<?php

/**
 * HTML Purifier's internal representation of a URI.
 * @note
 *      Internal data-structures are completely escaped. If the data needs
 *      to be used in a non-URI context (which is very unlikely), be sure
 *      to decode it first. The URI may not necessarily be well-formed until
 *      validate() is called.
 */
class HTMLPurifier_URI
{
    /**
     * @type string
     */
    public $scheme;

    /**
     * @type string
     */
    public $userinfo;

    /**
     * @type string
     */
    public $host;

    /**
     * @type int
     */
    public $port;

    /**
     * @type string
     */
    public $path;

    /**
     * @type string
     */
    public $query;

    /**
     * @type string
     */
    public $fragment;

    /**
     * @param string $scheme
     * @param string $userinfo
     * @param string $host
     * @param int $port
     * @param string $path
     * @param string $query
     * @param string $fragment
     * @note Automatically normalizes scheme and port
     */
    public function __construct($scheme, $userinfo, $host, $port, $path, $query, $fragment)
    {
        $this->scheme = is_null($scheme) || ctype_lower($scheme) ? $scheme : strtolower($scheme);
        $this->userinfo = $userinfo;
        $this->host = $host;
        $this->port = is_null($port) ? $port : (int)$port;
        $this->path = $path;
        $this->query = $query;
        $this->fragment = $fragment;
    }

    /**
     * Retrieves a scheme object corresponding to the URI's scheme/default
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return HTMLPurifier_URIScheme Scheme object appropriate for validating this URI
     */
    public function getSchemeObj($config, $context)
    {
        $registry = HTMLPurifier_URISchemeRegistry::instance();
        if ($this->scheme !== null) {
            $scheme_obj = $registry->getScheme($this->scheme, $config, $context);
            if (!$scheme_obj) {
                return false;
            } 
        } else {
            
            $def = $config->getDefinition('URI');
            $scheme_obj = $def->getDefaultScheme($config, $context);
            if (!$scheme_obj) {
                if ($def->defaultScheme !== null) {
                    
                    trigger_error(
                        'Default scheme object "' . $def->defaultScheme . '" was not readable',
                        E_USER_WARNING
                    );
                } 
                return false;
            }
        }
        return $scheme_obj;
    }

    /**
     * Generic validation method applicable for all schemes. May modify
     * this URI in order to get it into a compliant form.
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool True if validation/filtering succeeds, false if failure
     */
    public function validate($config, $context)
    {
        
        $chars_sub_delims = '!$&\'()*+,;=';
        $chars_gen_delims = ':/?#[]@';
        $chars_pchar = $chars_sub_delims . ':@';

        
        if (!is_null($this->host)) {
            $host_def = new HTMLPurifier_AttrDef_URI_Host();
            $this->host = $host_def->validate($this->host, $config, $context);
            if ($this->host === false) {
                $this->host = null;
            }
        }

        
        
        
        
        
        
        if (!is_null($this->scheme) && is_null($this->host) || $this->host === '') {
            
            
            $def = $config->getDefinition('URI');
            if ($def->defaultScheme === $this->scheme) {
                $this->scheme = null;
            }
        }

        
        if (!is_null($this->userinfo)) {
            $encoder = new HTMLPurifier_PercentEncoder($chars_sub_delims . ':');
            $this->userinfo = $encoder->encode($this->userinfo);
        }

        
        if (!is_null($this->port)) {
            if ($this->port < 1 || $this->port > 65535) {
                $this->port = null;
            }
        }

        
        $segments_encoder = new HTMLPurifier_PercentEncoder($chars_pchar . '/');
        if (!is_null($this->host)) { 
            
            
            
            
            
            
            
            
            $this->path = $segments_encoder->encode($this->path);
        } elseif ($this->path !== '') {
            if ($this->path[0] === '/') {
                
                
                
                if (strlen($this->path) >= 2 && $this->path[1] === '/') {
                    
                    
                    
                    
                    $this->path = '';
                } else {
                    $this->path = $segments_encoder->encode($this->path);
                }
            } elseif (!is_null($this->scheme)) {
                
                
                
                $this->path = $segments_encoder->encode($this->path);
            } else {
                
                
                
                $segment_nc_encoder = new HTMLPurifier_PercentEncoder($chars_sub_delims . '@');
                $c = strpos($this->path, '/');
                if ($c !== false) {
                    $this->path =
                        $segment_nc_encoder->encode(substr($this->path, 0, $c)) .
                        $segments_encoder->encode(substr($this->path, $c));
                } else {
                    $this->path = $segment_nc_encoder->encode($this->path);
                }
            }
        } else {
            
            $this->path = ''; 
        }

        
        $qf_encoder = new HTMLPurifier_PercentEncoder($chars_pchar . '/?');

        if (!is_null($this->query)) {
            $this->query = $qf_encoder->encode($this->query);
        }

        if (!is_null($this->fragment)) {
            $this->fragment = $qf_encoder->encode($this->fragment);
        }
        return true;
    }

    /**
     * Convert URI back to string
     * @return string URI appropriate for output
     */
    public function toString()
    {
        
        $authority = null;
        
        
        
        if (!is_null($this->host)) {
            $authority = '';
            if (!is_null($this->userinfo)) {
                $authority .= $this->userinfo . '@';
            }
            $authority .= $this->host;
            if (!is_null($this->port)) {
                $authority .= ':' . $this->port;
            }
        }

        
        
        
        
        
        
        $result = '';
        if (!is_null($this->scheme)) {
            $result .= $this->scheme . ':';
        }
        if (!is_null($authority)) {
            $result .= '//' . $authority;
        }
        $result .= $this->path;
        if (!is_null($this->query)) {
            $result .= '?' . $this->query;
        }
        if (!is_null($this->fragment)) {
            $result .= '#' . $this->fragment;
        }

        return $result;
    }

    /**
     * Returns true if this URL might be considered a 'local' URL given
     * the current context.  This is true when the host is null, or
     * when it matches the host supplied to the configuration.
     *
     * Note that this does not do any scheme checking, so it is mostly
     * only appropriate for metadata that doesn't care about protocol
     * security.  isBenign is probably what you actually want.
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool
     */
    public function isLocal($config, $context)
    {
        if ($this->host === null) {
            return true;
        }
        $uri_def = $config->getDefinition('URI');
        if ($uri_def->host === $this->host) {
            return true;
        }
        return false;
    }

    /**
     * Returns true if this URL should be considered a 'benign' URL,
     * that is:
     *
     *      - It is a local URL (isLocal), and
     *      - It has a equal or better level of security
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool
     */
    public function isBenign($config, $context)
    {
        if (!$this->isLocal($config, $context)) {
            return false;
        }

        $scheme_obj = $this->getSchemeObj($config, $context);
        if (!$scheme_obj) {
            return false;
        } 

        $current_scheme_obj = $config->getDefinition('URI')->getDefaultScheme($config, $context);
        if ($current_scheme_obj->secure) {
            if (!$scheme_obj->secure) {
                return false;
            }
        }
        return true;
    }
}


