<?php
#declare(strict_types=1);

# https://www.php.net/manual/en/language.oop5.autoload.php
require_once 'config.php';
require_once 'security.class.php';

# Initialize
$ENV = ENV::go();
$Security = new Security();
$Security->setupPitfalls();


/*-- Script Start Class --------------------------------*/
/*------------------------------------------------------*/
/* This isnt really a class but a way to tie other      */
/* classes and functions used all over the site to the  */
/* page currently being displayed.                      */
/*------------------------------------------------------*/
/* The code that includes the main php files and    */
/* generates the page are at the bottom.        */
/*------------------------------------------------------*/
/********************************************************/

require SERVER_ROOT.'/classes/proxies.class.php';

// Get the user's actual IP address if they're proxied.
// Or if cloudflare is used
if (isset($_SERVER['HTTP_CF_CONNECTING_IP'])) {
    $_SERVER['REMOTE_ADDR'] = $_SERVER['HTTP_CF_CONNECTING_IP'];
}

if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])
    && proxyCheck($_SERVER['REMOTE_ADDR'])
    && filter_var(
        $_SERVER['HTTP_X_FORWARDED_FOR'],
        FILTER_VALIDATE_IP,
        FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE
    )) {
    $_SERVER['REMOTE_ADDR'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
}

if (!isset($argv) && !empty($_SERVER['HTTP_HOST'])) {
    // Skip this block if running from cli or if the browser is old and shitty
    // This should really be done in nginx config
    // todo: Remove
    if ($_SERVER['HTTP_HOST'] == 'www.'.SITE_DOMAIN) {
        header('Location: https://'.SITE_DOMAIN.$_SERVER['REQUEST_URI']);
        error();
    }
}

$ScriptStartTime = microtime(true); // To track how long a page takes to create
if (!defined('PHP_WINDOWS_VERSION_MAJOR')) {
    $RUsage = getrusage();
    $CPUTimeStart = $RUsage['ru_utime.tv_sec'] * 1000000 + $RUsage['ru_utime.tv_usec'];
}
ob_start(); // Start a buffer, mainly in case there is a mysql error

require SERVER_ROOT.'/classes/debug.class.php'; // Require the debug class
require SERVER_ROOT.'/classes/mysql.class.php'; // Require the database wrapper
require SERVER_ROOT.'/classes/cache.class.php'; // Require the caching class
require SERVER_ROOT.'/classes/time.class.php'; // Require the time class
require SERVER_ROOT.'/classes/paranoia.class.php'; // Require the paranoia check_paranoia function
require SERVER_ROOT.'/classes/util.php';

$Debug = new DEBUG;
$Debug->handle_errors();
$Debug->set_flag('Debug constructed');

$DB = new DB_MYSQL;
$Cache = new Cache($ENV->getPriv('MEMCACHED_SERVERS'));

// Autoload classes.
require SERVER_ROOT.'/classes/autoload.php';

// Note: G::initialize is called twice.
// This is necessary as the code inbetween (initialization of $LoggedUser) makes use of G::$DB and G::$Cache.
// todo: Remove one of the calls once we're moving everything into that class
G::initialize();

// Begin browser identification
$Browser = UserAgent::browser($_SERVER['HTTP_USER_AGENT']);
$OperatingSystem = UserAgent::operating_system($_SERVER['HTTP_USER_AGENT']);

$Debug->set_flag('start user handling');

// Get classes
// todo: Remove these globals, replace by calls into Users
list($Classes, $ClassLevels) = Users::get_classes();


//-- Load user information
// User info is broken up into many sections
// Heavy - Things that the site never has to look at if the user isn't logged in (as opposed to things like the class, donor status, etc)
// Light - Things that appear in format_user
// Stats - Uploaded and downloaded - can be updated by a script if you want super speed
// Session data - Information about the specific session
// Enabled - if the user's enabled or not
// Permissions


/**
 * JSON API token support
 * @see https://github.com/OPSnet/Gazelle/commit/7c208fc4c396a16c77289ef886d0015db65f2af1#diff-2ea09cbf36b1d20fec7a6d7fc50780723b9f804c4e857003aa9a9c359dc9fd49
 */

// Set the document we are loading
$Document = basename(parse_url($_SERVER['SCRIPT_NAME'], PHP_URL_PATH), '.php');

