<?php
/*
	This is the primary class for WP Statistics recording hits on the WordPress site.  It is extended by the Hits class and the GeoIPHits class.

	This class handles; visits, visitors and pages.
*/

class WP_Statistics {

	// Setup our protected, private and public variables.
	protected $db;
	protected $tb_prefix;
	protected $ip = false;
	protected $ip_hash = false;
	protected $agent;

	private $result;
	private $historical;
	private $user_options_loaded = false;
	private $is_feed = false;
	private $tz_offset = 0;
	private $country_codes = false;
	private $referrer = false;

	public $coefficient = 1;
	public $plugin_dir = '';
	public $plugin_url = '';
	public $user_id = 0;
	public $options = array();
	public $user_options = array();
	public $menu_slugs = array();

	// Construction function.
	public function __construct() {

		global $wpdb;

		if( get_option('timezone_string') ) {
			$this->tz_offset = timezone_offset_get( timezone_open( get_option('timezone_string') ), new DateTime() );
		} else if( get_option('gmt_offset') ) {
			$this->tz_offset = get_option('gmt_offset') * 60 * 60;
		}

		$this->db = $wpdb;
		$this->tb_prefix = $wpdb->prefix;
		$this->agent = $this->get_UserAgent();
		$this->historical = array();

		// Load the options from the database
		$this->options = get_option( 'wp_statistics' );

		// Set the default co-efficient.
		$this->coefficient = $this->get_option('coefficient', 1);

		// Double check the co-efficient setting to make sure it's not been set to 0.
		if( $this->coefficient <= 0 ) { $this->coefficient = 1; }

		// This is a bit of a hack, we strip off the "includes/classes" at the end of the current class file's path.
		$this->plugin_dir = substr( dirname( __FILE__ ), 0, -17 );
		$this->plugin_url = substr( plugin_dir_url( __FILE__ ), 0, -17 );

		$this->get_IP();

		if( $this->get_option('hash_ips') == true ) { $this->ip_hash = '#hash#' . sha1( $this->ip + $_SERVER['HTTP_USER_AGENT'] ); }

	}

	// This function sets the current WordPress user id for the class.
	public function set_user_id() {
		if( $this->user_id == 0 ) {
			$this->user_id = get_current_user_id();
		}
	}

	// This function loads the options from WordPress, it is included here for completeness as the options are loaded automatically in the class constructor.
	public function load_options() {
		$this->options = get_option( 'wp_statistics' );
	}

	// This function loads the user options from WordPress.  It is NOT called during the class constructor.
	public function load_user_options( $force = false) {
		if( $this->user_options_loaded == true && $force != true ) { return; }

		$this->set_user_id();

		// Not sure why, but get_user_meta() is returning an array or array's unless $single is set to true.
		$this->user_options = get_user_meta( $this->user_id, 'wp_statistics', true );

		$this->user_options_loaded = true;
	}

	// The function mimics WordPress's get_option() function but uses the array instead of individual options.
	public function get_option($option, $default = null) {
		// If no options array exists, return FALSE.
		if( !is_array($this->options) ) { return FALSE; }

		// if the option isn't set yet, return the $default if it exists, otherwise FALSE.
		if( !array_key_exists($option, $this->options) ) {
			if( isset( $default ) ) {
				return $default;
			} else {
				return FALSE;
			}
		}

		// Return the option.
		return $this->options[$option];
	}

	// This function mimics WordPress's get_user_meta() function but uses the array instead of individual options.
	public function get_user_option($option, $default = null) {
		// If the user id has not been set or no options array exists, return FALSE.
		if( $this->user_id == 0 ) {return FALSE; }
		if( !is_array($this->user_options) ) { return FALSE; }

		// if the option isn't set yet, return the $default if it exists, otherwise FALSE.
		if( !array_key_exists($option, $this->user_options) ) {
			if( isset( $default ) ) {
				return $default;
			} else {
				return FALSE;
			}
		}

		// Return the option.
		return $this->user_options[$option];
	}

	// The function mimics WordPress's update_option() function but uses the array instead of individual options.
	public function update_option($option, $value) {
		// Store the value in the array.
		$this->options[$option] = $value;

