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 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
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 * modification, are permitted provided that the following conditions are met:
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 *       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.
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 *       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
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Reflection;
using System.Xml;
using log4net;
using OpenMetaverse;
using OpenSim.Framework;
using OpenSim.Region.Framework.Interfaces;
using OpenSim.Region.Framework.Scenes;

namespace OpenSim.Region.Framework.Scenes.Serialization
{
    /// <summary>
    /// Serialize and deserialize coalesced scene objects.
    /// </summary>
    public class CoalescedSceneObjectsSerializer
    {
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        /// <summary>
        /// Serialize coalesced objects to Xml
        /// </summary>
        /// <param name="coa"></param>
        /// <param name="doScriptStates">
        /// If true then serialize script states.  This will halt any running scripts
        /// </param>
        /// <returns></returns>
        public static string ToXml(CoalescedSceneObjects coa)
        {
            return ToXml(coa, true);
        }

        /// <summary>
        /// Serialize coalesced objects to Xml
        /// </summary>
        /// <param name="coa"></param>
        /// <param name="doScriptStates">
        /// If true then serialize script states.  This will halt any running scripts
        /// </param>
        /// <returns></returns>
        public static string ToXml(CoalescedSceneObjects coa, bool doScriptStates)
        {            
            using (StringWriter sw = new StringWriter())
            {
                using (XmlTextWriter writer = new XmlTextWriter(sw))
                {                                        
                    Vector3 size;
                    
                    List<SceneObjectGroup> coaObjects = coa.Objects;
                    
//                    m_log.DebugFormat(
//                        "[COALESCED SCENE OBJECTS SERIALIZER]: Writing {0} objects for coalesced object", 
//                        coaObjects.Count);
                    
                    // This is weak - we're relying on the set of coalesced objects still being identical
                    Vector3[] offsets = coa.GetSizeAndOffsets(out size);

                    writer.WriteStartElement("CoalescedObject");
                    
                    writer.WriteAttributeString("x", size.X.ToString());
                    writer.WriteAttributeString("y", size.Y.ToString());
                    writer.WriteAttributeString("z", size.Z.ToString());                    
                    
                    // Embed the offsets into the group XML
                    for (int i = 0; i < coaObjects.Count; i++)
                    {
                        SceneObjectGroup obj = coaObjects[i];
                        
//                        m_log.DebugFormat(
//                            "[COALESCED SCENE OBJECTS SERIALIZER]: Writing offset for object {0}, {1}", 
//                            i, obj.Name);                        
                        
                        writer.WriteStartElement("SceneObjectGroup");
                        writer.WriteAttributeString("offsetx", offsets[i].X.ToString());
                        writer.WriteAttributeString("offsety", offsets[i].Y.ToString());
                        writer.WriteAttributeString("offsetz", offsets[i].Z.ToString());
                        
                        SceneObjectSerializer.ToOriginalXmlFormat(obj, writer, doScriptStates);
                        
                        writer.WriteEndElement(); // SceneObjectGroup
                    }  
                    
                    writer.WriteEndElement(); // CoalescedObject
                }

                string output = sw.ToString();
                
//                Console.WriteLine(output);
                
                return output;
            }
        }
        
        public static bool TryFromXml(string xml, out CoalescedSceneObjects coa)
        {
//            m_log.DebugFormat("[COALESCED SCENE OBJECTS SERIALIZER]: TryFromXml() deserializing {0}", xml);
            
            coa = null;
            int i = 0;
            
            using (StringReader sr = new StringReader(xml))
            {                
                using (XmlTextReader reader = new XmlTextReader(sr))
                {
                    try
                    {
                        reader.Read();
                        if (reader.Name != "CoalescedObject")
                        {
    //                        m_log.DebugFormat(
    //                            "[COALESCED SCENE OBJECTS SERIALIZER]: TryFromXml() root element was {0} so returning false", 
    //                            reader.Name);
                            
                            return false;
                        }
                        
                        coa = new CoalescedSceneObjects(UUID.Zero);                    
                        reader.Read();                                            
                        
                        while (reader.NodeType != XmlNodeType.EndElement && reader.Name != "CoalescedObject")
                        {
                            if (reader.Name == "SceneObjectGroup")
                            {
                                string soXml = reader.ReadOuterXml();

                                SceneObjectGroup so = SceneObjectSerializer.FromOriginalXmlFormat(soXml);

                                if (so != null)
                                {
                                    coa.Add(so);
                                }
                                else
                                {
                                    // XXX: Possibly we should fail outright here rather than continuing if a particular component of the 
                                    // coalesced object fails to load.
                                    m_log.WarnFormat(
                                        "[COALESCED SCENE OBJECTS SERIALIZER]: Deserialization of xml for component {0} failed.  Continuing.", 
                                        i);
                                }

                                i++;
                            }
                        }
                        
                        reader.ReadEndElement(); // CoalescedObject
                    }
                    catch (Exception e)
                    {
                        m_log.ErrorFormat(
                            "[COALESCED SCENE OBJECTS SERIALIZER]: Deserialization of xml failed with {0} {1}", 
                            e.Message, e.StackTrace);
                        
                        return false;
                    }                        
                }
            }
            
            return true;
        }
    }
}