$LoggedUser = [];
$SessionID = false;
$FullToken = null;

// Only allow using the Authorization header for ajax endpoint
if (!empty($_SERVER['HTTP_AUTHORIZATION']) && $Document === 'ajax') {
    # Banned IP address
    if (IPv4::isBanned($_SERVER['REMOTE_ADDR'])) {
        header('Content-Type: application/json');
        json_die('failure', 'your ip address has been banned');
    }

    # Invalid auth header type
    # Bearer is correct according to RFC 6750
    # https://tools.ietf.org/html/rfc6750
    $AuthorizationHeader = explode(" ", (string) $_SERVER['HTTP_AUTHORIZATION']);
    if (count($AuthorizationHeader) === 2) {
        if ($AuthorizationHeader[0] !== 'Bearer') {
            header('Content-Type: application/json');
            json_die('failure', 'authorization type must be Bearer');
        }
        $FullToken = $AuthorizationHeader[1];
    } else {
        header('Content-Type: application/json');
        json_die('failure', 'authorization type must be Bearer');
    }

    $Revoked = 1;
    $UserID = (int) substr(Crypto::decrypt(base64UrlDecode($FullToken), $ENV->getPriv('ENCKEY')), 32);

    if (!empty($UserID)) {
        [$LoggedUser['ID'], $Revoked] =
        G::$DB->row("
        SELECT
          `UserID`,
          `Revoked`
        FROM
          `api_user_tokens`
        WHERE
          `UserID` = '$UserID'
        ");
    # AND `Token` = '$FullToken'
    } else {
        header('Content-Type: application/json');
        json_die('failure', 'invalid token format');
    }

    # No user or revoked API token
    if (empty($LoggedUser['ID']) || $Revoked === 1) {
        log_token_attempt(G::$DB);
        header('Content-Type: application/json');
        json_die('failure', 'token user mismatch');
    }

    # Checks if a user exists
    if (isset($LoggedUser['ID'])) {
        #$UserID = (int) $LoggedUser['ID'];
        #$Session = new Gazelle\Session($LoggedUser['ID']);
    
        # User doesn't own that token
        if (!is_null($FullToken) && !Users::hasApiToken($UserID, $FullToken)) {
            log_token_attempt(G::$DB, $LoggedUser['ID']);
            header('Content-type: application/json');
            json_die('failure', 'token revoked');
        }
    
        # User is disabled
        if (Users::isDisabled($UserID)) {
            if (is_null($FullToken)) {
                logout($LoggedUser['ID'], $SessionID);
            } else {
                log_token_attempt(G::$DB, $LoggedUser['ID']);
                header('Content-type: application/json');
                json_die('failure', 'user disabled');
            }
        }
    }
}

/*
# OPS pleasantly rewrote session handling
$UserSessions = [];
if (isset($_COOKIE['session'])) {
    $LoginCookie = Crypto::decrypt($_COOKIE['session'], $ENV->getPriv('ENCKEY'));
    if ($LoginCookie !== false) {
        [$SessionID, $LoggedUser['ID']] = explode('|~|', Crypto::decrypt($LoginCookie, $ENV->getPriv('ENCKEY')));
        $LoggedUser['ID'] = (int)$LoggedUser['ID'];

        if (!$LoggedUser['ID'] || !$SessionID) {
            logout($LoggedUser['ID'], $SessionID);
        }

        $Session = new Gazelle\Session($LoggedUser['ID']);
        $UserSessions = $Session->sessions();
        if (!array_key_exists($SessionID, $UserSessions)) {
            logout($LoggedUser['ID'], $SessionID);
        }
    }
}
*/
# End OPS API token additions


/**
 * Session handling and cookies
 */
if (isset($_COOKIE['session']) && isset($_COOKIE['userid'])) {
    $SessionID = $_COOKIE['session'];
    $LoggedUser['ID'] = (int) $_COOKIE['userid'];

    $UserID = $LoggedUser['ID']; // todo: UserID should not be LoggedUser
    if (!$LoggedUser['ID'] || !$SessionID) {
        logout();
    }

    $UserSessions = $Cache->get_value("users_sessions_$UserID");
    if (!is_array($UserSessions)) {
        $DB->query(
            "
        SELECT
          SessionID,
          Browser,
          OperatingSystem,
          IP,
          LastUpdate
        FROM users_sessions
          WHERE UserID = '$UserID'
          AND Active = 1
        ORDER BY LastUpdate DESC"
        );