		// Write the array to the database.
		update_option('wp_statistics', $this->options);
	}

	// The function mimics WordPress's update_user_meta() function but uses the array instead of individual options.
	public function update_user_option($option, $value) {
		// If the user id has not been set return FALSE.
		if( $this->user_id == 0 ) { return FALSE; }

		// Store the value in the array.
		$this->user_options[$option] = $value;

		// Write the array to the database.
		update_user_meta( $this->user_id, 'wp_statistics', $this->user_options );
	}

	// This function is similar to update_option, but it only stores the option in the array.  This save some writing to the database if you have multiple values to update.
	public function store_option($option, $value) {
		$this->options[$option] = $value;
	}

	// This function is similar to update_user_option, but it only stores the option in the array.  This save some writing to the database if you have multiple values to update.
	public function store_user_option($option, $value) {
		// If the user id has not been set return FALSE.
		if( $this->user_id == 0 ) { return FALSE; }

		$this->user_options[$option] = $value;
	}

	// This function saves the current options array to the database.
	public function save_options() {
		update_option('wp_statistics', $this->options);
	}

	// This function saves the current user options array to the database.
	public function save_user_options() {
		if( $this->user_id == 0 ) { return FALSE; }

		update_user_meta( $this->user_id, 'wp_statistics', $this->user_options );
	}

	// This function check to see if an option is currently set or not.
	public function isset_option($option) {
		if( !is_array($this->options) ) { return FALSE; }

		return array_key_exists( $option, $this->options );
	}

	// This function check to see if a user option is currently set or not.
	public function isset_user_option($option) {
		if( $this->user_id == 0 ) { return FALSE; }
		if( !is_array($this->user_options) ) { return FALSE; }

		return array_key_exists( $option, $this->user_options );
	}

	// During installation of WP Statistics some inital data needs to be loaded in to the database so errors are not displayed.
	// This function will add some inital data if the tables are empty.
	public function Primary_Values() {

		$this->result = $this->db->query("SELECT * FROM {$this->tb_prefix}statistics_useronline");

		if( !$this->result ) {

			$this->db->insert(
				$this->tb_prefix . "statistics_useronline",
				array(
					'ip'		=>	$this->get_IP(),
					'timestamp'	=>	$this->Current_Date('U'),
					'date'		=>	$this->Current_Date(),
					'referred'	=>	$this->get_Referred(),
					'agent'		=>	$this->agent['browser'],
					'platform'	=>	$this->agent['platform'],
					'version'	=> 	$this->agent['version']
				)
			);
		}

		$this->result = $this->db->query("SELECT * FROM {$this->tb_prefix}statistics_visit");

		if( !$this->result ) {

			$this->db->insert(
				$this->tb_prefix . "statistics_visit",
				array(
					'last_visit'	=>	$this->Current_Date(),
					'last_counter'	=>	$this->Current_date('Y-m-d'),
					'visit'			=>	1
				)
			);
		}

		$this->result = $this->db->query("SELECT * FROM {$this->tb_prefix}statistics_visitor");

		if( !$this->result ) {

			$this->db->insert(
				$this->tb_prefix . "statistics_visitor",
				array(
					'last_counter'	=>	$this->Current_date('Y-m-d'),
					'referred'		=>	$this->get_Referred(),
					'agent'			=>	$this->agent['browser'],
					'platform'		=>	$this->agent['platform'],
					'version'		=> 	$this->agent['version'],
					'ip'			=>	$this->get_IP(),
					'location'		=>	'000'
				)
			);
		}
	}

	// This function processes a string that represents an IP address and returns either FALSE if it's invalid or a valid IP4 address.
	private function get_ip_value( $ip ) {
		// Reject anything that's not a string.
		if( ! is_string( $ip ) ) {
			return false;
		}

		// Trim off any spaces.
		$ip = trim( $ip );

