<?php
/**
 * Piwik - free/libre analytics platform
 *
 * @link http://piwik.org
 * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 *
 */

namespace Piwik\Plugins\Live;

use Exception;
use Piwik\API\Request;
use Piwik\Common;
use Piwik\Container\StaticContainer;
use Piwik\Date;
use Piwik\Db;
use Piwik\Period;
use Piwik\Period\Range;
use Piwik\Piwik;
use Piwik\Segment;
use Piwik\Site;

class Model
{
    /**
     * @param $idSite
     * @param $period
     * @param $date
     * @param $segment
     * @param $limit
     * @param $visitorId
     * @param $minTimestamp
     * @param $filterSortOrder
     * @param $checkforMoreEntries
     * @return array
     * @throws Exception
     */
    public function queryLogVisits($idSite, $period, $date, $segment, $offset, $limit, $visitorId, $minTimestamp, $filterSortOrder, $checkforMoreEntries = false)
    {
        // to check for more entries increase the limit by one, but cut off the last entry before returning the result
        if ($checkforMoreEntries) {
            $limit++;
        }

        list($sql, $bind) = $this->makeLogVisitsQueryString($idSite, $period, $date, $segment, $offset, $limit, $visitorId, $minTimestamp, $filterSortOrder);

        $visits = Db::fetchAll($sql, $bind);

        if ($checkforMoreEntries) {
            if (count($visits) == $limit) {
                array_pop($visits);
                return [$visits, true];
            }

            return [$visits, false];
        }

        return $visits;
    }

    /**
     * @param $idSite
     * @param $lastMinutes
     * @param $segment
     * @return int
     * @throws Exception
     */
    public function getNumActions($idSite, $lastMinutes, $segment)
    {
        return $this->getLastMinutesCounterForQuery(
            $idSite,
            $lastMinutes,
            $segment,
            'COUNT(*)',
            'log_link_visit_action',
            'log_link_visit_action.server_time >= ?'
        );
    }

    /**
     * @param $idSite
     * @param $lastMinutes
     * @param $segment
     * @return int
     * @throws Exception
     */
    public function getNumVisitsConverted($idSite, $lastMinutes, $segment)
    {
        return $this->getLastMinutesCounterForQuery(
            $idSite,
            $lastMinutes,
            $segment,
            'COUNT(*)',
            'log_conversion',
            'log_conversion.server_time >= ?'
        );
    }

    /**
     * @param $idSite
     * @param $lastMinutes
     * @param $segment
     * @return int
     * @throws Exception
     */
    public function getNumVisits($idSite, $lastMinutes, $segment)
    {
        return $this->getLastMinutesCounterForQuery(
            $idSite,
            $lastMinutes,
            $segment,
            'COUNT(log_visit.visit_last_action_time)',
            'log_visit',
            'log_visit.visit_last_action_time >= ?'
        );
    }

    /**
     * @param $idSite
     * @param $lastMinutes
     * @param $segment
     * @return int
     * @throws Exception
     */
    public function getNumVisitors($idSite, $lastMinutes, $segment)
    {
        return $this->getLastMinutesCounterForQuery(
            $idSite,
            $lastMinutes,
            $segment,
            'COUNT(DISTINCT log_visit.idvisitor)',
            'log_visit',
            'log_visit.visit_last_action_time >= ?'
        );
    }

    private function getLastMinutesCounterForQuery($idSite, $lastMinutes, $segment, $select, $from, $where)
    {
        $lastMinutes = (int)$lastMinutes;

        if (empty($lastMinutes)) {
            return 0;
        }

        list($whereIdSites, $idSites) = $this->getIdSitesWhereClause($idSite, $from);

        $now = null;
        try {
            $now = StaticContainer::get('Tests.now');
        } catch (\Exception $ex) {
            // ignore
        }
        $now = $now ?: time();

        $bind   = $idSites;
        $bind[] = Date::factory($now - $lastMinutes * 60)->toString('Y-m-d H:i:s');

        $where = $whereIdSites . "AND " . $where;

        $segment = new Segment($segment, $idSite);
        $query   = $segment->getSelectQuery($select, $from, $where, $bind);

