////////////////////////////////////////////////////////////////////////////////////////
// Class     : user.class.php
// Purpose   : Creates a user object containing informtion about current user
// Author    : Gavin Taylor
// Copyright : gavtaylor.co.uk
// Version   : 1.0
//
// Version History
//  1.0 - 29/03/09 - process_login_state(), load_user_details(), added sessioncheck()
//
///////////////////////////////////////////////////////////////////////////////////////

class user
{
  public $error;
	
	public $session_id;
  public $login_state;
  public $ip_address;
  public $useragent;
  public $access_level;
	
	public $id;
  public $username;
  public $password;
  public $email;
  
  public $firstname;
  public $lastname;
  public $address_street;
  public $address_district;
  public $address_city;
  public $address_county;
  public $address_postcode;
  public $address_country;
  public $address_phone;
  public $address_mobile;
  
  public $active;
  public $registered;
  public $last_login;
  
  
  /* class constructor ------------------------------------------------- */
  function __construct($user_id = 0)
  {    
		//start the session if needed
		if(!isset($_SESSION)) { session_start(); }
    
    //populate default variables    
    $this->session_id      = session_id();
    $this->login_state     = FALSE;
		$this->ip_address			 = $_SERVER['REMOTE_ADDR'];
		$this->useragent       = $_SERVER['HTTP_USER_AGENT'];
		$this->access_level		 = "public";
    
    //determine login state
    $this->process_login_state();
    
		if($user_id>0)
		{
			$this->id = $user_id;
			$this->load();
		}
		
    return TRUE;
  }
  
  /* public functions -------------------------------------------------- */
  
	//load user object
  public function load()
	{
		$result = mysql_query("SELECT * FROM user WHERE user_active = 'yes' and user_id = '".mysql_real_escape_string($this->id)."' LIMIT 1");
		
		if(mysql_numrows($result)>0)
		{
			$row = mysql_fetch_assoc($result);
			
			foreach($row as $key => $value)
			{
				$this->{str_replace('user_','',$key)} = $value;
			}
			
		}
		
	}
	
	//checks if user is logged in or not
  public function sessioncheck()
	{
	  //check if session is empty, if it is check for auto login cookie
	  if(empty($_SESSION['user_username']) or empty($_SESSION['user_password']))
	  {
	  	if(isset($HTTP_COOKIE_VARS["user_username"]) and isset($HTTP_COOKIE_VARS["user_password"]))
	  	{  
    		$_SESSION['user_username'] = $HTTP_COOKIE_VARS["user_username"];
				$_SESSION['user_password'] = $HTTP_COOKIE_VARS["user_password"];
        
				return TRUE;
	    }
			else
			{
				// session is empty and cookie does not exist so user is not logged in
				return FALSE;
			}
	  } 
	  else
	  {
	    // user session vaiables are present so user is logged in
			return TRUE;
	  }   
	}
  
	//check the database to be sure user is valid
	public function is_valid_user()
	{
		//check required variables
    if(empty($this->username)) { $this->error[] = "You have not entered your username"; return FALSE; }
		if(empty($this->password)) { $this->error[] = "You have not entered your password"; return FALSE; }
    
		$result = mysql_query("SELECT user_id FROM user WHERE user_username = '".mysql_real_escape_string($this->username)."' AND user_password = '".mysql_real_escape_string($this->password)."'", DB_LINK);
		
    if($result and mysql_numrows($result)>0)
    {
      if(empty($this->user_id)) { $this->user_id = mysql_result($result, 0); }
      
      return TRUE;
    }
    
		$this->error[] = "Your login details were not found in our system";
		
		return FALSE;
	}
  
  //populate class vaiables with user data
  public function load_user_details()
  {
    //check databse for valid user
    if($this->is_valid_user())
    {
      //load user details
      $result = mysql_query("SELECT * FROM user WHERE user_username = '".mysql_real_escape_string($this->username)."' AND user_password = '".mysql_real_escape_string($this->password)."'", DB_LINK);
      
      if($result and mysql_numrows($result)>0)
      {
        $row = mysql_fetch_assoc($result);
				
				if($row['user_active'] == 'yes')
				{
					$this->login_state				= TRUE;
					$this->access_level 			= $row['user_access'];
					
					$this->id 								= $row['user_id'];
					$this->email 							= $row['user_email'];
					
					$this->firstname 					= $row['user_firstname'];
					$this->lastname 					= $row['user_lastname'];
					$this->address_street 		= $row[''];
					$this->address_district 	= $row[''];
					$this->address_city 			= $row[''];
					$this->address_county 		= $row[''];
					$this->address_postcode 	= $row[''];
					$this->address_country 		= $row[''];
					$this->address_phone 			= $row[''];
					$this->address_mobile 		= $row[''];
					
					$this->active 						= $row['user_active'];
					$this->registered 				= $row['user_registered'];
					$this->last_login 				= $row['user_last_login'];
					
					return TRUE;
				}
				else
				{
					$this->error[] = "Your account is not currently active, please contact us to activate it";
				}
      }
			else
			{
				$this->error[] = "Unable to load user data";
			}
    }
    
    return FALSE;
  }
	
	//destroy session data and any cookies to logout the user  -- move to login class **************
	public function logout()
	{
		//set cookies to 1 hour ago to trigger browser to auto delete
		setcookie("user_username",$_SESSION['user_username'], time()-604800, '/');
		setcookie("user_password",$_SESSION['user_password'], time()-604800, '/');
		
		//destroy the current session
		session_destroy();
		
		return TRUE;
	}
  
	/* public static functions ------------------------------------------------- */
	
	//update a users password with new hash
	public static function update_password($user_id, $password)
	{
		$result = mysql_query("UPDATE user SET user_password = '".mysql_real_escape_string(user::hash_password($password))."' WHERE user_id = '".mysql_real_escape_string($user_id)."'", DB_LINK);
		if($result) { return TRUE; } else { return FALSE; }
	}
	
	//get user id from email address
	public static function id_from_email($email_address)
	{
		$result = mysql_query("SELECT user_id FROM user
													 WHERE user_email = '".mysql_real_escape_string($email_address)."'
													  AND user_active = 'yes'", DB_LINK);
		if($result and mysql_numrows($result)>0) { return mysql_result($result, 0); } else { return FALSE; }
	}
	
	
	//returns a string encrypted via the currently set hash
	public static function hash_password($password)
	{
		return md5($password);
	}
	
	
	
  /* private functions ------------------------------------------------- */
  
  //determine users login state and populate appropriate fields
  private function process_login_state()
  {
    if($this->sessioncheck())
    {
      //load user details
      $this->username = $_SESSION['user_username'];
      $this->password = $_SESSION['user_password'];
      
      if($this->load_user_details())
      {
        //user is logged in so update status flag
        $this->login_state = TRUE;
      }
    }
    else
    {
      //user is logged out
    }
		
    return TRUE;
  }
  
}