#!/usr/bin/env node

const fs = require('fs');
const moment = require('moment');
const _ = require('lodash');
const path = require('path');
const agent = require('superagent-promise')(require('superagent'), Promise);
const { translate } = require('google-translate-api-browser');
let dicc = {};

//Lang Codes https://ctrlq.org/code/19899-google-translate-languages

if (process.argv.length >= 4) {
    //Args
    const inputFile = process.argv[2];
    const destinationCodes = process.argv[3].split(',');
    const apiKey = process.argv.length > 4 && process.argv[4];

    const apiUrl = _.template('https://www.googleapis.com/language/translate/v2?key=<%= apiKey %>&q=<%= value %>&source=en&target=<%= languageKey %>');

    const transformResponse = (res) => {
        return _.get(JSON.parse(res.text), ['data', 'translations', 0, 'translatedText'], '');
    };

    const getCache = (languageKey) => {
        try {
            dicc[languageKey] = {};
            let fileContent = fs.readFileSync(`./translateCache-${languageKey}.txt`, 'utf-8').split('\n');
            fileContent.map((line) => {
                let cached = line.split('|');
                if (cached[0]) dicc[languageKey][cached[0]] = cached[1];
            });
        } catch (error) {}
    };
    const cachedIndex = (key, value, languageKey) => {
        const line = key + '|' + value + '\n';
        dicc[languageKey][key] = value;
        fs.appendFileSync(`./translateCache-${languageKey}.txt`, line);
        return value;
    };

    function iterLeaves(value, keyChain, accumulator, languageKey) {
        accumulator = accumulator || {};
        keyChain = keyChain || [];
        if (_.isObject(value)) {
            return _.chain(value)
                .reduce((handlers, v, k) => {
                    return handlers.concat(iterLeaves(v, keyChain.concat(k), accumulator, languageKey));
                }, [])
                .flattenDeep()
                .value();
        } else {
            if (typeof value !== 'string') return value;

            return function () {
                if (!(value in dicc[languageKey])) {
                    console.log(
                        _.template('Translating <%= value %> to <%= languageKey %>')({
                            value,
                            languageKey
                        })
                    );

                    let prom;
                    //Translates individual string to language code
                    if (apiKey != '') {
                        //using apiKey
                        prom = agent(
                            'GET',
                            apiUrl({
                                value: encodeURI(value),
                                languageKey,
                                apiKey
                            })
                        ).then(transformResponse);
                    } else {
                        //using free api key
                        prom = translate(value, { to: languageKey });
                    }

                    return prom
                        .then((res) => cachedIndex(value, res, languageKey))
                        .catch((err) => console.log(err))
                        .then((text) => {
                            //Sets the value in the accumulator
                            _.set(accumulator, keyChain, text);

                            //This needs to be returned to it's eventually written to json
                            return accumulator;
                        });
                } else {
                    console.log(value + ' cached: ' + dicc[languageKey][value]);
                    _.set(accumulator, keyChain, dicc[languageKey][value]);
                    return accumulator;
                }
            };
        }
    }

    Promise.all(
        _.reduce(
            destinationCodes,
            (sum, languageKey) => {
                const fileName = _.template('<%= languageKey %>.json')({
                    languageKey
                });

                //read languageKey Cache.
                getCache(languageKey);

                //Starts with the top level strings
                return sum.concat(
                    _.reduce(
                        iterLeaves(JSON.parse(fs.readFileSync(path.resolve(inputFile), 'utf-8')), undefined, undefined, languageKey),
                        (promiseChain, fn) => {
                            return promiseChain.then(fn);
                        },
                        Promise.resolve()
                    )
                        .then((payload) => {
                            fs.writeFileSync('./../../apps/red-ui/src/assets/i18n/' + fileName, JSON.stringify(payload));
                        })
                        .then(_.partial(console.log, 'Successfully translated all nodes, file output at ' + fileName))
                );
            },
            []
        )
    ).then(() => {
        process.exit();
    });
} else {
    console.error('You must provide an input json file and a comma-separated list of destination language codes.');
}