<?php
class TrustlinkClient {
    var $tl_version           = 'T0.3';
    var $tl_verbose           = false;
    var $tl_debug             = false;
    var $tl_isrobot           = false;
    var $tl_test              = false;
    var $tl_test_count        = 4;
    var $tl_template          = 'template';
    var $tl_charset           = 'DEFAULT';
    var $tl_use_ssl           = false;
    var $tl_server            = 'db.trustlink.ru';
    var $tl_cache_lifetime    = 3600;
    var $tl_cache_reloadtime  = 300;
    var $tl_links_db_file     = '';
    var $tl_links             = array();
    var $tl_links_page        = array();
    var $tl_error             = '';
    var $tl_host              = '';
    var $tl_request_uri       = '';
    var $tl_fetch_remote_type = '';
    var $tl_socket_timeout    = 6;
    var $tl_force_show_code   = false;
    var $tl_multi_site        = false;
    var $tl_is_static         = false;

    function TrustlinkClient($options = null) {
        $host = '';

        if (is_array($options)) {
            if (isset($options['host'])) {
                $host = $options['host'];
            }
        } elseif (strlen($options) != 0) {
            $host = $options;
            $options = array();
        } else {
            $options = array();
        }

        if (strlen($host) != 0) {
            $this->tl_host = $host;
        } else {
            $this->tl_host = $_SERVER['HTTP_HOST'];
        }

        $this->tl_host = preg_replace('{^https?://}i', '', $this->tl_host);
        $this->tl_host = preg_replace('{^www\.}i', '', $this->tl_host);
        $this->tl_host = strtolower( $this->tl_host);

        if (isset($options['is_static']) && $options['is_static']) {
            $this->tl_is_static = true;
        }

        if (isset($options['request_uri']) && strlen($options['request_uri']) != 0) {
            $this->tl_request_uri = $options['request_uri'];
        } else {
            if ($this->tl_is_static) {
                $this->tl_request_uri = preg_replace( '{\?.*$}', '', $_SERVER['REQUEST_URI']);
                $this->tl_request_uri = preg_replace( '{/+}', '/', $this->tl_request_uri);
            } else {
                $this->tl_request_uri = $_SERVER['REQUEST_URI'];
            }
        }

        $this->tl_request_uri = rawurldecode($this->tl_request_uri);

        if (isset($options['multi_site']) && $options['multi_site'] == true) {
            $this->tl_multi_site = true;
        }

        if ((isset($options['verbose']) && $options['verbose']) ||
            isset($this->tl_links['__trustlink_debug__'])) {
            $this->tl_verbose = true;
        }

        if (isset($options['charset']) && strlen($options['charset']) != 0) {
            $this->tl_charset = $options['charset'];
        }

        if (isset($options['fetch_remote_type']) && strlen($options['fetch_remote_type']) != 0) {
            $this->tl_fetch_remote_type = $options['fetch_remote_type'];
        }

        if (isset($options['socket_timeout']) && is_numeric($options['socket_timeout']) && $options['socket_timeout'] > 0) {
            $this->tl_socket_timeout = $options['socket_timeout'];
        }

        if ((isset($options['force_show_code']) && $options['force_show_code']) ||
            isset($this->tl_links['__trustlink_debug__'])) {
            $this->tl_force_show_code = true;
        }

        if (!defined('TRUSTLINK_USER')) {
            return $this->raise_error("Constant TRUSTLINK_USER is not defined.");
        }

		if (isset($_SERVER['HTTP_TRUSTLINK']) && $_SERVER['HTTP_TRUSTLINK']==TRUSTLINK_USER){
			$this->tl_test=true;
			$this->tl_isrobot=true;
			$this->tl_verbose = true;
		}

        $this->load_links();
    }

    function load_links() {
        if ($this->tl_multi_site) {
            $this->tl_links_db_file = dirname(__FILE__) . '/trustlink.' . $this->tl_host . '.links.db';
        } else {
            $this->tl_links_db_file = dirname(__FILE__) . '/trustlink.links.db';
        }

        if (!is_file($this->tl_links_db_file)) {
            if (@touch($this->tl_links_db_file, time() - $this->tl_cache_lifetime)) {
                @chmod($this->tl_links_db_file, 0666);
            } else {
                return $this->raise_error("There is no file " . $this->tl_links_db_file  . ". Fail to create. Set mode to 777 on the folder.");
            }
        }

        if (!is_writable($this->tl_links_db_file)) {
            return $this->raise_error("There is no permissions to write: " . $this->tl_links_db_file . "! Set mode to 777 on the folder.");
        }

        @clearstatcache();

        if (filemtime($this->tl_links_db_file) < (time()-$this->tl_cache_lifetime) ||
           (filemtime($this->tl_links_db_file) < (time()-$this->tl_cache_reloadtime) && filesize($this->tl_links_db_file) == 0)) {

            @touch($this->tl_links_db_file, time());

