/**
 * @license
 * Copyright (C) 2013 KO GmbH <copyright@kogmbh.com>
 *
 * @licstart
 * The JavaScript code in this page is free software: you can redistribute it
 * and/or modify it under the terms of the GNU Affero General Public License
 * (GNU AGPL) as published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.  The code is distributed
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU AGPL for more details.
 *
 * As additional permission under GNU AGPL version 3 section 7, you
 * may distribute non-source (e.g., minimized or compacted) forms of
 * that code without the copy of the GNU GPL normally required by
 * section 4, provided you include this license notice and a URL
 * through which recipients can access the Corresponding Source.
 *
 * As a special exception to the AGPL, any HTML file which merely makes function
 * calls to this code, and for that purpose includes it by reference shall be
 * deemed a separate work for copyright law purposes. In addition, the copyright
 * holders of this code give you permission to combine this code with free
 * software libraries that are released under the GNU LGPL. You may copy and
 * distribute such a system following the terms of the GNU AGPL for this code
 * and the LGPL for the libraries. If you modify this code, you may extend this
 * exception to your version of the code, but you are not obligated to do so.
 * If you do not wish to do so, delete this exception statement from your
 * version.
 *
 * This license applies to this entire compilation.
 * @licend
 * @source: http://www.webodf.org/
 * @source: http://gitorious.org/webodf/webodf/
 */
/*global define,runtime */
define("webodf/editor/UserList",
       ["webodf/editor/EditorSession"],

  function (EditorSession) {
    "use strict";

    return function UserList(editorSession, userListDiv) {
        var self = this;

        editorSession.subscribe(EditorSession.signalUserAdded, function (memberId) {
            self.addUser(memberId);
        });

        editorSession.subscribe(EditorSession.signalUserRemoved, function (memberId) {
            self.removeUser(memberId);
        });

        /**
         * @param {!string} memberId
         */
        function updateAvatarButton(memberId, userDetails) {
            var node = userListDiv.firstChild;
            if (userDetails === null) {
                // 'null' here means finally unknown user
                // (and not that the data is still loading)
                userDetails = {
                    memberid: memberId, fullname: "Unknown",
                    color: "black", imageurl: "avatar-joe.png"
                };
            }
            while (node) {
                if (node.memberId === memberId) {
                    node = node.firstChild;
                    while (node) {
                        if (node.localName === "img") {
                            // update avatar image
                            node.src = userDetails.imageurl;
                            // update border color
                            node.style.borderColor = userDetails.color;
                        } else if (node.localName === "div") {
                            node.setAttribute('fullname', userDetails.fullname);
                        }
                        node = node.nextSibling;
                    }
                    return;
                }
                node = node.nextSibling;
            }
        }

        /**
         * @param {!string} memberId
         */
        function createAvatarButton(memberId) {
            runtime.assert(userListDiv, "userListDiv unavailable");
            var doc = userListDiv.ownerDocument,
                htmlns = doc.documentElement.namespaceURI,
                avatarDiv = doc.createElementNS(htmlns, "div"),
                imageElement = doc.createElement("img"),
                fullnameNode = doc.createElement("div");

            avatarDiv.className = "userListButton";
            fullnameNode.className = "userListLabel";
            avatarDiv.appendChild(imageElement);
            avatarDiv.appendChild(fullnameNode);
            avatarDiv.memberId = memberId; // TODO: namespace?

            avatarDiv.onmouseover = function () {
                //avatar.getCaret().showHandle();
            };
            avatarDiv.onmouseout = function () {
                //avatar.getCaret().hideHandle();
            };
            avatarDiv.onclick = function () {
                var caret = editorSession.sessionView.getCaret(memberId);
                if (caret) {
                    caret.toggleHandleVisibility();
                }
            };
            userListDiv.appendChild(avatarDiv);

            // preset bogus data
            // TODO: indicate loading state
            // (instead of setting the final 'unknown identity' data)
            updateAvatarButton(memberId, null);
        }

        /**
         * @param {!string} memberId
         */
        function removeAvatarButton(memberId) {
            var node = userListDiv.firstChild;
            while (node) {
                if (node.memberId === memberId) {
                    userListDiv.removeChild(node);
                    return;
                }
                node = node.nextSibling;
            }
        }

        /**
         * @param {!string} memberId
         */
        this.addUser = function (memberId) {
            createAvatarButton(memberId);
            editorSession.getUserDetailsAndUpdates(memberId, updateAvatarButton);
        };

        /**
         * @param {!string} memberId
         */
        this.removeUser = function (memberId) {
            editorSession.unsubscribeUserDetailsUpdates(memberId, updateAvatarButton);
            removeAvatarButton(memberId);
        };
    };
});
