<?php
/**
 * DropPHP - A simple Dropbox client that works without cURL.
 *
 * http://fabi.me/en/php-projects/dropphp-dropbox-api-client/
 *
 *
 * @author     Fabian Schlieper <fabian@fabi.me>
 * @copyright  Fabian Schlieper 2014
 * @version    1.7.1
 * @license    See LICENSE
 *
 */

require_once(dirname(__FILE__) . "/OAuthSimple.php");

class DropboxClient
{

    const API_URL = "https://api.dropbox.com/1/";
    const API_CONTENT_URL = "https://api-content.dropbox.com/1/";

    const BUFFER_SIZE = 4096;

    const MAX_UPLOAD_CHUNK_SIZE = 150000000; // 150MB

    const UPLOAD_CHUNK_SIZE = 4000000; // 4MB

    private $appParams;
    private $consumerToken;

    private $requestToken;
    private $accessToken;

    private $locale;
    private $rootPath;

    private $useCurl;

    function __construct($app_params, $locale = "en")
    {
        $this->appParams = $app_params;
        if (empty($app_params['app_key']))
            throw new DropboxException("App Key is empty!");

        $this->consumerToken = array('t' => $this->appParams['app_key'], 's' => $this->appParams['app_secret']);
        $this->locale = $locale;
        $this->rootPath = empty($app_params['app_full_access']) ? "sandbox" : "dropbox";

        $this->requestToken = null;
        $this->accessToken = null;

        $this->useCurl = function_exists('curl_init');
    }

    function __wakeup()
    {
        $this->useCurl = $this->useCurl && function_exists('curl_init');
    }

    /**
     * Sets whether to use cURL if its available or PHP HTTP wrappers otherwise
     *
     * @access public
     * @return boolean Whether to actually use cURL (always false if not installed)
     */
    public function SetUseCUrl($use_it)
    {
        return ($this->useCurl = ($use_it && function_exists('curl_init')));
    }

    // ##################################################
    // Authorization

    /**
     * Step 1 of authentication process. Retrieves a request token or returns a previously retrieved one.
     *
     * @access public
     * @param boolean $get_new_token Optional (default false). Wether to retrieve a new request token.
     * @return array Request Token array.
     */
    public function GetRequestToken($get_new_token = false)
    {
        if (!empty($this->requestToken) && !$get_new_token)
            return $this->requestToken;

        $rt = $this->authCall("oauth/request_token");
        if (empty($rt) || empty($rt['oauth_token']))
            throw new DropboxException('Could not get request token!');

        return ($this->requestToken = array('t' => $rt['oauth_token'], 's' => $rt['oauth_token_secret']));
    }

    /**
     * Step 2. Returns a URL the user must be redirected to in order to connect the app to their Dropbox account
     *
     * @access public
     * @param string $return_url URL users are redirected after authorization
     * @return string URL
     */
    public function BuildAuthorizeUrl($return_url)
    {
        $rt = $this->GetRequestToken();
        if (empty($rt) || empty($rt['t'])) throw new DropboxException('Request Token Invalid (' . print_r($rt, true) . ').');
        return "https://www.dropbox.com/1/oauth/authorize?oauth_token=" . $rt['t'] . "&oauth_callback=" . urlencode($return_url);
    }

    /**
     * Step 3. Acquires an access token. This is the final step of authentication.
     *
     * @access public
     * @param array $request_token Optional. The previously retrieved request token. This parameter can only be skipped if the DropboxClient object has been (de)serialized.
     * @return array Access Token array.
     */
    public function GetAccessToken($request_token = null)
    {
        if (!empty($this->accessToken)) return $this->accessToken;

        if (empty($request_token)) $request_token = $this->requestToken;
        if (empty($request_token)) throw new DropboxException('Request token required!');

        $at = $this->authCall("oauth/access_token", $request_token);
        if (empty($at))
            throw new DropboxException(sprintf('Could not get access token! (request token: %s)', $request_token['t']));

        return ($this->accessToken = array('t' => $at['oauth_token'], 's' => $at['oauth_token_secret']));
    }