        $numVisitors = Db::fetchOne($query['sql'], $query['bind']);

        return $numVisitors;
    }

    /**
     * @param $idSite
     * @param string $table
     * @return array
     */
    private function getIdSitesWhereClause($idSite, $table = 'log_visit')
    {
        if (is_array($idSite)) {
            $idSites = $idSite;
        } else {
            $idSites = array($idSite);
        }

        Piwik::postEvent('Live.API.getIdSitesString', array(&$idSites));

        $idSitesBind = Common::getSqlStringFieldsArray($idSites);
        $whereClause = $table . ".idsite in ($idSitesBind) ";
        return array($whereClause, $idSites);
    }


    /**
     * Returns the ID of a visitor that is adjacent to another visitor (by time of last action)
     * in the log_visit table.
     *
     * @param int $idSite The ID of the site whose visits should be looked at.
     * @param string $visitorId The ID of the visitor to get an adjacent visitor for.
     * @param string $visitLastActionTime The last action time of the latest visit for $visitorId.
     * @param string $segment
     * @param bool $getNext Whether to retrieve the next visitor or the previous visitor. The next
     *                      visitor will be the visitor that appears chronologically later in the
     *                      log_visit table. The previous visitor will be the visitor that appears
     *                      earlier.
     * @return string The hex visitor ID.
     * @throws Exception
     */
    public function queryAdjacentVisitorId($idSite, $visitorId, $visitLastActionTime, $segment, $getNext)
    {
        if ($getNext) {
            $visitLastActionTimeCondition = "sub.visit_last_action_time <= ?";
            $orderByDir = "DESC";
        } else {
            $visitLastActionTimeCondition = "sub.visit_last_action_time >= ?";
            $orderByDir = "ASC";
        }

        $visitLastActionDate = Date::factory($visitLastActionTime);
        $dateOneDayAgo = $visitLastActionDate->subDay(1);
        $dateOneDayInFuture = $visitLastActionDate->addDay(1);

        $select = "log_visit.idvisitor, MAX(log_visit.visit_last_action_time) as visit_last_action_time";
        $from = "log_visit";
        $where = "log_visit.idsite = ? AND log_visit.idvisitor <> ? AND visit_last_action_time >= ? and visit_last_action_time <= ?";
        $whereBind = array($idSite, @Common::hex2bin($visitorId), $dateOneDayAgo->toString('Y-m-d H:i:s'), $dateOneDayInFuture->toString('Y-m-d H:i:s'));
        $orderBy = "MAX(log_visit.visit_last_action_time) $orderByDir";
        $groupBy = "log_visit.idvisitor";

        $segment = new Segment($segment, $idSite);
        $queryInfo = $segment->getSelectQuery($select, $from, $where, $whereBind, $orderBy, $groupBy);

        $sql = "SELECT sub.idvisitor, sub.visit_last_action_time FROM ({$queryInfo['sql']}) as sub
                 WHERE $visitLastActionTimeCondition
                 LIMIT 1";
        $bind = array_merge($queryInfo['bind'], array($visitLastActionTime));

        $visitorId = Db::fetchOne($sql, $bind);
        if (!empty($visitorId)) {
            $visitorId = bin2hex($visitorId);
        }
        return $visitorId;
    }

    /**
     * @param $idSite
     * @param $period
     * @param $date
     * @param $segment
     * @param int $offset
     * @param int $limit
     * @param $visitorId
     * @param $minTimestamp
     * @param $filterSortOrder
     * @return array
     * @throws Exception
     */
    public function makeLogVisitsQueryString($idSite, $period, $date, $segment, $offset, $limit, $visitorId, $minTimestamp, $filterSortOrder)
    {
        // If no other filter, only look at the last 24 hours of stats
        if (empty($visitorId)
            && empty($limit)
            && empty($offset)
            && empty($period)
            && empty($date)
        ) {
            $period = 'day';
            $date = 'yesterdaySameTime';
        }


        list($whereClause, $bindIdSites) = $this->getIdSitesWhereClause($idSite);

        list($whereBind, $where) = $this->getWhereClauseAndBind($whereClause, $bindIdSites, $idSite, $period, $date, $visitorId, $minTimestamp);

        if (strtolower($filterSortOrder) !== 'asc') {
            $filterSortOrder = 'DESC';
        }

        $segment = new Segment($segment, $idSite);

