#!/usr/bin/env node

/**
 * Module dependencies.
 */

var fs = require('fs')
  , os = require('os')
  , exec = require('child_process').exec
  , mkdirp = require('mkdirp');

/**
 * Package information.
 */

var pkg = JSON.parse(fs.readFileSync(__dirname + '/../package.json'));

/**
 * Framework version.
 */

var version = pkg.version;

/**
 * Add session support.
 */

var sessions = false;

/**
 * CSS engine to utilize.
 */

var cssEngine;

/**
 * End-of-line code.
 */

var eol = os.platform
  ? ('win32' == os.platform() ? '\r\n' : '\n')
  : '\n';

/**
 * Template engine to utilize.
 */

var templateEngine = 'jade';

/**
 * Usage documentation.
 */

var usage = ''
  + '\n'
  + '  Usage: express [options] [path]\n'
  + '\n'
  + '  Options:\n'
  + '    -s, --sessions           add session support\n'
  + '    -t, --template <engine>  add template <engine> support (jade|ejs). default=jade\n'
  + '    -c, --css <engine>       add stylesheet <engine> support (stylus). default=plain css\n'
  + '    -v, --version            output framework version\n'
  + '    -h, --help               output help information\n'
  ;

/**
 * Routes index template.
 */

var index = [
    ''
  , '/*'
  , ' * GET home page.'
  , ' */'
  , ''
  , 'exports.index = function(req, res){'
  , '  res.render(\'index\', { title: \'Express\' })'
  , '};'
].join(eol);

/**
 * Jade layout template.
 */

var jadeLayout = [
    '!!!'
  , 'html'
  , '  head'
  , '    title= title'
  , '    link(rel=\'stylesheet\', href=\'/stylesheets/style.css\')'
  , '  body!= body'
].join(eol);

/**
 * Jade index template.
 */

var jadeIndex = [
    'h1= title'
  , 'p Welcome to #{title}'
].join(eol);

/**
 * EJS layout template.
 */

var ejsLayout = [
    '<!DOCTYPE html>'
  , '<html>'
  , '  <head>'
  , '    <title><%= title %></title>'
  , '    <link rel=\'stylesheet\' href=\'/stylesheets/style.css\' />'
  , '  </head>'
  , '  <body>'
  , '    <%- body %>'
  , '  </body>'
  , '</html>'
].join(eol);

/**
 * EJS index template.
 */

var ejsIndex = [
    '<h1><%= title %></h1>'
  , '<p>Welcome to <%= title %></p>'
  ].join(eol);

/**
 * Default css template.
 */

var css = [
    'body {'
  , '  padding: 50px;'
  , '  font: 14px "Lucida Grande", Helvetica, Arial, sans-serif;'
  , '}'
  , ''
  , 'a {'
  , '  color: #00B7FF;'
  , '}'
].join(eol);

/**
 * Default stylus template.
 */

var stylus = [
    'body'
  , '  padding: 50px'
  , '  font: 14px "Lucida Grande", Helvetica, Arial, sans-serif'
  , 'a'
  , '  color: #00B7FF'
].join(eol);

/**
 * App template.
 */

var app = [
    ''
  , '/**'
  , ' * Module dependencies.'
  , ' */'
  , ''
  , 'var express = require(\'express\')'
  , '  , routes = require(\'./routes\');'
  , ''
  , 'var app = module.exports = express.createServer();'
  , ''
  , '// Configuration'
  , ''
  , 'app.configure(function(){'
  , '  app.set(\'views\', __dirname + \'/views\');'
  , '  app.set(\'view engine\', \':TEMPLATE\');'
  , '  app.use(express.bodyParser());'
  , '  app.use(express.methodOverride());{sess}{css}'
  , '  app.use(app.router);'
  , '  app.use(express.static(__dirname + \'/public\'));'
  , '});'
  , ''
  , 'app.configure(\'development\', function(){'
  , '  app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));'
  , '});'
  , ''
  , 'app.configure(\'production\', function(){'
  , '  app.use(express.errorHandler());'
  , '});'
  , ''
  , '// Routes'
  , ''
  , 'app.get(\'/\', routes.index);'
  , ''
  , 'app.listen(3000, function(){'
  , '  console.log("Express server listening on port %d in %s mode", app.address().port, app.settings.env);'
  , '});'
  , ''
].join(eol);

// Parse arguments

var args = process.argv.slice(2)
  , path = '.';

while (args.length) {
  var arg = args.shift();
  switch (arg) {
    case '-h':
    case '--help':
      abort(usage);
      break;
    case '-v':
    case '--version':
      abort(version);
      break;
    case '-s':
    case '--session':
    case '--sessions':
      sessions = true;
      break;
    case '-c':
    case '--css':
      args.length
        ? (cssEngine = args.shift())
        : abort('--css requires an argument');
      break;
    case '-t':
    case '--template':
      args.length
        ? (templateEngine = args.shift())
        : abort('--template requires an argument');
      break;
    default:
        path = arg;
  }
}