    /**
     * Sets a previously retrieved (and stored) access token.
     *
     * @access public
     * @param string|object $token The Access Token
     * @return none
     */
    public function SetAccessToken($token)
    {
        if (empty($token['t']) || empty($token['s'])) throw new DropboxException('Passed invalid access token.');
        $this->accessToken = $token;
    }

    /**
     * Checks if an access token has been set.
     *
     * @access public
     * @return boolean Authorized or not
     */
    public function IsAuthorized()
    {
        if (empty($this->accessToken)) return false;
        return true;
    }


    // ##################################################
    // API Functions


    /**
     * Retrieves information about the user's account.
     *
     * @access public
     * @return object Account info object. See https://www.dropbox.com/developers/reference/api#account-info
     */
    public function GetAccountInfo()
    {
        return $this->apiCall("account/info", "GET");
    }


    /**
     * Get file list of a dropbox folder.
     *
     * @access public
     * @param string|object $dropbox_path Dropbox path of the folder
     * @return array An array with metadata of files/folders keyed by paths
     */
    public function GetFiles($dropbox_path = '', $recursive = false, $include_deleted = false)
    {
        if (is_object($dropbox_path) && !empty($dropbox_path->path)) $dropbox_path = $dropbox_path->path;
        return $this->getFileTree($dropbox_path, $include_deleted, $recursive ? 1000 : 0);
    }

    /**
     * Get file or folder metadata
     *
     * @access public
     * @param $dropbox_path string Dropbox path of the file or folder
     */
    public function GetMetadata($dropbox_path, $include_deleted = false, $rev = null)
    {
        if (is_object($dropbox_path) && !empty($dropbox_path->path)) $dropbox_path = $dropbox_path->path;
        return $this->apiCall("metadata/$this->rootPath/$dropbox_path", "GET", compact('include_deleted', 'rev'));
    }

    /**
     * Download a file to the webserver
     *
     * @access public
     * @param string|object $dropbox_file Dropbox path or metadata object of the file to download.
     * @param string $dest_path Local path for destination
     * @param string $rev Optional. The revision of the file to retrieve. This defaults to the most recent revision.
     * @param callback $progress_changed_callback Optional. Callback that will be called during download with 2 args: 1. bytes loaded, 2. file size
     * @return object Dropbox file metadata
     */
    public function DownloadFile($dropbox_file, $dest_path = '', $rev = null, $progress_changed_callback = null)
    {
        if (is_object($dropbox_file) && !empty($dropbox_file->path))
            $dropbox_file = $dropbox_file->path;

        if (empty($dest_path)) $dest_path = basename($dropbox_file);

        $url = $this->cleanUrl(self::API_CONTENT_URL . "/files/$this->rootPath/$dropbox_file")
            . (!empty($rev) ? ('?' . http_build_query(array('rev' => $rev), '', '&')) : '');
        $context = $this->createRequestContext($url, "GET");

        $fh = @fopen($dest_path, 'wb'); // write binary
        if ($fh === false) {
            @fclose($rh);
            throw new DropboxException("Could not create file $dest_path !");
        }

        if ($this->useCurl) {
            curl_setopt($context, CURLOPT_BINARYTRANSFER, true);
            curl_setopt($context, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($context, CURLOPT_FILE, $fh);
            $response_headers = array();
            self::execCurlAndClose($context, $response_headers);
            fclose($fh);
            $meta = self::getMetaFromHeaders($response_headers, true);
            $bytes_loaded = filesize($dest_path);
        } else {
            $rh = @fopen($url, 'rb', false, $context); // read binary
            if ($rh === false)
                throw new DropboxException("HTTP request to $url failed!");


