<?php
/*
	VK SOLUTIONS ROTATOR
	Version 0.6 - January 24, 2009
	
	Author: Van Kham CHIEM (http://www.askvk.com) in the scope of his tech research activities for VK Labs (http://www.vklabs.com), a tech research cell, subsidiary of VK Solutions (http://www.vksolutions.com).


	LICENSE
	
	This work is released under GPLv3. Please consult the README.html file or the URL http://www.opensource.org/licenses/gpl-3.0.html for more information.
	
	If you like this work, please show your support by keeping the credits and link backs at the footer intact with the link backs active and unaltered for this work and any derivative works.

*/

  function file_rotate_array($n_file_url_to_generate, $file_extensions, $file_dir_base, $url_base) {
		if (is_dir($file_dir_base)) {
			if ($dh = opendir($file_dir_base)) {
				while (($filename = readdir($dh)) !== false) {
					if ( ( $filename != "." ) && ( $filename != ".." ) ) {
						$path_parts = pathinfo($filename);
						$file_extension = strtolower($path_parts['extension']);
						if ( in_array ($file_extension, $file_extensions ) ) {
								$filenames[] = $filename;
						}
					}
				}
				closedir($dh);
			}
		}
		$n_total_existing_files = count($filenames);
		if ( $n_total_existing_files > 0 ) {
		  $array_url_to_generate = array($n_file_url_to_generate);
			for ($i_files_to_generate = 0; $i_files_to_generate < $n_file_url_to_generate; $i_files_to_generate++) {
  			$fRepeat = true;
				do {
					srand((double)microtime()*1000000);
					$rand_num = rand(0, $n_total_existing_files-1);
					$random_url = $url_base . "/" . $filenames[$rand_num];
					if ( $i_files_to_generate < $n_total_existing_files ) {
						if ( !in_array ($random_url, $array_url_to_generate) ) {
							$fRepeat = false;
						}
					} else {
						$fRepeat = false;
					}
				} while ( $fRepeat );
				$array_url_to_generate[$i_files_to_generate] = $random_url;
			} 
		} else {
			$array_url_to_generate = null;
		}
		return $array_url_to_generate;
	}

  function get_file_rotate_array_values($n_file_url_to_generate, $file_extensions, $file_dir_base, $url_base) {
    $array_values  = file_rotate_array($n_file_url_to_generate, $file_extensions, $file_dir_base, $url_base);
		if ( isset($array_values) ) { 
		  $array_values = array_values($array_values);
		}  
	  return $array_values;
	}
	
	function get_file_rotate_string_value($file_extensions, $file_dir_base, $url_base) {
    $array_values  = get_file_rotate_array_values(1, $file_extensions, $file_dir_base, $url_base);
		if ( ( isset($array_values) ) && ( count($array_values) > 0 ) ) {
		    $string_value = $array_values[0];
		} else {
		  $string_value = "";
		}
	  return $string_value;
	}
?>