = q.get_bbox();

    boost::mutex::scoped_lock lock(knd_list_mutex);
    return boost::make_shared<kismet_featureset>(knd_list, desc_.get_encoding());

    // TODO: if illegal:
    // return featureset_ptr();
}

featureset_ptr kismet_datasource::features_at_point(coord2d const& pt) const
{
    if (!is_bound_) bind();
    
    //cout << "kismet_datasource::features_at_point()" << endl;

    return featureset_ptr();
}

void kismet_datasource::run (const std::string &ip_host, const unsigned int port)
{
#ifdef MAPNIK_DEBUG
    std::clog << "Kismet Plugin: enter run" << std::endl;
#endif
  
    int sockfd, n;
    struct sockaddr_in sock_addr;
    struct in_addr inadr;
    struct hostent* host;
    char buffer[MAX_TCP_BUFFER]; // TCP data send from kismet_server
    std::string command;

    if (inet_aton(ip_host.c_str (), &inadr))
    {
        host = gethostbyaddr((char *) &inadr, sizeof(inadr), AF_INET);
    }  
    else
    {
        host = gethostbyname(ip_host.c_str ());
    }

    if (host == NULL)
    {
        herror ("Kismet Plugin: Error while searching host");
        return;
    }

    sock_addr.sin_family = AF_INET;
    sock_addr.sin_port = htons(port);
    memcpy(&sock_addr.sin_addr, host->h_addr_list[0], sizeof(sock_addr.sin_addr));

    if ( (sockfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
    {
        std::cerr << "Kismet Plugin: error while creating socket" << std::endl;
        return;
    }

    if (connect(sockfd, (struct sockaddr *) &sock_addr, sizeof(sock_addr)))
    {
        std::cerr << "KISMET Plugin: Error while connecting" << std::endl;
        return;
    }

    command = "!1 ENABLE NETWORK ssid,bssid,wep,bestlat,bestlon\n";

    if (write(sockfd, command.c_str (), command.length ()) != (signed) command.length ())
    {
        std::cerr << "KISMET Plugin: Error sending command to " << ip_host << std::endl;
        close(sockfd);
        return;
    }

    char ssid[MAX_KISMET_LINE] = {};
    char bssid[MAX_KISMET_LINE] = {};
    double bestlat = 0;
    double bestlon = 0;
    int crypt = crypt_none;
  
    // BUG: if kismet_server is active sending after mapnik was killed and then restarted the 
    // assert is called. Needs to be analyzed!
    while ((n = read(sockfd, buffer, sizeof(buffer))) > 0)
    {
        assert (n < MAX_TCP_BUFFER);
    
        buffer[n] = '\0';
        std::string bufferObj (buffer); // TCP data send from kismet_server as STL string
    
#ifdef MAPNIK_DEBUG
        std::clog << "Kismet Plugin: buffer_obj=" << bufferObj << "[END]" << std::endl;
#endif
    
        std::string::size_type found = 0;
        std::string::size_type search_start = 0;
        std::string kismet_line; // contains a line from kismet_server
        do 
        {
            found = bufferObj.find ('\n', search_start);
            if (found != std::string::npos)
            {
                kismet_line.assign (bufferObj, search_start, found - search_start);

#ifdef MAPNIK_DEBUG
                std::clog << "Kismet Plugin: line=" << kismet_line << " [ENDL]" << std::endl;
#endif
        
                int param_number = 5; // the number of parameters to parse
        
                // Attention: string length specified to the constant!
                if (sscanf (kismet_line.c_str (),
                            KISMET_COMMAND,
                            ssid,
                            bssid,
                            &crypt,
                            &bestlat,
                            &bestlon) == param_number)
                {
#ifdef MAPNIK_DEBUG
                    std::clog << "Kismet Plugin: ssid=" << ssid << ", bssid=" << bssid
                        << ", crypt=" << crypt << ", bestlat=" << bestlat << ", bestlon=" << bestlon << std::endl;
#endif

                    kismet_network_data knd (ssid, bssid, bestlat, bestlon, crypt);
          
                    boost::mutex::scoped_lock lock(knd_list_mutex);
                      
                    // the queue only grows to a max size
                    if (knd_list.size () >= queue_size)
                    {
                        knd_list.pop_front ();
                    }
          
                    knd_list.push_back (knd);
                }  
                else
                {
                    // do nothing if not matched!
                }

                search_start = found + 1;      
            }
        }
        while (found != std::string::npos);
    }

    if (n < 0)
    {
        std::cerr << "Kismet Plugin: error while reading from socket" << std::endl;
    }

    close(sockfd);

#ifdef MAPNIK_DEBUG
    std::clog << "Kismet Plugin: exit run" << std::endl;
#endif
}