/*
* Copyright (c) Contributors, http://www.openmetaverse.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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*       derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS AND ANY
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*/
using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using OpenSim.Framework.Data;
using libsecondlife;
using System.Reflection;

using System.Xml;
using Nwc.XmlRpc;
using OpenSim.Framework.Sims;
using OpenSim.Framework.Inventory;
using OpenSim.Framework.Utilities;

using System.Security.Cryptography;

namespace OpenSim.Framework.UserManagement
{
    public class UserManagerBase
    {
        public OpenSim.Framework.Interfaces.UserConfig _config;
        Dictionary<string, IUserData> _plugins = new Dictionary<string, IUserData>();

        /// <summary>
        /// Adds a new user server plugin - user servers will be requested in the order they were loaded.
        /// </summary>
        /// <param name="FileName">The filename to the user server plugin DLL</param>
        public void AddPlugin(string FileName)
        {
            OpenSim.Framework.Console.MainLog.Instance.Verbose( "Userstorage: Attempting to load " + FileName);
            Assembly pluginAssembly = Assembly.LoadFrom(FileName);

            OpenSim.Framework.Console.MainLog.Instance.Verbose( "Userstorage: Found " + pluginAssembly.GetTypes().Length + " interfaces.");
            foreach (Type pluginType in pluginAssembly.GetTypes())
            {
                if (!pluginType.IsAbstract)
                {
                    Type typeInterface = pluginType.GetInterface("IUserData", true);

                    if (typeInterface != null)
                    {
                        IUserData plug = (IUserData)Activator.CreateInstance(pluginAssembly.GetType(pluginType.ToString()));
                        plug.Initialise();
                        this._plugins.Add(plug.getName(), plug);
                        OpenSim.Framework.Console.MainLog.Instance.Verbose( "Userstorage: Added IUserData Interface");
                    }

                    typeInterface = null;
                }
            }

            pluginAssembly = null;
        }

        #region Get UserProfile 
        /// <summary>
        /// Loads a user profile from a database by UUID
        /// </summary>
        /// <param name="uuid">The target UUID</param>
        /// <returns>A user profile</returns>
        public UserProfileData getUserProfile(LLUUID uuid)
        {
            foreach (KeyValuePair<string, IUserData> plugin in _plugins)
            {
                try
                {
                    UserProfileData profile = plugin.Value.getUserByUUID(uuid);
                    profile.currentAgent = getUserAgent(profile.UUID);
                    return profile;
                }
                catch (Exception e)
                {
                    OpenSim.Framework.Console.MainLog.Instance.Verbose( "Unable to find user via " + plugin.Key + "(" + e.ToString() + ")");
                }
            }

            return null;
        }


        /// <summary>
        /// Loads a user profile by name
        /// </summary>
        /// <param name="name">The target name</param>
        /// <returns>A user profile</returns>
        public UserProfileData getUserProfile(string name)
        {
            foreach (KeyValuePair<string, IUserData> plugin in _plugins)
            {
                try
                {
                    UserProfileData profile = plugin.Value.getUserByName(name);
                    profile.currentAgent = getUserAgent(profile.UUID);
                    return profile;
                }
                catch (Exception e)
                {
                    OpenSim.Framework.Console.MainLog.Instance.Verbose( "Unable to find user via " + plugin.Key + "(" + e.ToString() + ")");
                }
            }

            return null;
        }

        /// <summary>
        /// Loads a user profile by name
        /// </summary>
        /// <param name="fname">First name</param>
        /// <param name="lname">Last name</param>
        /// <returns>A user profile</returns>
        public UserProfileData getUserProfile(string fname, string lname)
        {
            foreach (KeyValuePair<string, IUserData> plugin in _plugins)
            {
                try
                {
                    UserProfileData profile = plugin.Value.getUserByName(fname,lname);
                    try
                    {
                        profile.currentAgent = getUserAgent(profile.UUID);
                    }
                    catch (Exception e)
                    {
                        // Ignore
                    }
                    return profile;
                }
                catch (Exception e)
                {
                    OpenSim.Framework.Console.MainLog.Instance.Verbose( "Unable to find user via " + plugin.Key + "(" + e.ToString() + ")");
                }
            }

