<?php
/** DomFramework
    @package domframework
    @author Dominique Fournier <dominique@fournier38.fr> */

/** Manage the mail content */
class mail
{
  /** The differents parts of the mail. Will be added to multipart/mixed
    */
  private $parts = array ();

  /** The inline parts of HTML body. Will be added to multipart/related
    */
  private $inlineParts = array ();

  /** The displayed part of the mail (the body) in TEXT and/or HTML.
    * This is the alternative part of MIME mails
    * Will be added to multipart/alternative
    */
  private $bodyContent = array ();

  /** The EML part of the body (with the boundaries if needed)
    * Contain the Text and/or HTML part of the body. For HTML, contain the
    * inline parts too
    */
  private $bodyContentEML = "";

  /** The Headers of the Body in an array form. Will be appended to the mail
    * headers if there is no multipart/alternative, or keep in the mail in case
    * of multipart/alternative
    */
  private $bodyHeaders = array ();

  /** The main headers of the mail
    */
  private $headers = array ();

  /** Private the separator between the headers and the mail. Should be
    * \r\n on a line, but special crafted mails may use something else
    */
  private $headerBodySeparator = "\r\n";

  /** The constuctor verify if the external libraries are available
    */
  public function __construct ()
  {
    if (! function_exists ("finfo_buffer"))
      throw new \Exception (_("Missing FileInfo PHP Extension"), 500);
    if (! function_exists ("openssl_random_pseudo_bytes"))
      throw new \Exception (_("Missing OpenSSL PHP Extension"), 500);
    // Define default headers
    $this->setHeader ("Date", date ("r"));
    $this->setHeader ("Message-ID", $this->getMessageID ());
    $user = posix_getpwuid (posix_geteuid());
    $this->setHeader ("From", $user["name"]."@".php_uname('n'));
    $this->setHeader ("MIME-Version", "1.0");
  }

  /** Get the textual mail provided and use it as default
    * @param $textualMail The complete mail to read
    */
  public function readMail ($textualMail)
  {
    // TBD
  }

  /** Define a HTML body. If the HTML body already exists, overwrite it
    * If there is an text body, manage the boundary in alternative mode
    * @param $htmlContent in UTF-8
    * @param $charset to be stored in the mail
    * @param $encoding the encoding in the mail
    */
  public function setBodyHTML ($htmlContent, $charset="utf-8",
                                             $encoding="quoted-printable")
  {
    $oldPart = end ($this->bodyContent);
    if (count ($oldPart) &&
        substr ($oldPart["Content-Type"], 0, 9) === "text/html")
    {
      // There is already a html body. Remove it to create a new one
      array_pop ($this->bodyContent);
    }
    $htmlContent = iconv ("utf-8", $charset, $htmlContent);
    $part["_charset"] = $charset;
    $part["_content"] = $this->encodingEncode ($htmlContent, $encoding);
    $part["Content-Type"] = "text/html; charset=$charset";
    $part["Content-Transfer-Encoding"] = $encoding;
    // Order the HTML after the text if exists
    array_push ($this->bodyContent, $part);
    $this->createBodyEML ();
  }

  /** Add a Text body. If the text body already exists, overwrite it
    * If there is an HTML body, manage the boundary in alternative mode
    * @param $textContent in UTF-8
    * @param $charset to be stored in the mail
    * @param $encoding the encoding in the mail
    */
  public function setBodyText ($textContent, $charset="utf-8",
                                             $encoding="quoted-printable")
  {
    if (isset ($this->bodyContent[0]) &&
        substr ($this->bodyContent[0]["Content-Type"], 0, 10) === "text/plain")
    {
      // There is already a text body. Remove it to create a new one
      unset ($this->bodyContent[0]);
    }
    $textContent = iconv ("utf-8", $charset, $textContent);
    $part["_charset"] = $charset;
    $part["Content-Type"] = "text/plain; charset=$charset";
    $part["Content-Transfer-Encoding"] = $encoding;
    $part["_content"] = $this->encodingEncode ($textContent, $encoding);
    // Order the text before the html if exists
    array_unshift ($this->bodyContent, $part);
    $this->createBodyEML ();
  }

  /** Return the HTML body if exists in UTF-8. If the body is not in UTF-8, it
    * is converted
    * Return false if it doesn't exists
    */
  public function getBodyHTML ()
  {
    foreach ($this->bodyContent as $part)
    {
      if (substr ($part["Content-Type"], 0, 9) === "text/html")
      {
        $body = $this->encodingDecode ($part["_content"],
                                       $part["Content-Transfer-Encoding"]);
        return iconv ($part["_charset"], "UTF-8", $body);
      }
    }
    return false;
  }

