<?php
/**
 * @package    solo
 * @copyright  Copyright (c)2014-2019 Nicholas K. Dionysopoulos / Akeeba Ltd
 * @license    GNU GPL version 3 or later
 */

namespace Solo\Model;

use Akeeba\Engine\Factory;
use AkeebaUsagestats;
use Awf\Mvc\Model;
use Awf\Uri\Uri;

class Stats extends Model
{
    /**
     * Get an existing unique site ID or create a new one
     *
     * @return string
     */
    public function getSiteId()
    {
        // Can I load a site ID from the database?
        $siteId  = $this->getCommonVariable('stats_siteid', null);
        // Can I load the site Url from the database?
        $siteUrl = $this->getCommonVariable('stats_siteurl', null);

        // No id or the saved URL is not the same as the current one (ie site restored to a new url)?
        // Create a new, random site ID and save it to the database
        if (empty($siteId) || (md5(Uri::base()) != $siteUrl))
        {
            $siteUrl = md5(Uri::base());
            $this->setCommonVariable('stats_siteurl', $siteUrl);

            $randomData = $this->getRandomData(120);
            $siteId = sha1($randomData);

            $this->setCommonVariable('stats_siteid', $siteId);
        }

        return $siteId;
    }

    /**
     * Send site information to the remove collection service
     *
     * @param  bool  $useIframe  Should I use an IFRAME?
     *
     * @return bool
     */
    public function collectStatistics($useIframe)
    {

        // Do not collect statistics on localhost
        if (
            (strpos(Uri::root(), 'localhost') !== false) ||
            (strpos(Uri::root(), '127.0.0.1') !== false)
        )
        {
            return false;
        }

        // Make sure there is a site ID set
        $siteId = $this->getSiteId();

        // UsageStats file is missing, no need to continue
        if (!file_exists($this->container->basePath . '/assets/stats/usagestats.php'))
        {
            return false;
        }

        require_once $this->container->basePath . '/assets/stats/usagestats.php';

        // UsageStats file is missing, no need to continue
        if (!class_exists('AkeebaUsagestats'))
        {
            return false;
        }

        $lastrun = $this->getCommonVariable('stats_lastrun', 0);

        // Data collection is turned off
        if (!$this->container->appConfig->get('stats_enabled', 1))
        {
            return false;
        }

        // It's not time to collect the stats
        if (time() < ($lastrun + 3600 * 24))
        {
            return false;
        }

        require_once APATH_BASE . '/version.php';

        $db = Factory::getDatabase();
        $stats = new AkeebaUsagestats();

        $stats->setSiteId($siteId);

        // I can't use list since dev release don't have any dots
        $at_parts = explode('.', AKEEBABACKUP_VERSION);
        $at_major = $at_parts[0];
        $at_minor = isset($at_parts[1]) ? $at_parts[1] : '';
        $at_revision = isset($at_parts[2]) ? $at_parts[2] : '';

        list($php_major, $php_minor, $php_revision) = explode('.', phpversion());
        $php_qualifier = strpos($php_revision, '~') !== false ? substr($php_revision, strpos($php_revision, '~')) : '';

        list($db_major, $db_minor, $db_revision) = explode('.', $db->getVersion());
        $db_qualifier = strpos($db_revision, '~') !== false ? substr($db_revision, strpos($db_revision, '~')) : '';

		switch ($db->getDriverType())
		{
			case 'mysql':
				$stats->setValue('dt', 1);
				break;

			case 'mssql':
				$stats->setValue('dt', 2);
				break;

			case 'pgsql':
				$stats->setValue('dt', 3);
				break;

			default:
				$stats->setValue('dt', 0);
		}

		$stats->setValue('ct', 0);

        $inCMS = $this->container->segment->get('insideCMS', false);

        if($inCMS)
        {
            if(function_exists('get_bloginfo'))
            {
	            $cmsType  = function_exists('classicpress_version') ? 3 : 2;
                $wp_parts = explode('.', get_bloginfo('version'));

                $cms_major = $wp_parts[0];
                $cms_minor = $wp_parts[1];
                $cms_revision = isset($wp_parts[2]) ? $wp_parts[2] : 0;

				$stats->setValue('ct', $cmsType); // cms_type
                $stats->setValue('cm', $cms_major); // cms_major
                $stats->setValue('cn', $cms_minor); // cms_minor
                $stats->setValue('cr', $cms_revision); // cms_revision

				$stats->setValue('dt', 1); // db_type
            }
        }

        $stats->setValue('sw',  $inCMS ? (AKEEBABACKUP_PRO ? 8 : 7) : 6); // software
        $stats->setValue('pro', AKEEBABACKUP_PRO); // pro
        $stats->setValue('sm', $at_major); // software_major
        $stats->setValue('sn', $at_minor); // software_minor
        $stats->setValue('sr', $at_revision); // software_revision
        $stats->setValue('pm', $php_major); // php_major
        $stats->setValue('pn', $php_minor); // php_minor
        $stats->setValue('pr', $php_revision); // php_revision
        $stats->setValue('pq', $php_qualifier); // php_qualifiers
        $stats->setValue('dm', $db_major); // db_major
        $stats->setValue('dn', $db_minor); // db_minor
        $stats->setValue('dr', $db_revision); // db_revision
        $stats->setValue('dq', $db_qualifier); // db_qualifiers

        // Store the last execution time. We must store it even if we fail since we don't want a failed stats collection
        // to cause the site to stop responding.
        $this->setCommonVariable('stats_lastrun', time());