            return null;
        }
        #endregion

        #region Get UserAgent
        /// <summary>
        /// Loads a user agent by uuid (not called directly)
        /// </summary>
        /// <param name="uuid">The agents UUID</param>
        /// <returns>Agent profiles</returns>
        public UserAgentData getUserAgent(LLUUID uuid)
        {
            foreach (KeyValuePair<string, IUserData> plugin in _plugins)
            {
                try
                {
                    return plugin.Value.getAgentByUUID(uuid);
                }
                catch (Exception e)
                {
                    OpenSim.Framework.Console.MainLog.Instance.Verbose( "Unable to find user via " + plugin.Key + "(" + e.ToString() + ")");
                }
            }

            return null;
        }

        /// <summary>
        /// Loads a user agent by name (not called directly)
        /// </summary>
        /// <param name="name">The agents name</param>
        /// <returns>A user agent</returns>
        public UserAgentData getUserAgent(string name)
        {
            foreach (KeyValuePair<string, IUserData> plugin in _plugins)
            {
                try
                {
                    return plugin.Value.getAgentByName(name);
                }
                catch (Exception e)
                {
                    OpenSim.Framework.Console.MainLog.Instance.Verbose( "Unable to find user via " + plugin.Key + "(" + e.ToString() + ")");
                }
            }

            return null;
        }

        /// <summary>
        /// Loads a user agent by name (not called directly)
        /// </summary>
        /// <param name="fname">The agents firstname</param>
        /// <param name="lname">The agents lastname</param>
        /// <returns>A user agent</returns>
        public UserAgentData getUserAgent(string fname, string lname)
        {
            foreach (KeyValuePair<string, IUserData> plugin in _plugins)
            {
                try
                {
                    return plugin.Value.getAgentByName(fname,lname);
                }
                catch (Exception e)
                {
                    OpenSim.Framework.Console.MainLog.Instance.Verbose( "Unable to find user via " + plugin.Key + "(" + e.ToString() + ")");
                }
            }

            return null;
        }

        #endregion

        #region CreateAgent
        /// <summary>
        /// Creates and initialises a new user agent - make sure to use CommitAgent when done to submit to the DB
        /// </summary>
        /// <param name="profile">The users profile</param>
        /// <param name="request">The users loginrequest</param>
        public void CreateAgent(ref UserProfileData profile, XmlRpcRequest request)
        {
            Hashtable requestData = (Hashtable)request.Params[0];

            UserAgentData agent = new UserAgentData();

            // User connection
            agent.agentIP = "";
            agent.agentOnline = true;
            agent.agentPort = 0;

            // Generate sessions
            RNGCryptoServiceProvider rand = new RNGCryptoServiceProvider();
            byte[] randDataS = new byte[16];
            byte[] randDataSS = new byte[16];
            rand.GetBytes(randDataS);
            rand.GetBytes(randDataSS);

            agent.secureSessionID = new LLUUID(randDataSS, 0);
            agent.sessionID = new LLUUID(randDataS, 0);

            // Profile UUID
            agent.UUID = profile.UUID;

            // Current position (from Home)
            agent.currentHandle = profile.homeRegion;
            agent.currentPos = profile.homeLocation;

            // If user specified additional start, use that
            if (requestData.ContainsKey("start"))
            {
                string startLoc = ((string)requestData["start"]).Trim();
                if (!(startLoc == "last" || startLoc == "home"))
                {
                    // Format: uri:Ahern&162&213&34
                    try
                    {
                        string[] parts = startLoc.Remove(0, 4).Split('&');
                        string region = parts[0];