		// Process IPv4 and v6 addresses separately.
		if( $this->isValidIPv6( $ip ) ) {
			// Reject any IPv6 addresses if IPv6 is not compiled in to this version of PHP.
			if( ! defined( 'AF_INET6' ) ) {
				return false;
			}
		} else {
			// Trim off any port values that exist.
			if( strstr( $ip, ':' ) !== FALSE ) {
				$temp = explode( ':', $ip );
				$ip = $temp[0];
			}

			// Check to make sure the http header is actually an IP address and not some kind of SQL injection attack.
			$long = ip2long( $ip );

			// ip2long returns either -1 or FALSE if it is not a valid IP address depending on the PHP version, so check for both.
			if( $long == -1 || $long === FALSE ) {
				return false;
			}
		}

		// If the ip address is blank, reject it.
		if( $ip == '' ) {
			return false;
		}

		// We're got a real IP address, return it.
		return $ip;

	}

	// This function returns the current IP address of the remote client.
	public function get_IP() {

		// Check to see if we've already retrieved the IP address and if so return the last result.
		if( $this->ip !== FALSE ) {
			return $this->ip;
		}

		// By default we use the remote address the server has.
		if( array_key_exists( 'REMOTE_ADDR', $_SERVER ) ) {
			$temp_ip = $this->get_ip_value( $_SERVER['REMOTE_ADDR'] );
		} else {
			$temp_ip = '127.0.0.1';
		}

		if( FALSE !== $temp_ip ) {
			$this->ip = $temp_ip;
		}

		/* Check to see if any of the HTTP headers are set to identify the remote user.
		 * These often give better results as they can identify the remote user even through firewalls etc,
		 * but are sometimes used in SQL injection attacks.
		 *
		 * We only want to take the first one we find, so search them in order and break when we find the first
		 * one.
		 *
		 */
		$envs = array( 'HTTP_CLIENT_IP', 'HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED', 'HTTP_FORWARDED_FOR', 'HTTP_FORWARDED' );

		foreach( $envs as $env ) {
			$temp_ip = $this->get_ip_value( getenv( $env ) );

			if( FALSE !== $temp_ip ) {
				$this->ip = $temp_ip;

				break;
			}
		}

		// If no valid ip address has been found, use 127.0.0.1 (aka localhost).
		if( FALSE === $this->ip ) {
			$this->ip = '127.0.0.1';
		}

		return $this->ip;
	}

	/**
	 * Validate an IPv6 IP address
	 *
	 * @param  string $ip
	 * @return boolean - true/false
	 */
	private function isValidIPv6( $ip ) {
	   if( false === filter_var( $ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6 ) ) {
		   return false;
	   } else {
		   return true;
	   }
	}

	// This function calls the user agent parsing code.
	public function get_UserAgent() {

		// Parse the agent stirng.
		try
			{
			$agent = parse_user_agent();
			}
		catch( Exception $e )
			{
			$agent = array( 'browser' => 'Unknown', 'platform' => 'Unknown', 'version' => 'Unknown' );
			}

		// null isn't a very good default, so set it to Unknown instead.
		if( $agent['browser'] == null ) { $agent['browser'] = "Unknown"; }
		if( $agent['platform'] == null ) { $agent['platform'] = "Unknown"; }
		if( $agent['version'] == null ) { $agent['version'] = "Unknown"; }

		// Uncommon browsers often have some extra cruft, like brackets, http:// and other strings that we can strip out.
		$strip_strings = array('"', "'", '(', ')', ';', ':', '/', '[', ']', '{', '}', 'http' );
		foreach( $agent as $key => $value ) {
			$agent[$key] = str_replace( $strip_strings, '', $agent[$key] );
		}

		return $agent;
	}

	// This function will return the referrer link for the current user.
	public function get_Referred($default_referrer = false) {

		if( $this->referrer !== false ) { return $this->referrer; }

		$this->referrer = '';

		if( isset($_SERVER['HTTP_REFERER']) ) { $this->referrer = $_SERVER['HTTP_REFERER']; }
		if( $default_referrer ) { $this->referrer = $default_referrer; }

