// ==========================================
// BOWER: Install API
// ==========================================
// Copyright 2012 Twitter, Inc
// Licensed under The MIT License
// http://opensource.org/licenses/MIT
// ==========================================
// 1. Recursively resolve dependencies
// 2. Intelligently work out which deps to
//    use (versioning)
// 3. Throw if deps conflict
// ==========================================

var Emitter = require('events').EventEmitter;
var nopt    = require('nopt');
var fs      = require('fs');
var path    = require('path');

var Manager = require('../core/manager');
var config  = require('../core/config');
var source  = require('../core/source');
var save    = require('../util/save');
var help    = require('./help');

var optionTypes = { help: Boolean, save: Boolean, force: Boolean };
var shorthand   = { 'h': ['--help'], 'S': ['--save'], 'f': ['--force'] };

module.exports = function (paths, options) {
  var emitter = new Emitter;
  var manager = new Manager(paths, { force: options && options.force });

  if (options && options.save) save(manager, paths);

  manager
    .on('data', emitter.emit.bind(emitter, 'data'))
    .on('error', emitter.emit.bind(emitter, 'error'))
    .on('resolve', emitter.emit.bind(emitter, 'end', null))
    .resolve();

  return emitter;
};

module.exports.line = function (argv) {
  var options = nopt(optionTypes, shorthand, argv);
  var paths   = options.argv.remain.slice(1);

  if (options.help) return help('install');
  return module.exports(paths, options);
};

module.exports.completion = function (opts, cb) {
  var word = opts.word;

  // completing options?
  if (opts.words[0] === 'install' && word.charAt(0) === '-') {
    return cb(null, Object.keys(optionTypes).map(function (option) {
      return '--' + option;
    }));
  }

  var cache = path.join(config.completion, 'install.json');
  var done = function done(err, results) {
    if (err) return cb(err);
    var names = results.map(function (pkg) {
      return pkg.name;
    });

    return cb(null, names);
  };

  fs.readFile(cache, function (err, body) {
    if (!err) return done(null, JSON.parse(body));

    // expected error, do the first request and cache the results
    source.all(function (err, results) {
      if (err) return cb(err);
      fs.writeFile(cache, JSON.stringify(results, null, 2), function (err) {
        done(err, results);
      });
    });
  });
};