            // get file meta from HTTP header
            $s_meta = stream_get_meta_data($rh);
            $meta = self::getMetaFromHeaders($s_meta['wrapper_data'], true);
            $bytes_loaded = 0;
            while (!feof($rh)) {
                if (($s = fwrite($fh, fread($rh, self::BUFFER_SIZE))) === false) {
                    @fclose($rh);
                    @fclose($fh);
                    throw new DropboxException("Writing to file $dest_path failed!'");
                }
                $bytes_loaded += $s;
                if (!empty($progress_changed_callback)) {
                    call_user_func($progress_changed_callback, $bytes_loaded, $meta->bytes);
                }
            }

            fclose($rh);
            fclose($fh);
        }

        if ($meta->bytes != $bytes_loaded)
            throw new DropboxException("Download size mismatch! (header:{$meta->bytes} vs actual:{$bytes_loaded}; curl:{$this->useCurl})");

        return $meta;
    }

    /**
     * Upload a file to dropbox
     *
     * @access public
     * @param $src_file string Local file to upload
     * @param $dropbox_path string Dropbox path for destination
     * @return object Dropbox file metadata
     */
    public function UploadFile($src_file, $dropbox_path = '', $overwrite = true, $parent_rev = null)
    {
        if (empty($dropbox_path)) $dropbox_path = basename($src_file);
        elseif (is_object($dropbox_path) && !empty($dropbox_path->path)) $dropbox_path = $dropbox_path->path;

        // make sure the dropbox_path is not a dir. if it is, append baseneme of $src_file
        $dropbox_bn = basename($dropbox_path);
        if (strpos($dropbox_bn, '.') === false) { // check if ext. is missing -> could be a directory!
            try {
                $meta = $this->GetMetadata($dropbox_path);
                if ($meta && $meta->is_dir)
                    $dropbox_path = $dropbox_path . '/' . basename($src_file);
            } catch (Exception $e) {
            }
        }

        $file_size = filesize($src_file);

        if ($file_size > self::MAX_UPLOAD_CHUNK_SIZE) {
            $fh = fopen($src_file, 'rb');
            if ($fh === false)
                throw new DropboxException();

            $upload_id = null;
            $offset = 0;


            while (!feof($fh)) {
                $url = $this->cleanUrl(self::API_CONTENT_URL . "/chunked_upload") . '?' . http_build_query(compact('upload_id', 'offset'), '', '&');
                $content = fread($fh, self::UPLOAD_CHUNK_SIZE);
                $context = $this->createRequestContext($url, "PUT", $content);

                if ($this->useCurl) {
                    curl_setopt($context, CURLOPT_BINARYTRANSFER, true);
                    $response = json_decode(self::execCurlAndClose($context));
                } else {
                    $response = json_decode(file_get_contents($url, false, $context));
                }
                $offset += strlen($content);
                unset($content);
                unset($context);

                self::checkForError($response);

                if (empty($upload_id)) {
                    $upload_id = $response->upload_id;
                    if (empty($upload_id)) throw new DropboxException("Upload ID empty!");
                }
                if ($offset >= $file_size)
                    break;
            }

            @fclose($fh);

            return $this->apiCall("commit_chunked_upload/$this->rootPath/$dropbox_path", "POST", compact('overwrite', 'parent_rev', 'upload_id'), true);
        }

        $query = http_build_query(array_merge(compact('overwrite', 'parent_rev'), array('locale' => $this->locale)), '', '&');
        $url = $this->cleanUrl(self::API_CONTENT_URL . "/files_put/$this->rootPath/$dropbox_path") . "?$query";

        if ($this->useCurl) {
            $context = $this->createRequestContext($url, "PUT");
            curl_setopt($context, CURLOPT_BINARYTRANSFER, true);
            $fh = fopen($src_file, 'rb');
            curl_setopt($context, CURLOPT_PUT, 1);
            curl_setopt($context, CURLOPT_INFILE, $fh); // file pointer
            curl_setopt($context, CURLOPT_INFILESIZE, filesize($src_file));
            $meta = json_decode(self::execCurlAndClose($context));
            fclose($fh);
            return self::checkForError($meta);
        } else {
            $content = file_get_contents($src_file);
            if (strlen($content) == 0)
                throw new DropboxException("Could not read file $src_file or file is empty!");

