define([
    'jquery',
    '/bower_components/chainpad-listmap/chainpad-listmap.js',
    '/bower_components/chainpad-crypto/crypto.js',
    '/common/common-util.js',
    '/common/outer/network-config.js',
    '/customize/credential.js',
    '/bower_components/chainpad/chainpad.dist.js',
    '/common/common-realtime.js',
    '/common/common-constants.js',
    '/common/common-interface.js',
    '/common/common-feedback.js',
    '/common/outer/local-store.js',
    '/customize/messages.js',
    '/bower_components/nthen/index.js',
    '/common/outer/login-block.js',
    '/common/common-hash.js',

    '/bower_components/tweetnacl/nacl-fast.min.js',
    '/bower_components/scrypt-async/scrypt-async.min.js', // better load speed
], function ($, Listmap, Crypto, Util, NetConfig, Cred, ChainPad, Realtime, Constants, UI,
            Feedback, LocalStore, Messages, nThen, Block, Hash) {
    var Exports = {
        Cred: Cred,
        // this is depended on by non-customizable files
        // be careful when modifying login.js
        requiredBytes: 192,
    };

    var Nacl = window.nacl;
    var allocateBytes = Exports.allocateBytes = function (bytes) {
        var dispense = Cred.dispenser(bytes);

        var opt = {};

        // dispense 18 bytes of entropy for your encryption key
        var encryptionSeed = dispense(18);
        // 16 bytes for a deterministic channel key
        var channelSeed = dispense(16);
        // 32 bytes for a curve key
        var curveSeed = dispense(32);

        var curvePair = Nacl.box.keyPair.fromSecretKey(new Uint8Array(curveSeed));
        opt.curvePrivate = Nacl.util.encodeBase64(curvePair.secretKey);
        opt.curvePublic = Nacl.util.encodeBase64(curvePair.publicKey);

        // 32 more for a signing key
        var edSeed = opt.edSeed = dispense(32);

        // 64 more bytes to seed an additional signing key
        opt.blockSeed = new Uint8Array(dispense(64));

        var blockKeys = opt.blockKeys = Block.genkeys(opt.blockSeed);
        opt.blockHash = Block.getBlockHash(blockKeys);

        // derive a private key from the ed seed
        var signingKeypair = Nacl.sign.keyPair.fromSeed(new Uint8Array(edSeed));

        opt.edPrivate = Nacl.util.encodeBase64(signingKeypair.secretKey);
        opt.edPublic = Nacl.util.encodeBase64(signingKeypair.publicKey);

        var keys = opt.keys = Crypto.createEditCryptor(null, encryptionSeed);

        // 24 bytes of base64
        keys.editKeyStr = keys.editKeyStr.replace(/\//g, '-');

        // 32 bytes of hex
        var channelHex = opt.channelHex = Util.uint8ArrayToHex(channelSeed);

        // should never happen
        if (channelHex.length !== 32) { throw new Error('invalid channel id'); }

        opt.channel64 = Util.hexToBase64(channelHex);

        opt.userHash = '/1/edit/' + [opt.channel64, opt.keys.editKeyStr].join('/');

        return opt;
    };


    var loginOptionsFromBlock = function (blockInfo) { // userHash
        var opt = {};

        var secrets = Hash.getSecrets('drive', blockInfo.userHash);

        console.log(opt, blockInfo);

        opt.channelHex = secrets.channel;
        opt.keys = secrets.keys;
        opt.edPublic = blockInfo.edPublic; // XXX make sure everything that creates a block serializes the edPublic
        // XXX maybe it's a good idea to include edPrivate too

        console.log(opt);

        return opt;
    };

    var loadUserObject = function (opt, cb) {
        var config = {
            websocketURL: NetConfig.getWebsocketURL(),
            channel: opt.channelHex,
            data: {},
            validateKey: opt.keys.validateKey, // derived validation key
            crypto: Crypto.createEncryptor(opt.keys),
            logLevel: 1,
            classic: true,
            ChainPad: ChainPad,
            owners: [opt.edPublic]
        };

        var rt = opt.rt = Listmap.create(config);
        rt.proxy
        .on('ready', function () {
            setTimeout(function () { cb(void 0, rt); });
        })
        .on('disconnect', function (info) {
            cb('E_DISCONNECT', info);
        });
    };

    var isProxyEmpty = function (proxy) {
        return Object.keys(proxy).length === 0;
    };

    var setMergeAnonDrive = function () {
        sessionStorage.migrateAnonDrive = 1;
    };

    var setCreateReadme = function () {
        sessionStorage.createReadme = 1;
    };