        $UserSessions = $DB->to_array('SessionID', MYSQLI_ASSOC);
        $Cache->cache_value("users_sessions_$UserID", $UserSessions, 0);
    }

    if (!array_key_exists($SessionID, $UserSessions)) {
        logout();
    }

    // Check if user is enabled
    $Enabled = $Cache->get_value('enabled_'.$LoggedUser['ID']);
    if ($Enabled === false) {
        $DB->query("
        SELECT Enabled
          FROM users_main
          WHERE ID = '$LoggedUser[ID]'");

        list($Enabled) = $DB->next_record();
        $Cache->cache_value('enabled_'.$LoggedUser['ID'], $Enabled, 0);
    }

    # todo: Check strict equality
    if ($Enabled == 2) {
        logout();
    }

    // Up/Down stats
    $UserStats = $Cache->get_value('user_stats_'.$LoggedUser['ID']);
    if (!is_array($UserStats)) {
        $DB->query("
        SELECT Uploaded AS BytesUploaded, Downloaded AS BytesDownloaded, RequiredRatio
        FROM users_main
          WHERE ID = '$LoggedUser[ID]'");

        $UserStats = $DB->next_record(MYSQLI_ASSOC);
        $Cache->cache_value('user_stats_'.$LoggedUser['ID'], $UserStats, 3600);
    }

    // Get info such as username
    $LightInfo = Users::user_info($LoggedUser['ID']);
    $HeavyInfo = Users::user_heavy_info($LoggedUser['ID']);


    /**
     * OPS API tokens
     * @see https://github.com/OPSnet/Gazelle/commit/7c208fc4c396a16c77289ef886d0015db65f2af1#diff-2ea09cbf36b1d20fec7a6d7fc50780723b9f804c4e857003aa9a9c359dc9fd49
     */
    // TODO: These globals need to die, and just use $LoggedUser
    // TODO: And then instantiate $LoggedUser from Gazelle\Session when needed
    if (empty($LightInfo['Username'])) { // Ghost
        logout($LoggedUser['ID'], $SessionID);
        if (!is_null($FullToken)) {
            #$UserID->flushCache();
            log_token_attempt(G::$DB, $LoggedUser['ID']);
            header('Content-type: application/json');
            json_die('error', 'invalid token');
        } else {
            logout($LoggedUser['ID'], $SessionID);
        }
    }
    # End OPS API token additions


    // Create LoggedUser array
    $LoggedUser = array_merge($HeavyInfo, $LightInfo, $UserStats);
    $LoggedUser['RSS_Auth'] = md5($LoggedUser['ID'] . $ENV->getPriv('RSS_HASH') . $LoggedUser['torrent_pass']);

    // $LoggedUser['RatioWatch'] as a bool to disable things for users on Ratio Watch
    $LoggedUser['RatioWatch'] = (
        $LoggedUser['RatioWatchEnds']
     && time() < strtotime($LoggedUser['RatioWatchEnds'])
     && ($LoggedUser['BytesDownloaded'] * $LoggedUser['RequiredRatio']) > $LoggedUser['BytesUploaded']
    );

    // Load in the permissions
    $LoggedUser['Permissions'] = Permissions::get_permissions_for_user($LoggedUser['ID'], $LoggedUser['CustomPermissions']);
    $LoggedUser['Permissions']['MaxCollages'] += Donations::get_personal_collages($LoggedUser['ID']);

    // Change necessary triggers in external components
    $Cache->CanClear = check_perms('admin_clear_cache');

    // Because we <3 our staff
    if (check_perms('site_disable_ip_history')) {
        $_SERVER['REMOTE_ADDR'] = '127.0.0.1';
    }

    // Update LastUpdate every 10 minutes
    if (strtotime($UserSessions[$SessionID]['LastUpdate']) + 600 < time()) {
        $DB->query("
        UPDATE users_main
        SET LastAccess = NOW()
        WHERE ID = '$LoggedUser[ID]'
        ");

        $SessionQuery =
       "UPDATE users_sessions
          SET ";

        // Only update IP if we have an encryption key in memory
        if (apcu_exists('DBKEY')) {
            $SessionQuery .= "IP = '".Crypto::encrypt($_SERVER['REMOTE_ADDR'])."', ";
        }

