AJAX的简单聊天

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;



using System;

using System.Data;

using System.Configuration;

using System.Collections;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Threading;

using System.Globalization;



namespace SpilafisChatLogic

{

    /// <summary>

    /// License and Disclaimer: All the intructions, code, html

    /// and everything presented with this solution



    /// is provided 'as is' with no warranties what so ever.

    /// The only condition for you to use this software is that you keep

    /// the link to http://www.spilafis.com.ar in the chat page as provided.

    /// Please support freeware keeping the link and clicking on my sponsors.

    /// Thank you!

    /// </summary>

    public class Business

    {

        public Business()

        {

        }



        public static User CurrentUser

        {

            get

            {

                if (HttpContext.Current.Session["ChatCurrentUser"] == null)

                    HttpContext.Current.Session["ChatCurrentUser"] = new User();



                return (User)HttpContext.Current.Session["ChatCurrentUser"];

            }

            set

            {

                HttpContext.Current.Session["ChatCurrentUser"] = value;

            }

        }



        public static App CurrentApp

        {

            get

            {

                if (HttpContext.Current.Application["ChatCurrentApp"] == null)

                    HttpContext.Current.Application["ChatCurrentApp"] = new App();



                return (App)HttpContext.Current.Application["ChatCurrentApp"];

            }

            set

            {

                HttpContext.Current.Application["ChatCurrentApp"] = value;

            }

        }

    }



    public class User

    {

        #region Private Members



        private bool m_ajax_chat_counted;

        private string m_ajax_chat_user_name;

        private int m_ajax_chat_last_read_id;



        private bool m_code_access_enabled;



        #endregion



        public User()

        {

            m_ajax_chat_counted = false;

            m_ajax_chat_user_name = "";

            m_ajax_chat_last_read_id = -1;



            m_code_access_enabled = false;

        }



        #region Properties



        public bool AjaxChatCounted

        {

            get { return m_ajax_chat_counted; }

            set { m_ajax_chat_counted = value; }

        }



        public string AjaxChatUserName

        {

            get { return m_ajax_chat_user_name; }

            set { m_ajax_chat_user_name = value; }

        }



        public int AjaxChatLastReadId

        {

            get { return m_ajax_chat_last_read_id; }

            set { m_ajax_chat_last_read_id = value; }

        }



        #endregion



    }





    public class App

    {

        #region Private Members



        private int m_ajax_chat_users_r;

        private Hashtable m_ajax_chat_users_w;

        private Hashtable m_ajax_chat_users_w_last_activity;

        private ArrayList m_ajax_chat;



        #endregion





        public App()

        {

            m_ajax_chat_users_w = new Hashtable();

            m_ajax_chat_users_w_last_activity = new Hashtable();

            m_ajax_chat = new ArrayList();

        }





        #region Properties



        public int AjaxChatUsersR

        {

            get { return m_ajax_chat_users_r; }

            set { m_ajax_chat_users_r = value; }

        }



        public Hashtable AjaxChatUsersW

        {

            get { return m_ajax_chat_users_w; }

            set { m_ajax_chat_users_w = value; }

        }



        public Hashtable AjaxChatUsersWLastActivity

        {

            get { return m_ajax_chat_users_w_last_activity; }

            set { m_ajax_chat_users_w_last_activity = value; }

        }



        public ArrayList AjaxChat

        {

            get { return m_ajax_chat; }

            set { m_ajax_chat = value; }

        }



        #endregion

    }





    public class Chat

    {

        #region Constants



        public static int MaxMessageLength = 100;

        public static int MaxChatLines = 50;

        public static int MaxLoggedInUsers = 5;

        public static string[] BadWords = { "a**hole", 

               "boludo"}; // Add your bad word dictionary here



        #endregion



        public Chat()

        {

        }



        #region Methods



        private static void IncrementUsersReading()

        {

            Business.CurrentApp.AjaxChatUsersR = GetIntUsersReading() + 1;

        }



        private static int GetIntUsersReading()

        {

            return Business.CurrentApp.AjaxChatUsersR;

        }



        private static int GetId(string message)

        {

            return Convert.ToInt32(message.Split('-')[0]);

        }



        private static string GetMessage(string message)

        {

            return message.Split('-')[1];

        }



        private static string GetNextId(ArrayList ajax_chat_list)

        {

            int id = GetMaxId(ajax_chat_list);

            if (id < Int32.MaxValue)

                id++;

            else

                id = 0;

            return id.ToString() + "-";

        }



        private static int GetMaxId(ArrayList ajax_chat_list)

        {

            if (ajax_chat_list.Count > 0)

                return GetId(ajax_chat_list[0].ToString());

            else

                return 0;

        }



        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.ReadWrite)]

        public static string GetUserName()

        {

            if (Business.CurrentUser.AjaxChatUserName == "")

                Chat.GetNextUserName();

            return Business.CurrentUser.AjaxChatUserName;