    Exports.loginOrRegister = function (uname, passwd, isRegister, shouldImport, cb) {
        if (typeof(cb) !== 'function') { return; }

        // Usernames are all lowercase. No going back on this one
        uname = uname.toLowerCase();

        // validate inputs
        if (!Cred.isValidUsername(uname)) { return void cb('INVAL_USER'); }
        if (!Cred.isValidPassword(passwd)) { return void cb('INVAL_PASS'); }
        if (isRegister && !Cred.isLongEnoughPassword(passwd)) {
            return void cb('PASS_TOO_SHORT');
        }

        // results...
        var res = {
            register: isRegister,
        };

        var RT, blockKeys, blockHash, Pinpad, rpc, userHash;

        nThen(function (waitFor) {
            // derive a predefined number of bytes from the user's inputs,
            // and allocate them in a deterministic fashion

            console.log('allocating bytes from user input')
            Cred.deriveFromPassphrase(uname, passwd, Exports.requiredBytes, waitFor(function (bytes) {
                console.log("allocated first set of bytes");
                res.opt = allocateBytes(bytes);
                blockHash = res.opt.blockHash;
                blockKeys = res.opt.blockKeys;
            }));
        }).nThen(function (waitFor) {
            // the allocated bytes can be used either in a legacy fashion,
            // or in such a way that a previously unused byte range determines
            // the location of a layer of indirection which points users to
            // an encrypted block, from which they can recover the location of
            // the rest of their data

            // determine where a block for your set of keys would be stored
            var blockUrl = Block.getBlockUrl(res.opt.blockKeys);

            // Check whether there is a block at that location
            Util.fetch(blockUrl, waitFor(function (err, block) {
                // if users try to log in or register, we must check
                // whether there is a block.

                // the block is only useful if it can be decrypted, though
                if (err) {
                    console.log("no block found");
                    return;
                }


                console.log("found a block");
                var decryptedBlock = Block.decrypt(block, blockKeys);
                if (!decryptedBlock) {
                    console.error("Found a login block but failed to decrypt");
                    return;
                }
                res.blockInfo = decryptedBlock;
                console.log("valid block", decryptedBlock);
            }));
        }).nThen(function (waitFor) {
            // we assume that if there is a block, it was created in a valid manner
            // so, just proceed to the next block which handles that stuff
            if (res.blockInfo) { return; }

            var opt = res.opt;

            console.log("preparing to load legacy user object");

            // load the user's object using the legacy credentials
            loadUserObject(opt, waitFor(function (err, rt) {
                if (err) { return void cb(err); }

                console.log("legacy user object loaded");

                if (isRegister) {
                    if (isProxyEmpty(rt.proxy)) {
                        console.log("proxy is empty");

                        // If they are trying to register,
                        // and the proxy is empty, then there is no 'legacy user' either
                        // so we should just shut down this session and disconnect.
                        rt.network.disconnect();
                        return; // proceed to the next async block
                    } else {
                        // they're trying to register but legacy proxy is not empty
                    }
                }

                // they tried to just log in but there's no such user
                // and since we're here at all there is no modern-block
                if (!isRegister && isProxyEmpty(rt.proxy)) {
                    rt.network.disconnect(); // clean up after yourself
                    waitFor.abort();
                    return void cb('NO_SUCH_USER', res);
                }

                // they tried to register, but those exact credentials exist
                if (isRegister && !isProxyEmpty(rt.proxy)) {
                    rt.network.disconnect();
                    waitFor.abort();
                    Feedback.send('LOGIN', true);
                    return void cb('ALREADY_REGISTERED', res);
                }

                // if you are here, then there is no block, the user is trying
                // to log in. The proxy is **not** empty. All values assigned here
                // should have been deterministically created using their credentials
                // so setting them is just a precaution to keep things in good shape
                res.proxy = rt.proxy;
                res.realtime = rt.realtime;
                res.network = rt.network;

                // they're registering...
                res.userHash = opt.userHash;
                res.userName = uname;

                // export their signing key
                res.edPrivate = opt.edPrivate;
                res.edPublic = opt.edPublic;

                // export their encryption key
                res.curvePrivate = opt.curvePrivate;
                res.curvePublic = opt.curvePublic;

                if (shouldImport) { setMergeAnonDrive(); }

                // don't proceed past this async block.
                waitFor.abort();

