/*
 * 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.Collections.Generic;
using System.Net;
using OpenMetaverse;
using OpenMetaverse.StructuredData;
using OpenSim.Framework;

namespace AssetServer
{
    /// <summary>
    /// Response from a call to a backend provider
    /// </summary>
    public enum BackendResponse
    {
        /// <summary>The call succeeded</summary>
        Success,
        /// <summary>The resource requested was not found</summary>
        NotFound,
        /// <summary>A server failure prevented the call from
        /// completing</summary>
        Failure
    }

    public class AssetServerPluginInitialiser : PluginInitialiserBase
    {
        private AssetServer server;

        public AssetServerPluginInitialiser (AssetServer server)
        {
            this.server = server;
        }

        public override void Initialise (IPlugin plugin)
        {
            IAssetServerPlugin p = plugin as IAssetServerPlugin;
            p.Initialise (server);
        }
    }

    #region Interfaces

    public interface IAssetServerPlugin : IPlugin
    {
        void Initialise(AssetServer server);
    }

    public interface IStorageProvider
    {
        BackendResponse TryFetchMetadata(UUID assetID, out Metadata metadata);
        BackendResponse TryFetchData(UUID assetID, out byte[] assetData);
        BackendResponse TryFetchDataMetadata(UUID assetID, out Metadata metadata, out byte[] assetData);
        BackendResponse TryCreateAsset(Metadata metadata, byte[] assetData);
        BackendResponse TryCreateAsset(Metadata metadata, byte[] assetData, out UUID assetID);
        int ForEach(Action<Metadata> action, int start, int count);
    }

    public interface IAssetStorageProvider : IAssetServerPlugin
    {
        BackendResponse TryFetchMetadata(UUID assetID, out Metadata metadata);
        BackendResponse TryFetchData(UUID assetID, out byte[] assetData);
        BackendResponse TryFetchDataMetadata(UUID assetID, out Metadata metadata, out byte[] assetData);
        BackendResponse TryCreateAsset(Metadata metadata, byte[] assetData);
        BackendResponse TryCreateAsset(Metadata metadata, byte[] assetData, out UUID assetID);
        int ForEach(Action<Metadata> action, int start, int count);
    }

    public interface IInventoryProvider
    {
        BackendResponse TryFetchItem(Uri owner, UUID itemID, out InventoryItem item);
        BackendResponse TryFetchFolder(Uri owner, UUID folderID, out InventoryFolder folder);
        BackendResponse TryFetchFolderContents(Uri owner, UUID folderID, out InventoryCollection contents);
        BackendResponse TryFetchFolderList(Uri owner, out List<InventoryFolder> folders);
        BackendResponse TryFetchInventory(Uri owner, out InventoryCollection inventory);

        BackendResponse TryFetchActiveGestures(Uri owner, out List<InventoryItem> gestures);

        BackendResponse TryCreateItem(Uri owner, InventoryItem item);
        BackendResponse TryCreateFolder(Uri owner, InventoryFolder folder);
        BackendResponse TryCreateInventory(Uri owner, InventoryFolder rootFolder);

        BackendResponse TryDeleteItem(Uri owner, UUID itemID);
        BackendResponse TryDeleteFolder(Uri owner, UUID folderID);
        BackendResponse TryPurgeFolder(Uri owner, UUID folderID);
    }

    public interface IAuthenticationProvider
    {
        void AddIdentifier(UUID authToken, Uri identifier);
        bool RemoveIdentifier(UUID authToken);
        bool TryGetIdentifier(UUID authToken, out Uri identifier);
    }

    public interface IAuthorizationProvider
    {
        bool IsMetadataAuthorized(UUID authToken, UUID assetID);
        /// <summary>
        /// Authorizes access to the data for an asset. Access to asset data
        /// also implies access to the metadata for that asset
        /// </summary>
        /// <param name="authToken">Authentication token to check for access</param>
        /// <param name="assetID">ID of the requested asset</param>
        /// <returns>True if access is granted, otherwise false</returns>
        bool IsDataAuthorized(UUID authToken, UUID assetID);
        bool IsCreateAuthorized(UUID authToken);

        bool IsInventoryReadAuthorized(UUID authToken, Uri owner);
        bool IsInventoryWriteAuthorized(UUID authToken, Uri owner);
    }

    public interface IMetricsProvider
    {
        void LogAssetMetadataFetch(string extension, BackendResponse response, UUID assetID, DateTime time);
        void LogAssetDataFetch(string extension, BackendResponse response, UUID assetID, int dataSize, DateTime time);
        void LogAssetCreate(string extension, BackendResponse response, UUID assetID, int dataSize, DateTime time);

        void LogInventoryFetch(string extension, BackendResponse response, Uri owner, UUID objID, bool folder, DateTime time);
        void LogInventoryFetchFolderContents(string extension, BackendResponse response, Uri owner, UUID folderID, DateTime time);
        void LogInventoryFetchFolderList(string extension, BackendResponse response, Uri owner, DateTime time);
        void LogInventoryFetchInventory(string extension, BackendResponse response, Uri owner, DateTime time);
        void LogInventoryFetchActiveGestures(string extension, BackendResponse response, Uri owner, DateTime time);
        void LogInventoryCreate(string extension, BackendResponse response, Uri owner, bool folder, DateTime time);
        void LogInventoryCreateInventory(string extension, BackendResponse response, DateTime time);
        void LogInventoryDelete(string extension, BackendResponse response, Uri owner, UUID objID, bool folder, DateTime time);
        void LogInventoryPurgeFolder(string extension, BackendResponse response, Uri owner, UUID folderID, DateTime time);
    }

    #endregion Interfaces
}