// Generate application

(function createApplication(path) {
  emptyDirectory(path, function(empty){
    if (empty) {
      createApplicationAt(path);
    } else {
      confirm('destination is not empty, continue? ', function(ok){
        if (ok) {
          process.stdin.destroy();
          createApplicationAt(path);
        } else {
          abort('aborting');
        }
      });
    }
  });
})(path);

/**
 * Create application at the given directory `path`.
 *
 * @param {String} path
 */

function createApplicationAt(path) {
  console.log();
  process.on('exit', function(){
    console.log();
    console.log('   dont forget to install dependencies:');
    console.log('   $ cd %s && npm install', path);
    console.log();
  });

  mkdir(path, function(){
    mkdir(path + '/public');
    mkdir(path + '/public/javascripts');
    mkdir(path + '/public/images');
    mkdir(path + '/public/stylesheets', function(){
      switch (cssEngine) {
        case 'stylus':
          write(path + '/public/stylesheets/style.styl', stylus);
          break;
        default:
          write(path + '/public/stylesheets/style.css', css);
      }
    });

    mkdir(path + '/routes', function(){
      write(path + '/routes/index.js', index);
    });

    mkdir(path + '/views', function(){
      switch (templateEngine) {
        case 'ejs':
          write(path + '/views/layout.ejs', ejsLayout);
          write(path + '/views/index.ejs', ejsIndex);
          break;
        case 'jade':
          write(path + '/views/layout.jade', jadeLayout);
          write(path + '/views/index.jade', jadeIndex);
          break;
      }
    });

    // CSS Engine support
    switch (cssEngine) {
      case 'stylus':
        app = app.replace('{css}', eol + '  app.use(require(\'stylus\').middleware({ src: __dirname + \'/public\' }));');
        break;
      default:
        app = app.replace('{css}', '');
    }

    // Session support
    app = app.replace('{sess}', sessions
      ? eol + '  app.use(express.cookieParser());' + eol + '  app.use(express.session({ secret: \'your secret here\' }));'
      : '');

    // Template support
    app = app.replace(':TEMPLATE', templateEngine);

    // package.json
    var json = '{' + eol;
    json += '    "name": "application-name"' + eol;
    json += '  , "version": "0.0.1"' + eol;
    json += '  , "private": true' + eol;
    json += '  , "dependencies": {' + eol;
    json += '      "express": "' + version + '"' + eol;
    if (cssEngine) json += '    , "' + cssEngine + '": ">= 0.0.1"' + eol;
    if (templateEngine) json += '    , "' + templateEngine + '": ">= 0.0.1"' + eol;
    json += '  }' + eol;
    json += '}';


    write(path + '/package.json', json);
    write(path + '/app.js', app);
  });
}

/**
 * Check if the given directory `path` is empty.
 *
 * @param {String} path
 * @param {Function} fn
 */

function emptyDirectory(path, fn) {
  fs.readdir(path, function(err, files){
    if (err && 'ENOENT' != err.code) throw err;
    fn(!files || !files.length);
  });
}

/**
 * echo str > path.
 *
 * @param {String} path
 * @param {String} str
 */

function write(path, str) {
  fs.writeFile(path, str);
  console.log('   \x1b[36mcreate\x1b[0m : ' + path);
}

/**
 * Prompt confirmation with the given `msg`.
 *
 * @param {String} msg
 * @param {Function} fn
 */

function confirm(msg, fn) {
  prompt(msg, function(val){
    fn(/^ *y(es)?/i.test(val));
  });
}

/**
 * Prompt input with the given `msg` and callback `fn`.
 *
 * @param {String} msg
 * @param {Function} fn
 */

function prompt(msg, fn) {
  // prompt
  if (' ' == msg[msg.length - 1]) {
    process.stdout.write(msg);
  } else {
    console.log(msg);
  }

  // stdin
  process.stdin.setEncoding('ascii');
  process.stdin.once('data', function(data){
    fn(data);
  }).resume();
}

/**
 * Mkdir -p.
 *
 * @param {String} path
 * @param {Function} fn
 */

function mkdir(path, fn) {
  mkdirp(path, 0755, function(err){
    if (err) throw err;
    console.log('   \033[36mcreate\033[0m : ' + path);
    fn && fn();
  });
}

/**
 * Exit with the given `str`.
 *
 * @param {String} str
 */

function abort(str) {
  console.error(str);
  process.exit(1);
}