                        ////////////////////////////////////////////////////
                        //SimProfile SimInfo = new SimProfile();
                        //SimInfo = SimInfo.LoadFromGrid(theUser.currentAgent.currentHandle, _config.GridServerURL, _config.GridSendKey, _config.GridRecvKey);
                    }
                    catch (Exception e)
                    {

                    }
                }
            }

            // What time did the user login?
            agent.loginTime = Util.UnixTimeSinceEpoch();
            agent.logoutTime = 0;

            // Current location
            agent.regionID = new LLUUID(); // Fill in later
            agent.currentRegion = new LLUUID();      // Fill in later

            profile.currentAgent = agent;
        }

        /// <summary>
        /// Saves a target agent to the database
        /// </summary>
        /// <param name="profile">The users profile</param>
        /// <returns>Successful?</returns>
        public bool CommitAgent(ref UserProfileData profile)
        {
            // Saves the agent to database
            return true;
        }

        #endregion

        /// <summary>
        /// Checks a user against it's password hash
        /// </summary>
        /// <param name="profile">The users profile</param>
        /// <param name="password">The supplied password</param>
        /// <returns>Authenticated?</returns>
        public virtual bool AuthenticateUser(ref UserProfileData profile, string password)
        {
            OpenSim.Framework.Console.MainLog.Instance.Verbose(
                "Authenticating " + profile.username + " " + profile.surname);

            password = password.Remove(0, 3); //remove $1$

            string s = Util.Md5Hash(password + ":" + profile.passwordSalt);

            return profile.passwordHash.Equals(s.ToString(), StringComparison.InvariantCultureIgnoreCase);
        }

        #region Xml Response

        /// <summary>
        /// 
        /// </summary>
        /// <param name="firstname"></param>
        /// <param name="lastname"></param>
        /// <returns></returns>
        public virtual UserProfileData GetTheUser(string firstname, string lastname)
        {
            return getUserProfile(firstname, lastname);
        }

        /// <summary>
        /// 
        /// </summary>
        /// <returns></returns>
        public virtual string GetMessage()
        {
            return _config.DefaultStartupMsg;
        }

        /// <summary>
        /// Customises the login response and fills in missing values.
        /// </summary>
        /// <param name="response">The existing response</param>
        /// <param name="theUser">The user profile</param>
        public virtual void CustomiseResponse(ref LoginResponse response, ref UserProfileData theUser)
        {
       
        }

        /// <summary>
        /// Main user login function
        /// </summary>
        /// <param name="request">The XMLRPC request</param>
        /// <returns>The response to send</returns>
        public XmlRpcResponse XmlRpcLoginMethod(XmlRpcRequest request)
        {
            XmlRpcResponse response = new XmlRpcResponse();
            Hashtable requestData = (Hashtable)request.Params[0];

            bool GoodXML = (requestData.Contains("first") && requestData.Contains("last") && requestData.Contains("passwd"));
            bool GoodLogin = false;
            string firstname = "";
            string lastname = "";
            string passwd = "";

            UserProfileData TheUser;
            LoginResponse logResponse = new LoginResponse();

            if (GoodXML)
            {
                firstname = (string)requestData["first"];
                lastname = (string)requestData["last"];
                passwd = (string)requestData["passwd"];

                TheUser = GetTheUser(firstname, lastname);
                if (TheUser == null)
                    return logResponse.CreateLoginFailedResponse();

                GoodLogin = AuthenticateUser(ref TheUser, passwd);
            }
            else
            {
                return logResponse.CreateGridErrorResponse();
            }

            if (!GoodLogin)
            {
                return logResponse.CreateLoginFailedResponse();
            }
            else
            {
                // If we already have a session...
                if (TheUser.currentAgent != null && TheUser.currentAgent.agentOnline)
                {
                    // Reject the login
                    return logResponse.CreateAlreadyLoggedInResponse();
                }
                // Otherwise...
                // Create a new agent session
                CreateAgent(ref TheUser, request);

                try
                {

                    LLUUID AgentID = TheUser.UUID;

