<?php

namespace app\components\language;

use app\models\Users;
use Yii;
use yii\helpers\ArrayHelper;

class LanguageHelper
{
    public static $js2dbMap = array(
        'en' => 'eng',
        'ru' => 'rus',
        'uk' => 'ukr',
    );

    public static $db2jsMap = array(
        'eng' => 'en',
        'rus' => 'ru',
        'ukr' => 'uk',
    );

    /**
     * @throws \yii\base\InvalidConfigException
     * @return string eng|ukr|rus
     */
    public static function getLanguage()
    {
        if (($languageId = ArrayHelper::getValue($_COOKIE, 'language')) && isset(self::$db2jsMap[$languageId])) {
            self::setLanguage($languageId);
        } else {
            if (null === ($languageId = Yii::$app->getSession()->get('languageId')) || empty(self::$db2jsMap[$languageId])) {
                if (Yii::$app->getDb()->getIsActive()
                    && Yii::$app->user->identity
                    && ($preferredLanguage = Yii::$app->user->identity->preferredLanguage)
                    && array_key_exists($preferredLanguage, self::$db2jsMap)
                ) {
                    $languageId = $preferredLanguage;
                    self::setLanguage($languageId);
                } else {
                    $languageId = self::parseBrowserLanguage();
                }
            }
        }

//        if (null === ($languageId = Yii::$app->getSession()->get('languageId')) || empty(self::$db2jsMap[$languageId])) {
//            if (Yii::$app->getDb()->getIsActive()
//                && Yii::$app->user->identity
//                && ($preferredLanguage = Yii::$app->user->identity->preferredLanguage)
//                && array_key_exists($preferredLanguage, self::$db2jsMap)
//            ) {
//                $languageId = $preferredLanguage;
//                self::setLanguage($languageId);
//            } else if (null == ($languageId = ArrayHelper::getValue($_COOKIE, 'language')) || empty(self::$db2jsMap[$languageId])) {
//                $languageId = self::parseBrowserLanguage();
//            }
//        }

        return $languageId && isset(self::$db2jsMap[$languageId])
            ? $languageId
            : self::getDefaultLanguage();
    }

    /**
     * @param $languageId string eng|ukr|rus
     *
     * @throws \yii\base\InvalidParamException
     * @throws \yii\base\InvalidConfigException
     */
    public static function setLanguage($languageId)
    {
        if (null === $languageId || !array_key_exists($languageId, self::$db2jsMap)) {
            $languageId = self::parseBrowserLanguage();
        }
        Yii::$app->getSession()->set('languageId', $languageId);
        Users::setLanguage($languageId);
        unset($_COOKIE['language']);
        setcookie('language', null, -1, '/');
    }

    /**
     * @throws \yii\base\InvalidParamException
     * @throws \yii\base\InvalidConfigException
     * @return string eng|ukr|rus
     */
    public static function detectLanguage()
    {
        if (null == ($languageId = ArrayHelper::getValue($_COOKIE, 'language'))
            && null == ($languageId = Yii::$app->getSession()->get('languageId'))
        ) {
            $languageId = self::parseBrowserLanguage();
        }
//        if (null == ($languageId = Yii::$app->getSession()->get('languageId'))
//            && null == ($languageId = ArrayHelper::getValue($_COOKIE, 'language'))
//        ) {
//            $languageId = self::parseBrowserLanguage();
//        }
        return $languageId && isset(self::$db2jsMap[$languageId])
            ? $languageId
            : self::getDefaultLanguage();
    }

    /**
     * @return string eng|ukr|rus
     */
    public static function getDefaultLanguage()
    {
        reset(self::$db2jsMap);
        return key(self::$db2jsMap);
    }

    /**
     * @return string eng|ukr|rus
     */
    public static function parseBrowserLanguage()
    {
        $httpAccept = $_SERVER["HTTP_ACCEPT_LANGUAGE"];
        $language = null;
        if (isset($httpAccept) && strlen($httpAccept) > 1) {
            // Split possible languages into array
            $httpAcceptArray = explode(",", $httpAccept);
            $lang = array();
            foreach ($httpAcceptArray as $val) {
                // check for q-value and create associative array. No q-value means 1 by rule
                if (preg_match("/(.*);q=([0-1]{0,1}\.\d{0,4})/i", $val, $matches)) {
                    $lang[$matches[1]] = (float)$matches[2];
                } else {
                    $lang[$val] = 1.0;
                }
            }

            // return default language (highest q-value)
            $qValues = 0.0;
            foreach ($lang as $key => $value) {
                if ($value > $qValues) {
                    $qValues = (float)$value;
                    $language = $key;
                }
            }
        }

        $code = $language ? substr(strtolower($language), 0, 2) : null;
        return $language && isset(self::$js2dbMap[$code])
            ? self::$js2dbMap[$code]
            : self::getDefaultLanguage();
    }

}