        $return = $stats->sendInfo($useIframe);

        return $return;
    }

    /**
     * Load a variable from the common variables table. If it doesn't exist it returns $default
     *
     * @param  string  $key      The key to load
     * @param  mixed   $default  The default value if the key doesn't exist
     *
     * @return mixed The contents of the key or null if it's not present
     */
    public function getCommonVariable($key, $default = null)
    {
        $db = Factory::getDatabase();
        $query = $db->getQuery(true)
            ->select($db->qn('value'))
            ->from($db->qn('#__akeeba_common'))
            ->where($db->qn('key') . ' = ' . $db->q($key));

        try
        {
            $db->setQuery($query);
            $result = $db->loadResult();
        }
        catch (\Exception $e)
        {
            $result = $default;
        }

        return $result;
    }

    /**
     * Set a variable to the common variables table.
     *
     * @param  string  $key    The key to save
     * @param  mixed   $value  The value to save
     */
    public function setCommonVariable($key, $value)
    {
        $db = Factory::getDatabase();
        $query = $db->getQuery(true)
            ->select('COUNT(*)')
            ->from($db->qn('#__akeeba_common'))
            ->where($db->qn('key') . ' = ' . $db->q($key));

        try
        {
            $db->setQuery($query);
            $count = $db->loadResult();
        }
        catch (\Exception $e)
        {
            return;
        }

        if (!$count)
        {
            $query = $db->getQuery(true)
                ->insert($db->qn('#__akeeba_common'))
                ->columns(array($db->qn('key'), $db->qn('value')))
                ->values($db->q($key) . ', ' . $db->q($value));
        }
        else
        {
            $query = $db->getQuery(true)
                ->update($db->qn('#__akeeba_common'))
                ->set($db->qn('value') . ' = ' . $db->q($value))
                ->where($db->qn('key') . ' = ' . $db->q($key));
        }

        try
        {
            $db->setQuery($query)->execute();
        }
        catch (\Exception $e)
        {
        }
    }

    /**
     *
     * Returns a cryptographically secure random value.
     *
     * @param   integer  $bytes  How many bytes to return
     *
     * @return  string
     */
    public function getRandomData($bytes = 32)
    {
        if (extension_loaded('openssl') && (version_compare(PHP_VERSION, '5.3.4') >= 0 || IS_WIN))
        {
            $strong = false;
            $randBytes = openssl_random_pseudo_bytes($bytes, $strong);

            if ($strong)
            {
                return $randBytes;
            }
        }

        if (extension_loaded('mcrypt'))
        {
            return mcrypt_create_iv($bytes, MCRYPT_DEV_URANDOM);
        }

        return $this->genRandomBytes($bytes);
    }

    /**
     * Generate random bytes. Adapted from Joomla! 3.2.
     *
     * @param   integer  $length  Length of the random data to generate
     *
     * @return  string  Random binary data
     */
    public function genRandomBytes($length = 32)
    {
        $length = (int) $length;
        $sslStr = '';

        /*
         * Collect any entropy available in the system along with a number
         * of time measurements of operating system randomness.
         */
        $bitsPerRound = 2;
        $maxTimeMicro = 400;
        $shaHashLength = 20;
        $randomStr = '';
        $total = $length;

        // Check if we can use /dev/urandom.
        $urandom = false;
        $handle = null;

        // This is PHP 5.3.3 and up
        if (function_exists('stream_set_read_buffer') && @is_readable('/dev/urandom'))
        {
            $handle = @fopen('/dev/urandom', 'rb');

            if ($handle)
            {
                $urandom = true;
            }
        }

        while ($length > strlen($randomStr))
        {
            $bytes = ($total > $shaHashLength)? $shaHashLength : $total;
            $total -= $bytes;

            /*
             * Collect any entropy available from the PHP system and filesystem.
             * If we have ssl data that isn't strong, we use it once.
             */
            $entropy = rand() . uniqid(mt_rand(), true) . $sslStr;
            $entropy .= implode('', @fstat(fopen(__FILE__, 'r')));
            $entropy .= memory_get_usage();
            $sslStr = '';

            if ($urandom)
            {
                stream_set_read_buffer($handle, 0);
                $entropy .= @fread($handle, $bytes);
            }
            else
            {
                /*
                 * There is no external source of entropy so we repeat calls
                 * to mt_rand until we are assured there's real randomness in
                 * the result.
                 *
                 * Measure the time that the operations will take on average.
                 */
                $samples = 3;
                $duration = 0;

                for ($pass = 0; $pass < $samples; ++$pass)
                {
                    $microStart = microtime(true) * 1000000;
                    $hash = sha1(mt_rand(), true);

                    for ($count = 0; $count < 50; ++$count)
                    {
                        $hash = sha1($hash, true);
                    }

                    $microEnd = microtime(true) * 1000000;
                    $entropy .= $microStart . $microEnd;

                    if ($microStart >= $microEnd)
                    {
                        $microEnd += 1000000;
                    }

                    $duration += $microEnd - $microStart;
                }

                $duration = $duration / $samples;

                /*
                 * Based on the average time, determine the total rounds so that
                 * the total running time is bounded to a reasonable number.
                 */
                $rounds = (int) (($maxTimeMicro / $duration) * 50);

                /*
                 * Take additional measurements. On average we can expect
                 * at least $bitsPerRound bits of entropy from each measurement.
                 */
                $iter = $bytes * (int) ceil(8 / $bitsPerRound);

                for ($pass = 0; $pass < $iter; ++$pass)
                {
                    $microStart = microtime(true);
                    $hash = sha1(mt_rand(), true);

                    for ($count = 0; $count < $rounds; ++$count)
                    {
                        $hash = sha1($hash, true);
                    }

                    $entropy .= $microStart . microtime(true);
                }
            }

            $randomStr .= sha1($entropy, true);
        }

        if ($urandom)
        {
            @fclose($handle);
        }

        return substr($randomStr, 0, $length);
    }
}