  /** Get the text body if exists in UTF-8. If the body is not in UTF-8, it is
    * converted
    * Return false if it doesn't exists
    */
  public function getBodyText ()
  {
    foreach ($this->bodyContent as $part)
    {
      if (substr ($part["Content-Type"], 0, 10) === "text/plain")
      {
        $body = $this->encodingDecode ($part["_content"],
                                       $part["Content-Transfer-Encoding"]);
        return iconv ($part["_charset"], "UTF-8", $body);
      }
    }
    return false;
  }

  /** Add an attachment to the mail.
    * The allowed encodings are "quoted-printable" or "base64"
    */
  public function addAttachment ($name, $fileContent, $encoding="base64")
  {
    $finfo = new \finfo(FILEINFO_MIME);
    $mimetype = $finfo->buffer($fileContent);
    $part["Content-Type"] = "$mimetype; name=$name\r\n";
    $part["Content-Disposition"] = "attachment; filename=$name\r\n";
    $part["Content-Transfer-Encoding"] = "$encoding\r\n";
    $part["_name"] = $name;
    $part["_content"] = $this->encodingEncode ($fileContent, $encoding);
    $part["_mimetype"] = $mimetype;
    $part["_sizeReal"] = strlen ($fileContent);
    array_push ($this->parts, $part);
  }

  /** Add an inline attachment to the mail.
    * The allowed encodings are "quoted-printable" or "base64"
    * Return the Content-ID needed to be used in HTML page like :
    * <img src='cid:XXXXXXXXXX'/>
    */
  public function addAttachmentInline ($name, $fileContent,  $encoding="base64")
  {
    $finfo = new \finfo(FILEINFO_MIME);
    $mimetype = $finfo->buffer($fileContent);
    $part["Content-Type"] = "$mimetype; name=$name\r\n";
    $contentID = $this->getMessageID ();
    $part["Content-ID"] = "$contentID\r\n";
    $part["Content-Disposition"] = "inline; filename=$name\r\n";
    $part["Content-Transfer-Encoding"] = "$encoding\r\n";
    $part["_name"] = $name;
    $part["_content"] = $this->encodingEncode ($fileContent, $encoding);
    $part["_mimetype"] = $mimetype;
    $part["_sizeReal"] = strlen ($fileContent);
    array_push ($this->inlineParts, $part);
    $this->createBodyEML ();
    return substr ($contentID, 1, -1);
  }

  /** Get an attachment of the mail
    * @param $number the number of attach to get starting to 0
    * @return the content of the attachment. Can be binary
    */
  public function getAttachment ($number)
  {
    if (! array_key_exists ($number, $this->parts))
      throw new \Exception (_("Attachment not found"), 404);
    $part = $this->parts[$number];
    return $this->encodingDecode ($part["_content"],
                                  $part["Content-Transfer-Encoding"]);
  }

  /** Get the attachment details
    * @param $number the number of attach to get starting to 0
    * @return array containing the information of the attachment
    */
  public function getAttachmentDetails ($number)
  {
    if (! array_key_exists ($number, $this->parts))
      throw new \Exception (sprintf (_("Attachment '%d' not found"), $number),
                            404);
    $part = $this->parts[$number];
    $res = array ();
    foreach ($part as $key=>$val)
    {
      if ($key{0} === "_" && $key !== "_content")
        $res[substr ($key, 1)] = $val;
    }
    return $res;
  }

  /** Add a To: header. If it already exists, add a new recipient*/
  public function addTo ($toMail, $toName)
  {
    if (strspn ($toName, "abcdefghijklmnopqrstuvwxyz".
                         "ABCDEFGHIJKLMNOPQRSTUVWXYZ".
                         "0123456789 -_") !== strlen ($toName))
      $toName = $this->encodeHeaders ("From", $toName,
                                      "quoted-printable");
    $toField = "$toName <$toMail>";
    if (array_key_exists ("To", $this->headers))
      $this->setHeader ("To", $this->getHeaderValue ("To").",\r\n    $toField");
    else
      $this->setHeader ("To", $toField);
  }

  /** Get the To Header as it is written in the mail */
  public function getTo ()
  {
    return $this->headers["To"];
  }

