<?php

/**
 * Validates a URI as defined by RFC 3986.
 * @note Scheme-specific mechanics deferred to HTMLPurifier_URIScheme
 */
class HTMLPurifier_AttrDef_URI extends HTMLPurifier_AttrDef {
	
	/**
	 * @type HTMLPurifier_URIParser
	 */
	protected $parser;
	
	/**
	 * @type bool
	 */
	protected $embedsResource;
	
	/**
	 *
	 * @param bool $embeds_resource
	 *        	Does the URI here result in an extra HTTP request?
	 */
	public function __construct($embeds_resource = false) {
		$this->parser = new HTMLPurifier_URIParser ();
		$this->embedsResource = ( bool ) $embeds_resource;
	}
	
	/**
	 *
	 * @param string $string        	
	 * @return HTMLPurifier_AttrDef_URI
	 */
	public function make($string) {
		$embeds = ($string === 'embedded');
		return new HTMLPurifier_AttrDef_URI ( $embeds );
	}
	
	/**
	 *
	 * @param string $uri        	
	 * @param HTMLPurifier_Config $config        	
	 * @param HTMLPurifier_Context $context        	
	 * @return bool|string
	 */
	public function validate($uri, $config, $context) {
		if ($config->get ( 'URI.Disable' )) {
			return false;
		}
		
		$uri = $this->parseCDATA ( $uri );
		
		// parse the URI
		$uri = $this->parser->parse ( $uri );
		if ($uri === false) {
			return false;
		}
		
		// add embedded flag to context for validators
		$context->register ( 'EmbeddedURI', $this->embedsResource );
		
		$ok = false;
		do {
			
			// generic validation
			$result = $uri->validate ( $config, $context );
			if (! $result) {
				break;
			}
			
			// chained filtering
			$uri_def = $config->getDefinition ( 'URI' );
			$result = $uri_def->filter ( $uri, $config, $context );
			if (! $result) {
				break;
			}
			
			// scheme-specific validation
			$scheme_obj = $uri->getSchemeObj ( $config, $context );
			if (! $scheme_obj) {
				break;
			}
			if ($this->embedsResource && ! $scheme_obj->browsable) {
				break;
			}
			$result = $scheme_obj->validate ( $uri, $config, $context );
			if (! $result) {
				break;
			}
			
			// Post chained filtering
			$result = $uri_def->postFilter ( $uri, $config, $context );
			if (! $result) {
				break;
			}
			
			// survived gauntlet
			$ok = true;
		} while ( false );
		
		$context->destroy ( 'EmbeddedURI' );
		if (! $ok) {
			return false;
		}
		// back to string
		return $uri->toString ();
	}
}

// vim: et sw=4 sts=4