/*
 * Copyright (c) 2008 Intel Corporation
 * All rights reserved.
 * 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 Intel Corporation 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 COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``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 INTEL OR ITS
 * 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.IO;
using System.Reflection;
using System.Collections.Generic;
using System.Net;
using System.Xml;
using OpenMetaverse;
using OpenMetaverse.StructuredData;
using HttpServer;
using OpenSim.Framework;
using OpenSim.Framework.Servers;
using log4net;

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

        public ReferenceFrontendPlugin()
        {
        }

        #region IPlugin implementation

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

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

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

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

            m_log.Info("[ASSET] Reference Frontend loaded.");
        }

        /// <summary>
        /// <para>Initialises asset interface</para>
        /// </summary>
        public void Initialise()
        {
            m_log.InfoFormat("[ASSET]: {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 "AssetInventoryServer Reference asset frontend"; }
        }

        #endregion IPlugin implementation

        public class MetadataRequestHandler : IStreamedRequestHandler
        {
            AssetInventoryServer m_server;
            string m_contentType;
            string m_httpMethod;
            string m_path;

            public MetadataRequestHandler(AssetInventoryServer server)
            {
                m_server = server;
                m_contentType = null;
                m_httpMethod = "GET";
                m_path = @"^/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/metadata";
            }

            #region IStreamedRequestHandler implementation

            public string ContentType
            {
                get { return m_contentType; }
            }

            public string HttpMethod
            {
                get { return m_httpMethod; }
            }

            public string Path
            {
                get { return m_path; }
            }

            public byte[] Handle(string path, Stream request, OSHttpRequest httpRequest, OSHttpResponse httpResponse)
            {
                byte[] serializedData = null;
                UUID assetID;
                // Split the URL up into an AssetID and a method
                string[] rawUrl = httpRequest.Url.PathAndQuery.Split('/');

                if (rawUrl.Length >= 3 && UUID.TryParse(rawUrl[1], out assetID))
                {
                    UUID authToken = Utils.GetAuthToken(httpRequest);

                    if (m_server.AuthorizationProvider.IsMetadataAuthorized(authToken, assetID))
                    {
                        Metadata metadata;
                        BackendResponse storageResponse = m_server.StorageProvider.TryFetchMetadata(assetID, out metadata);

                        if (storageResponse == BackendResponse.Success)
                        {
                            // If the asset data location wasn't specified in the metadata, specify it
                            // manually here by pointing back to this asset server
                            if (!metadata.Methods.ContainsKey("data"))
                            {
                                metadata.Methods["data"] = new Uri(String.Format("{0}://{1}/{2}/data",
                                    httpRequest.Url.Scheme, httpRequest.Url.Authority, assetID));
                            }

                            serializedData = metadata.SerializeToBytes();

                            httpResponse.StatusCode = (int) HttpStatusCode.OK;
                            httpResponse.ContentType = "application/json";
                            httpResponse.ContentLength = serializedData.Length;
                            httpResponse.Body.Write(serializedData, 0, serializedData.Length);
                        }
                        else if (storageResponse == BackendResponse.NotFound)
                        {
                            m_log.Warn("Could not find metadata for asset " + assetID.ToString());
                            httpResponse.StatusCode = (int) HttpStatusCode.NotFound;
                        }
                        else
                        {
                            httpResponse.StatusCode = (int) HttpStatusCode.InternalServerError;
                        }
                    }
                    else
                    {
                        httpResponse.StatusCode = (int) HttpStatusCode.Forbidden;
                    }

                    return serializedData;
                }

                httpResponse.StatusCode = (int) HttpStatusCode.NotFound;
                return serializedData;
            }

            #endregion IStreamedRequestHandler implementation
        }

        public class DataRequestHandler : IStreamedRequestHandler
        {
            AssetInventoryServer m_server;
            string m_contentType;
            string m_httpMethod;
            string m_path;

            public DataRequestHandler(AssetInventoryServer server)
            {
                m_server = server;
                m_contentType = null;
                m_httpMethod = "GET";
                m_path = @"^/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/data";
            }

            #region IStreamedRequestHandler implementation

            public string ContentType
            {
                get { return m_contentType; }
            }

            public string HttpMethod
            {
                get { return m_httpMethod; }
            }

            public string Path
            {
                get { return m_path; }
            }

            public byte[] Handle(string path, Stream request, OSHttpRequest httpRequest, OSHttpResponse httpResponse)
            {
                byte[] assetData = null;
                UUID assetID;
                // Split the URL up into an AssetID and a method
                string[] rawUrl = httpRequest.Url.PathAndQuery.Split('/');

                if (rawUrl.Length >= 3 && UUID.TryParse(rawUrl[1], out assetID))
                {
                    UUID authToken = Utils.GetAuthToken(httpRequest);

                    if (m_server.AuthorizationProvider.IsDataAuthorized(authToken, assetID))
                    {
                        BackendResponse storageResponse = m_server.StorageProvider.TryFetchData(assetID, out assetData);

