/**
 * The main application controller
 */
define(function(require) {
    'use strict';

    var $ = require('jquery'),
        ImapClient = require('ImapClient'),
        SmtpClient = require('SmtpClient'),
        EmailDAO = require('js/dao/email-dao'),
        KeychainDAO = require('js/dao/keychain-dao'),
        cloudstorage = require('js/dao/cloudstorage-dao'),
        app = require('js/app-config');
    require('cordova');

    var self = {};

    /**
     * Start the application by loading the view templates
     */
    self.start = function(callback) {
        // the views to load
        var views = [
            'login', 'compose', 'folderlist', 'folderlistitem',
            'messagelist', 'messagelistitem', 'read'
        ];

        // are we running in native app or in browser?
        if (document.URL.indexOf("http") === 0 || document.URL.indexOf("app") === 0 || document.URL.indexOf("chrome") === 0) {
            console.log('Assuming Browser environment...');
            onDeviceReady();
        } else {
            console.log('Assuming Cordova environment...');
            document.addEventListener("deviceready", onDeviceReady, false);
        }

        function onDeviceReady() {
            console.log('Starting app.');
            loadTemplates(views, callback);
        }
    };

    /**
     * Executes a number of commands
     */
    self.execute = function(cmd, args, callback) {
        if (cmd === 'login') {
            // login user
            fetchOAuthToken(args.password, function(err, userId) {
                callback({
                    err: err,
                    userId: userId
                });
            });

        } else if (cmd === 'listFolders') {
            // list folders in users mailbox
            self._emailDao.imapListFolders(function(err, folders) {
                callback({
                    err: err,
                    folders: folders
                });
            });

        } else if (cmd === 'syncEmails') {
            // self._emailDao.syncFromCloud(args.folder, function(err) {
            //  callback({
            //      err: err
            //  });
            // });

            // Syncing to local storage is not yet supported for imap
            callback({
                err: 'Not yet implemented!'
            });

        } else if (cmd === 'listEmails') {
            // list emails from folder
            self._emailDao.imapListMessages(args, function(err, emails) {
                callback({
                    err: err,
                    emails: emails
                });
            });

        } else if (cmd === 'getEmail') {
            // list emails from folder
            self._emailDao.imapGetMessage({
                folder: args.folder,
                uid: args.messageId
            }, function(err, email) {
                callback({
                    err: err,
                    email: email
                });
            });

        } else if (cmd === 'sendEmail') {
            // list emails from folder
            self._emailDao.smtpSend(args.email, function(err) {
                callback({
                    err: err
                });
            });

        } else {
            // error: invalid message from sandbox
            callback({
                err: {
                    errMsg: 'Invalid message posted from sandbox!'
                }
            });
        }
    };

    //
    // Helper methods
    //

    function fetchOAuthToken(password, callback) {
        // get OAuth Token from chrome
        chrome.identity.getAuthToken({
                'interactive': true
            },
            function(token) {
                // fetch gmail user's email address from the Google Authorization Server endpoint
                $.ajax({
                    url: 'https://www.googleapis.com/oauth2/v1/tokeninfo?access_token=' + token,
                    type: 'GET',
                    dataType: 'json',
                    success: function(info) {
                        // login using the received email address
                        self.login(info.email, password, token, function(err) {
                            // send email address to sandbox
                            callback(err, info.email);
                        });
                    },
                    error: function(xhr, textStatus, err) {
                        callback({
                            errMsg: xhr.status + ': ' + xhr.statusText,
                            err: err
                        });
                    }
                });

            }
        );
    }

    self.login = function(userId, password, token, callback) {
        var auth, imapOptions, smtpOptions,
            keychain, imapClient, smtpClient;

        // create mail credentials objects for imap/smtp
        auth = {
            XOAuth2: {
                user: userId,
                clientId: '440907777130.apps.googleusercontent.com',
                accessToken: token
            }
        };
        imapOptions = {
            secure: true,
            port: 993,
            host: 'imap.gmail.com',
            auth: auth
        };
        smtpOptions = {
            secure: true,
            port: 465,
            host: 'smtp.gmail.com',
            auth: auth
        };

        // init objects and inject dependencies
        keychain = new KeychainDAO(cloudstorage);
        imapClient = new ImapClient(imapOptions);
        smtpClient = new SmtpClient(smtpOptions);
        self._emailDao = new EmailDAO(keychain, imapClient, smtpClient);

        // init email dao
        var account = {
            emailAddress: userId,
            symKeySize: app.config.symKeySize,
            symIvSize: app.config.symIvSize,
            asymKeySize: app.config.asymKeySize
        };
        self._emailDao.init(account, password, callback);
    };

    function loadTemplates(names, callback) {
        var loadTemplate = function(index) {
            var name = names[index];
            console.log('Loading template: ' + name);
            $.get('tpl/' + name + '.html', function(data) {
                app.util.tpl.templates[name] = data;
                index++;
                if (index < names.length) {
                    loadTemplate(index);
                } else {
                    callback();
                }
            });
        };
        loadTemplate(0);
    }

    return self;
});