                    // Inventory Library Section
                    ArrayList AgentInventoryArray = new ArrayList();
                    Hashtable TempHash;

                    AgentInventory Library = new AgentInventory();
                    Library.CreateRootFolder(AgentID, true);

                    foreach (InventoryFolder InvFolder in Library.InventoryFolders.Values)
                    {
                        TempHash = new Hashtable();
                        TempHash["name"] = InvFolder.FolderName;
                        TempHash["parent_id"] = InvFolder.ParentID.ToStringHyphenated();
                        TempHash["version"] = (Int32)InvFolder.Version;
                        TempHash["type_default"] = (Int32)InvFolder.DefaultType;
                        TempHash["folder_id"] = InvFolder.FolderID.ToStringHyphenated();
                        AgentInventoryArray.Add(TempHash);
                    }

                    Hashtable InventoryRootHash = new Hashtable();
                    InventoryRootHash["folder_id"] = Library.InventoryRoot.FolderID.ToStringHyphenated();
                    ArrayList InventoryRoot = new ArrayList();
                    InventoryRoot.Add(InventoryRootHash);

                    // Circuit Code
                    uint circode = (uint)(Util.RandomClass.Next());

                    logResponse.Lastname = TheUser.surname;
                    logResponse.Firstname = TheUser.username;
                    logResponse.AgentID = AgentID.ToStringHyphenated();
                    logResponse.SessionID = TheUser.currentAgent.sessionID.ToStringHyphenated();
                    logResponse.SecureSessionID = TheUser.currentAgent.secureSessionID.ToStringHyphenated();
                    logResponse.InventoryRoot = InventoryRoot;
                    logResponse.InventorySkeleton = AgentInventoryArray;
                    logResponse.CircuitCode = (Int32)circode;
                    logResponse.RegionX = 0; //overwritten
                    logResponse.RegionY = 0; //overwritten
                    logResponse.Home = "!!null temporary value {home}!!";   // Overwritten
                    //logResponse.LookAt = "\n[r" + TheUser.homeLookAt.X.ToString() + ",r" + TheUser.homeLookAt.Y.ToString() + ",r" + TheUser.homeLookAt.Z.ToString() + "]\n";
                    logResponse.SimAddress = "127.0.0.1"; //overwritten
                    logResponse.SimPort = 0; //overwritten
                    logResponse.Message = this.GetMessage();
                    
                    try
                    {
                        this.CustomiseResponse(ref logResponse, ref TheUser);
                    }
                    catch (Exception e)
                    {
                        System.Console.WriteLine(e.ToString());
                        return logResponse.CreateDeadRegionResponse();
                    }
                    CommitAgent(ref TheUser);

                    return logResponse.ToXmlRpcResponse();

                }
                catch (Exception E)
                {
                    System.Console.WriteLine(E.ToString());
                }
                //}
            }
            return response;

        }

        #endregion

        /// <summary>
        /// Deletes an active agent session
        /// </summary>
        /// <param name="request">The request</param>
        /// <param name="path">The path (eg /bork/narf/test)</param>
        /// <param name="param">Parameters sent</param>
        /// <returns>Success "OK" else error</returns>
        public string RestDeleteUserSessionMethod(string request, string path, string param)
        {
            // TODO! Important!

            return "OK";
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="user"></param>
        public void AddUserProfile(string firstName, string lastName, string pass, uint regX, uint regY)
        {
            UserProfileData user = new UserProfileData();
            user.homeLocation = new LLVector3(128, 128, 100);
            user.UUID = LLUUID.Random();
            user.username = firstName;
            user.surname = lastName;
            user.passwordHash = pass;
            user.passwordSalt = "";
            user.created = Util.UnixTimeSinceEpoch();
            user.homeLookAt = new LLVector3(100, 100, 100);
            user.homeRegion = Util.UIntsToLong((regX * 256), (regY * 256));

            foreach (KeyValuePair<string, IUserData> plugin in _plugins)
            {
                try
                {
                    plugin.Value.addNewUserProfile(user);