        }



        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.ReadWrite)]

        public static string GetNextUserName()

        {

            string user_name = "";

            // Count user reading if not counted yet

            if (!Business.CurrentUser.AjaxChatCounted)

            {

                Business.CurrentUser.AjaxChatCounted = true;

                IncrementUsersReading();  // Is decremented in session end

            }

            else

            {

                if (Business.CurrentUser.AjaxChatUserName != null && 

                          Business.CurrentUser.AjaxChatUserName != "")

                    return Business.CurrentUser.AjaxChatUserName;

            }



            int user_number = Business.CurrentApp.AjaxChatUsersW.Count + 1;

            // If user may log in 

            if (user_number <= MaxLoggedInUsers)

            {

                // Get first not used guest user name

                while (Business.CurrentApp.AjaxChatUsersW["ChatGuest" + 

                            user_number.ToString()] != null)

                {

                    if (user_number < int.MaxValue)

                        user_number++;

                    else

                        return "";

                }



                // Add to writing users list

                Business.CurrentApp.AjaxChatUsersW.Add("Guest" + 

                                    user_number.ToString(), 1);



                // Save user name to session

                Business.CurrentUser.AjaxChatUserName = 

                   "Guest" + user_number.ToString();



                UpdateUserLastActivityTime();

            }

            return user_name;

        }



        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.ReadWrite)]

        public static void ChangeUserName(string tentative_name)

        {

            if (Business.CurrentUser.AjaxChatUserName == "")

            {

                int user_number = Business.CurrentApp.AjaxChatUsersW.Count + 1;

                // If user may not log in inform

                if (user_number > MaxLoggedInUsers)

                    throw new Exception("Max. number of writing " + 

                       "users reached. You'll be inform when someone leaves.");

            }



            tentative_name = tentative_name.Trim();

            if (tentative_name == "")

                throw new Exception("You must enter a user name to be able to chat.");

            if (tentative_name.IndexOf('-') >= 0)

                throw new Exception("Character '-' is not allowed in the user name.");

            if (tentative_name.Length > 10)

                tentative_name = tentative_name.Substring(0, 10);



            // If exists inform

            if (Business.CurrentApp.AjaxChatUsersW[tentative_name] != null)

                throw new Exception("User name already in use. Please enter another.");



            // Remove old user name from the list

            // Add to writing users list

            ChangeUserNameInWList(tentative_name);



            // Save user name to session

            Business.CurrentUser.AjaxChatUserName = tentative_name;



            UpdateUserLastActivityTime();

        }



        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.ReadWrite)]

        public static void ChangeUserNameInWList(string new_name)

        {

            // If it already had a user name then remove from writing users

            if (Business.CurrentUser.AjaxChatUserName != null && 

                    Business.CurrentUser.AjaxChatUserName != "")

            {

                Business.CurrentApp.AjaxChatUsersW.Remove(

                           Business.CurrentUser.AjaxChatUserName);



                // If it had a saved last activity time remove it



                Business.CurrentApp.AjaxChatUsersWLastActivity.Remove(

                         Business.CurrentUser.AjaxChatUserName);



                // Add to writing users list

                Business.CurrentApp.AjaxChatUsersW.Add(new_name, 1);

                // NOTE: It is not necessary to add it to the last activity

                // table because it will be added after this

            }

        }



        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.ReadWrite)]

        public static void Post(string message)

        {

            // Cut max message length

            message = message.Trim();

            if (message.Length > MaxMessageLength)

                message = message.Substring(0, MaxMessageLength);



            if (message != "")

            {

                // Add time and nickname to identify message

                string message_head = 

                  Business.CurrentUser.AjaxChatUserName + " says: ";

                message = message_head + message;



                ValidateMessage(Business.CurrentApp.AjaxChat, message);



                // Add message id

                message = GetNextId(Business.CurrentApp.AjaxChat) + message;



                // Insert new message

                Business.CurrentApp.AjaxChat.Insert(0, message);



                // Delete lines after MaxChatLines

                while (Business.CurrentApp.AjaxChat.Count > MaxChatLines)

                    Business.CurrentApp.AjaxChat.RemoveAt(

                    Business.CurrentApp.AjaxChat.Count - 1);



                UpdateUserLastActivityTime();

            }

        }



        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.ReadWrite)]

        public static void ValidateMessage(ArrayList ajax_chat_list, string message)

        {

            int index;

            // Create array list of chat without message numbers

            ArrayList ajax_chat_nonumbers = new ArrayList();



            for (index = 0; index < ajax_chat_list.Count; index++)

                ajax_chat_nonumbers.Add(ajax_chat_list[index].ToString().Split('-')[1]);



            // Check for spam

            if (ajax_chat_nonumbers.Contains(message))

                throw new Exception("Please no spam...");



            // Create message words array

            string[] m_w = message.Replace("\n", " ").Replace("\r", "").Split(' ');

