<?php

/* Wifi Hotspot app for YunoHost 
 * Copyright (C) 2015 Julien Vaubourg <julien@vaubourg.com>
 * Contribute at https://github.com/jvaubourg/hotspot_ynh
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program 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 Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

function moulinette_get($var) {
  return htmlspecialchars(exec('sudo yunohost app setting hotspot '.escapeshellarg($var)));
}

function moulinette_set($var, $value) {
  return exec('sudo yunohost app setting hotspot '.escapeshellarg($var).' -v '.escapeshellarg($value));
}

function stop_service() {
  exec('sudo service ynh-hotspot stop');
}

function start_service() {
  exec('sudo service ynh-hotspot start', $output, $retcode);

  return $retcode;
}

function service_status() {
  exec('sudo service ynh-hotspot status', $output);

  return $output;
}

function service_faststatus() {
  exec('sudo service hostapd status', $output, $retcode);

  return $retcode;
}

function ipv6_expanded($ip) {
  exec('ipv6_expanded '.escapeshellarg($ip), $output);

  return $output[0];
}

function ipv6_compressed($ip) {
  exec('ipv6_compressed '.escapeshellarg($ip), $output);

  return $output[0];
}

function is_connected_through_hotspot($ip6_net, $ip4_nat_prefix) {
  $ip = $_SERVER['REMOTE_ADDR'];
  $ip6_regex = '/^'.preg_quote(preg_replace('/::$/', '', $ip6_net)).':/';
  $ip4_regex = '/^'.preg_quote($ip4_nat_prefix).'\./';

  return (preg_match($ip6_regex, $ip) || preg_match($ip4_regex, $ip));
}

dispatch('/', function() {
  exec('sudo iwconfig', $devs);
  $wifi_device = moulinette_get('wifi_device');
  $devs_list = '';

  foreach($devs AS $dev) {
    if(preg_match('/802.11/', $dev)) {
      $dev = explode(' ', $dev);
      $dev = $dev[0];

      $active = ($dev == $wifi_device) ? 'class="active"' : '';
      $devs_list .= "<li $active><a href='#'>$dev</a></li>\n";
    }
  }

  $ip6_net = moulinette_get('ip6_net');
  $ip6_net = ($ip6_net == 'none') ? '' : $ip6_net;
  $ip4_nat_prefix = moulinette_get('ip4_nat_prefix');

  set('service_enabled', moulinette_get('service_enabled'));
  set('wifi_ssid', moulinette_get('wifi_ssid'));
  set('wifi_secure', moulinette_get('wifi_secure'));
  set('wifi_passphrase', moulinette_get('wifi_passphrase'));
  set('wifi_channel', moulinette_get('wifi_channel'));
  set('wifi_n', moulinette_get('wifi_n'));
  set('wifi_device', $wifi_device);
  set('wifi_device_list', $devs_list);
  set('ip6_net', $ip6_net);
  set('ip6_dns0', moulinette_get('ip6_dns0'));
  set('ip6_dns1', moulinette_get('ip6_dns1'));
  set('ip4_nat_prefix', $ip4_nat_prefix);
  set('ip4_dns0', moulinette_get('ip4_dns0'));
  set('ip4_dns1', moulinette_get('ip4_dns1'));
  set('faststatus', service_faststatus() == 0);
  set('is_connected_through_hotspot', is_connected_through_hotspot($ip6_net, $ip4_nat_prefix));

  return render('settings.html.php');
});

dispatch_put('/settings', function() {
  exec('ip link show '.escapeshellarg($_POST['wifi_device']), $output, $retcode);
  $wifi_device_exists = ($retcode == 0);

  $ip6_net = empty($_POST['ip6_net']) ? 'none' : $_POST['ip6_net'];
  $ip6_addr = 'none';
  $ip6_dns0 = $_POST['ip6_dns0'];
  $ip6_dns1 = $_POST['ip6_dns1'];
  $service_enabled = isset($_POST['service_enabled']) ? 1 : 0;
  $wifi_secure = isset($_POST['wifi_secure']) ? 1 : 0;

  if($service_enabled == 1) {
    try {
      if(empty($_POST['wifi_ssid']) || empty($_POST['wifi_passphrase']) || empty($_POST['wifi_channel'])) {
        throw new Exception(T_('Your Wifi Hotspot needs a name, a password and a channel'));
      }
  
      if(strlen($_POST['wifi_passphrase']) < 8 || strlen($_POST['wifi_passphrase']) > 63) {
        throw new Exception(T_('Your password must from 8 to 63 characters (WPA2 passphrase)'));
      }
  
      if(preg_match('/[^[:print:]]/', $_POST['wifi_passphrase'])) {
        throw new Exception(T_('Only printable ASCII characters are permitted in your password'));
      }
  
      if(!$wifi_device_exists) {
        throw new Exception(T_('The wifi antenna interface seems not exist on the system'));
      }
  
      if($ip6_net != 'none') {
        $ip6_net = ipv6_expanded($ip6_net);
    
        if(empty($ip6_net)) {
          throw new Exception(T_('The IPv6 Delegated Prefix format looks bad'));
        }
    
