<?php

namespace App\Training;

use App\Training\Language\Model as LanguageModel;
use App\User\Auth as UserAuth;
use Qs_Db;
use Qs_Translate;
use Zend_Db_Expr;

class Model
{
    const SEPARATOR_LABEL = "\x0F";
    const SEPARATOR_FIELD = "\x0E";

    /**
     * Training mode with Result saving
     */
    const MODE_TRAINING = 'training';

    /**
     * Training mode without Result saving (used for admin)
     */
    const MODE_ADMIN    = 'admin';

    const SHOW_HOME = 'home';
    const SHOW_LIST = 'list';

    protected static $languageId;

    public static function getLanguageId()
    {
        if (self::$languageId === null) {
            self::$languageId = LanguageModel::LANG_DEFAULT;
            $auth = UserAuth::getInstance();
            if ($auth->isLoggedIn()
                && ($languageId = (int)$auth->getData('languageId'))
                && array_key_exists($languageId, LanguageModel::get4Select())
            ) {
                self::$languageId = $languageId;
            }
        }
        return self::$languageId;
    }

    public static function setLanguageId($languageId)
    {
        if (empty($languageId)) {
            self::$languageId = ($languageId === false) ? $languageId : null;
        } elseif (array_key_exists($languageId, LanguageModel::get4Select())) {
            self::$languageId = (int) $languageId;
        } else {
            self::$languageId = LanguageModel::LANG_DEFAULT;
        }
    }

    public static function getLangFilter($alias)
    {
        if (($languageId = self::getLanguageId())) {
            return ["`{$alias}`.`languageId` = ?" => $languageId];
        }
        return null;
    }

    public static function getStartPage($userId)
    {
        if (empty($userId)) {
            return self::SHOW_HOME;
        }
        $testCount = Model::getTestCount();
        if ($testCount == 0 || $testCount > 1) {
            return self::SHOW_LIST;
        } else {
            $testId = Model::getFirstTestId();
            $attempt = Model::getLastAttempt($testId, $userId);
            if ($attempt) {
                if ($attempt['success'] === 'y') {
                    return self::SHOW_HOME;
                } else if ((int) Model::getAttemptCount($testId, $userId) >= 2) {
                    return self::SHOW_HOME;
                } else {
                    return $testId;
                }
            } else {
                return $testId;
            }
        }
    }

    public static function getContinuePage($userId, $testId)
    {
        $result = [
            'target'   => self::SHOW_HOME,
            'showTest' => null,
            'showList' => false,
        ];

        if (empty($userId) || empty($testId)) {
            return $result;
        }
        $attempt = Model::getLastAttempt($testId, $userId, ['success']);
        $testCount = Model::getTestCount();
        $result['showList'] = $testCount == 0 || $testCount > 1;
        if ($attempt) {
            if ($attempt['success'] === 'y') {
                $result['target'] = $result['showList'] ? self::SHOW_LIST : self::SHOW_HOME;
            } else if ((int) Model::getAttemptCount($testId, $userId) >= 2) {
                $result['target'] = $result['showList'] ? self::SHOW_LIST : self::SHOW_HOME;
            } else {
                $result['target'] = $result['showList'] ? self::SHOW_LIST : $testId;
                $result['showTest'] = $testId;
            }
        } else {
            $result['target'] = $testId;
            $result['showTest'] = $testId;
        }
        return $result;
    }

    public static function getHasAnotherTry($userId, $testId)
    {
        $attempt = Model::getLastAttempt($testId, $userId, ['success']);
        if (empty($attempt)) {
            return true;
        } elseif ($attempt['success'] === 'n') {
            $attemptCount = Model::getAttemptCount($testId, $userId);
            return $attemptCount < 2;
        } else {
            return false;
        }
    }

    /**
     * @param bool $attemptSuccess
     * @param int  $attemptCount
     *
     * @return bool
     */
    public static function checkHasAttempt($attemptSuccess, $attemptCount)
    {
        if (empty($attemptCount)) {
            return true;
        } elseif (!$attemptSuccess) {
            return (int) $attemptCount < 2;
        } else {
            return false;
        }
    }

    public static function getAttemptCountSelect($testId, $userId)
    {
        if (null == $testId || null == $userId) {
            return null;
        }