            $path = '/' . TRUSTLINK_USER . '/' . strtolower( $this->tl_host ) . '/' . strtoupper( $this->tl_charset);

            if ($links = $this->fetch_remote_file($this->tl_server, $path)) {
                if (substr($links, 0, 12) == 'FATAL ERROR:' && $this->tl_debug) {
                    $this->raise_error($links);
                } else if (@unserialize($links) !== false) {
                    $this->lc_write($this->tl_links_db_file, $links);
                } else if ($this->tl_debug) {
                    $this->raise_error("Cans't unserialize received data.");
                }
            }
        }

        $links = $this->lc_read($this->tl_links_db_file);
        $this->tl_file_change_date = gmstrftime ("%d.%m.%Y %H:%M:%S",filectime($this->tl_links_db_file));
        $this->tl_file_size = strlen( $links);
        if (!$links) {
            $this->tl_links = array();
            if ($this->tl_debug)
            	$this->raise_error("Empty file.");
        } else if (!$this->tl_links = @unserialize($links)) {
            $this->tl_links = array();
            if ($this->tl_debug)
            	$this->raise_error("Can't unserialize data from file.");
        }

        if (isset($this->tl_links['__trustlink_delimiter__'])) {
            $this->tl_links_delimiter = $this->tl_links['__trustlink_delimiter__'];
        }

		if ($this->tl_test)
		{
        	if (isset($this->tl_links['__test_tl_link__']) && is_array($this->tl_links['__test_tl_link__']))
        		for ($i=0;$i<$this->tl_test_count;$i++)
					$this->tl_links_page[$i]=$this->tl_links['__test_tl_link__'];
		} else {

            $tl_links_temp=array();
            foreach($this->tl_links as $key=>$value){
                $tl_links_temp[rawurldecode($key)]=$value;
            }
            $this->tl_links=$tl_links_temp;

            //if ($this->tl_request_uri[strlen($this->tl_request_uri)-1]=='/') $this->tl_request_uri=substr($this->tl_request_uri,0,-1);
            $this->tl_links_page=array();
            if (array_key_exists($this->tl_request_uri, $this->tl_links) && is_array($this->tl_links[$this->tl_request_uri])) {
                $this->tl_links_page = array_merge($this->tl_links_page, $this->tl_links[$this->tl_request_uri]);
            }
            if (array_key_exists($this->tl_request_uri.'/', $this->tl_links) && is_array($this->tl_links[$this->tl_request_uri.'/'])) {
                $this->tl_links_page =array_merge($this->tl_links_page, $this->tl_links[$this->tl_request_uri.'/']);
            }
		}

        $this->tl_links_count = count($this->tl_links_page);
    }

    function fetch_remote_file($host, $path) {
        $user_agent = 'Trustlink Client PHP ' . $this->tl_version;

        @ini_set('allow_url_fopen', 1);
        @ini_set('default_socket_timeout', $this->tl_socket_timeout);
        @ini_set('user_agent', $user_agent);

        if (
            $this->tl_fetch_remote_type == 'file_get_contents' || (
                $this->tl_fetch_remote_type == '' && function_exists('file_get_contents') && ini_get('allow_url_fopen') == 1
            )
        ) {
            if ($data = @file_get_contents('http://' . $host . $path)) {
                return $data;
            }
        } elseif (
            $this->tl_fetch_remote_type == 'curl' || (
                $this->tl_fetch_remote_type == '' && function_exists('curl_init')
            )
        ) {
            if ($ch = @curl_init()) {
                @curl_setopt($ch, CURLOPT_URL, 'http://' . $host . $path);
                @curl_setopt($ch, CURLOPT_HEADER, false);
                @curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
                @curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $this->tl_socket_timeout);
                @curl_setopt($ch, CURLOPT_USERAGENT, $user_agent);

                if ($data = @curl_exec($ch)) {
                    return $data;
                }

                @curl_close($ch);
            }
        } else {
            $buff = '';
            $fp = @fsockopen($host, 80, $errno, $errstr, $this->tl_socket_timeout);
            if ($fp) {
                @fputs($fp, "GET {$path} HTTP/1.0\r\nHost: {$host}\r\n");
                @fputs($fp, "User-Agent: {$user_agent}\r\n\r\n");
                while (!@feof($fp)) {
                    $buff .= @fgets($fp, 128);
                }
                @fclose($fp);

                $page = explode("\r\n\r\n", $buff);

                return $page[1];
            }
        }

        return $this->raise_error("Can't connect to server: " . $host . $path);
    }

    function lc_read($filename) {
        $fp = @fopen($filename, 'rb');
        @flock($fp, LOCK_SH);
        if ($fp) {
            clearstatcache();
            $length = @filesize($filename);
            $mqr = get_magic_quotes_runtime();
            set_magic_quotes_runtime(0);
            if ($length) {
                $data = @fread($fp, $length);
            } else {
                $data = '';
            }
            set_magic_quotes_runtime($mqr);
            @flock($fp, LOCK_UN);
            @fclose($fp);

