/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the OpenSimulator Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;
using System.Xml;
using log4net;
using OpenMetaverse;
using OpenSim.Services.Interfaces;

namespace OpenSim.Framework.Serialization.External
{
    /// <summary>
    /// Utilities for manipulating external representations of data structures in OpenSim
    /// </summary>
    public class ExternalRepresentationUtils
    {
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        /// <summary>
        /// Populate a node with data read from xml using a dictinoary of processors
        /// </summary>
        /// <param name="nodeToFill"></param>
        /// <param name="processors">/param>
        /// <param name="xtr"></param>
        /// <returns>true on successful, false if there were any processing failures</returns>
        public static bool ExecuteReadProcessors<NodeType>(
            NodeType nodeToFill, Dictionary<string, Action<NodeType, XmlTextReader>> processors, XmlTextReader xtr)
        {
            return ExecuteReadProcessors(
                nodeToFill,
                processors,
                xtr,
                (o, name, e)
                    => m_log.DebugFormat(
                        "[ExternalRepresentationUtils]: Exception while parsing element {0}, continuing.  Exception {1}{2}",
                        name, e.Message, e.StackTrace));
        }

        /// <summary>
        /// Populate a node with data read from xml using a dictinoary of processors
        /// </summary>
        /// <param name="nodeToFill"></param>
        /// <param name="processors"></param>
        /// <param name="xtr"></param>
        /// <param name="parseExceptionAction">
        /// Action to take if there is a parsing problem.  This will usually just be to log the exception
        /// </param>
        /// <returns>true on successful, false if there were any processing failures</returns>
        public static bool ExecuteReadProcessors<NodeType>(
            NodeType nodeToFill,
            Dictionary<string, Action<NodeType, XmlTextReader>> processors,
            XmlTextReader xtr,
            Action<NodeType, string, Exception> parseExceptionAction)
        {
            bool errors = false;

            string nodeName = string.Empty;
            while (xtr.NodeType != XmlNodeType.EndElement)
            {
                nodeName = xtr.Name;

//                        m_log.DebugFormat("[ExternalRepresentationUtils]: Processing: {0}", nodeName);

                Action<NodeType, XmlTextReader> p = null;
                if (processors.TryGetValue(xtr.Name, out p))
                {
//                            m_log.DebugFormat("[ExternalRepresentationUtils]: Found {0} processor, nodeName);

                    try
                    {
                        p(nodeToFill, xtr);
                    }
                    catch (Exception e)
                    {
                        errors = true;
                        parseExceptionAction(nodeToFill, nodeName, e);

                        if (xtr.NodeType == XmlNodeType.EndElement)
                            xtr.Read();
                    }
                }
                else
                {
                    // m_log.DebugFormat("[LandDataSerializer]: caught unknown element {0}", nodeName);
                    xtr.ReadOuterXml(); // ignore
                }
            }

            return errors;
        }

        /// <summary>
        /// Takes a XML representation of a SceneObjectPart and returns another XML representation
        /// with creator data added to it.
        /// </summary>
        /// <param name="xml">The SceneObjectPart represented in XML2</param>
        /// <param name="homeURL">The URL of the user agents service (home) for the creator</param>
        /// <param name="userService">The service for retrieving user account information</param>
        /// <param name="scopeID">The scope of the user account information (Grid ID)</param>
        /// <returns>The SceneObjectPart represented in XML2</returns>
        public static string RewriteSOP(string xml, string homeURL, IUserAccountService userService, UUID scopeID)
        {
            if (xml == string.Empty || homeURL == string.Empty || userService == null)
                return xml;

            XmlDocument doc = new XmlDocument();
            doc.LoadXml(xml);
            XmlNodeList sops = doc.GetElementsByTagName("SceneObjectPart");

            foreach (XmlNode sop in sops)
            {
                UserAccount creator = null;
                bool hasCreatorData = false;
                XmlNodeList nodes = sop.ChildNodes;
                foreach (XmlNode node in nodes)
                {
                    if (node.Name == "CreatorID")
                    {
                        UUID uuid = UUID.Zero;
                        UUID.TryParse(node.InnerText, out uuid);
                        creator = userService.GetUserAccount(scopeID, uuid);
                    }

                    if (node.Name == "CreatorData" && node.InnerText != null && node.InnerText != string.Empty)
                        hasCreatorData = true;

                    //if (node.Name == "OwnerID")
                    //{
                    //    UserAccount owner = GetUser(node.InnerText);
                    //    if (owner != null)
                    //        node.InnerText = m_ProfileServiceURL + "/" + node.InnerText + "/" + owner.FirstName + " " + owner.LastName;
                    //}
                }
                if (!hasCreatorData && creator != null)
                {
                    XmlElement creatorData = doc.CreateElement("CreatorData");
                    creatorData.InnerText = homeURL + ";" + creator.FirstName + " " + creator.LastName;
                    sop.AppendChild(creatorData);
                }
            }

            using (StringWriter wr = new StringWriter())
            {
                doc.Save(wr);
                return wr.ToString();
            }
        }
    }
}