Logger.js

/*jshint regexp:false*/

'use strict';

var colors = require('colors');
var mout   = require('mout');
var Stream = require('stream');

colors.setTheme({
    automaton_debug:   'white',
    automaton_info:    'cyan',
    automaton_warn:    'yellow',
    automaton_error:   'red',
    automaton_success: 'green'
});

/**
 * Logger.
 *
 * Available options:
 *  - verbosity - 0 means no logging
 *                1 means only 1 deep level tasks and so on..
 *                -1 means log every level
 *  - debug     - true to log debug messages, false otherwise
 *  - color     - true to keep colors in messages, false otherwise
 *
 * @param {Object} [options] The options
 */
function Logger(options) {
    this._options = mout.object.mixIn({
        verbosity: -1,
        debug: false,
        color: true
    }, options);

    this._stream = new Stream();
    this._stream.writable = false;

    this._ln = true;
    this._depth = 1;
    this._padding = '';
}

/**
 * Get the read stream for the logger.
 *
 * @return {Stream} The readonly stream
 */
Logger.prototype.getStream = function () {
    return this._stream;
};

/**
 * Set the current depth.
 *
 * @param {Number} depth The depth
 *
 * @return {Logger} Chainable!
 */
Logger.prototype.setDepth = function (depth) {
    this._depth = depth < 1 ? 1 : depth;
    this._padding = this._depth > 1 ? mout.string.repeat('  ', this._depth - 1) : '';

    return this;
};

/**
 * Mutes the logger.
 *
 * @return {Logger} Chainable!
 */
Logger.prototype.mute = function () {
    this._muted = true;

    return this;
};

/**
 * Unmutes the logger.
 *
 * @return {Logger} Chainable!
 */
Logger.prototype.unmute = function () {
    this._muted = false;

    return this;
};

/**
 * Check if the logger is muted.
 *
 * @return {Boolean} True if muted, false otherwise
 */
Logger.prototype.isMuted = function () {
    return this._muted;
};

/**
 * Logs an simple message.
 *
 * @param {Mixed} ..data The data to log
 *
 * @return {Logger} Chaining!
 */
Logger.prototype.write = function () {
    return this._log(this._arr2str.apply(this, arguments));
};

/**
 * Logs an simple message adding a new line.
 *
 * @param {Mixed} ..data The data to log
 *
 * @return {Logger} Chaining!
 */
Logger.prototype.writeln = function () {
    return this._logln(this._arr2str.apply(this, arguments));
};

/**
 * Logs an info message.
 *
 * @param {Mixed} ..data The data to log
 *
 * @return {Logger} Chaining!
 */
Logger.prototype.info = function () {
    return this._log(this._arr2str.apply(this, arguments), 'info');
};

/**
 * Logs an info message adding a new line.
 *
 * @param {Mixed} ..data The data to log
 *
 * @return {Logger} Chaining!
 */
Logger.prototype.infoln = function () {
    return this._logln(this._arr2str.apply(this, arguments), 'info');
};

/**
 * Logs a warning message.
 *
 * @param {Mixed} ..data The data to log
 *
 * @return {Logger} Chaining!
 */
Logger.prototype.warn = function () {
    return this._log(this._arr2str.apply(this, arguments), 'warn');
};

/**
 * Logs a warning message adding a new line.
 *
 * @param {Mixed} ..data The data to log
 *
 * @return {Logger} Chaining
 */
Logger.prototype.warnln = function () {
    return this._logln(this._arr2str.apply(this, arguments), 'warn');
};

/**
 * Logs an error message.
 *
 * @param {Mixed} ..data The data to log
 *
 * @return {Logger} Chaining!
 */
Logger.prototype.error = function () {
    return this._log(this._arr2str.apply(this, arguments), 'error');
};

/**
 * Logs an error message adding a new line.
 *
 * @param {Mixed} ..data The data to log
 *
 * @return {Logger} Chaining!
 */
Logger.prototype.errorln = function () {
    return this._logln(this._arr2str.apply(this, arguments), 'error');
};