        // Subquery to use the indexes for ORDER BY
        $select = "log_visit.*";
        $from = "log_visit";
        $groupBy = false;
        $limit = $limit >= 1 ? (int)$limit : 0;
        $offset = $offset >= 1 ? (int)$offset : 0;

        $orderBy = '';
        if (count($bindIdSites) <= 1) {
            $orderBy = 'idsite ' . $filterSortOrder . ', ';
        }

        $orderBy .= "visit_last_action_time " . $filterSortOrder;
        $orderByParent = "sub.visit_last_action_time " . $filterSortOrder;

        // this $innerLimit is a workaround (see https://github.com/piwik/piwik/issues/9200#issuecomment-183641293)
        $innerLimit = $limit;
        if (!$segment->isEmpty()) {
            $innerLimit = $limit * 10;
        }

        $innerQuery = $segment->getSelectQuery($select, $from, $where, $whereBind, $orderBy, $groupBy, $innerLimit, $offset);

        $bind = $innerQuery['bind'];
        // Group by idvisit so that a given visit appears only once, useful when for example:
        // 1) when a visitor converts 2 goals
        // 2) when an Action Segment is used, the inner query will return one row per action, but we want one row per visit
        $sql = "
			SELECT sub.* FROM (
				" . $innerQuery['sql'] . "
			) AS sub
			GROUP BY sub.idvisit
			ORDER BY $orderByParent
		";
        if($limit) {
            $sql .= sprintf("LIMIT %d \n", $limit);
        }
        return array($sql, $bind);
    }

    /**
     * @param $idSite
     * @return Site
     */
    protected function makeSite($idSite)
    {
        return new Site($idSite);
    }

    /**
     * @param string $whereClause
     * @param array $bindIdSites
     * @param $idSite
     * @param $period
     * @param $date
     * @param $visitorId
     * @param $minTimestamp
     * @return array
     * @throws Exception
     */
    private function getWhereClauseAndBind($whereClause, $bindIdSites, $idSite, $period, $date, $visitorId, $minTimestamp)
    {
        $where = array();
        if (!empty($whereClause)) {
            $where[] = $whereClause;
        }
        $whereBind = $bindIdSites;

        if (!empty($visitorId)) {
            $where[] = "log_visit.idvisitor = ? ";
            $whereBind[] = @Common::hex2bin($visitorId);
        }

        if (!empty($minTimestamp)) {
            $where[] = "log_visit.visit_last_action_time > ? ";
            $whereBind[] = date("Y-m-d H:i:s", $minTimestamp);
        }

        // SQL Filter with provided period
        if (!empty($period) && !empty($date)) {
            if ($idSite === 'all' || is_array($idSite)) {
                $currentTimezone = Request::processRequest('SitesManager.getDefaultTimezone');
            } else {
                $currentSite = $this->makeSite($idSite);
                $currentTimezone = $currentSite->getTimezone();
            }

            $dateString = $date;
            if ($period == 'range') {
                $processedPeriod = new Range('range', $date);
                if ($parsedDate = Range::parseDateRange($date)) {
                    $dateString = $parsedDate[2];
                }
            } else {
                $processedDate = Date::factory($date);
                if ($date == 'today'
                    || $date == 'now'
                    || $processedDate->toString() == Date::factory('now', $currentTimezone)->toString()
                ) {
                    $processedDate = $processedDate->subDay(1);
                }
                $processedPeriod = Period\Factory::build($period, $processedDate);
            }
            $dateStart = $processedPeriod->getDateStart()->setTimezone($currentTimezone);
            $where[] = "log_visit.visit_last_action_time >= ?";
            $whereBind[] = $dateStart->toString('Y-m-d H:i:s');

            if (!in_array($date, array('now', 'today', 'yesterdaySameTime'))
                && strpos($date, 'last') === false
                && strpos($date, 'previous') === false
                && Date::factory($dateString)->toString('Y-m-d') != Date::factory('now', $currentTimezone)->toString()
            ) {
                $dateEnd = $processedPeriod->getDateEnd()->setTimezone($currentTimezone);
                $where[] = " log_visit.visit_last_action_time <= ?";
                $dateEndString = $dateEnd->addDay(1)->toString('Y-m-d H:i:s');
                $whereBind[] = $dateEndString;
            }
        }

        if (count($where) > 0) {
            $where = join("
				AND ", $where);
        } else {
            $where = false;
        }
        return array($whereBind, $where);
    }
}