		$this->referrer = esc_sql(strip_tags($this->referrer) );

		if( !$this->referrer ) { $this->referrer = get_bloginfo('url'); }

		if( $this->get_option( 'addsearchwords', false ) ) {
			// Check to see if this is a search engine referrer
			$SEInfo = $this->Search_Engine_Info( $this->referrer );

			if( is_array( $SEInfo ) ) {
				// If we're a known SE, check the query string
				if( $SEInfo['tag'] != '' ) {
					$result = $this->Search_Engine_QueryString( $this->referrer );

					// If there were no search words, let's add the page title
					if( $result == '' || $result == 'No search query found!' ) {
						$result = wp_title('', false);
						if( $result != '' ) {
							$this->referrer = esc_url( add_query_arg( $SEInfo['querykey'], urlencode( '~"' . $result . '"' ), $this->referrer ) );
						}
					}
				}
			}
		}

		return $this->referrer;
	}

	// This function returns a date string in the desired format with a passed in timestamp.
	public function Local_Date($format, $timestamp ) {
		return date( $format, $timestamp + $this->tz_offset );
	}

	// This function returns a date string in the desired format.
	public function Current_Date($format = 'Y-m-d H:i:s', $strtotime = null, $relative = null) {

		if( $strtotime ) {
			if( $relative ) {
				return date($format, strtotime("{$strtotime} day", $relative) + $this->tz_offset );
			}
			else {
				return date($format, strtotime("{$strtotime} day") + $this->tz_offset );
			}
		} else {
			return date($format, time() + $this->tz_offset);
		}
	}

	// This function returns a date string in the desired format.
	public function Real_Current_Date($format = 'Y-m-d H:i:s', $strtotime = null, $relative = null) {

		if( $strtotime ) {
			if( $relative ) {
				return date($format, strtotime("{$strtotime} day", $relative) );
			}
			else {
				return date($format, strtotime("{$strtotime} day") );
			}
		} else {
			return date($format, time());
		}
	}

	// This function returns an internationalized date string in the desired format.
	public function Current_Date_i18n($format = 'Y-m-d H:i:s', $strtotime = null, $day=' day') {

		if( $strtotime ) {
			return date_i18n($format, strtotime("{$strtotime}{$day}") + $this->tz_offset );
		} else {
			return date_i18n($format, time() + $this->tz_offset);
		}
	}

	public function strtotimetz( $timestring ) {
		return strtotime( $timestring ) + $this->tz_offset;
	}

	public function timetz() {
		return time() + $this->tz_offset;
	}

	// This function checks to see if a search engine exists in the current list of search engines.
	public function Check_Search_Engines ($search_engine_name, $search_engine = null) {

		if( strstr($search_engine, $search_engine_name) ) {
			return 1;
		}
	}

	// This function returns an array of information about a given search engine based on the url passed in.
	// It is used in several places to get the SE icon or the sql query to select an individual SE from the database.
	public function Search_Engine_Info($url = false) {

		// If no URL was passed in, get the current referrer for the session.
		if(!$url) {
			$url = isset($_SERVER['HTTP_REFERER']) ? $this->get_Referred() : false;
		}

		// If there is no URL and no referrer, always return false.
		if($url == false) {
			return false;
		}

		// Parse the URL in to it's component parts.
		$parts = parse_url($url);

		// Get the list of search engines we currently support.
		$search_engines = wp_statistics_searchengine_list();

		// Loop through the SE list until we find which search engine matches.
		foreach( $search_engines as $key => $value ) {
			$search_regex = wp_statistics_searchengine_regex($key);

			preg_match( '/' . $search_regex . '/', $parts['host'], $matches);

			if( isset($matches[1]) )
				{
				// Return the first matched SE.
				return $value;
				}
		}

		// If no SE matched, return some defaults.
		return array('name' => 'Unknown', 'tag' => '', 'sqlpattern' => '', 'regexpattern' => '', 'querykey' => 'q', 'image' => 'unknown.png' );
	}

	// This function returns an array of information about a given search engine based on the url passed in.
	// It is used in several places to get the SE icon or the sql query to select an individual SE from the database.
	public function Search_Engine_Info_By_Engine($engine = false) {

		// If there is no URL and no referrer, always return false.
		if($engine == false) {
			return false;
		}

