<?php
/* Handle Access to User files */

// Exit if accessed directly
if ( ! defined('ABSPATH') ) {
   exit;
}

// Clean all output buffers to prevent corruption or delays by directly serving the file (mainly for large files)
while (ob_get_level()) ob_end_clean();

$srvr =  isset($_GET[ 'srvr' ]) ? sanitize_text_field($_GET[ 'srvr' ]) : '';
$pblc =  isset($_GET[ 'pblc' ]) ? sanitize_text_field($_GET[ 'pblc' ]) : '';
$file = isset($_GET[ 'file' ]) ? sanitize_text_field($_GET[ 'file' ]) : '';

$upfp_enable_doc_viewer = get_option('upfp_enable_doc_viewer');

$is_user_logged_in = false;
global $upf_app_plugin_activated;
$auth_header = $_SERVER['HTTP_AUTHORIZATION'] ?? '';
if ($auth_header && $upf_app_plugin_activated) {

	$jwt_service = new Upf_App_Jwt();
	list($type, $token) = explode(' ', $auth_header);

	if ($type == 'Bearer') {
		$result = $jwt_service->verify_jwt($token);

		if (!is_wp_error($result)) {

			wp_set_current_user($result);
			$is_user_logged_in = true;
			
		}
 
	}

} else {
	$is_user_logged_in = is_user_logged_in();
}

if( !$is_user_logged_in && $pblc != "true" && ($upfp_enable_doc_viewer == 'no' || !str_contains($_SERVER['HTTP_USER_AGENT'], 'Google AppsViewer') )){
	status_header(403);
	die('403 &#8212; Not allowed.');
}

list($basedir) = array_values(array_intersect_key(wp_upload_dir(), array('basedir' => 1)))+array(NULL);

if($srvr == "true") {

	$file = ABSPATH . $file;

} else if($pblc == "true") {

	$basedir .= '/upf-pblc';
    $file =  rtrim($basedir,'/').'/'.str_replace('..', '', isset($_GET[ 'file' ])?sanitize_text_field($_GET[ 'file' ]):'');

} else {

	$basedir .= '/upf-docs';
    $file =  rtrim($basedir,'/').'/'.str_replace('..', '', isset($_GET[ 'file' ])?sanitize_text_field($_GET[ 'file' ]):'');
    
}

if (!$basedir || !is_file($file)) {
	status_header(404);
	die('404 &#8212; File not found.');
}

if(isset($_GET[ 'file' ])){
	if($srvr == "true") {
        $private_file = sanitize_text_field($_GET[ 'file' ]);
    } else if($pblc == "true") {
		$private_file = 'upf-pblc/' . sanitize_text_field($_GET[ 'file' ]);
	} else {
        $private_file = 'upf-docs/' . sanitize_text_field($_GET[ 'file' ]);
    }
	$file_raw_name = sanitize_text_field($_GET[ 'file' ]);
}

$allowed = $doc_id = 0;

if( $upfp_enable_doc_viewer == 'yes' && str_contains($_SERVER['HTTP_USER_AGENT'], 'Google AppsViewer') ){

    $allowed = 1;

} else {

	$curr_user_id = get_current_user_id();
	$user = get_userdata($curr_user_id);
	$user_roles = array();
	if($user) {
		$user_roles = $user->roles;
		array_push($user_roles, 'All Users');
	}
	
	$upfp_file_manager_roles = get_option('upfp_file_manager_roles');
	
	if(!$upfp_file_manager_roles){
	    $upfp_file_manager_roles = array();
	}

	// allow access to admin users
	if(user_can( $curr_user_id, 'administrator' ) || array_intersect($user_roles, $upfp_file_manager_roles)){
		$allowed = 1;
	} else{
		// if file-author or allowed-user is viewing the file
		$the_query = new WP_Query( array( 'post_type' => 'attachment', 'post_status' => array('inherit', 'trash'), 'meta_key' => '_wp_attached_file', 'meta_value' => $private_file ) );
		if ( $the_query->have_posts() ) {
			while ( $the_query->have_posts() ) {
				
				$the_query->the_post();
				$doc_id = get_the_ID();
				$doc_author = get_the_author_meta("ID");
				$doc_owner = get_post_meta($doc_id, 'upf_owner', true);
				$is_public = get_post_meta($doc_id, 'upf_public', true);

				if($is_public) {

					$file_pwd = get_post_meta($doc_id, 'upf_file_pwd', true);
					if($file_pwd) {

						$pwd = upf_get_password($doc_id);
						if($pwd == $file_pwd) {
							$allowed = 1;
						}
					} else {
						$allowed = 1;
					}

