<?php

/*
 * This class can be used to retrieve messages from an IMAP, POP3 and NNTP server
 * @author Kiril Kirkov
 * GitHub: https://github.com/kirilkirkov
 * Usage example:
  1. $imap = new Imap();
  2. $connection_result = $imap->connect('{imap.gmail.com:993/imap/ssl}INBOX', 'user@gmail.com', 'secret_password');
  if ($connection_result !== true) {
  echo $connection_result; //Error message!
  exit;
  }
  3. $messages = $imap->getMessages('text'); //Array of messages
 * in $attachments_dir property set directory for attachments
 * in the __destructor set errors log
 */

class Imap {
    private $imapStream;
    private $plaintextMessage;
    private $htmlMessage;
    private $emails;
    private $errors = array();
    private $attachments = array();
    private $attachments_dir = 'attachments';
    public function connect($hostname, $username, $password) {
        $connection = imap_open($hostname, $username, $password) or die('Cannot connect to Mail: ' . imap_last_error());
        if (!preg_match("/Resource.id.*/", (string) $connection)) {
            return $connection; //return error message
        }
        $this->imapStream = $connection;
        return true;
    }
    public function getMessages($type = 'text') {
        $this->attachments_dir = rtrim($this->attachments_dir, '/');
        $stream = $this->imapStream;
        $emails = imap_search($stream, 'ALL');
        $messages = array();
        if ($emails) {
            $this->emails = $emails;
            foreach ($emails as $email_number) {
                $this->attachments = array();
                $uid = imap_uid($stream, $email_number);
                $cabeca = imap_headerinfo($stream,  $email_number);
                $messages[] = $this->loadMessage($uid, $type);
                $assunto_decodificado = imap_mime_header_decode($cabeca->subject);
                $remetente_decodificado = imap_mime_header_decode($cabeca->fromaddress);
                $messages[$email_number]["subject"] = $assunto_decodificado[0]->text;
                $messages[$email_number]["from"]["name"] = $remetente_decodificado[0]->text;

                /* tentando pegar os anexos */
                /*Codigo funcional porém pega todos os anexos dos emails de uma vez só*/
                /*
                $structure = imap_fetchstructure($stream,  $email_number);
                $attachments = array();
                if(isset($structure->parts) && count($structure->parts))
                {
                    for($i = 0; $i < count($structure->parts); $i++)
                    {
                        $attachments[$i] = array(
                            'is_attachment' => false,
                            'filename' => '',
                            'name' => '',
                            'attachment' => ''
                        );

                        if($structure->parts[$i]->ifdparameters)
                        {
                            foreach($structure->parts[$i]->dparameters as $object)
                            {
                                if(strtolower($object->attribute) == 'filename')
                                {
                                    $attachments[$i]['is_attachment'] = true;
                                    $attachments[$i]['filename'] = $object->value;
                                }
                            }
                        }

                        if($structure->parts[$i]->ifparameters)
                        {
                            foreach($structure->parts[$i]->parameters as $object)
                            {
                                if(strtolower($object->attribute) == 'name')
                                {
                                    $attachments[$i]['is_attachment'] = true;
                                    $attachments[$i]['name'] = $object->value;
                                }
                            }
                        }

                        if($attachments[$i]['is_attachment'])
                        {
                            $attachments[$i]['attachment'] = imap_fetchbody($stream,  $email_number, $i+1);

                            // 3 = BASE64 encoding
                            if($structure->parts[$i]->encoding == 3)
                            {
                                $attachments[$i]['attachment'] = base64_decode($attachments[$i]['attachment']);
                            }
                            // 4 = QUOTED-PRINTABLE encoding
                            elseif($structure->parts[$i]->encoding == 4)
                            {
                                $attachments[$i]['attachment'] = quoted_printable_decode($attachments[$i]['attachment']);
                            }
                        }
                    }
                }

                //iterate through each attachment and save it
                foreach($attachments as $attachment)
                {
                    if($attachment['is_attachment'] == 1)
                    {
                        $filename = $attachment['name'];
                        if(empty($filename)) $filename = $attachment['filename'];

                        if(empty($filename)) $filename = time() . ".dat";
                        $folder = "attachment";
                        if(!is_dir($folder))
                        {
                             mkdir($folder);
                        }
                        $fp = fopen("./". $assunto_decodificado ."/". $email_number . "-" . $filename, "w+");
                        fwrite($fp, $attachment['attachment']);
                        fclose($fp);
                    }
                } */