                        if (storageResponse == BackendResponse.Success)
                        {
                            httpResponse.StatusCode = (int) HttpStatusCode.OK;
                            httpResponse.ContentType = "application/octet-stream";
                            httpResponse.AddHeader("Content-Disposition", "attachment; filename=" + assetID.ToString());
                            httpResponse.ContentLength = assetData.Length;
                            httpResponse.Body.Write(assetData, 0, assetData.Length);
                        }
                        else if (storageResponse == BackendResponse.NotFound)
                        {
                            httpResponse.StatusCode = (int) HttpStatusCode.NotFound;
                        }
                        else
                        {
                            httpResponse.StatusCode = (int) HttpStatusCode.InternalServerError;
                        }
                    }
                    else
                    {
                        httpResponse.StatusCode = (int) HttpStatusCode.Forbidden;
                    }

                    return assetData;
                }

                httpResponse.StatusCode = (int) HttpStatusCode.BadRequest;
                return assetData;
            }

            #endregion IStreamedRequestHandler implementation
        }

        public class CreateRequestHandler : IStreamedRequestHandler
        {
            AssetInventoryServer m_server;
            string m_contentType;
            string m_httpMethod;
            string m_path;

            public CreateRequestHandler(AssetInventoryServer server)
            {
                m_server = server;
                m_contentType = null;
                m_httpMethod = "POST";
                m_path = "^/createasset";
            }

            #region IStreamedRequestHandler implementation

            public string ContentType
            {
                get { return m_contentType; }
            }

            public string HttpMethod
            {
                get { return m_httpMethod; }
            }

            public string Path
            {
                get { return m_path; }
            }

            public byte[] Handle(string path, Stream request, OSHttpRequest httpRequest, OSHttpResponse httpResponse)
            {
                byte[] responseData = null;
                UUID authToken = Utils.GetAuthToken(httpRequest);

                if (m_server.AuthorizationProvider.IsCreateAuthorized(authToken))
                {
                    try
                    {
                        OSD osdata = OSDParser.DeserializeJson(httpRequest.InputStream);

                        if (osdata.Type == OSDType.Map)
                        {
                            OSDMap map = (OSDMap)osdata;
                            Metadata metadata = new Metadata();
                            metadata.Deserialize(map);

                            byte[] assetData = map["data"].AsBinary();

                            if (assetData != null && assetData.Length > 0)
                            {
                                BackendResponse storageResponse;

                                if (metadata.ID != UUID.Zero)
                                    storageResponse = m_server.StorageProvider.TryCreateAsset(metadata, assetData);
                                else
                                    storageResponse = m_server.StorageProvider.TryCreateAsset(metadata, assetData, out metadata.ID);

                                if (storageResponse == BackendResponse.Success)
                                {
                                    httpResponse.StatusCode = (int) HttpStatusCode.Created;
                                    OSDMap responseMap = new OSDMap(1);
                                    responseMap["id"] = OSD.FromUUID(metadata.ID);
                                    LitJson.JsonData jsonData = OSDParser.SerializeJson(responseMap);
                                    responseData = System.Text.Encoding.UTF8.GetBytes(jsonData.ToJson());
                                    httpResponse.Body.Write(responseData, 0, responseData.Length);
                                    httpResponse.Body.Flush();
                                }
                                else if (storageResponse == BackendResponse.NotFound)
                                {
                                    httpResponse.StatusCode = (int) HttpStatusCode.NotFound;
                                }
                                else
                                {
                                    httpResponse.StatusCode = (int) HttpStatusCode.InternalServerError;
                                }
                            }
                            else
                            {
                                httpResponse.StatusCode = (int) HttpStatusCode.BadRequest;
                            }
                        }
                        else
                        {
                            httpResponse.StatusCode = (int) HttpStatusCode.BadRequest;
                        }
                    }
                    catch (Exception ex)
                    {
                        httpResponse.StatusCode = (int) HttpStatusCode.InternalServerError;
                        httpResponse.StatusDescription = ex.Message;
                    }
                }
                else
                {
                    httpResponse.StatusCode = (int) HttpStatusCode.Forbidden;
                }

                return responseData;
            }

            #endregion IStreamedRequestHandler implementation
        }
    }
}