var fs = require('fs');
var path = require('path');

var params = {};

TranslationPlugin.loader = function(options) {

    let path = options.path ? options.path : "none";
    return require.resolve("./loader") + "?path="+path;
};


function TranslationPlugin(options) {
  // Setup the plugin instance with options...
  params = options;
}

requireContext = function(base, scan_subdirectories, regular_expression) {

    const contents = {};

    function read_directory(directory) {

        for (let child of fs.readdirSync(directory)) {

            const full_path = path.join(directory, child);

            if (fs.statSync(full_path).isDirectory()) {

                if (scan_subdirectories) {

                    read_directory(full_path);
                }
            } else {

                if (regular_expression && !full_path.match(regular_expression)) {

                    continue;
                }

                contents[path.relative(base, full_path)] = require(full_path);
                delete require.cache[require.resolve(full_path)]
            }
        }

    }

    read_directory(base);
    return contents;
}

function compare(first, second) {

    let secondKeys= Object.keys(second);
    let firstKeys = Object.keys(first);

    for(let key of firstKeys) {

        if ( secondKeys.indexOf(key)  === -1 || second[key].localeCompare(first[key])) {

            return false;
        }
    }

    for(let key of secondKeys) {

        if ( firstKeys.indexOf(key)  === -1 || first[key].localeCompare(second[key])) {

            return false;
        }
    }

    return true;
}

TranslationPlugin.prototype.apply = function(compiler) {
  compiler.plugin('done', function() {

        try {

            let translations = {};
            let chunks = requireContext(params.path, false, /\.json$/);

            Object.keys(chunks).forEach(function(chunk, index) {
                translations = Object.assign({}, translations, chunks[chunk]);
            });

            let data = {};
            const path = params.output+"/"+params.lang+".json";


            let write = true;
            let old = {};

            try {

                old = require(path)[params.lang];
                delete require.cache[require.resolve(path)];

            } catch (Exception) {
                console.log("Can't load file");
            }

            write = !compare(translations, old);

            data[params.lang] = translations;


            if (write) {

                try {
                    fs.unlinkSync(path);
                } catch(err) {

                }

                fs.writeFile(path, JSON.stringify(data), function(err) {
                    if(err) {
                        return console.log(err);
                    }
                });
            }
        } catch (Exception) {
            console.error(Exception);
        }
    });
};

module.exports = TranslationPlugin;