  /** Add a From: header. If it already exists, overwrite the existing one*/
  public function setFrom ($fromMail, $fromName)
  {
    if (strspn ($fromName, "abcdefghijklmnopqrstuvwxyz".
                           "ABCDEFGHIJKLMNOPQRSTUVWXYZ".
                           "0123456789 -_") !== strlen ($fromName))
      $fromName = $this->encodeHeaders ("From", $fromName,
                                        "quoted-printable");
    $this->setHeader ("From", "$fromName <$fromMail>");
  }

  /** Return the From header as it is written in the mail */
  public function getFrom ()
  {
    return $this->headers["From"];
  }

  /** Return the From header converted to array with mail and name keys */
  public function getFromArray ()
  {
    $res = array ();
    $from = $this->decodeHeaders ("From", $this->headers["From"]);
    return reset ($this->convertPeopleToArray ($from));
  }

  /** Set the Date
    * @param $date In RFC 2822 format
    */
  public function setDate ($date)
  {
    // TODO : Check if the date format is valid
    $this->setHeader ("Date", $date);
  }

  /** Set the Date
    * @param $date In Timestamp format
    */
  public function setDateTimestamp ($timestamp)
  {
    // TODO : Check if the timestamp is valid
    $this->setHeader ("Date", date ("r", $timestamp));
  }

  /** Return the Date header if defined.
      Return false if not defined */
  public function getDate ()
  {
    return $this->getHeader ("Date");
  }

  /** Return the Date header (if defined) in timestamp
    * Return false if not defined */
  public function getDateTimestamp ()
  {
    $datetimestamp = false;
    $date = rtrim ($this->getDate ());
    if ($date !== false)
    {
      $dateTimestamp = DateTime::createFromFormat (DateTime::RFC2822,
                                                   $date);
      if ($dateTimestamp === false)
        $dateTimestamp = DateTime::createFromFormat (DateTime::RFC822,
                                                     $date);
      if ($dateTimestamp !== false)
        $dateTimestamp  = $dateTimestamp->getTimestamp();
    }
    return $dateTimestamp;
  }

  /** Set a generic header
    * @param $header The name of the Header (without colon)
    * @param $value The value the store. The format must be correct !
    */
  public function setHeader ($header, $value)
  {
    if (substr ($value, -1) !== "\n" &&
        substr ($value, -1) !== "\r" &&
        substr ($value, -2) !== "\r\n")
      $value .= "\r\n";
    $this->headers[$header] = $value;
  }

  /** Delete a specific header
    * @param $header The header to remove
    */
  public function delHeader ($header)
  {
    unset ($this->headers[$header]);
  }

  /** Get a generic header
    * @param $header The header to get
    * @return the literal value or false if it doesn't exist
    */
  public function getHeader ($header)
  {
    if (! isset ($this->headers[$header]))
      return false;
    return $this->headers[$header];
  }

  /** Get a generic header with removing the carraige return
    *@param $header The header to get
    * @return the literal value or false if it doesn't exist
    */
  public function getHeaderValue ($header)
  {
    if (! isset ($this->headers[$header]))
      return false;
    if (substr ($this->headers[$header], -1) !== "\n" &&
        substr ($this->headers[$header], -1) !== "\r")
      return substr ($this->headers[$header], 0, -1);
    return substr ($this->headers[$header], 0, -2);
  }

  /** Create the Body EML part for HTML
    * @param $bodyContentHTML the $this->part corresponding to HTML Body
    * @return the EML part for HTML with multipart/related if needed
    */
  public function createBodyEMLHTML ($bodyContentHTML)
  {
    $html = "";
    if (count ($this->inlineParts))
    {
      $inlineBoundary = $this->getBoundary ();
      $html .= "Content-Type: multipart/related;\r\n".
               "  boundary=\"$inlineBoundary\"\r\n\r\n";
      $html .= "--$inlineBoundary\r\n";
    }
    foreach ($bodyContentHTML as $key=>$val)
    {
      if ($key{0} === "_") continue;
      $html .= "$key: $val\r\n";
    }
    $html .= "\r\n".$bodyContentHTML["_content"]."\r\n";
    foreach ($this->inlineParts as $part)
    {
      $html .= "--$inlineBoundary\r\n";
      foreach ($part as $key=>$val)
      {
        if ($key{0} === "_") continue;
        $html .= "$key: $val";
      }
      $html .= "\r\n".$part["_content"]."\r\n";
    }
    if (count ($this->inlineParts))
    {
      $html .= "--$inlineBoundary--\r\n";
    }
    return $html;
  }

