<?php

namespace ski;



/**
 * A utility class for performing operations on paths.
 */
class path
{
    /* PUBLIC */

    /**
     * Constructs the full URL with query string - oddly, there is not a single PHP $_SERVER value already.
     * @return string The full URL along with query string
     */
    public static function get_current_url()
    {
        //  Get the current URL, complete with query string, if present..
        $fullURL = array_key_exists( 'SCRIPT_URI', $_SERVER ) ? $_SERVER[ 'SCRIPT_URI' ] : $_SERVER[ 'PHP_SELF' ];
        if ( !empty ( $_SERVER[ 'QUERY_STRING' ] ) )
        {
            $fullURL = sprintf( '%s?%s', $_SERVER[ 'SCRIPT_URI' ], $_SERVER[ 'QUERY_STRING' ] );
        }

        //  Return the ultimate URL..
        return $fullURL;
    }

    /**
     * Takes a relative URL and changes it into an absolute
     * URL considering the base URL page.
     * 
     * From:
     * http://www.geekality.net/2011/05/12/php-dealing-with-absolute-and-relative-urls/
     * @param string $url The relative URL to convert
     * @param string $base The URL that the relative URL resides, directories must end with a front-slash
     * @return string The converted absolute URL
     */
    public static function make_absolute( $url, $base ) 
    {
        //  Return base if no url..
        if( !$url ) return $base;

        //  Return if already absolute URL
        if( parse_url( $url, PHP_URL_SCHEME ) != '' ) return $url;

        //  URLs only containing query or anchor..
        if( ( $url[0] == '#' ) || ( $url[0] == '?' ) ) return $base.$url;

        //  Parse base URL and convert to local variables: $scheme, $host, $path..
        extract( parse_url( $base ) );

        //  If no path, use /..
        if( !isset( $path ) ) $path = '/';

        //  Remove non-directory element from path..
        $path = preg_replace( '#/[^/]*$#', '', $path );

        //  Destroy path if relative url points to root..
        if( $url[0] == '/' ) $path = '';

        //  Dirty absolute URL..
        $abs = "$host$path/$url";

        //  Replace '//' or '/./' or '/foo/../' with '/'..
        $re = array( '#(/\.?/)#', '#/(?!\.\.)[^/]+/\.\./#' );
        for( $n = 1; $n > 0; $abs = preg_replace( $re, '/', $abs, -1, $n ) ) {}

        //  Absolute URL is ready..
        return $scheme.'://'.$abs;
    }

    /**
     * Changes the extension of a file.
     * 
     * @param string $file_path The full file name/path to change
     * @param string $new_extension The extension to change to (no leading dot)
     * @return string The newly-changed full file name/path
     */
    public static function change_extension( $file_path, $new_extension )
    {
        $info = pathinfo( $file_path );

        $print_dirname = ( empty( $info['dirname'] ) || ( $info['dirname'] == '.' ) ) ? '' : ( $info['dirname'].'/' );
        $print_extension = ( empty( $new_extension ) ) ? '' : ( '.'.$new_extension );

        return $print_dirname.$info['filename'].$print_extension;
    }

    /**
     * Returns an array of files found under a specific directory.
     * 
     * @param string $folder The directory path to search for files
     * @param string $pattern A regex pattern to be used to filter in results (take care that this could match the whole path)
     * @param boolean $include_subdirectories Set to 'true' if all subfolder should be searched; set to 'false' if just the top-level
     * @return array The list of fule filepaths that met the criteria
     */
    public static function get_files( $folder, $pattern = '/.*/', $include_subdirectories = false )
    {
        $dir = $include_subdirectories ? new \RecursiveDirectoryIterator( $folder ) : new \DirectoryIterator( $folder );
        $iters = $include_subdirectories ? new \RecursiveIteratorIterator( $dir ) : new \IteratorIterator( $dir );
        $file_list = array();
        foreach ( $iters as $iter )
        {
            $file = $iter->getPathname();
            if ( !preg_match( $pattern, $file ) ) continue;
            if ( !is_file( $file ) ) continue;
            $file_list[] = $file;
        }
        return $file_list;
    }

    /**
     * Changes all occurences of backslashes to forward slashes - can come
     * in handy when working with a windows path that needs to look like
     * a *nix path instead.
     * 
     * @param string $path The path to change
     * @return string The path with forward slashes
     */
    public static function force_forward_slashes( $path )
    {
        return str_replace( '\\', '/', $path );
    }

    /**
     * Trying to figure out the ski.web directory for both local and remote
     * versions has become ridiculous.  As a result, it is a requirement for
     * installation that the programmer define the SKI_URI.  Should be something
     * like 'http://localhost/mysite' instead of 'e:\wamp\www\mysite'.
     * 
     * @return string The full path to where ski.web resides
     */
    public static function get_ski_directory_uri()
    {
        //  If the programmer properly set the installation directory.
        if ( defined( 'SKI_URI' ) )
        {
            return SKI_URI;
        }
        
        //  Making it here means they have not, so cut out with information.
        die( 'You must define the SKI_URI just before you include the ski.web library' );
    }
    
    /**
     * Looks at the URL that was used to open the current page (from the server).
     * Note:    Do not rely on $_SERVER['REQUEST_SCHEME']; some older versions of
     *          Apache do not fill that value in properly.
     * 
     * @return string Something like 'http', 'https', 'ftp', etc.  No '://' is included.
     */
    public static function get_request_protocol()
    {
        if ( isset( $_SERVER['HTTPS'] ) && $_SERVER['HTTPS'] === 'on' )
            return 'https';
        else if ( isset( $_SERVER['REQUEST_SCHEME'] ) )
            return $_SERVER['REQUEST_SCHEME'];
        
        return 'http';
    }

    /* PRIVATE */

    /**
     * Only use this class as a utility..
     */
    private function __construct()
    {
        //  Intentionally blank..
    }
}


?>