            }
        }
        return array(
            "status" => "success",
            "data" => array_reverse($messages)
        );
    }
    public function getFiles($r) { //save attachments to directory
        $pullPath = $this->attachments_dir . '/' . $r['file'];
        $res = true;
        if (file_exists($pullPath)) {
            $res = false;
        } elseif (!is_dir($this->attachments_dir)) {
            $this->errors[] = 'Cant find directory for email attachments! Message ID:' . $r['uid'];
            return false;
        } elseif (!is_writable($this->attachments_dir)) {
            $this->errors[] = 'Attachments directory is not writable! Message ID:' . $r['uid'];
            return false;
        }
        if($res && !preg_match('/\.php/i', $r['file']) && !preg_match('/\.cgi/i', $r['file']) && !preg_match('/\.exe/i', $r['file']) && !preg_match('/\.dll/i', $r['file']) && !preg_match('/\.mobileconfig/i', $r['file'])){
            if (($filePointer = fopen($pullPath, 'w')) == false) {
                $this->errors[] = 'Cant open file at imap class to save attachment file! Message ID:' . $r['uid'];
                return false;
            }
            switch ($r['encoding']) {
                case 3: //base64
                    $streamFilter = stream_filter_append($filePointer, 'convert.base64-decode', STREAM_FILTER_WRITE);
                    break;
                case 4: //quoted-printable
                    $streamFilter = stream_filter_append($filePointer, 'convert.quoted-printable-decode', STREAM_FILTER_WRITE);
                    break;
                default:
                    $streamFilter = null;
            }
            imap_savebody($this->imapStream, $filePointer, $r['uid'], $r['part'], FT_UID);
            if ($streamFilter) {
                stream_filter_remove($streamFilter);
            }
            fclose($filePointer);
            return array("status" => "success", "path" => $pullPath);
        }else{
            return array("status" => "success", "path" => $pullPath);
        }
    }
    private function loadMessage($uid, $type) {
        $overview = $this->getOverview($uid);
        $array = array();
        $array['uid'] = $overview->uid;
        $array['subject'] = isset($overview->subject) ? $this->decode($overview->subject) : '';
        $array['date'] = date('Y-m-d h:i:sa', strtotime($overview->date));
        $headers = $this->getHeaders($uid);
        $array['from'] = isset($headers->from) ? $this->processAddressObject($headers->from) : array('');
        $structure = $this->getStructure($uid);
        if (!isset($structure->parts)) { // not multipart
            $this->processStructure($uid, $structure);
        } else { // multipart
            foreach ($structure->parts as $id => $part) {
                $this->processStructure($uid, $part, $id + 1);
            }
        }
        $array['message'] = $type == 'text' ? $this->plaintextMessage : $this->htmlMessage;
        $array['attachments'] = $this->attachments;
        return $array;
    }
    private function processStructure($uid, $structure, $partIdentifier = null) {
        $parameters = $this->getParametersFromStructure($structure);
       // var_dump($parameters);
        if ((isset($parameters['name']) || isset($parameters['filename'])) || (isset($structure->subtype) && strtolower($structure->subtype) == 'rfc822')
        ) {
            if (isset($parameters['filename'])) {
                $this->setFileName($parameters['filename']);
            } elseif (isset($parameters['name'])) {
                $this->setFileName($parameters['name']);
            }
            $this->encoding = $structure->encoding;
            $result_save = $this->saveToDirectory($uid, $partIdentifier);
            $this->attachments[] = $result_save;
        } elseif ($structure->type == 0 || $structure->type == 1) {
            $messageBody = isset($partIdentifier) ?
                    imap_fetchbody($this->imapStream, $uid, $partIdentifier, FT_UID | FT_PEEK) : imap_body($this->imapStream, $uid, FT_UID | FT_PEEK);
            $messageBody = $this->decodeMessage($messageBody, $structure->encoding);
            if (!empty($parameters['charset']) && $parameters['charset'] !== 'UTF-8') {
                if (function_exists('mb_convert_encoding')) {
                    if (!in_array($parameters['charset'], mb_list_encodings())) {
                        if ($structure->encoding === 0) {
                            $parameters['charset'] = 'US-ASCII';
                        } else {
                            $parameters['charset'] = 'UTF-8';
                        }
                    }
                    $messageBody = mb_convert_encoding($messageBody, 'UTF-8', $parameters['charset']);
