calebthebrewer/gulp-selectors

var _ = require('lodash'),
    multimatch = require('multimatch'),
    generateShortname = require('./generate-shortname');

/**
 * Provides libraries.
 */
module.exports = Library;

/**
 * This handy function returns an empty library. This should be a module on its own so that the
 * logic of retrieving a library does not get mixed up with the library logic itself.
 *
 * @returns {object} Library
 * @constructor
 */
function Library(ignores) {
    var _library = {},
        _ignores = ignores || [],
        size = 0;

    /**
     * Tests if a value exists in the library.
     *
     * @params {string} name
     * @returns {boolean} Bool for if it exists
     */
    this.has = function(name) {
        return _library[name] !== undefined;
    };

    /**
     * Ensures the name is set and returns it. If generates an ignored name,
     * will increase size and try again
     *
     * @param name String name to get shortname for from the library
     * @param dontCount Bool to not to count this as a use in the code
     * @returns {string} Shortname of the minified name
     */
    this.get = function(name, dontCount) {
        //catch all for ignoring IDs
        if (ignores === true) return name;

        var shortname;

        if (_library[name]) {
            shortname = _library[name].shortname;
            if (!dontCount) {
                _library[name].hits++;
            }
        } else if (!multimatch(name, _ignores).length) {
            do {
                shortname = generateShortname(size);
                size++;
            } while (~_ignores.indexOf(shortname));

            _library[name] = {
                shortname: shortname,
                hits: dontCount ? 0 : 1
            };
        } else {
            shortname = name;
        }

        return shortname;
    };

    /**
     * Returns all of the shortnames in the library.
     * Does not count towards usage.
     *
     * @returns {array} Of all shortnames.
     */
    this.getAll = function() {
        return _.pluck(_library, 'shortname');
    };

    /**
     * Retrieves shortnames which are not used in the code processed.
     *
     * @returns {array} Of unused names
     */
    this.getUnused = function() {
        return _.pluck(
            _.filter(
                _library,
                function(entry) {
                    return entry.hits === 0;
                }), 'shortname');
    };

    /**
     * Returns the size of the library.
     *
     * @returns {number} Number of entries in the library
     */
    this.size = function() {
        return size;
    };

    /**
     * Returns the full selector names which have been entered so far.
     *
     * @returns {Array} All full selector names
     */
    this.getFullNames = function() {
        return Object.keys(_library);
    };

    this.stats = function() {
        return {
            size: this.size(),
            unused: this.getUnused().length
        };
    }
}