        $SessionQuery .=
       "Browser = '$Browser',
        OperatingSystem = '$OperatingSystem',
        LastUpdate = NOW()
        WHERE UserID = '$LoggedUser[ID]'
        AND SessionID = '".db_string($SessionID)."'";

        $DB->query($SessionQuery);
        $Cache->begin_transaction("users_sessions_$UserID");
        $Cache->delete_row($SessionID);

        $UsersSessionCache = array(
        'SessionID' => $SessionID,
        'Browser' => $Browser,
        'OperatingSystem' => $OperatingSystem,
        'IP' => (apcu_exists('DBKEY') ? Crypto::encrypt($_SERVER['REMOTE_ADDR']) : $UserSessions[$SessionID]['IP']),
        'LastUpdate' => sqltime() );

        $Cache->insert_front($SessionID, $UsersSessionCache);
        $Cache->commit_transaction(0);
    }

    // Notifications
    if (isset($LoggedUser['Permissions']['site_torrents_notify'])) {
        $LoggedUser['Notify'] = $Cache->get_value('notify_filters_'.$LoggedUser['ID']);
        if (!is_array($LoggedUser['Notify'])) {
            $DB->query("
            SELECT ID, Label
            FROM users_notify_filters
              WHERE UserID = '$LoggedUser[ID]'");

            $LoggedUser['Notify'] = $DB->to_array('ID');
            $Cache->cache_value('notify_filters_'.$LoggedUser['ID'], $LoggedUser['Notify'], 2592000);
        }
    }

    // We've never had to disable the wiki privs of anyone.
    if ($LoggedUser['DisableWiki']) {
        unset($LoggedUser['Permissions']['site_edit_wiki']);
    }

    // IP changed
    if (apcu_exists('DBKEY') && Crypto::decrypt($LoggedUser['IP']) != $_SERVER['REMOTE_ADDR'] && !check_perms('site_disable_ip_history')) {
        if (Tools::site_ban_ip($_SERVER['REMOTE_ADDR'])) {
            error('Your IP address has been banned.');
        }

        $CurIP = db_string($LoggedUser['IP']);
        $NewIP = db_string($_SERVER['REMOTE_ADDR']);
        $DB->query("
        SELECT IP
        FROM users_history_ips
          WHERE EndTime IS NULL
          AND UserID = '$LoggedUser[ID]'");

        while (list($EncIP) = $DB->next_record()) {
            if (Crypto::decrypt($EncIP) == $CurIP) {
                $CurIP = $EncIP;
                // CurIP is now the encrypted IP that was already in the database (for matching)
                break;
            }
        }

        $DB->query("
        UPDATE users_history_ips
        SET EndTime = NOW()
          WHERE EndTime IS NULL
          AND UserID = '$LoggedUser[ID]'
          AND IP = '$CurIP'");

        $DB->query("
        INSERT IGNORE INTO users_history_ips
          (UserID, IP, StartTime)
        VALUES
          ('$LoggedUser[ID]', '".Crypto::encrypt($NewIP)."', NOW())");

        $Cache->begin_transaction('user_info_heavy_'.$LoggedUser['ID']);
        $Cache->update_row(false, array('IP' => Crypto::encrypt($_SERVER['REMOTE_ADDR'])));
        $Cache->commit_transaction(0);
    }

    // Get stylesheets
    $Stylesheets = $Cache->get_value('stylesheets');
    if (!is_array($Stylesheets)) {
        $DB->query('
        SELECT
          ID,
          LOWER(REPLACE(Name, " ", "_")) AS Name,
          Name AS ProperName,
          LOWER(REPLACE(Additions, " ", "_")) AS Additions,
          Additions AS ProperAdditions
        FROM stylesheets');

        $Stylesheets = $DB->to_array('ID', MYSQLI_BOTH);
        $Cache->cache_value('stylesheets', $Stylesheets, 0);
    }

    // todo: Clean up this messy solution
    $LoggedUser['StyleName'] = $Stylesheets[$LoggedUser['StyleID']]['Name'];
    if (empty($LoggedUser['Username'])) {
        logout(); // Ghost
    }
}

G::initialize();
$Debug->set_flag('end user handling');
$Debug->set_flag('start function definitions');

