<?php
/*
    This file is part of Hotseat Corner.

    Hotseat Corner is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Hotseat Corner is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Hotseat Corner.  If not, see <http://www.gnu.org/licenses/>.
*/
	class HSUtils_Stack implements Iterator {
		private $_total;
		private $_limit;
		private $_name;
		private $_stack;
		private $_count;
		private $_offset = -1;
		private $_nexturi;
		private $_backuri;
		private $_stackpos = 0;
		
		private static $inner_glue = '^';
		private static $outer_glue = '|';
		private static $props;
		private static $loaded = false;
		
		public function __construct () 
		{
		}
		
		public static function get ($name) 
		{
			if (self::$loaded === false) {
				if ($_GET['components']) {
					$components = explode(self::$outer_glue, $_GET['components']);
					foreach ($components as $component) {
						list($id, $offset) = explode(self::$inner_glue, $component);
						self::$props[$id] = $offset;
					}
					self::$loaded = true;
				}
			}
			return (self::$props[$name] > 0)? self::$props[$name] : 0;
		}
		
		public static function genArgs ($newkey, $newpos = 0) 
		{
			$inner_glue = self::$inner_glue;
			if (self::$props !== null) {
				foreach (self::$props as $key => $pos) {
					$urlparts[$key] = "{$key}{$inner_glue}{$pos}";
				}
			}
			if ($newpos > 0) {
				$urlparts[$newkey] = "{$newkey}{$inner_glue}{$newpos}";
			}
			else {
				unset($urlparts[$newkey]);
			}
			if ($urlparts !== null)	{
				return implode(self::$outer_glue, $urlparts);
			}
		}
		
		public function __get ($key) 
		{
			switch ($key) {
				case 'upper':
					return (($this->_offset + $this->_limit) > $this->_total)? $this->_total : $this->_offset + $this->_limit;
				case 'lower':
					return $this->_offset+1;
				case 'nexturi':
					if (($this->_offset + $this->_limit) >= $this->_total) {
						return null;
					}
					if ($this->_nexturi === null) {
						foreach ($_GET as $key=>$val) {
							$pairs[$key] = $key.'='.$val;
						}
						$next = (($this->_offset + $this->_limit) < $this->_total && $this->_limit > 0)? $this->_offset + $this->_limit : 0;
						$components = self::genArgs($this->_name, $next);
						if ($components != null) {
							$pairs['components'] = 'components='.$components;
						}
						else {
							unset($pairs['components']);
						}
						if ($pairs !== null) {
							$argstring = implode('&', $pairs);
						}
						$this->_nexturi = basename($_SERVER['SCRIPT_URI']).'?'.$argstring;
					}
					return $this->_nexturi;
				case 'backuri':
					if ($this->_offset <= 0) {
						return null;
					}
					if ($this->_backuri === null) {
						foreach ($_GET as $key=>$val) {
							$pairs[$key] = $key.'='.$val;
						}
						$back = ($this->_offset > 0 && ($this->_offset - $this->_limit) > 0 && $this->_limit > 0)? $this->_offset - $this->_limit : 0;
						$components = self::genArgs($this->_name, $back);
						if ($components != null) {
							$pairs['components'] = 'components='.$components;
						}
						else {
							unset($pairs['components']);
						}
						if ($pairs !== null) {
							$argstring = implode('&', $pairs);
						}
						$this->_backuri = basename($_SERVER['SCRIPT_URI']).'?'.$argstring;
					}
					return $this->_backuri;
			}
			$k = '_'.$key;
			return $this->$k;
		}
		
		public function __set ($key, $val) 
		{
			switch ($key) {
				case 'total':
					if ($this->_total === null) {
						$this->_total = $val;
					}
					return;
				case 'stack':
					if ($this->_stack === null) {
						$this->_stack = $val;
						$this->_count = count($val);
					}
					return;
				case 'name':
					if ($this->_name === null) {
						$this->_name = $val;
					}
					return;
				case 'limit':
					if ($this->_limit === null) {
						$this->_limit = $val;
					}
					return;
				case 'offset':
					if ($this->_offset === null) {
						$this->_offset = $val;
					}
					return;
			}
		}
		
		public function rewind ()
		{
			$this->_stackpos = 0;
		}
		
		public function next()
		{
			$this->_stackpos++;
		}
		
		public function valid ()
		{
			return ($this->stack[$this->_stackpos] !== null)? true : false;
		}
		
		public function current ()
		{
			return $this->stack[$this->_stackpos];
		}
		
		public function key ()
		{
			return $this->_stackpos;
		}
	}
?>