            $context = $this->createRequestContext($url, "PUT", $content);

            return self::checkForError(json_decode(file_get_contents($url, false, $context)));
        }
    }

    /**
     * Get thumbnail for a specified image
     *
     * @access public
     * @param $dropbox_file string Path to the image
     * @param $format string Image format of the thumbnail (jpeg or png)
     * @param $size string Thumbnail size (xs, s, m, l, xl)
     * @return mime/* Returns the thumbnail as binary image data
     */
    public function GetThumbnail($dropbox_file, $size = 's', $format = 'jpeg', $echo = false)
    {
        if (is_object($dropbox_file) && !empty($dropbox_file->path)) $dropbox_file = $dropbox_file->path;
        $url = $this->cleanUrl(self::API_CONTENT_URL . "thumbnails/$this->rootPath/$dropbox_file")
            . '?' . http_build_query(array('format' => $format, 'size' => $size), '', '&');
        $context = $this->createRequestContext($url, "GET");

        if ($this->useCurl) {
            curl_setopt($context, CURLOPT_BINARYTRANSFER, true);
            curl_setopt($context, CURLOPT_RETURNTRANSFER, true);
        }

        $thumb = $this->useCurl ? self::execCurlAndClose($context) : file_get_contents($url, NULL, $context);

        if ($echo) {
            header('Content-type: image/' . $format);
            echo $thumb;
            unset($thumb);
            return;
        }

        return $thumb;
    }


    function GetLink($dropbox_file, $preview = true, $short = true, &$expires = null)
    {
        if (is_object($dropbox_file) && !empty($dropbox_file->path)) $dropbox_file = $dropbox_file->path;
        $url = $this->apiCall(($preview ? "shares" : "media") . "/$this->rootPath/$dropbox_file", "POST", array('locale' => null, 'short_url' => $preview ? $short : null));
        $expires = strtotime($url->expires);
        return $url->url;
    }

    function Delta($cursor)
    {
        return $this->apiCall("delta", "POST", compact('cursor'));
    }

    function GetRevisions($dropbox_file, $rev_limit = 10)
    {
        if (is_object($dropbox_file) && !empty($dropbox_file->path)) $dropbox_file = $dropbox_file->path;
        return $this->apiCall("revisions/$this->rootPath/$dropbox_file", "GET", compact('rev_limit'));
    }

    function Restore($dropbox_file, $rev)
    {
        if (is_object($dropbox_file) && !empty($dropbox_file->path)) $dropbox_file = $dropbox_file->path;
        return $this->apiCall("restore/$this->rootPath/$dropbox_file", "POST", compact('rev'));
    }

    function Search($path, $query, $file_limit = 1000, $include_deleted = false)
    {
        return $this->apiCall("search/$this->rootPath/$path", "POST", compact('query', 'file_limit', 'include_deleted'));
    }

    function GetCopyRef($dropbox_file, &$expires = null)
    {
        if (is_object($dropbox_file) && !empty($dropbox_file->path)) $dropbox_file = $dropbox_file->path;
        $ref = $this->apiCall("copy_ref/$this->rootPath/$dropbox_file", "GET", array('locale' => null));
        $expires = strtotime($ref->expires);
        return $ref->copy_ref;
    }


    function Copy($from_path, $to_path, $copy_ref = false)
    {
        if (is_object($from_path) && !empty($from_path->path)) $from_path = $from_path->path;
        return $this->apiCall("fileops/copy", "POST", array('root' => $this->rootPath, ($copy_ref ? 'from_copy_ref' : 'from_path') => $from_path, 'to_path' => $to_path));
    }