        $select = Qs_Db::getSelect();
        $select->from(Qs_Db::getPair('Result'), []);
        $select->join(Qs_Db::getPair('ResultAttempt'), 'ResultAttempt.resultId = Result.id', ['count' => new Zend_Db_Expr('COUNT(*)')]);
        $select->where('Result.testId = ' . Qs_Db::quoteIdField($testId));
        $select->where('Result.userId = ?', $userId, Qs_Db::INT_TYPE);
        $select->limit(1);
        return $select;
    }

    public static function getAttemptCount($testId, $userId)
    {
        if (($select = self::getAttemptCountSelect($testId, $userId))) {
            return Qs_Db::getInstance()->fetchOne($select);
        }
        return null;
    }

    public static function getLastAttemptSelect($testId, $userId, array $columns = ['*'])
    {
        if (null == $testId || null == $userId) {
            return null;
        }
        $select = Qs_Db::getSelect();
        $select->from(Qs_Db::getPair('Result'), []);
        $select->join(Qs_Db::getPair('ResultAttempt'), 'ResultAttempt.resultId = Result.id', $columns);
        $select->where('Result.testId = ' . Qs_Db::quoteIdField($testId));
        $select->where('Result.userId = ?', $userId);
        $select->limit(1);
        return $select;
    }

    public static function getLastAttempt($testId, $userId, array $columns = ['*'])
    {
        if (($select = self::getLastAttemptSelect($testId, $userId, $columns))) {
            return Qs_Db::getInstance()->fetchRow($select);
        }
       return null;
    }

    public static function getTestSlideExists($testId)
    {
        $select = Qs_Db::getSelect();
        $select->from(Qs_Db::getPair('TestSlide'), ['found' => new Zend_Db_Expr('1')]);
        $select->where('TestSlide.testId = ' . Qs_Db::quoteIdField($testId));
        $select->where('TestSlide.enabled = "y"');
        $select->limit(1);
        return new Zend_Db_Expr('EXISTS (' . $select . ')');
    }

    public static function getTestCount()
    {
        $select = Qs_Db::getSelect();
        $select->from(Qs_Db::getPair('Test'), ['count' => new Zend_Db_Expr('COUNT(*)')]);
        $select->where('Test.enabled = "y"');
        $select->where(self::getTestSlideExists('Test.id'));
        if (($langFilter = self::getLangFilter('Test'))) {
            $select->where(Qs_Db::getWhereSql($langFilter));
        }
        $select->limit(1);
        return Qs_Db::getInstance()->fetchOne($select);
    }

    public static function getFirstTestId()
    {
        $select = Qs_Db::getSelect();
        $select->from(Qs_Db::getPair('Test'), ['id']);
        $select->where('Test.enabled = "y"');
        $select->where(self::getTestSlideExists('Test.id'));
        if (($langFilter = self::getLangFilter('Test'))) {
            $select->where(Qs_Db::getWhereSql($langFilter));
        }
        $select->order('Test.id');
        $select->limit(1);
        return Qs_Db::getInstance()->fetchOne($select);
    }

    public static function getDurationText($seconds)
    {
        $seconds = (int) $seconds;
        $periods = [
            'day'    => 86400,
            'hour'   => 3600,
            'minute' => 60,
            'second' => 1,
        ];
        $result = '';
        foreach ($periods as $name => $value) {
            if ($seconds >= $value) {
                $tmp = floor($seconds / $value);
                $seconds -= $value * $tmp;
                $result .= ($result ? ' ' : '') . $tmp . ' ' . Qs_Translate::getPlural($name, $tmp);
            }
        }
        return $result;
    }

    public static function getTestFilter(Entity $entity, $alias = 'Test')
    {
        $result = [];
        $result["`{$alias}`.`id` = ?"] = $entity->getTestId();
        if ($entity->getMode() === static::MODE_TRAINING) {
            $result["`{$alias}`.`enabled` = ?"] = 'y';
        }
        if (($langFilter = self::getLangFilter($alias))) {
            $result += $langFilter;
        }
        $result[] = self::getTestSlideExists('Test.id');
        return $result;
    }

    public static function getTestSlideFilter(Entity $entity, $filter = [], $alias = 'TestSlide')
    {
        $result = [];
        if (!array_key_exists('testId', $filter) && $entity->getTestId()) {
            $filter['testId'] = $entity->getTestId();
        }
        if (!array_key_exists('id', $filter) && $entity->getSlideId()) {
            $filter['id'] = $entity->getSlideId();
        }
        if (!array_key_exists('enabled', $filter)
            && (
                $entity->getMode() === static::MODE_TRAINING
                || ($entity->getMode() === static::MODE_ADMIN && !$entity->getSlideId())
            )
        ) {
            $filter['enabled'] = 'y';
        }
        foreach ($filter as $name => $value) {
            $result["`{$alias}`.`{$name}` = ?"] = $value;
        }
        return $result;
    }

}