/**
 * Logs an success message.
 *
 * @param {Mixed} ..data The data to log
 *
 * @return {Logger} Chaining!
 */
Logger.prototype.success = function () {
    return this._log(this._arr2str.apply(this, arguments), 'success');
};

/**
 * Logs an success message adding a new line.
 *
 * @param {Mixed} ..data The data to log
 *
 * @return {Logger} Chaining!
 */
Logger.prototype.successln = function () {
    return this._logln(this._arr2str.apply(this, arguments), 'success');
};

/**
 * Logs a debug message.
 * It will only actually log if the debug option is enabled.
 *
 * @param {Mixed} ..data The data to log
 *
 * @return {Logger} Chaining!
 */
Logger.prototype.debug = function () {
    return this._log(this._arr2str.apply(this, arguments), 'debug', true);
};

/**
 * Logs a debug message adding a new line.
 * It will only actually log if the debug option is enabled.
 *
 * @param {Mixed} ..data The data to log
 *
 * @return {Logger} Chaining!
 */
Logger.prototype.debugln = function () {
    return this._logln(this._arr2str.apply(this, arguments), 'debug', true);
};

/**
 * Removes any colors (and aditional styles) from a string.
 *
 * @param {String} str The string to strip colors and styles from
 *
 * @return {String} The uncolored string
 */
Logger.prototype.uncolor = function (str) {
    return Logger.removeColors(str);
};

/**
 * Indents a string with new lines in the corpus.
 *
 * @param {String} str The string
 *
 * @return {String} The indented string
 */
Logger.prototype._indent = function (str) {
    return str.replace(/(\r?)\n(.+?)/gm, '$1\n' + this._padding + '$2');
};

/**
 * Checks if a message should be really logged.
 * Debug, depth and verbosity are taken into account.
 *
 * @param {Boolean} [debug] True if it's a debug message, false otherwise (default to false)
 *
 * @return {Boolean} True if it should be logged, false otherwise
 */
Logger.prototype._checkLevel = function (debug) {
    if (debug && !this._options.debug) {
        return false;
    }

    return this._options.verbosity === -1 || this._depth <= this._options.verbosity;
};

/**
 * Converts an array of arguments to a string for logging.
 *
 * @param {Mixed} ...args Any number of arguments of any type
 */
Logger.prototype._arr2str = function () {
    var str = '';

    mout.lang.toArray(arguments).forEach(function (arg) {
        str += arg + ' ';
    }, this);

    return str.slice(0, -1);
};

/**
 * Logs a message.
 *
 * @param {Mixed}   data    The data to log
 * @param {String}  type    The type of the message (info, success, etc)
 * @param {Boolean} [debug] True if it is a debug message, false otherwise
 */
Logger.prototype._log = function (data, type, debug) {
    if (!this._muted && this._checkLevel(debug)) {
        // if the last printed line was a new line, then pad the data
        if (this._ln) {
            data = this._padding + data;
            this._ln = false;
        }

        // if the actual data ends with a new line, set the ln flag to true
        if (mout.string.endsWith(data, '\n')) {
            this._ln = true;
        }

        // indent new lines in the middle of the data
        data = this._indent(data + '');

        data = !this._options.color ? this.uncolor(data) : (type ? data['automaton_' + type] : data);
        this._stream.emit('data', data);
    }
};

/**
 * Logs a message with a new line at the end.
 *
 * @param {Mixed}   data    The data to log
 * @param {String}  type    The type of the message (info, success, etc)
 * @param {Boolean} [debug] True if it is a debug message, false otherwise
 */
Logger.prototype._logln = function (data, type, debug) {
    if (!this._muted && this._checkLevel(debug)) {
        this._ln = true;

        // indent new lines in the middle of the data
        data = this._padding + this._indent(data + '');

        data = !this._options.color ? this.uncolor(data) : (type ? data['automaton_' + type] : data);
        this._stream.emit('data', data + '\n');
    }
};

/**
 * Removes any colors (and aditional styles) from a string.
 *
 * @param {String} str The string to strip colors and styles from
 *
 * @return {String} The uncolored string
 */
Logger.removeColors = function (str) {
    return str.replace(/\x1B\[\d+m/g, '');
};

module.exports = Logger;