www.pudn.com > AjaxChatUchat.rar > ChatEngine.cs
using System;
using System.Text;
using System.Threading;
using System.Collections;
using System.Collections.Specialized;
namespace UChat.ChatEngine
{
public class ChatEngine : IChatEngine
{
const string msg = "{1}\r\n";
const string userlistfmt = "{0}\r\n";
const string serverstyle = "servermsg";
const string userstyle = "usermsg";
const string actionstyle = "actionmsg";
const string timeoutfmt = "User {0} timed out";
const string textlimitfmt = "{0}, your message was {1} characters long. The limit is {2} characters.";
const string nickinusefmt = "{0} a user with this nick already exists";
const string joinedfmt = "User {0} has joined";
const string nickfmt = "{0} is now known as {1}";
const string killfmt = "User {0} has been terminated!";
const string clearfmt = "User {0} has cleared all chat log!";
const string unknowcmdfmt = "User {0} : Unknow command";
const string mefmt = "{0} {1}";
const string txtfmt = "{0}: {1}";
const long timerdelay = 300000;
const int maxbuffer = 20;
const int textlimit = 100;
Timer timer;
Hashtable users;
StringCollection chat;
StringCollection pings;
object syncRoot = new object();
///
/// Default constructor
///
public ChatEngine()
{
users = new Hashtable();
chat = new StringCollection();
pings = new StringCollection();
TimerCallback OnTimerTick = new TimerCallback( TimerTick );
timer = new Timer( OnTimerTick, null, timerdelay, timerdelay );
}
///
/// Check for pinged out users
///
private void TimerTick( object state )
{
lock( syncRoot )
{
string[] current = new string[ users.Keys.Count ];
users.Keys.CopyTo( current, 0 );
foreach( string guid in current )
{
if( !pings.Contains( guid ) )
{
chat.Add(
this.MakeServerMessage(
string.Format( timeoutfmt, users[ guid ].ToString() )
)
);
users.Remove( guid );
}
}
pings.Clear();
}
}
///
/// Gets the current list of
/// users
///
public string[] Users
{
get
{
string[] nicks = new string[ users.Count ];
users.Values.CopyTo( nicks, 0 );
return nicks;
}
}
///
/// HTML Formatted user list
///
public string UserList
{
get
{
StringBuilder sb = new StringBuilder();
string[] nicks = new string[ users.Count ];
users.Values.CopyTo( nicks, 0 );
foreach( string user in nicks )
{
sb.Append( string.Format( userlistfmt, user ) );
}
return sb.ToString();
}
}
///
/// Gets the current buffer of chat text
///
public string BufferText
{
get
{
StringBuilder sb = new StringBuilder();
foreach( string line in chat )
{
sb.Append( line );
}
return sb.ToString();
}
}
///
/// Does a user exist based on a guid
///
public bool GuidExists( string guid )
{
return users.ContainsKey( guid );
}
///
/// Checks to see if the current user
/// exists in the list
///
public bool UserExists(string user)
{
return users.ContainsValue( user );
}
///
/// Adds a user to the list
///
public void AddUser(string id, string user)
{
lock( syncRoot )
if( !UserExists( user ) )
{
users.Add( id, user );
pings.Add( id );
chat.Add(
this.MakeServerMessage(
string.Format( joinedfmt, user )
)
);
}
}
///
/// Pings this chat server and keeps
/// a user alive
///
public void Ping(string guid)
{
lock( syncRoot )
pings.Add( guid );
}
///
/// Adds text to the buffer
///
public void AddText(string guid, string text)
{
if( text.Trim().Length == 0 )
return;
if( text.Length > textlimit )
{
chat.Add(
MakeServerMessage(
string.Format(
textlimitfmt,
users[ guid ].ToString(),
text.Length,
textlimit
)
)
);
return;
}
while( chat.Count > maxbuffer )
{
chat.RemoveAt( 0 );
}
if( !pings.Contains( guid ) )
{
pings.Add( guid );
}
chat.Add(
ParseText( users[ guid ].ToString(), text )
);
}
///
/// Format the users chat depending on whether
/// a control command was supplied.
///
private string ParseText( string user, string text )
{
if( text.StartsWith( "/me " ) )
{
return MakeActionMessage(
string.Format( mefmt, user, text.Replace( "/me", string.Empty ) )
);
}
if( text.StartsWith( "/admin " ) )
{
string command = text.Replace("/admin", string.Empty).Trim();
string result = string.Empty;
switch(command)
{
case "clear":
chat.Clear();
result = MakeServerMessage(
string.Format(clearfmt, user)
);
break;
default:
result = MakeServerMessage(
string.Format(unknowcmdfmt, user)
);
break;
}
return result;
}
if( text.StartsWith( "/nick " ) )
{
string newnick = text.Replace( "/nick", string.Empty ).Trim();
if( UserExists( newnick ) )
{
return MakeServerMessage(
string.Format( nickinusefmt, user )
);
}
string[] keys = new string[ users.Count ];
users.Keys.CopyTo( keys, 0 );
foreach( string key in keys )
{
if( users[ key ].ToString() == user )
{
users[ key ] = newnick;
return MakeServerMessage(
string.Format(nickfmt, user, newnick
)
);
}
}
}
return MakeUserMessage(
string.Format( txtfmt, user, text )
);
}
///
/// Remove the user
///
public void Remove( string user, string password )
{
//
// TODO: Add your password here
if( password != "Add password here!" )
return;
if( this.UserExists( user ) )
{
string[] keys = new string[ users.Count ];
foreach( DictionaryEntry e in users )
{
if( e.Value.ToString() == user )
{
chat.Add(
this.MakeServerMessage(
string.Format( killfmt, user )
)
);
users.Remove( e.Key );
return;
}
}
}
if( pings.Contains( user ) )
pings.Remove( user );
}
///
/// Format a server message by wrapping
/// text in a list item with the server
/// css class selector
///
private string MakeServerMessage( string text )
{
return string.Format( msg, serverstyle, text );
}
///
/// Format a user message by wrapping text
/// in a list item with the user css class
/// selector
///
private string MakeUserMessage( string text )
{
return string.Format( msg, userstyle, text );
}
///
/// Format a user action message by wrapping text
/// in a list item with the action css class
/// selector
///
private string MakeActionMessage( string text )
{
return string.Format( msg, actionstyle, text );
}
}
}