            ArrayList message_words = new ArrayList();

            for (index = 0; index < m_w.Length; index++)

                message_words.Add(m_w[index]);



            // Check for bad words

            for (index = 0; index < BadWords.Length; index++)

                if (message_words.Contains(BadWords[index]))

                    throw new Exception("Please no bad words...");

        }



        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.ReadWrite)]

        public static void UpdateUserLastActivityTime()

        {

            if (Business.CurrentUser.AjaxChatUserName != null && 

                       Business.CurrentUser.AjaxChatUserName != "")

              UpdateUserLastActivityTime(

                    Business.CurrentApp.AjaxChatUsersWLastActivity);

        }



        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.ReadWrite)]

        public static void UpdateUserLastActivityTime(

               Hashtable ajax_chat_users_w_last_activity)

        {

            if (ajax_chat_users_w_last_activity<Business.CurrentUser.AjaxChatUserName> 

                                                                                 == null)

                ajax_chat_users_w_last_activity.Add(

                     Business.CurrentUser.AjaxChatUserName, DateTime.Now);

            else

                ajax_chat_users_w_last_activity<

                   Business.CurrentUser.AjaxChatUserName> = DateTime.Now;

        }



        public static DataTable GetUsersDataSource()

        {

            // Create data source

            DataTable dtSource = new DataTable();

            dtSource.Columns.Add(new DataColumn("ChatUsers"));

            dtSource.Columns.Add(new DataColumn("ChatLastActivity"));

            DataRow drSource;

            DateTime last_activity;



            if (Business.CurrentApp.AjaxChatUsersW.Keys.Count > 0)

            {

                // Add list of users to datasource

                foreach (object key in Business.CurrentApp.AjaxChatUsersW.Keys)

                {

                    drSource = dtSource.NewRow();

                    drSource["ChatUsers"] = key.ToString();

                    // Get last activity time

                    if (Business.CurrentApp.AjaxChatUsersWLastActivity[key] != null)

                    {

                      last_activity = 

                        (DateTime)Business.CurrentApp.AjaxChatUsersWLastActivity[key];

                      // Convert to GMT time

                      Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");

                      string dateFormat = 

                        CultureInfo.InvariantCulture.DateTimeFormat.RFC1123Pattern.Replace(

                        "'GMT'", "zzz");

                      string dateString = last_activity.ToString(dateFormat);

                      drSource["ChatLastActivity"] = dateString;

                    }

                    else

                        drSource["ChatLastActivity"] = "<none>";

                    dtSource.Rows.Add(drSource);

                }

            }

            else

            {

                drSource = dtSource.NewRow();

                drSource["ChatUsers"] = "<none>";

                drSource["ChatLastActivity"] = "<none>";

                dtSource.Rows.Add(drSource);

            }





            // Sort by user name

            dtSource.DefaultView.Sort = "ChatUsers";



            return dtSource;

        }



        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.ReadWrite)]

        public static string Read()

        {

            int id;

            int max_id = 0;

            string message;



            // Create chat list if not created

            System.Text.StringBuilder chat = new System.Text.StringBuilder();



            // Get chat from application level

            ArrayList ajax_chat_list = Business.CurrentApp.AjaxChat;



            // Get last read id from user session if already saved

            int last_read_id = Business.CurrentUser.AjaxChatLastReadId;



            // Write it to a string

            int index;

            ArrayList chat_arr = new ArrayList();

            for (index = 0; index < ajax_chat_list.Count; index++)

            {

                id = GetId(ajax_chat_list[index].ToString());

                if (index == 0)

                    max_id = id;

                message = GetMessage(ajax_chat_list[index].ToString());



                // If last read message read reached then stop reading

                if (id == last_read_id)

                    break;

                // Note: Why not "<="?

                //       Because "<=" may cause stop of reading

                // Example: If last message read is 9, and then the id 10 message was sent

                //          and then the id message 1 was sent,

                //          first message read would be id 1 that is < than 9

                //          and wouldn't be read although it should be

                //          (if read, comparing just equal,

                //           then id 10 would be read and in 9 it would stop)



                chat_arr.Add(System.Web.HttpUtility.HtmlEncode(message) + "\n");

                //chat.Append(Server.HtmlEncode(message) + "\n");



            }



            // Build inverted order chat string

            for (index = chat_arr.Count - 1; index >= 0; index--)

                chat.Append(chat_arr[index].ToString());



            // Set max_id as new last_read_id to user session

            Business.CurrentUser.AjaxChatLastReadId = max_id;



            UpdateUserLastActivityTime();



            // Return chat string to user with max_id to set as new last_read_id

            return chat.ToString();

        }



        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.ReadWrite)]

        public static string GetUsersWriting()

        {

            return Business.CurrentApp.AjaxChatUsersW.Count.ToString();

        }



        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.ReadWrite)]

        public static string GetUsersReading()

        {

            return GetIntUsersReading().ToString();

        }



        #endregion

    }

}