/**
 * Log out the current session
 */
function logout()
{
    global $SessionID;
    setcookie('session', '', time() - 60 * 60 * 24 * 365, '/', '', false);
    setcookie('userid', '', time() - 60 * 60 * 24 * 365, '/', '', false);
    setcookie('keeplogged', '', time() - 60 * 60 * 24 * 365, '/', '', false);

    if ($SessionID) {
        G::$DB->query("
        DELETE FROM users_sessions
          WHERE UserID = '" . G::$LoggedUser['ID'] . "'
          AND SessionID = '".db_string($SessionID)."'");

        G::$Cache->begin_transaction('users_sessions_' . G::$LoggedUser['ID']);
        G::$Cache->delete_row($SessionID);
        G::$Cache->commit_transaction(0);
    }

    G::$Cache->delete_value('user_info_' . G::$LoggedUser['ID']);
    G::$Cache->delete_value('user_stats_' . G::$LoggedUser['ID']);
    G::$Cache->delete_value('user_info_heavy_' . G::$LoggedUser['ID']);

    header('Location: login.php');
    error();
}

function logout_all_sessions()
{
    $UserID = G::$LoggedUser['ID'];

    G::$DB->query("
    DELETE FROM users_sessions
      WHERE UserID = '$UserID'");

    G::$Cache->delete_value('users_sessions_' . $UserID);
    logout();
}

function enforce_login()
{
    global $SessionID;
    if (!$SessionID || !G::$LoggedUser) {
        setcookie('redirect', $_SERVER['REQUEST_URI'], time() + 60 * 30, '/', '', false);
        logout();
    }
}

/**
 * Make sure $_GET['auth'] is the same as the user's authorization key
 * Should be used for any user action that relies solely on GET.
 *
 * @param Are we using ajax?
 * @return authorisation status. Prints an error message to DEBUG_CHAN on IRC on failure.
 */
function authorize($Ajax = false)
{
    # Ugly workaround for API tokens
    if (!empty($_SERVER['HTTP_AUTHORIZATION']) && $Document === 'ajax') {
        return true;
    } else {
        if (empty($_REQUEST['auth']) || $_REQUEST['auth'] !== G::$LoggedUser['AuthKey']) {
            send_irc(DEBUG_CHAN, G::$LoggedUser['Username']." just failed authorize on ".$_SERVER['REQUEST_URI'].(!empty($_SERVER['HTTP_REFERER']) ? " coming from ".$_SERVER['HTTP_REFERER'] : ""));
            error('Invalid authorization key. Go back, refresh, and try again.', $NoHTML = true);
            return false;
        }
    }
}

$Debug->set_flag('ending function definitions');
$Document = basename(parse_url($_SERVER['SCRIPT_FILENAME'], PHP_URL_PATH), '.php');

if (!preg_match('/^[a-z0-9]+$/i', $Document)) {
    error(404);
}

$StripPostKeys = array_fill_keys(array('password', 'cur_pass', 'new_pass_1', 'new_pass_2', 'verifypassword', 'confirm_password', 'ChangePassword', 'Password'), true);
$Cache->cache_value('php_' . getmypid(), array(
  'start' => sqltime(),
  'document' => $Document,
  'query' => $_SERVER['QUERY_STRING'],
  'get' => $_GET,
  'post' => array_diff_key($_POST, $StripPostKeys)), 600);

// Locked account constant
define('STAFF_LOCKED', 1);

$AllowedPages = ['staffpm', 'ajax', 'locked', 'logout', 'login'];
if (isset(G::$LoggedUser['LockedAccount']) && !in_array($Document, $AllowedPages)) {
    require(SERVER_ROOT . '/sections/locked/index.php');
} else {
    require(SERVER_ROOT . '/sections/' . $Document . '/index.php');
}

$Debug->set_flag('completed module execution');

/* Required in the absence of session_start() for providing that pages will change
upon hit rather than being browser cached for changing content.

Old versions of Internet Explorer choke when downloading binary files over HTTPS with disabled cache.
Define the following constant in files that handle file downloads */
if (!defined('SKIP_NO_CACHE_HEADERS')) {
    header('Cache-Control: no-cache, must-revalidate, post-check=0, pre-check=0');
    header('Pragma: no-cache');
}

// Flush to user
ob_end_flush();

$Debug->set_flag('set headers and send to user');

// Attribute profiling
$Debug->profile();