  /** Create the Body EML part
    */
  public function createBodyEML ()
  {
    // Create the alternative/part body for TEXT/HTML part
    $bodyContent = "";
    $bodyHeaders = array ();
    $body = "";
    // TODO : Check if the mail contain only attached file
    if (count ($this->bodyContent) === 0)
      throw new \Exception (_("No content in the mail"), 406);
    elseif (count ($this->bodyContent) === 2)
    {
      // Text + HTML available : manage the alternative part
      $boundary = $this->getBoundary ();
      $bodyHeaders["Content-Type"] = "multipart/alternative;\r\n".
                                     "    boundary=\"$boundary\"\r\n";
      // Store the Text part
      $bodyContent .= "--$boundary\r\n";
      foreach ($this->bodyContent[0] as $key=>$val)
      {
        if ($key{0} === "_") continue;
        $bodyContent .= "$key: $val\r\n";
      }
      $bodyContent .= "\r\n".$this->bodyContent[0]["_content"]."\r\n";

      // Store the HTML part
      $bodyContent .= "--$boundary\r\n";
      $bodyContent .= $this->createBodyEMLHTML ($this->bodyContent[1]);
      $bodyContent .= "--$boundary--\r\n";
    }
    else
    {
      // Text or HTML but not both
      $part = reset ($this->bodyContent);
      if (substr ($part["Content-Type"], 0, 10) === "text/plain")
      {
        // Only TEXT part
        foreach ($part as $key=>$val)
        {
          if ($key{0} === "_")
            $bodyContent = "$val\r\n";
          else
            $bodyHeaders[$key] = "$val\r\n";
        }
        $body .= $bodyContent;
      }
      elseif (substr ($part["Content-Type"], 0, 9) === "text/html")
      {
        // Only HTML part
        foreach ($part as $key=>$val)
        {
          if ($key{0} === "_")
            $bodyContent = "$val\r\n";
          else
            $bodyHeaders[$key] = "$val\r\n";
        }
        $body .= $this->createBodyEMLHTML ($part);
      }
      else
        throw new \Exception (_("No text/plain nor text/html available"),
                              500);
    }

    $this->bodyContentEML = $bodyContent;
    $this->bodyHeaders = $bodyHeaders;
  }

  /** Return the complete mail
    */
  public function getMail ()
  {
    $complete = "";
    if (count ($this->parts) === 0)
    {
      // No attached files available : manage the body in text and/or html
      foreach ($this->headers as $key=>$val)
      {
        $complete .= "$key: $val";
      }
      foreach ($this->bodyHeaders as $key=>$val)
      {
        $complete .= "$key: $val";
      }
      $complete .= $this->headerBodySeparator;
      $complete .= $this->bodyContentEML;
    }
    else
    {
      // Attached files available : the main Content-Type is multipart/mixed;
      $boundary = $this->getBoundary ();
      $this->headers["Content-Type"] = "multipart/mixed;\r\n".
                                       "    boundary=\"$boundary\"\r\n";
      foreach ($this->headers as $key=>$val)
      {
        $complete .= "$key: $val";
      }
      $complete .= $this->headerBodySeparator;
      if ($this->bodyContentEML !== "")
      {
        $complete .= "--$boundary\r\n";
        foreach ($this->bodyHeaders as $key=>$val)
        {
          $complete .= "$key: $val";
        }
        $complete .= $this->headerBodySeparator;
        $complete .= $this->bodyContentEML;
      }
      foreach ($this->parts as $part)
      {
        $complete .= "--$boundary\r\n";
        foreach ($part as $key=>$val)
        {
          if ($key{0} === "_") continue;
          $complete .= "$key: $val";
        }
        $complete .= $this->headerBodySeparator;
        $complete .= $part["_content"];
      }
      $complete .= "--$boundary--\r\n";
    }
    return $complete;
  }

  /** Return an array with the details of the mail :
    * the number of attachments, the from, to, subject in UTF-8, if there is
    * a text and/or html body
    * @return array
    */
  public function getDetails ()
  {
    $attachmentNb = count ($this->parts);
    for ($i = 0 ; $i < count ($this->parts) ; $i ++)
      $attachmentDetails[$i] = $this->getAttachmentDetails($i);
    unset ($i);
    $bodyTextExists = (isset ($this->bodyContent[0]) &&
        substr ($this->bodyContent[0]["Content-Type"], 0, 10) === "text/plain")?
        true: false;
    $oldPart = end ($this->bodyContent);
    $bodyHtmlExists = (count ($oldPart) &&
                       substr ($oldPart["Content-Type"], 0, 9) === "text/html")?
                       true:false;
    unset ($oldPart);
    $size = strlen ($this->getMail());
    $from = $this->getHeader ("From");
    if ($from !== false)
    {
      $fromArray = $this->convertPeopleToArray (
                         $this->decodeHeaders ("From", $from));
    }
    $to = $this->getHeader ("To");
    if ($to !== false)
    {
      $toArray = $this->convertPeopleToArray (
                       $this->decodeHeaders ("To", $to));
    }
    $date = $this->getDate ();
    $dateTimestamp = $this->getDateTimestamp ();
    return get_defined_vars();
  }