                // We have to call whenRealtimeSyncs asynchronously here because in the current
                // version of listmap, onLocal calls `chainpad.contentUpdate(newValue)`
                // asynchronously.
                // The following setTimeout is here to make sure whenRealtimeSyncs is called after
                // `contentUpdate` so that we have an update userDoc in chainpad.
                setTimeout(function () {
                    Realtime.whenRealtimeSyncs(rt.realtime, function () {
                        // the following stages are there to initialize a new drive
                        // if you are registering

                        // XXX maybe this should be off in the UI function ?
                        console.log("persisting login");
                        LocalStore.login(res.userHash, res.userName, function () {
                            setTimeout(function () { cb(void 0, res); });
                        });
                    });
                });
            }));
        }).nThen(function (waitFor) { // MODERN REGISTRATION
            // allocate some random bytes

            var opt;
            if (res.blockInfo && isRegister) {
                // XXX they probably want to log in with their existing creds
                // load the object specified in their block
                // and confirm that the object is in good standing
                console.log("the user is trying to register, but a block already exists here");
                opt = loginOptionsFromBlock(res.blockInfo);
            } else {
                console.log("allocating random bytes for a new user object");
                opt = allocateBytes(Nacl.randomBytes(Exports.requiredBytes));
                userHash = opt.userHash;
            }

            console.log("loading new user object");

            // according to the location derived from the credentials which you entered
            loadUserObject(opt, waitFor(function (err, rt) {
                if (err) {
                    waitFor.abort();
                    return void cb('MODERN_REGISTRATION_INIT');
                }

                console.log("object loaded");
                console.log(JSON.stringify(rt.proxy));

                // XXX validate the rest of this logic

                // export the realtime object you checked
                RT = rt;

                res.proxy = rt.proxy;
                res.realtime = rt.realtime;
                res.network = rt.network;

                // they're registering...
                res.userHash = opt.userHash;
                res.userName = uname;

                // export their signing key
                res.edPrivate = opt.edPrivate || rt.edPrivate;
                res.edPublic = opt.edPublic || rt.edPublic;

                res.curvePrivate = opt.curvePrivate || rt.curvePrivate;
                res.curvePublic = opt.curvePublic || rt.curvePublic;

                // they tried to just log in but there's no such user
                // XXX in fact you should get NO_SUCH_USER if the block does not exist
                // and the proxy from above was empty
                // tl;dr this shouldn't be here.
                if (!isRegister && isProxyEmpty(rt.proxy)) {
                    rt.network.disconnect(); // clean up after yourself
                    waitFor.abort();
                    return void cb('NO_SUCH_USER', res);
                }

                // they tried to register, but those exact credentials exist
                // XXX we should not need to worry about randomly landing on an existing channel
                // ALREADY_REGISTERED should depend on whether or not a block exists, at this point
                // XXX also this block should be up higher
                if (isRegister && !isProxyEmpty(rt.proxy)) {
                    rt.network.disconnect();
                    waitFor.abort();
                    return void cb('ALREADY_REGISTERED', res);
                }

                if (isRegister && isProxyEmpty(rt.proxy)) {
                    console.log("handling registration in object");
                console.log(JSON.stringify(rt.proxy));
                    var proxy = rt.proxy;
                    proxy.edPublic = res.edPublic || proxy.edPublic;
                    proxy.edPrivate = res.edPrivate || proxy.edPrivate;
                    proxy.curvePublic = res.curvePublic || proxy.curvePublic;
                    proxy.curvePrivate = res.curvePrivate || proxy.curvePrivate;
                    proxy.login_name = uname;
                    proxy[Constants.displayNameKey] = uname;
                    setCreateReadme();
                    if (!shouldImport) { proxy.version = 6; }
                    Feedback.send('REGISTRATION', true);
                } else {
                    Feedback.send('LOGIN', true);
                }

                console.log(JSON.stringify(rt.proxy));
                setTimeout(waitFor(function () {
                    Realtime.whenRealtimeSyncs(RT.realtime, waitFor(function () {
                        // the following stages are there to initialize a new drive
                        // if you are registering
                        //waitFor.abort();
                        /*
                        LocalStore.login(res.userHash, res.userName, waitFor(function () {
                            setTimeout(function () { cb(void 0, res); });
                        }));*/
                    }));
                }));
            }));
        }).nThen(function (waitFor) {
            require(['/common/pinpad.js'], waitFor(function (_Pinpad) {
                console.log("loaded rpc module");
                Pinpad = _Pinpad;
            }));
        }).nThen(function (waitFor) {
            // send an RPC to store the block which you created.
            console.log("initializing rpc interface");
            // XXX missing edPrivate signing key.