                } else {
                    $messageBody = iconv($parameters['charset'], 'UTF-8//TRANSLIT', $messageBody);
                }
            }
            if (strtolower($structure->subtype) === 'plain' || ($structure->type == 1 && strtolower($structure->subtype) !== 'alternative')) {
                $this->plaintextMessage = '';
                $this->plaintextMessage .= trim(htmlentities($messageBody));
                $this->plaintextMessage = nl2br($this->plaintextMessage);
            } elseif (strtolower($structure->subtype) === 'html') {
                $this->htmlMessage = '';
                $this->htmlMessage .= $messageBody;
            }
        }
        if (isset($structure->parts)) {
            foreach ($structure->parts as $partIndex => $part) {
                $partId = $partIndex + 1;
                if (isset($partIdentifier))
                    $partId = $partIdentifier . '.' . $partId;
                $this->processStructure($uid, $part, $partId);
            }
        }
    }
    private function setFileName($text) {
       // $this->filename = $this->decode($text);
        $this->filename = $text;
    }
    private function saveToDirectory($uid, $partIdentifier) { //save attachments to directory
        $array = array();
        $array['part'] = $partIdentifier;
        $array['file'] = $this->filename;
        $array['encoding'] = $this->encoding;
        return $array;
    }
    private function decodeMessage($data, $encoding) {
        if (!is_numeric($encoding)) {
            $encoding = strtolower($encoding);
        }
        switch (true) {
            case $encoding === 'quoted-printable':
            case $encoding === 4:
                return quoted_printable_decode($data);
            case $encoding === 'base64':
            case $encoding === 3:
                return base64_decode($data);
            default:
                return $data;
        }
    }
    private function getParametersFromStructure($structure) {
        $parameters = array();
        if (isset($structure->parameters))
            foreach ($structure->parameters as $parameter)
                $parameters[strtolower($parameter->attribute)] = $parameter->value;
        if (isset($structure->dparameters))
            foreach ($structure->dparameters as $parameter)
                $parameters[strtolower($parameter->attribute)] = $parameter->value;
        return $parameters;
    }
    private function getOverview($uid) {
        $results = imap_fetch_overview($this->imapStream, $uid, FT_UID);
        $messageOverview = array_shift($results);
        if (!isset($messageOverview->date)) {
            $messageOverview->date = null;
        }
        return $messageOverview;
    }
    private function decode($text) {
        if (null === $text) {
            return null;
        }
        $result = '';
        foreach (imap_mime_header_decode($text) as $word) {
            $ch = 'default' === $word->charset ? 'ascii' : $word->charset;
          //  $result .= iconv($ch, 'utf-8', $word->text);
        }
        return $result;
    }
    private function processAddressObject($addresses) {
        $outputAddresses = array();
        if (is_array($addresses))
            foreach ($addresses as $address) {
                if (property_exists($address, 'mailbox') && $address->mailbox != 'undisclosed-recipients') {
                    $currentAddress = array();
                    $currentAddress['address'] = $address->mailbox . '@' . $address->host;
                    if (isset($address->personal)) {
                        $currentAddress['name'] = $this->decode($address->personal);
                    }
                    $outputAddresses = $currentAddress;
                }
            }
        return $outputAddresses;
    }
    private function getHeaders($uid) {
        $rawHeaders = $this->getRawHeaders($uid);
        $headerObject = imap_rfc822_parse_headers($rawHeaders);
        if (isset($headerObject->date)) {
            $headerObject->udate = strtotime($headerObject->date);
        } else {
            $headerObject->date = null;
            $headerObject->udate = null;
        }
        $this->headers = $headerObject;
        return $this->headers;
    }
    private function getRawHeaders($uid) {
        $rawHeaders = imap_fetchheader($this->imapStream, $uid, FT_UID);
        return $rawHeaders;
    }
    private function getStructure($uid) {
        $structure = imap_fetchstructure($this->imapStream, $uid, FT_UID);
        return $structure;
    }
    public function __destruct() {
        if (!empty($this->errors)) {
            foreach ($this->errors as $error) {
                echo $error;
            }
        }
    }
}