                }
                catch (Exception e)
                {
                    OpenSim.Framework.Console.MainLog.Instance.Verbose("Unable to add user via " + plugin.Key + "(" + e.ToString() + ")");
                }
            }
        }

        /// <summary>
        /// Returns an error message that the user could not be found in the database
        /// </summary>
        /// <returns>XML string consisting of a error element containing individual error(s)</returns>
        public string CreateUnknownUserErrorResponse()
        {
            System.IO.StringWriter sw = new System.IO.StringWriter();
            XmlTextWriter xw = new XmlTextWriter(sw);

            // Header
            xw.Formatting = Formatting.Indented;
            xw.WriteStartDocument();
            xw.WriteDocType("error", null, null, null);
            xw.WriteComment("An error occured");
            xw.WriteStartElement("error");

            // User
            xw.WriteElementString("unknownuser", "Unable to find a user with that name");

            // Footer
            xw.WriteEndElement();
            xw.Flush();
            xw.Close();

            return sw.ToString();
        }

        /// <summary>
        /// Converts a user profile to an XML element which can be returned
        /// </summary>
        /// <param name="profile">The user profile</param>
        /// <returns>A string containing an XML Document of the user profile</returns>
        public string ProfileToXml(UserProfileData profile)
        {
            System.IO.StringWriter sw = new System.IO.StringWriter();
            XmlTextWriter xw = new XmlTextWriter(sw);

            // Header
            xw.Formatting = Formatting.Indented;
            xw.WriteStartDocument();
            xw.WriteDocType("userprofile", null, null, null);
            xw.WriteComment("Found user profiles matching the request");
            xw.WriteStartElement("users");

            // User
            xw.WriteStartElement("user");
            // Account information
            xw.WriteAttributeString("firstname", profile.username);
            xw.WriteAttributeString("lastname", profile.surname);
            xw.WriteAttributeString("uuid", profile.UUID.ToStringHyphenated());
            // Server Information
            xw.WriteAttributeString("server_inventory", profile.userInventoryURI);
            xw.WriteAttributeString("server_asset", profile.userAssetURI);
            // Profile Information
            xw.WriteAttributeString("profile_about", profile.profileAboutText);
            xw.WriteAttributeString("profile_firstlife_about", profile.profileFirstText);
            xw.WriteAttributeString("profile_firstlife_image", profile.profileFirstImage.ToStringHyphenated());
            xw.WriteAttributeString("profile_can_do", profile.profileCanDoMask.ToString());
            xw.WriteAttributeString("profile_want_do", profile.profileWantDoMask.ToString());
            xw.WriteAttributeString("profile_image", profile.profileImage.ToStringHyphenated());
            xw.WriteAttributeString("profile_created",profile.created.ToString());
            xw.WriteAttributeString("profile_lastlogin",profile.lastLogin.ToString());
            // Home region information
            xw.WriteAttributeString("home_coordinates", profile.homeLocation.ToString());
            xw.WriteAttributeString("home_region", profile.homeRegion.ToString());
            xw.WriteAttributeString("home_look", profile.homeLookAt.ToString());

            xw.WriteEndElement();

            // Footer
            xw.WriteEndElement();
            xw.Flush();
            xw.Close();

            return sw.ToString();
        }

        #region REST Methods 
        //should most likely move out of here and into the grid's userserver sub class
        public string RestGetUserMethodName(string request, string path, string param)
        {
            UserProfileData userProfile = getUserProfile(param.Trim());

            if (userProfile == null)
            {
                return CreateUnknownUserErrorResponse();
            }

            return ProfileToXml(userProfile);
        }

        public string RestGetUserMethodUUID(string request, string path, string param)
        {
            UserProfileData userProfile = getUserProfile(new LLUUID(param));

            if (userProfile == null)
            {
                return CreateUnknownUserErrorResponse();
            }

            return ProfileToXml(userProfile);
        }
        #endregion

    }
}