/**

* 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)
  .split('\n').map(function(str) {
    return str.trim()
  }).join(' ');

};

/**

* 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());