gnavalesi/music-tag

var fs = require('fs');
var Q = require('q');
var _ = require('underscore');

(function () {
    'use strict';

    var validatePath = function (path) {
        var deferred = Q.defer();

        fs.stat(path, function (err, stats) {
            if (err) {
                deferred.reject(err);
            } else {
                var data = {
                    isDirectory: stats.isDirectory(),
                    isFile: stats.isFile()
                };

                deferred.resolve(data);
            }
        });

        return deferred.promise;
    };

    var resolvePath = function (path) {
        var deferred = Q.defer();

        fs.realpath(path, function (err, resolvedPath) {
            if (err) {
                deferred.reject(err);
            } else {
                deferred.resolve(resolvedPath);
            }
        });

        return deferred.promise;
    };

    var isMusicFile = function (path) {
        var regex = /.+.(mp3|flac|wav)/i;
        return path.toString().match(regex) !== null;
    };

    var getFiles = function (path, getFolders) {
        var deferred = Q.defer();

        fs.readdir(path, function (err, files) {
            if (err) {
                deferred.reject(new Error(err));
            } else {
                files = _.chain(files)
                    .map(_.partial(addPath, path))
                    .filter(function (file) {
                        return (getFolders && isDirectory(file)) || isMusicFile(file);
                    })
                    .map(function (fullPath) {
                        return validatePath(fullPath).then(function (pathData) {
                            if ((pathData.isDirectory && getFolders) || pathData.isFile) {
                                return _.extend(pathData, {path: fullPath});
                            }
                        });
                    }).value();
                Q.all(files).then(function (result) {
                    deferred.resolve(result);
                }).catch(deferred.reject);
            }
        });

        return deferred.promise;
    };

    var addPath = function (path, file) {
        return normalizePath(path) + file;
    };

    var normalizePath = function (path) {
        return (('' + path).endsWith('/') ? path : path + '/');
    };

    var isDirectory = function (path) {
        return path.toString().endsWith('/') || path.toString().match(/^.+\/[^\.]+$/) !== null;
    };

    var validateOptions = function(options, defaultOptions) {
        var result = null;

        if (_.isUndefined(options)) {
            result = _.clone(defaultOptions);
        } else if (_.isObject(options)) {
            result = _.extend(_.clone(defaultOptions), options);
        }

        return result;
    };

    module.exports = {
        validatePath: validatePath,
        resolvePath: resolvePath,
        isMusicFile: isMusicFile,
        getFiles: getFiles,
        validateOptions: validateOptions
    };
}());