(function () {
var factory = function (Util, Cred, nThen) {
    nThen = nThen; // XXX
    var Invite = {};

/*  INPUTS

    * password (for scrypt)
    * message (personal note)
    * link hash
    * bytes64 (scrypt output)
    * preview_hash

*/


/*  DERIVATIONS

    * components corresponding to www/common/invitation.js
    * preview_hash => components
      * channel
      * cryptKey
    * b64_bytes
      * curvePrivate => curvePublic
      * edSeed => edPrivate => edPublic

*/


/*  IO / FUNCTIONALITY

    * creator
      * generate a random signKey (prevent writes to preview channel)
      * encrypt and upload the preview content
        * via CryptGet
        * owned by:
          * the ephemeral edPublic
          * the invite creator
      * create a roster entry for the invitation
        * with encrypted notes for the creator
    * redeemer
      * get the preview content
      * redeem the invite
        * add yourself to the roster
        * add the team to your proxy-manager

*/


    var BYTES_REQUIRED = 256;

    Invite.deriveKeys = function (seed, passwd, cb) {
        cb = cb; // XXX
        // TODO validate has cb
        // TODO onceAsync the cb
        // TODO cb with err if !(seed && passwd)

        Cred.deriveFromPassphrase(seed, passwd, BYTES_REQUIRED, function (bytes) {
            var dispense = Cred.dispenser(bytes);
            dispense = dispense; // XXX

            // edPriv => edPub
            // curvePriv => curvePub
            // channel
            // cryptKey
        });
    };

    Invite.createSeed = function () {
        // XXX
        // return a seed
    };

    Invite.create = function (cb) {
        cb = cb; // XXX
        // TODO validate has cb
        // TODO onceAsync the cb
        // TODO cb with err if !(seed && passwd)



        // required
            // password
            // validateKey
            // creatorEdPublic
                // for owner
        // ephemeral
            // signingKey
                // for owner to write invitation
        // derived
            // edPriv
                // edPublic
                    // for invitee ownership
            // curvePriv
                // curvePub
                    // for acceptance OR
                    // authenticated decline message via mailbox
            // channel
                // for owned deletion
                // for team pinning
            // cryptKey
                // for protecting channel content
    };

    return Invite;
};
    if (typeof(module) !== 'undefined' && module.exports) {
        module.exports = factory(
            require("../common-util"),
            require("../common-credential.js"),
            require("nthen")
        );
    } else if ((typeof(define) !== 'undefined' && define !== null) && (define.amd !== null)) {
        define([
            '/common/common-util.js',
            '/common/common-credential.js',
            '/bower_components/nthen/index.js',
        ], function (Util, Cred, nThen) {
            return factory(Util, nThen);
        });
    }
}());