#!/usr/bin/env node

/*
    Converts the existing .po translation files in the module to JSON files.
    Requires po2json in order to work. Takes as input a directory
    in which to store the resulting json translation files.

    Takes in as an argument an output directory to put translation files.
    Searches for files named `l10n.json` in the `src/views/` directory to get
    template english strings (as well as the general template at `src/l10n.json`).

    It compiles the template strings into a flat object that is compared against the
    translations in the .po files from the `scratchr2_translations` dependency, using
    an md5 of the template string without whitespace, and an md5 of the .po msgid string
    without whitespace.

    The output files are javascript files that declare objects by locale. Each locale
    has a sub-object with FormattedMessage ids as keys, and translated strings as
    values. If no translation was found for a string, the default english will be the
    value.

    Output Example:
    '''
    var message = {
        en: {
            'general.inAWorld': 'In a world, where bears are invisible...',
            'general.question': 'Are there bears here?',
            'general.answer': 'I dunno, but there could be...'
        },
        es: {
            'general.inAWorld': 'En un mundo, donde hay osos invisibles',
            'general.question': 'Are there bears here?',
            'general.answer': 'No sé, pero es posible...'
        }
    }
    '''
*/
var fs = require('fs');
var glob = require('glob');
var merge = require('lodash.merge');
var path = require('path');
var po2icu = require('po2icu');

var localeCompare = require('./lib/locale-compare');

// -----------------------------------------------------------------------------
// Main script
// -----------------------------------------------------------------------------


var args = process.argv.slice(2);

if (!args.length) {
    process.stdout.write('A destination directory must be specified.');
    process.exit(1);
}
var verbose = false;
if (args.length > 1) {
    verbose = (args[1] === '-v') ? true : false;
}

var poUiDir = path.resolve(__dirname, '../node_modules/scratchr2_translations/ui');
var outputDir = path.resolve(__dirname, '../', args[0]);
try {
    fs.accessSync(outputDir, fs.F_OK);
} catch (err) {
    // Doesn't exist - create it.
    fs.mkdirSync(outputDir);
}

// get global locale strings first.
var globalTemplateFile = path.resolve(__dirname, '../src/l10n.json');
// message key with english string values (i.e. default values)
var generalIds = JSON.parse(fs.readFileSync(globalTemplateFile, 'utf8'));
var viewLocales = {};
var generalLocales = {
    en: generalIds
};

// FormattedMessage id with english string as value. Use for default values in translations
// Sample structure: { 'general-general.blah': 'blah', 'about-about.blah': 'blahblah' }
var idsWithICU = {};

// reverse (i.e. english string with message key as the value) object for searching po files.
// Sample structure: { 'blah': 'general-general.blah', 'blahblah': 'about-about.blah' }
var icuWithIds = {};

for (var id in generalIds) {
    idsWithICU['general-' + id] = generalIds[id];
    icuWithIds[generalIds[id]] = 'general-' + id;
}

// get view-specific locale strings.
var files = glob.sync(path.resolve(__dirname, '../src/views/**/l10n.json'));
files.forEach(function (file) {
    var dirPath = file.split('/');
    dirPath.pop();
    var view = dirPath.pop();

    var viewIds = JSON.parse(fs.readFileSync(file, 'utf8'));
    viewLocales[view] = {
        en: viewIds
    };
    for (var id in viewIds) {
        idsWithICU[view + '-' + id] = viewIds[id];
        icuWithIds[viewIds[id]] = view + '-' + id; // add viewName to identifier for later
    }
});

// md5 of english strings with message key as the value for searching po files.
// Sample structure: { 'sdfas43534sdfasdf': 'general-general.blah', 'lkjfasdf4t342asdfa': 'about-about.blah' }
var md5WithIds = localeCompare.getMD5Map(icuWithIds);

// Get ui localization strings first
glob(poUiDir + '/*', function (err, files) {
    if (err) throw new Error(err);
    
    files.forEach(function (file) {
        var lang = file.split('/').pop();
        var jsFile = path.resolve(file, 'LC_MESSAGES/djangojs.po');
        var pyFile = path.resolve(file, 'LC_MESSAGES/django.po');

        var translations = {};

        try {
            var jsTranslations = po2icu.poFileToICUSync(lang, jsFile);
            translations = localeCompare.mergeNewTranslations(translations, jsTranslations, idsWithICU, md5WithIds);
        } catch (err) {
            if (verbose) process.stdout.write(lang + ': ' + err + '\n');
        }

        try {
            var pyTranslations = po2icu.poFileToICUSync(lang, pyFile);
            translations = localeCompare.mergeNewTranslations(translations, pyTranslations, idsWithICU, md5WithIds);
        } catch (err) {
            if (verbose) process.stdout.write(lang + ': ' + err + '\n');
        }

        // add new translations to locale object
        for (var id in translations) {
            var ids = id.split('-'); // [viewName, stringId]
            var viewName = ids[0];
            var stringId = ids[1];
            if (viewLocales.hasOwnProperty(viewName)) {
                if (!viewLocales[viewName].hasOwnProperty(lang)) viewLocales[viewName][lang] = {};
                viewLocales[viewName][lang][stringId] = translations[id];
            } else {
                // default to general
                if (!generalLocales.hasOwnProperty(lang)) generalLocales[lang] = {};
                generalLocales[lang][stringId] = translations[id];
            }
        }
    });
    
    for (var view in viewLocales) {
        var viewTranslations = merge(viewLocales[view], generalLocales);
        var objectString = JSON.stringify(viewTranslations);
        var fileString = 'window._messages = ' + objectString + ';';
        fs.writeFileSync(outputDir + '/' + view + '.intl.js', fileString);
    }
});