<?php

/**
 * SMTP 邮件类
 */

define('SMTP_STATUS_NOT_CONNECTED', 1, true);
define('SMTP_STATUS_CONNECTED', 2, true);

class smtp
{
 public $connection;
 public $recipients;
 public $headers;
 public $timeout;
 public $errors;
 public $status;
 public $body;
 public $from;
 public $host;
 public $port;
 public $helo;
 public $auth;
 public $user;
 public $pass;

 /**
 * 参数为一个数组
 * host SMTP 服务器的主机 默认:localhost
 * port SMTP 服务器的端口 默认:25
 * helo 发送HELO命令的名称 默认:localhost
 * user SMTP 服务器的用户名 默认:空值
 * pass SMTP 服务器的登陆密码 默认:空值
 * timeout 连接超时的时间 默认:5
 * @return bool
 */
 public function __construct($params = array())
 {
 if (!defined('CRLF')) {
 define('CRLF', "\r\n", true);
 }

 $this->timeout = 10;
 $this->status = SMTP_STATUS_NOT_CONNECTED;
 $this->host = 'localhost';
 $this->port = 25;
 $this->auth = false;
 $this->user = '';
 $this->pass = '';
 $this->errors = array();

 foreach ($params as $key => $value) {
 $this->$key = $value;
 }

 $this->helo = $this->host;

 // 如果没有设置用户名则不验证
 $this->auth = ('' == $this->user) ? false : true;
 }

 public function connect($params = array())
 {
 if (!isset($this->status)) {
 $obj = new smtp($params);

 if ($obj->connect()) {
 $obj->status = SMTP_STATUS_CONNECTED;
 }

 return $obj;
 } else {
 $smtp_ssl = C('smtp_ssl');
 if (!empty($smtp_ssl)) {
 $this->host = "ssl://" . $this->host;
 }
 $this->connection = @fsockopen($this->host, $this->port, $errno, $errstr, $this->timeout);

 if ($this->connection === false) {
 $this->errors[] = 'Access is denied.';

 return false;
 }

 @socket_set_timeout($this->connection, 0, 250000);

 $greeting = $this->get_data();

 if (is_resource($this->connection)) {
 $this->status = 2;

 return $this->auth ? $this->ehlo() : $this->helo();
 } else {
 log_write($errstr, __FILE__, __LINE__);
 $this->errors[] = 'Failed to connect to server: ' . $errstr;

 return false;
 }
 }
 }

 /**
 * 参数为数组
 * recipients 接收人的数组
 * from 发件人的地址,也将作为回复地址
 * headers 头部信息的数组
 * body 邮件的主体
 */

 public function send($params = array())
 {
 foreach ($params as $key => $value) {
 $this->$key = $value;
 }

 if ($this->is_connected()) {
 // 服务器是否需要验证
 if ($this->auth) {
 if (!$this->auth()) {
 return false;
 }
 }

 $this->mail($this->from);

 if (is_array($this->recipients)) {
 foreach ($this->recipients as $value) {
 $this->rcpt($value);
 }
 } else {
 $this->rcpt($this->recipients);
 }

 if (!$this->data()) {
 return false;
 }

 $headers = str_replace(CRLF . '.', CRLF . '..', trim(implode(CRLF, $this->headers)));
 $body = str_replace(CRLF . '.', CRLF . '..', $this->body);
 $body = substr($body, 0, 1) == '.' ? '.' . $body : $body;

 $this->send_data($headers);
 $this->send_data('');
 $this->send_data($body);
 $this->send_data('.');

 return (substr($this->get_data(), 0, 3) === '250');
 } else {
 $this->errors[] = 'Not connected!';

 return false;
 }
 }

 public function helo()
 {
 if (is_resource($this->connection)
 and $this->send_data('HELO ' . $this->helo)
 and substr($error = $this->get_data(), 0, 3) === '250') {
 return true;
 } else {
 $this->errors[] = 'HELO command failed, output: ' . trim(substr($error, 3));

 return false;
 }
 }

 public function ehlo()
 {
 if (is_resource($this->connection)
 and $this->send_data('EHLO ' . $this->helo)
 and substr($error = $this->get_data(), 0, 3) === '250') {
 return true;
 } else {
 $this->errors[] = 'EHLO command failed, output: ' . trim(substr($error, 3));

 return false;
 }
 }

 public function auth()
 {
 if (is_resource($this->connection)
 and $this->send_data('AUTH LOGIN')
 and substr($error = $this->get_data(), 0, 3) === '334'
 and $this->send_data(base64_encode($this->user)) // Send username
 and substr($error = $this->get_data(), 0, 3) === '334'
 and $this->send_data(base64_encode($this->pass)) // Send password
 and substr($error = $this->get_data(), 0, 3) === '235') {
 return true;
 } else {
 $this->errors[] = 'AUTH command failed: ' . trim(substr($error, 3));

 return false;
 }
 }

 public function mail($from)
 {
 if ($this->is_connected()
 and $this->send_data('MAIL FROM:<' . $from . '>')
 and substr($this->get_data(), 0, 2) === '250') {
 return true;
 } else {
 return false;
 }
 }

 public function rcpt($to)
 {
 if ($this->is_connected()
 and $this->send_data('RCPT TO:<' . $to . '>')
 and substr($error = $this->get_data(), 0, 2) === '25') {
 return true;
 } else {
 $this->errors[] = trim(substr($error, 3));

 return false;
 }
 }

 public function data()
 {
 if ($this->is_connected()
 and $this->send_data('DATA')
 and substr($error = $this->get_data(), 0, 3) === '354') {
 return true;
 } else {
 $this->errors[] = trim(substr($error, 3));

 return false;
 }
 }

 public function is_connected()
 {
 return (is_resource($this->connection) and ($this->status === SMTP_STATUS_CONNECTED));
 }

 public function send_data($data)
 {
 if (is_resource($this->connection)) {
 return fwrite($this->connection, $data . CRLF, strlen($data) + 2);
 } else {
 return false;
 }
 }

 public function get_data()
 {
 $return = '';
 $line = '';

 if (is_resource($this->connection)) {
 while (strpos($return, CRLF) === false or $line{3} !== ' ') {
 $line = fgets($this->connection, 512);
 $return .= $line;
 }

 return trim($return);
 } else {
 return '';
 }
 }

 /**
 * 获得最后一个错误信息
 *
 * @access public
 * @return string
 */
 public function error_msg()
 {
 if (!empty($this->errors)) {
 $len = count($this->errors) - 1;
 return $this->errors[$len];
 } else {
 return '';
 }
 }
}