    /**
     * Creates a new folder in the DropBox
     *
     * @access public
     * @param $path string The path to the new folder to create
     * @return object Dropbox folder metadata
     */
    function CreateFolder($path)
    {
        return $this->apiCall("fileops/create_folder", "POST", array('root' => $this->rootPath, 'path' => $path));
    }

    /**
     * Delete file or folder
     *
     * @access public
     * @param $path mixed The path or metadata of the file/folder to be deleted.
     * @return object Dropbox metadata of deleted file or folder
     */
    function Delete($path)
    {
        if (is_object($path) && !empty($path->path)) $path = $path->path;
        return $this->apiCall("fileops/delete", "POST", array('locale' => null, 'root' => $this->rootPath, 'path' => $path));
    }

    function Move($from_path, $to_path)
    {
        if (is_object($from_path) && !empty($from_path->path)) $from_path = $from_path->path;
        return $this->apiCall("fileops/move", "POST", array('root' => $this->rootPath, 'from_path' => $from_path, 'to_path' => $to_path));
    }

    function getFileTree($path = "", $include_deleted = false, $max_depth = 0, $depth = 0)
    {
        static $files;
        if ($depth == 0) $files = array();

        $dir = $this->apiCall("metadata/$this->rootPath/$path", "GET", compact('include_deleted'));

        if (empty($dir) || !is_object($dir)) return false;

        if (!empty($dir->error)) throw new DropboxException($dir->error);

        foreach ($dir->contents as $item) {
            $files[trim($item->path, '/')] = $item;
            if ($item->is_dir && $depth < $max_depth) {
                $this->getFileTree($item->path, $include_deleted, $max_depth, $depth + 1);
            }
        }

        return $files;
    }

    function createCurl($url, $http_context)
    {
        $ch = curl_init($url);

        $curl_opts = array(
            CURLOPT_HEADER => false, // exclude header from output
            //CURLOPT_MUTE => true, // no output!
            CURLOPT_RETURNTRANSFER => true, // but return!
            CURLOPT_SSL_VERIFYPEER => false,
        );

        $curl_opts[CURLOPT_CUSTOMREQUEST] = $http_context['method'];

        if (!empty($http_context['content'])) {
            $curl_opts[CURLOPT_POSTFIELDS] =& $http_context['content'];
            if (defined("CURLOPT_POSTFIELDSIZE"))
                $curl_opts[CURLOPT_POSTFIELDSIZE] = strlen($http_context['content']);
        }

        $curl_opts[CURLOPT_HTTPHEADER] = array_map('trim', explode("\n", $http_context['header']));

        curl_setopt_array($ch, $curl_opts);
        return $ch;
    }

    static private $_curlHeadersRef;

    static function _curlHeaderCallback($ch, $header)
    {
        self::$_curlHeadersRef[] = trim($header);
        return strlen($header);
    }

    static function &execCurlAndClose($ch, &$out_response_headers = null)
    {
        if (is_array($out_response_headers)) {
            self::$_curlHeadersRef =& $out_response_headers;
            curl_setopt($ch, CURLOPT_HEADERFUNCTION, array(__CLASS__, '_curlHeaderCallback'));
        }
        $res = curl_exec($ch);
        $err_no = curl_errno($ch);
        $err_str = curl_error($ch);
        curl_close($ch);
        if ($err_no || $res === false) {
            throw new DropboxException("cURL-Error ($err_no): $err_str");
        }

        return $res;
    }

    private function createRequestContext($url, $method, &$content = null, $oauth_token = -1)
    {
        if ($oauth_token === -1)
            $oauth_token = $this->accessToken;

        $method = strtoupper($method);
        $http_context = array('method' => $method, 'header' => '');

