/*
 * 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.Reflection;
using System.Net;
using System.IO;
using System.Text;
using System.Xml;
using System.Xml.Serialization;
using OpenMetaverse;
using OpenSim.Framework;
using OpenSim.Framework.Servers;
using OpenSim.Framework.Servers.HttpServer;
using log4net;

namespace OpenSim.Grid.AssetInventoryServer.Plugins.OpenSim
{
    public class OpenSimAssetFrontendPlugin : IAssetInventoryServerPlugin
    {
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
        private AssetInventoryServer m_server;

        public OpenSimAssetFrontendPlugin()
        {
        }

        #region IPlugin implementation

        public void Initialise(AssetInventoryServer server)
        {
            m_server = server;

            // Asset request
            m_server.HttpServer.AddStreamHandler(new AssetRequestHandler(server));

            // Asset creation
            m_server.HttpServer.AddStreamHandler(new AssetPostHandler(server));

            m_log.Info("[OPENSIMASSETFRONTEND]: OpenSim Asset Frontend loaded.");
        }

        /// <summary>
        /// <para>Initialises asset interface</para>
        /// </summary>
        public void Initialise()
        {
            m_log.InfoFormat("[OPENSIMASSETFRONTEND]: {0} cannot be default-initialized!", Name);
            throw new PluginNotInitialisedException(Name);
        }

        public void Dispose()
        {
        }

        public string Version
        {
            // TODO: this should be something meaningful and not hardcoded?
            get { return "0.1"; }
        }

        public string Name
        {
            get { return "OpenSimAssetFrontend"; }
        }

        #endregion IPlugin implementation

        public class AssetRequestHandler : BaseStreamHandler
        {
            AssetInventoryServer m_server;

            //public AssetRequestHandler(AssetInventoryServer server) : base("GET", "^/assets")
            public AssetRequestHandler(AssetInventoryServer server) : base("GET", "/assets")
            {
                m_server = server;
            }

            public override byte[] Handle(string path, Stream request, OSHttpRequest httpRequest, OSHttpResponse httpResponse)
            {
                byte[] buffer = new byte[] {};
                UUID assetID;
                // Split the URL up to get the asset ID out
                string[] rawUrl = httpRequest.Url.PathAndQuery.Split('/');

                if (rawUrl.Length >= 3 && rawUrl[2].Length >= 36 && UUID.TryParse(rawUrl[2].Substring(0, 36), out assetID))
                {
                    BackendResponse dataResponse;

                    AssetBase asset = new AssetBase();
                    if ((dataResponse = m_server.StorageProvider.TryFetchDataMetadata(assetID, out asset)) == BackendResponse.Success)
                    {
                        if (rawUrl.Length >= 4 && rawUrl[3] == "data")
                        {
                            httpResponse.StatusCode = (int)HttpStatusCode.OK;
                            httpResponse.ContentType = Utils.SLAssetTypeToContentType(asset.Type);
                            buffer=asset.Data;
                        }
                        else
                        {
                            XmlSerializer xs = new XmlSerializer(typeof(AssetBase));
                            MemoryStream ms = new MemoryStream();
                            XmlTextWriter xw = new XmlTextWriter(ms, Encoding.UTF8);
                            xs.Serialize(xw, asset);
                            xw.Flush();

                            ms.Seek(0, SeekOrigin.Begin);
                            buffer = ms.GetBuffer();
                            Array.Resize<byte>(ref buffer, (int)ms.Length);
                            ms.Close();
                            httpResponse.StatusCode = (int)HttpStatusCode.OK;
                        }
                    }
                    else
                    {
                        m_log.WarnFormat("[OPENSIMASSETFRONTEND]: Failed to fetch asset data or metadata for {0}: {1}", assetID, dataResponse);
                        httpResponse.StatusCode = (int) HttpStatusCode.NotFound;
                    }
                }
                else
                {
                    m_log.Warn("[OPENSIMASSETFRONTEND]: Unrecognized OpenSim asset request: " + httpRequest.Url.PathAndQuery);
                }

                return buffer;
            }
        }

        public class AssetPostHandler : BaseStreamHandler
        {
            AssetInventoryServer m_server;

            //public AssetPostHandler(AssetInventoryServer server) : base("POST", "/^assets")
            public AssetPostHandler(AssetInventoryServer server) : base("POST", "/assets")
            {
                m_server = server;
            }

            public override byte[] Handle(string path, Stream request, OSHttpRequest httpRequest, OSHttpResponse httpResponse)
            {
                AssetBase asset = null;

                try
                {
                    asset = (AssetBase) new XmlSerializer(typeof (AssetBase)).Deserialize(httpRequest.InputStream);
                }
                catch (Exception ex)
                {
                    m_log.Warn("[OPENSIMASSETFRONTEND]: Failed to parse POST data (expecting AssetBase): " + ex.Message);
                    httpResponse.StatusCode = (int) HttpStatusCode.BadRequest;
                }

                if (asset != null && asset.Data != null && asset.Data.Length > 0)
                {
                    BackendResponse storageResponse = m_server.StorageProvider.TryCreateAsset(asset);

                    if (storageResponse == BackendResponse.Success)
                        httpResponse.StatusCode = (int) HttpStatusCode.Created;
                    else if (storageResponse == BackendResponse.NotFound)
                        httpResponse.StatusCode = (int) HttpStatusCode.NotFound;
                    else
                        httpResponse.StatusCode = (int) HttpStatusCode.InternalServerError;
                }
                else
                {
                    m_log.Warn("[OPENSIMASSETFRONTEND]: AssetPostHandler called with no asset data");
                    httpResponse.StatusCode = (int) HttpStatusCode.BadRequest;
                }

                return new byte[] {};
            }
        }
    }
}