            return $data;
        }

        return $this->raise_error("Can't get data from the file: " . $filename);
    }

    function lc_write($filename, $data) {
        $fp = @fopen($filename, 'wb');
        if ($fp) {
            @flock($fp, LOCK_EX);
            $length = strlen($data);
            @fwrite($fp, $data, $length);
            @flock($fp, LOCK_UN);
            @fclose($fp);

            if (md5($this->lc_read($filename)) != md5($data)) {
                return $this->raise_error("Integrity was violated while writing to file: " . $filename);
            }

            return true;
        }

        return $this->raise_error("Can't write to file: " . $filename);
    }

    function raise_error($e) {
        $this->tl_error = '<!--ERROR: ' . $e . '-->';
        return false;
    }

    function build_links()
    {
        $links = $this->tl_links_page;
    	$result = '';
        if (isset($this->tl_links['__trustlink_start__']) && strlen($this->tl_links['__trustlink_start__']) != 0 &&
            (in_array($_SERVER['REMOTE_ADDR'], $this->tl_links['__trustlink_robots__']) || $this->tl_force_show_code)
        ) {
            $result .= $this->tl_links['__trustlink_start__'];
        }

        if (isset($this->tl_links['__trustlink_robots__']) && in_array($_SERVER['REMOTE_ADDR'], $this->tl_links['__trustlink_robots__']) || $this->tl_verbose) {

            if ($this->tl_error != '' && $this->tl_debug) {
                $result .= $this->tl_error;
            }

            $result .= '<!--REQUEST_URI=' . $_SERVER['REQUEST_URI'] . "-->\n";
            $result .= "\n<!--\n";
            $result .= 'L ' . $this->tl_version . "\n";
            $result .= 'REMOTE_ADDR=' . $_SERVER['REMOTE_ADDR'] . "\n";
            $result .= 'request_uri=' . $this->tl_request_uri . "\n";
            $result .= 'charset=' . $this->tl_charset . "\n";
            $result .= 'is_static=' . $this->tl_is_static . "\n";
            $result .= 'multi_site=' . $this->tl_multi_site . "\n";
            $result .= 'file change date=' . $this->tl_file_change_date . "\n";
            $result .= 'lc_file_size=' . $this->tl_file_size . "\n";
            $result .= 'lc_links_count=' . $this->tl_links_count . "\n";
            $result .= 'left_links_count=' . count($this->tl_links_page) . "\n";
            $result .= 'n=' . $n . "\n";
            $result .= '-->';
        }

    	$tpl_filename = dirname(__FILE__)."/".$this->tl_template.".tpl.html";
        $tpl = $this->lc_read($tpl_filename);
        if (!$tpl)
            return $this->raise_error("Template file not found");

        if (!preg_match("/<{block}>(.+)<{\/block}>/is", $tpl, $block))
            return $this->raise_error("Wrong template format: no <{block}><{/block}> tags");

        $tpl = str_replace($block[0], "%s", $tpl);
        $block = $block[0];
        $blockT = substr($block, 9, -10);

        if (strpos($blockT, '<{link}>')===false)
            return $this->raise_error("Wrong template format: no <{link}> tag.");
        if (strpos($blockT, '<{text}>')===false)
            return $this->raise_error("Wrong template format: no <{text}> tag.");
        if (strpos($blockT, '<{host}>')===false)
            return $this->raise_error("Wrong template format: no <{host}> tag.");

        foreach ($links as $link)
        {
            //$link is array('anchor'=>$anchor,'url'=>$url,'text'=>$text
            if (!is_array($link)) {
                return $this->raise_error("link must be an array");
            } elseif (!isset($link['anchor']) || !isset($link['url']) || !isset($link['text'])) {
                return $this->raise_error("format of link must be an array('anchor'=>\$anchor,'url'=>\$url,'text'=>\$text");
            } elseif (!($parsed=@parse_url($link['url'])) || !isset($parsed['host'])) {
                return $this->raise_error("wrong format of url: ".$link['url']);
            }
            if (($level=count(explode(".",$parsed['host'])))<2) {
                return $this->raise_error("wrong host: ".$parsed['host']." in url ".$link['url']);
            }
            $host=strtolower(($level>2 && strpos(strtolower($parsed['host']),'www.')===0)?substr($parsed['host'],4):$parsed['host']);
        	$block = str_replace("<{text}>", $link['text'], $blockT);
        	$block = str_replace("<{link}>", '<a href="'.$link['url'].'">'.$link['anchor'].'</a>', $block);
            $block = str_replace("<{host}>", $host, $block);
            $text .= $block;
        }
        if (is_array($links) && (count($links)>0)){
            $tpl = sprintf($tpl, $text);
            $result .= $tpl;
        }

        if (isset($this->tl_links['__trustlink_end__']) && strlen($this->tl_links['__trustlink_end__']) != 0 &&
            (in_array($_SERVER['REMOTE_ADDR'], $this->tl_links['__trustlink_robots__']) || $this->tl_force_show_code)
        ) {
            $result .= $this->tl_links['__trustlink_end__'];
        }

        if ($this->tl_test && !$this->tl_isrobot)
        	$result = '<noindex>'.$result.'</noindex>';
        return $result;
    }
}
?>