        $ip6_blocs = explode(':', $ip6_net);
        $ip6_addr = "${ip6_blocs[0]}:${ip6_blocs[1]}:${ip6_blocs[2]}:${ip6_blocs[3]}:${ip6_blocs[4]}:${ip6_blocs[5]}:${ip6_blocs[6]}:42";
    
        $ip6_net = ipv6_compressed($ip6_net);
        $ip6_addr = ipv6_compressed($ip6_addr);
      }
  
      if(!empty($ip6_dns0)) {
        $ip6_dns0 = ipv6_expanded($ip6_dns0);
  
        if(empty($ip6_dns0)) {
          throw new Exception(T_('The format of the first IPv6 DNS Resolver looks bad'));
        }

        $ip6_dns0 = ipv6_compressed($ip6_dns0);

        if(!empty($ip6_dns1)) {
          $ip6_dns1 = ipv6_expanded($ip6_dns1);
    
          if(empty($ip6_dns1)) {
             throw new Exception(T_('The format of the second IPv6 DNS Resolver looks bad'));
          }

          $ip6_dns1 = ipv6_compressed($ip6_dns1);
        }
      }
  
      if(inet_pton($_POST['ip4_dns0']) === false) {
        throw new Exception(T_('The format of the first IPv4 DNS Resolver looks bad'));
      }
  
      if(inet_pton($_POST['ip4_dns1']) === false) {
        throw new Exception(T_('The format of the second IPv4 DNS Resolver looks bad'));
      }
  
      if(inet_pton("${_POST['ip4_nat_prefix']}.0") === false) {
        throw new Exception(T_('The format of the IPv4 NAT Prefix (/24) looks bad : x.x.x expected)'));
      }
  
      if(filter_var("${_POST['ip4_nat_prefix']}.0", FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE) !== false) {
        throw new Exception(T_('The IPv4 NAT Prefix must be from a private range'));
      }
  
    } catch(Exception $e) {
      flash('error', $e->getMessage().' ('.T_('configuration not updated').').');
      goto redirect;
    }
  }

  stop_service();

  moulinette_set('service_enabled', $service_enabled);

  if($service_enabled == 1) {
    moulinette_set('wifi_ssid', $_POST['wifi_ssid']);
    moulinette_set('wifi_secure', $wifi_secure);

    if($wifi_secure == 1) {
      moulinette_set('wifi_passphrase', $_POST['wifi_passphrase']);
    }

    moulinette_set('wifi_channel', $_POST['wifi_channel']);
    moulinette_set('wifi_n', isset($_POST['wifi_n']) ? 1 : 0);
    moulinette_set('wifi_device', $_POST['wifi_device']);
    moulinette_set('ip6_net', $ip6_net);
    moulinette_set('ip6_addr', $ip6_addr);
    moulinette_set('ip6_dns0', $_POST['ip6_dns0']);
    moulinette_set('ip6_dns1', $_POST['ip6_dns1']);
    moulinette_set('ip4_nat_prefix', $_POST['ip4_nat_prefix']);
    moulinette_set('ip4_dns0', $_POST['ip4_dns0']);
    moulinette_set('ip4_dns1', $_POST['ip4_dns1']);

    $retcode = start_service();

    if($retcode == 0) {
      flash('success', T_('Configuration updated and service successfully reloaded'));
    } else {
      flash('error', T_('Configuration updated but service reload failed'));
    }

  } else {
      flash('success', T_('Service successfully disabled'));
  }

  redirect:
  redirect_to('/');
});

dispatch('/status', function() {
  $status_lines = service_status();
  $status_list = '';

  foreach($status_lines AS $status_line) {
    if(preg_match('/^\[INFO\]/', $status_line)) {
      $status_list .= '<li class="status-info">'.htmlspecialchars($status_line).'</li>';
    }
    elseif(preg_match('/^\[OK\]/', $status_line)) {
      $status_list .= '<li class="status-success">'.htmlspecialchars($status_line).'</li>';
    }
    elseif(preg_match('/^\[WARN\]/', $status_line)) {
      $status_list .= '<li class="status-warning">'.htmlspecialchars($status_line).'</li>';
    }
    elseif(preg_match('/^\[ERR\]/', $status_line)) {
      $status_list .= '<li class="status-danger">'.htmlspecialchars($status_line).'</li>';
    }
  }

  echo $status_list;
});

dispatch('/lang/:locale', function($locale = 'en') {
  switch ($locale) {
    case 'fr':
      $_SESSION['locale'] = 'fr';
      break;

    default:
      $_SESSION['locale'] = 'en';
  }

  if(!empty($_GET['redirect_to'])) {
    redirect_to($_GET['redirect_to']);
  } else {
    redirect_to('/');
  }
});