				} else if($curr_user_id == $doc_author){
					$allowed = 1;
				}else if($curr_user_id == $doc_owner){
					$allowed = 1;
				}
				else{
					$upf_allowed_users = get_post_meta($doc_id, 'upf_allowed', true);
					$upf_allowed_roles = get_post_meta($doc_id, 'upf_allowed_roles', true);
					if($upf_allowed_users || $upf_allowed_roles){
						if((is_array($upf_allowed_users) && in_array($curr_user_id, $upf_allowed_users)) || (is_array($upf_allowed_roles) && array_intersect($user_roles, $upf_allowed_roles))){
							$allowed = 1;
						}
					}
				}
				
			}
		}
		wp_reset_query();

		// If doc is image and not original but different size
		if(!$doc_id){
            
			$args = array(
				'post_type' => 'attachment',
				'post_status' => array('inherit', 'trash'),
				'meta_query' => array(
					array(
						'key' => '_wp_attachment_metadata',
						'value' => $file_raw_name,
						'compare' => 'LIKE'
					)
				)
			);
			$the_query = new WP_Query( $args );
			if ( $the_query->have_posts() ) {
				while ( $the_query->have_posts() ) {
                    
					$the_query->the_post();
					$doc_id = get_the_ID();
					$doc_author = get_the_author_meta("ID");
					$doc_owner = get_post_meta($doc_id, 'upf_owner', true);
					$is_public = get_post_meta($doc_id, 'upf_public', true);

					if($is_public) {
						$file_pwd = get_post_meta($doc_id, 'upf_file_pwd', true);
						if($file_pwd) {

							$pwd = upf_get_password($doc_id);
							if($pwd == $file_pwd) {
								$allowed = 1;
							}
						} else {
							$allowed = 1;
						}
					} else if($curr_user_id == $doc_author){
						$allowed = 1;
					}else if($curr_user_id == $doc_owner){
						$allowed = 1;
					}
					else{
						$upf_allowed_users = get_post_meta($doc_id, 'upf_allowed', true);
						$upf_allowed_roles = get_post_meta($doc_id, 'upf_allowed_roles', true);
						if($upf_allowed_users || $upf_allowed_roles){
							if((is_array($upf_allowed_users) && in_array($curr_user_id, $upf_allowed_users)) || (is_array($upf_allowed_roles) && array_intersect($user_roles, $upf_allowed_roles))){
								$allowed = 1;
							}
						}
					}
				}
			}
			wp_reset_query();
		}
	}

}

if(!$allowed){
	status_header(403);
	die('403 &#8212; You do not have Permission to view this file.');
}

$mime = wp_check_filetype($file);
if( false === $mime[ 'type' ] && function_exists( 'mime_content_type' ) )
	$mime[ 'type' ] = mime_content_type( $file );

if( $mime[ 'type' ] )
	$mimetype = $mime[ 'type' ];
else
	$mimetype = 'image/' . substr( $file, strrpos( $file, '.' ) + 1 );

header( 'Content-Type: ' . $mimetype ); // always send this
if ( false === strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS' ) )
	header( 'Content-Length: ' . filesize( $file ) );

$last_modified = gmdate( 'D, d M Y H:i:s', filemtime( $file ) );
$etag = '"' . md5( $last_modified ) . '"';
header( "Last-Modified: $last_modified GMT" );
header( 'ETag: ' . $etag );
header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', time() + 100000000 ) . ' GMT' );

// Support for Conditional GET
$client_etag = isset( $_SERVER['HTTP_IF_NONE_MATCH'] ) ? stripslashes( sanitize_text_field( $_SERVER['HTTP_IF_NONE_MATCH'] ) ) : false;

if( ! isset( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) )
	$_SERVER['HTTP_IF_MODIFIED_SINCE'] = false;

$client_last_modified = trim( rest_sanitize_boolean( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) );

// If string is empty, return 0. If not, attempt to parse into a timestamp
$client_modified_timestamp = $client_last_modified ? strtotime( $client_last_modified ) : 0;

// Make a timestamp for our most recent modification...
$modified_timestamp = strtotime($last_modified);

if ( ( $client_last_modified && $client_etag )
	? ( ( $client_modified_timestamp >= $modified_timestamp) && ( $client_etag == $etag ) )
	: ( ( $client_modified_timestamp >= $modified_timestamp) || ( $client_etag == $etag ) )
	) {
	status_header( 304 );
	exit;
}

// If we made it this far, just serve the file
status_header( 200 );
readfile( $file );
exit;