/*
Copyright 2017 MTRNord and Cooperative EITA

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import request from 'browser-request';
// Workaround for broken export
import * as counterpart from 'counterpart-riot';
import UserSettingsStore from './UserSettingsStore';
var q = require('q');

const i18nFolder = 'i18n/';

module.exports.setLanguage = function(languages, extCounterpart=null) {
    if (!languages || !Array.isArray(languages)) {
    const languages = this.getNormalizedLanguageKeys(this.getLanguageFromBrowser());
    console.log("no language found. Got from browser: " + JSON.stringify(languages));
    }

    request(i18nFolder + 'languages.json', function(err, response, body) {
        function getLanguage(langPath, langCode, callback) {
            let response_return = {};
            let resp_raw = {};
            request(
                { method: "GET", url: langPath },
                (err, response, body) => {
                    if (err || response.status < 200 || response.status >= 300) {
                        if (response) {
                            if (response.status == 404 || (response.status == 0 && body == '')) {
                                resp_raw = {};
                            }
                        }
                        const resp = {err: err, response: resp_raw};
                        err = resp['err'];
                        const response_cb = resp['response'];
                        callback(err, response_cb, langCode);
                        return;
                    }

                    response_return = JSON.parse(body);
                    callback(null, response_return, langCode);
                    return;
                }
            );
            return;
        }

        function registerTranslations(err, langJson, langCode){
            if (err !== null) {
                var ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
                Modal.createDialog(ErrorDialog, {
                    title: counterpart.translate('Error changing language'),
                    description: counterpart.translate('Riot was unable to find the correct Data for the selected Language.'),
                    button: counterpart.translate("OK"),
                });
                return;
            } else {
                if (extCounterpart) {
                    extCounterpart.registerTranslations(langCode, langJson);
                }
                counterpart.registerTranslations(langCode, langJson);
            }
        }

        let languageFiles = {};
        if(err){
            console.error(err);
            return;
        } else {
            if (body) {
                languageFiles = JSON.parse(body);
            } else {
                languageFiles = JSON.parse('{"en": "en_EN.json"}');
            }
        }


        const isValidFirstLanguage = (languageFiles.hasOwnProperty(languages[0]));
        var validLanguageKey = "";
        if ((isValidFirstLanguage) || (languages.length==2 && languageFiles.hasOwnProperty(languages[1]))) {
            validLanguageKey = (isValidFirstLanguage) ? languages[0] : languages[1];
            getLanguage(i18nFolder + languageFiles[validLanguageKey], validLanguageKey, registerTranslations);
            if (extCounterpart) {
                extCounterpart.setLocale(validLanguageKey);
            }
            counterpart.setLocale(validLanguageKey);
            UserSettingsStore.setLocalSetting('language', validLanguageKey);
            console.log("set language to "+validLanguageKey);
        } else {
            console.log("didnt find any language file");
        }

        //Set 'en' as fallback language:
        if (validLanguageKey!="en") {
            getLanguage(i18nFolder + languageFiles['en'], 'en', registerTranslations);
        }
        if (extCounterpart) {
            extCounterpart.setFallbackLocale('en');
        }
        counterpart.setFallbackLocale('en');
    });
};

module.exports.getAllLanguageKeysFromJson = function() {
    let deferred = q.defer();

    request(
        { method: "GET", url: i18nFolder + 'languages.json' },
        (err, response, body) => {
            if (err || response.status < 200 || response.status >= 300) {
                if (response) {
                    if (response.status == 404 || (response.status == 0 && body == '')) {
                        deferred.resolve({});
                    }
                }
                deferred.reject({err: err, response: response});
                return;
            }
            var languages = JSON.parse(body);
            // If no language is found, fallback to 'en':
            if (!languages) {
                languages = [{"en": "en_EN.json"}];
            }
            const languageKeys = Object.keys(languages);
            deferred.resolve(languageKeys);
        }
    );
    return deferred.promise;
}

module.exports.getLanguageFromBrowser = function() {
    return navigator.languages[0] || navigator.language || navigator.userLanguage;
};

module.exports.getNormalizedLanguageKeys = function(language) {
    if (!language) {
        return;
    }
    const languageKeys = [];
    const normalizedLanguage = this.normalizeLanguageKey(language);
    const languageParts = normalizedLanguage.split('-');
    if (languageParts.length==2 && languageParts[0]==languageParts[1]) {
        languageKeys.push(languageParts[0]);
    } else {
        languageKeys.push(normalizedLanguage);
        if (languageParts.length==2) {
            languageKeys.push(languageParts[0]);
        }
    }
    return languageKeys;
};

module.exports.normalizeLanguageKey = function(language) {
    return language.toLowerCase().replace("_","-");
};