  /** Create a boundary
    * @return the textual boundary
    */
  private function getBoundary ()
  {
    $data = openssl_random_pseudo_bytes (16);
    $data[6] = chr(ord($data[6]) & 0x0f | 0x40); // set version to 0010
    $data[8] = chr(ord($data[8]) & 0x3f | 0x80); // set bits 6-7 to 10
    return "-----=_".vsprintf ('%s%s-%s-%s-%s-%s%s%s',
                               str_split (bin2hex ($data), 4));
  }

  /** Create a messageID
    * @return the textual MessageID
    */
  private function getMessageID ()
  {
    $data = openssl_random_pseudo_bytes (16);
    $data[6] = chr(ord($data[6]) & 0x0f | 0x40); // set version to 0010
    $data[8] = chr(ord($data[8]) & 0x3f | 0x80); // set bits 6-7 to 10
    return "<".vsprintf ('%s%s-%s-%s-%s-%s%s%s',
                               str_split (bin2hex ($data), 4))."@".
            php_uname('n').">";
  }

  /** Convert the content to correct encoding.
    * The allowed encodings are "quoted-printable" or "base64"
    * Cut the long lines to 76 chars with the correct separator
    * @return the content encoded by $encoding
    */
  private function encodingEncode ($content, $encoding)
  {
    if ($encoding === "quoted-printable")
    {
      $tmp = quoted_printable_encode ($content);
      return $tmp;
    }
    elseif ($encoding === "base64")
    {
      $tmp = base64_encode ($content);
      return chunk_split ($tmp);
    }
    throw new \Exception (_("Invalid encoding provided to encodingEncode"),
                          500);
  }

  /** Decode the content with correct encoding.
    * The allowed encodings are "quoted-printable" or "base64"
    * @return the content decoded by $encoding
    */
  private function encodingDecode ($content, $encoding)
  {
    if ($encoding === "quoted-printable")
      return quoted_printable_decode ($content);
    elseif ($encoding === "base64")
      return base64_decode ($content);
    throw new \Exception (_("Invalid encoding provided to encodingDecode"),
                          500);
  }

  /** Encode a string to be compliant with MIME (used in headers)
    * @param $header The header to be used. Will not be returned, but the length
    * of the result will be adapted to it
    * @param $content The content to encode
    * @param $encoding The encoding to use.
    * The allowed encodings are "quoted-printable" or "base64"
    * @return the content encoded by $encoding
    */
  private function encodeHeaders ($header, $content, $encoding)
  {
    $prefs = array ("input-charset" => "utf-8",
                    "output-charset" => "utf-8");
    if ($encoding === "quoted-printable")
      $prefs["scheme"] = "Q";
    elseif ($encoding === "base64")
      $prefs["scheme"] = "B";
    else
      throw new \Exception (_("Invalid encoding provided to encodeHeaders"),
                          500);
    return substr (iconv_mime_encode ($header, $content, $prefs),
                   strlen ($header)+2);
  }

  /** Convert the header to text */
  private function decodeHeaders ($header, $content)
  {
    return substr (iconv_mime_decode ("$header: $content"),
                   strlen ($header)+2);
  }

  /** Convert a From/To string to array. Manage multiple recipients
    * Ex. : toto toto <toto@toto.com>, titi <titi@titi.com>
           array (array ("name"=>"toto toto", "mail"=>"toto@toto.com"),
                  array ("name"=>"titi", "mail"=>"titi@titi.com"))
    */
  public function convertPeopleToArray ($data)
  {
    $elements = explode (",", $data);
    $res = array ();
    foreach ($elements as $element)
    {
      @list ($name, $mail) = explode ("<", $element);
      if ($mail === null)
      {
        $mail = $name;
        $name = "";
      }
      else
      {
        $name = trim ($name);
        $mail = substr (trim ($mail), 0, -1);
      }
      $array = array ("name"=>$name, "mail"=>$mail);
      $res[] = $array;
    }
    return $res;
  }
}