/*
 * Copyright (c) 2015 Christopher M. Baker
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

var child_process = require('child_process');

/**
 * The **udhcpc** command is used to configure a dhcp client for a
 * network interface.
 *
 * @static
 * @category udhcpc
 *
 */
var udhcpc = module.exports = {
  exec: child_process.exec,
  disable: disable,
  enable: enable
};

/**
 * The **udhcpc disable** command is used to stop a dhcp client on a
 * specific network interface.
 *
 * @static
 * @category udhcpc
 * @param {string} interface The network interface.
 * @param {function} callback The callback function.
 * @returns {process} The child process.
 * @example
 *
 * var udhcpc = require('wireless-tools/udhcpc');
 *
 * udhcpc.disable('wlan0', function(err) {
 *   // the dhcp client was stopped
 * });
 *
 */
function disable(interface, callback) {
  var command = 'kill `pgrep -f "^udhcpc -i ' + interface + '"` || true';
  return this.exec(command, callback);
}

/**
 * The **udhcpc enable** command is used to start a dhcp client on a
 * specific network interface.
 *
 * @static
 * @category udhcpc
 * @param {object} options The dhcp client configuration.
 * @param {function} callback The callback function.
 * @returns {process} The child process.
 * @example
 *
 * var udhcpc = require('wireless-tools/udhcpc');
 *
 * var options = {
 *   interface: 'wlan0'
 * };
 *
 * udhcpc.enable(options, function(err) {
 *   // the dhcp client was started 
 * });
 *
 */
function enable(options, callback) {
  var command = 'udhcpc -i ' + options.interface + ' -n';
  return this.exec(command, callback);  
}