            console.error(RT);
            Pinpad.create(RT.network, RT.proxy, waitFor(function (e, _rpc) {
                if (e) {
                    waitFor.abort();
                    console.error(e); // INVALID_KEYS
                    return void cb('RPC_CREATION_ERROR');
                }
                rpc = _rpc;
                console.log("rpc initialized");
            }));
        }).nThen(function (waitFor) {
            console.log("creating request to publish a login block");

            // Finally, create the login block for the object you just created.
            var toPublish = {
                userHash: userHash,
                edPublic: res.edPublic,
            };

            console.log(toPublish);

            var blockRequest = Block.serialize(JSON.stringify(toPublish), res.opt.blockKeys);

            console.log("about to send block request:", blockRequest);

            rpc.writeLoginBlock(blockRequest, waitFor(function (e) {
                if (e) { return void console.error(e); }

                console.log("login block published");
                console.log(e);

                console.log("blockInfo should be available at:", blockHash);

                LocalStore.setBlockHash(blockHash);

                LocalStore.login(false, uname, function () {
                    cb(void 0, res);
                });
            }));
        });
    };
    Exports.redirect = function () {
        if (sessionStorage.redirectTo) {
            var h = sessionStorage.redirectTo;
            var parser = document.createElement('a');
            parser.href = h;
            if (parser.origin === window.location.origin) {
                delete sessionStorage.redirectTo;
                window.location.href = h;
                return;
            }
        }
        window.location.href = '/drive/';
    };

    var hashing;
    Exports.loginOrRegisterUI = function (uname, passwd, isRegister, shouldImport, testing, test) {
        if (hashing) { return void console.log("hashing is already in progress"); }
        hashing = true;

        var proceed = function (result) {
            hashing = false;
            if (test && typeof test === "function" && test()) { return; }
            Realtime.whenRealtimeSyncs(result.realtime, function () {
                Exports.redirect();
            });
        };

        // setTimeout 100ms to remove the keyboard on mobile devices before the loading screen
        // pops up
        window.setTimeout(function () {
            UI.addLoadingScreen({
                loadingText: Messages.login_hashing,
                hideTips: true,
            });

            // We need a setTimeout(cb, 0) otherwise the loading screen is only displayed
            // after hashing the password
            window.setTimeout(function () {
                Exports.loginOrRegister(uname, passwd, isRegister, shouldImport, function (err, result) {
                    var proxy;
                    if (result) { proxy = result.proxy; }

                    console.log('finished registering.');
                    console.log(err, result);
                    //return;

                    if (err) {
                        switch (err) {
                            case 'NO_SUCH_USER':
                                UI.removeLoadingScreen(function () {
                                    UI.alert(Messages.login_noSuchUser, function () {
                                        hashing = false;
                                    });
                                });
                                break;
                            case 'INVAL_USER':
                                UI.removeLoadingScreen(function () {
                                    UI.alert(Messages.login_invalUser, function () {
                                        hashing = false;
                                    });
                                });
                                break;
                            case 'INVAL_PASS':
                                UI.removeLoadingScreen(function () {
                                    UI.alert(Messages.login_invalPass, function () {
                                        hashing = false;
                                    });
                                });
                                break;
                            case 'PASS_TOO_SHORT':
                                UI.removeLoadingScreen(function () {
                                    var warning = Messages._getKey('register_passwordTooShort', [
                                        Cred.MINIMUM_PASSWORD_LENGTH
                                    ]);
                                    UI.alert(warning, function () {
                                        hashing = false;
                                    });
                                });
                                break;
                            case 'ALREADY_REGISTERED':
                                // logMeIn should reset registering = false
                                UI.removeLoadingScreen(function () {
                                    UI.confirm(Messages.register_alreadyRegistered, function (yes) {
                                        if (!yes) {
                                            hashing = false;
                                            return;
                                        }
                                        proxy.login_name = uname;

                                        if (!proxy[Constants.displayNameKey]) {
                                            proxy[Constants.displayNameKey] = uname;
                                        }
                                        LocalStore.eraseTempSessionValues();
                                        LocalStore.login(result.userHash, result.userName, function () {
                                            setTimeout(function () { proceed(result); });
                                        });
                                    });
                                });
                                break;
                            default: // UNHANDLED ERROR
                                hashing = false;
                                UI.errorLoadingScreen(Messages.login_unhandledError);
                        }
                        return;
                    }

                    if (testing) { return void proceed(result); }

                    proceed(result);
                });
            }, 500);
        }, 200);
    };

    return Exports;
});