/**

* Module dependencies.

*/

var tty = require('tty');

var util = require('util');

/**

* This is the Node.js implementation of `debug()`.

*

* Expose `debug()` as the module.

*/

exports = module.exports = require('./debug');

exports.init = init;

exports.log = log;

exports.formatArgs = formatArgs;

exports.save = save;

exports.load = load;

exports.useColors = useColors;

/**

* Colors.

*/

exports.colors = [6, 2, 3, 4, 5, 1];

/**

* Build up the default `inspectOpts` object from the environment variables.

*

* $ DEBUG_COLORS=no DEBUG_DEPTH=10 DEBUG_SHOW_HIDDEN=enabled node script.js

*/

exports.inspectOpts = Object.keys(process.env).filter(function (key) {

return /^debug_/i.test(key);

}).reduce(function (obj, key) {

// camel-case

var prop = key

.substring(6)

.toLowerCase()

.replace(/_([a-z])/g, function (_, k) { return k.toUpperCase() });

// coerce string value into JS value

var val = process.env[key];

if (/^(yes|on|true|enabled)$/i.test(val)) val = true;

else if (/^(no|off|false|disabled)$/i.test(val)) val = false;

else if (val === 'null') val = null;

else val = Number(val);

obj[prop] = val;

return obj;

}, {});

/**

* The file descriptor to write the `debug()` calls to.

* Set the `DEBUG_FD` env variable to override with another value. i.e.:

*

* $ DEBUG_FD=3 node script.js 3>debug.log

*/

var fd = parseInt(process.env.DEBUG_FD, 10) || 2;

if (1 !== fd && 2 !== fd) {

util.deprecate(function(){}, 'except for stderr(2) and stdout(1), any other usage of DEBUG_FD is deprecated. Override debug.log if you want to use a different log function (https://git.io/debug_fd)')()

}

var stream = 1 === fd ? process.stdout :

2 === fd ? process.stderr :

createWritableStdioStream(fd);

/**

* Is stdout a TTY? Colored output is enabled when `true`.

*/

function useColors() {

return 'colors' in exports.inspectOpts

? Boolean(exports.inspectOpts.colors)

: tty.isatty(fd);

}

/**

* Map %o to `util.inspect()`, all on a single line.

*/

exports.formatters.o = function(v) {

this.inspectOpts.colors = this.useColors;

return util.inspect(v, this.inspectOpts)

.replace(/\s*\n\s*/g, ' ');

};

/**

* Map %o to `util.inspect()`, allowing multiple lines if needed.

*/

exports.formatters.O = function(v) {

this.inspectOpts.colors = this.useColors;

return util.inspect(v, this.inspectOpts);

};

/**

* Adds ANSI color escape codes if enabled.

*

* @api public

*/

function formatArgs(args) {

var name = this.namespace;

var useColors = this.useColors;

if (useColors) {

var c = this.color;

var prefix = ' \u001b[3' + c + ';1m' + name + ' ' + '\u001b[0m';

args[0] = prefix + args[0].split('\n').join('\n' + prefix);

args.push('\u001b[3' + c + 'm+' + exports.humanize(this.diff) + '\u001b[0m');

} else {

args[0] = new Date().toUTCString()

+ ' ' + name + ' ' + args[0];

}

}

/**

* Invokes `util.format()` with the specified arguments and writes to `stream`.

*/

function log() {

return stream.write(util.format.apply(util, arguments) + '\n');

}

/**

* Save `namespaces`.

*

* @param {String} namespaces

* @api private

*/

function save(namespaces) {

if (null == namespaces) {

// If you set a process.env field to null or undefined, it gets cast to the

// string 'null' or 'undefined'. Just delete instead.

delete process.env.DEBUG;

} else {

process.env.DEBUG = namespaces;

}

}

/**

* Load `namespaces`.

*

* @return {String} returns the previously persisted debug modes

* @api private

*/

function load() {

return process.env.DEBUG;

}

/**

* Copied from `node/src/node.js`.

*

* XXX: It's lame that node doesn't expose this API out-of-the-box. It also

* relies on the undocumented `tty_wrap.guessHandleType()` which is also lame.

*/

function createWritableStdioStream (fd) {

var stream;

var tty_wrap = process.binding('tty_wrap');

// Note stream._type is used for test-module-load-list.js

switch (tty_wrap.guessHandleType(fd)) {

case 'TTY':

stream = new tty.WriteStream(fd);

stream._type = 'tty';

// Hack to have stream not keep the event loop alive.

// See https://github.com/joyent/node/issues/1726

if (stream._handle && stream._handle.unref) {

stream._handle.unref();

}

break;

case 'FILE':

var fs = require('fs');

stream = new fs.SyncWriteStream(fd, { autoClose: false });

stream._type = 'fs';

break;

case 'PIPE':

case 'TCP':

var net = require('net');

stream = new net.Socket({

fd: fd,

readable: false,

writable: true

});

// FIXME Should probably have an option in net.Socket to create a

// stream from an existing fd which is writable only. But for now

// we'll just add this hack and set the `readable` member to false.

// Test: ./node test/fixtures/echo.js < /etc/passwd

stream.readable = false;

stream.read = null;

stream._type = 'pipe';

// FIXME Hack to have stream not keep the event loop alive.

// See https://github.com/joyent/node/issues/1726

if (stream._handle && stream._handle.unref) {

stream._handle.unref();

}

break;

default:

// Probably an error on in uv_guess_handle()

throw new Error('Implement me. Unknown stream file type!');

}

// For supporting legacy API we put the FD here.

stream.fd = fd;

stream._isStdio = true;

return stream;

}

/**

* Init logic for `debug` instances.

*

* Create a new `inspectOpts` object in case `useColors` is set

* differently for a particular `debug` instance.

*/

function init (debug) {

debug.inspectOpts = {};

var keys = Object.keys(exports.inspectOpts);

for (var i = 0; i < keys.length; i++) {

debug.inspectOpts[keys[i]] = exports.inspectOpts[keys[i]];

}

}

/**

* Enable namespaces listed in `process.env.DEBUG` initially.

*/

exports.enable(load());