        $oauth = new OAuthSimple($this->consumerToken['t'], $this->consumerToken['s']);

        if (empty($oauth_token) && !empty($this->accessToken))
            $oauth_token = $this->accessToken;

        if (!empty($oauth_token)) {
            $oauth->setParameters(array('oauth_token' => $oauth_token['t']));
            $oauth->signatures(array('oauth_secret' => $oauth_token['s']));
        }

        if (!empty($content)) {
            $post_vars = ($method != "PUT" && preg_match("/^[a-z][a-z0-9_]*=/i", substr($content, 0, 32)));
            $http_context['header'] .= "Content-Length: " . strlen($content) . "\r\n";
            $http_context['header'] .= "Content-Type: application/" . ($post_vars ? "x-www-form-urlencoded" : "octet-stream") . "\r\n";
            $http_context['content'] =& $content;
            if ($method == "POST" && $post_vars)
                $oauth->setParameters($content);
        } elseif ($method == "POST") {
            // make sure that content-length is always set when post request (otherwise some wrappers fail!)
            $http_context['content'] = "";
            $http_context['header'] .= "Content-Length: 0\r\n";
        }


        // check for query vars in url and add them to oauth parameters (and remove from path)
        $path = $url;
        $query = strrchr($url, '?');
        if (!empty($query)) {
            $oauth->setParameters(substr($query, 1));
            $path = substr($url, 0, -strlen($query));
        }


        $signed = $oauth->sign(array(
            'action' => $method,
            'path' => $path));
        //print_r($signed);

        $http_context['header'] .= "Authorization: " . $signed['header'] . "\r\n";

        return $this->useCurl ? $this->createCurl($url, $http_context) : stream_context_create(array('http' => $http_context));
    }

    private function authCall($path, $request_token = null)
    {
        $url = $this->cleanUrl(self::API_URL . $path);
        $dummy = null;
        $context = $this->createRequestContext($url, "POST", $dummy, $request_token);

        $contents = $this->useCurl ? self::execCurlAndClose($context) : file_get_contents($url, false, $context);
        $data = array();
        parse_str($contents, $data);
        return $data;
    }

    private static function checkForError($resp)
    {
        if (!empty($resp->error))
            throw new DropboxException($resp->error);
        return $resp;
    }


    private function apiCall($path, $method, $params = array(), $content_call = false)
    {
        $url = $this->cleanUrl(($content_call ? self::API_CONTENT_URL : self::API_URL) . $path);
        $content = http_build_query(array_merge(array('locale' => $this->locale), $params), '', '&');

        if ($method == "GET") {
            $url .= "?" . $content;
            $content = null;
        }

        $context = $this->createRequestContext($url, $method, $content);
        $json = $this->useCurl ? self::execCurlAndClose($context) : file_get_contents($url, false, $context);
        //if($json === false)
//			throw new DropboxException();
        $resp = json_decode($json);
        return self::checkForError($resp);
    }


    private static function getMetaFromHeaders(&$header_array, $throw_on_error = false)
    {
        $obj = json_decode(substr(@array_shift(array_filter($header_array, create_function('$s', 'return stripos($s, "x-dropbox-metadata:") === 0;'))), 20));
        if ($throw_on_error && (empty($obj) || !is_object($obj)))
            throw new DropboxException("Could not retrieve meta data from header data: " . print_r($header_array, true));
        if ($throw_on_error)
            self::checkForError($obj);
        return $obj;
    }


    function cleanUrl($url)
    {
        $p = substr($url, 0, 8);
        $url = str_replace('//', '/', str_replace('\\', '/', substr($url, 8)));
        $url = rawurlencode($url);
        $url = str_replace('%2F', '/', $url);
        return $p . $url;
    }
}

class DropboxException extends Exception
{

    public function __construct($err = null, $isDebug = FALSE)
    {
        if (is_null($err)) {
            $el = error_get_last();
            $this->message = $el['message'];
            $this->file = $el['file'];
            $this->line = $el['line'];
        } else
            $this->message = $err;
        self::log_error($err);
        if ($isDebug) {
            self::display_error($err, TRUE);
        }
    }

    public static function log_error($err)
    {
        error_log($err, 0);
    }

    public static function display_error($err, $kill = FALSE)
    {
        print_r($err);
        if ($kill === FALSE) {
            die();
        }
    }
}