		// Get the list of search engines we currently support.
		$search_engines = wp_statistics_searchengine_list();

		if( array_key_exists( $engine, $search_engines ) ) {
			return $search_engines[$engine];
		}

		// If no SE matched, return some defaults.
		return array('name' => 'Unknown', 'tag' => '', 'sqlpattern' => '', 'regexpattern' => '', 'querykey' => 'q', 'image' => 'unknown.png' );
	}

	// This function will parse a URL from a referrer and return the search query words used.
	public function Search_Engine_QueryString($url = false) {

		// If no URL was passed in, get the current referrer for the session.
		if(!$url) {
			$url = isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : false;
		}

		// If there is no URL and no referrer, always return false.
		if($url == false) {
			return false;
		}

		// Parse the URL in to it's component parts.
		$parts = parse_url($url);

		// Check to see if there is a query component in the URL (everything after the ?).  If there isn't one
		// set an empty array so we don't get errors later.
		if( array_key_exists('query',$parts) ) { parse_str($parts['query'], $query); } else { $query = array(); }

		// Get the list of search engines we currently support.
		$search_engines = wp_statistics_searchengine_list();

		// Loop through the SE list until we find which search engine matches.
		foreach( $search_engines as $key => $value ) {
			$search_regex = wp_statistics_searchengine_regex($key);

			preg_match( '/' . $search_regex . '/', $parts['host'], $matches);

			if( isset($matches[1]) )
				{
				// Check to see if the query key the SE uses exists in the query part of the URL.
				if( array_key_exists($search_engines[$key]['querykey'], $query) ) {
					$words = strip_tags($query[$search_engines[$key]['querykey']]);
				}
				else {
					$words = '';
				}

				// If no words were found, return a pleasant default.
				if( $words == '' ) { $words = 'No search query found!'; }
				return $words;
				}
		}

		// We should never actually get to this point, but let's make sure we return something
		// just in case something goes terribly wrong.
		return 'No search query found!';
	}

	public function Get_Historical_Data($type, $id = '') {

		$count = 0;

		switch( $type ) {
			case 'visitors':
				if( array_key_exists( 'visitors', $this->historical ) ) {
					return $this->historical['visitors'];
				}
				else {
					$result = $this->db->get_var("SELECT value FROM {$this->tb_prefix}statistics_historical WHERE category = 'visitors'");
					if( $result > $count ) { $count = $result; }
					$this->historical['visitors'] = $count;
				}

				break;
			case 'visits':
				if( array_key_exists( 'visits', $this->historical ) ) {
					return $this->historical['visits'];
				}
				else {
					$result = $this->db->get_var("SELECT value FROM {$this->tb_prefix}statistics_historical WHERE category = 'visits'");
					if( $result > $count ) { $count = $result; }
					$this->historical['visits'] = $count;
				}

				break;
			case 'uri':
				if( array_key_exists( $id, $this->historical ) ) {
					return $this->historical[$id];
				}
				else {
					$result = $this->db->get_var($this->db->prepare("SELECT value FROM {$this->tb_prefix}statistics_historical WHERE category = 'uri' AND uri = %s", $id));
					if( $result > $count ) { $count = $result; }
					$this->historical[$id] = $count;
				}

				break;
			case 'page':
				if( array_key_exists( $id, $this->historical ) ) {
					return $this->historical[$id];
				}
				else {
					$result = $this->db->get_var($this->db->prepare("SELECT value FROM {$this->tb_prefix}statistics_historical WHERE category = 'uri' AND page_id = %d", $id));
					if( $result > $count ) { $count = $result; }
					$this->historical[$id] = $count;
				}

				break;
			}

		return $count;
	}

	public function feed_detected() {
		$this->is_feed = true;
	}

	public function check_feed() {
		return $this->is_feed;
	}

	public function get_country_codes() {
		if( $this->country_codes == false ) {
			$ISOCountryCode = array();
			include( $this->plugin_dir . "/includes/functions/country-codes.php");
			$this->country_codes = $ISOCountryCode;
		}

		return $this->country_codes;
	}
}