using System;
using System.Collections.Generic;
namespace ln.http.session
{
    public class SessionCache
    {
        Dictionary<Guid, Session> sessions = new Dictionary<Guid, Session>();

        public SessionCache()
        {
        }

        public bool Contains(Guid sessionID)
        {
            return this.sessions.ContainsKey(sessionID);
        }

        /*
         * Create a new Session instance
         * 
         */        
        public virtual Session CreateSession()
        {
            return new Session();
        }

        /*
         * Find and return SessionID from given HttpRequest
         * 
         */
        public virtual Guid FindSessionID(HttpRequest httpRequest)
        {
            if (httpRequest.ContainsCookie("SID_LN"))
            {
                return Guid.Parse(httpRequest.GetCookie("SID_LN"));
            }
            return Guid.Empty;
        }

        /*
         * Apply SessionID of the given Session to the given Response
         * 
         */
        public virtual void ApplySessionID(HttpResponse httpResponse,Session session)
        {
            HttpCookie sessionCookie = new HttpCookie("SID_LN",session.SessionID.ToString());
            sessionCookie.Path = "/";
            httpResponse.AddCookie(sessionCookie);
        }

        public Session GetSession(HttpRequest httpRequest)
        {
            Guid sessionID = FindSessionID(httpRequest);
            if (!Guid.Empty.Equals(sessionID) && Contains(sessionID))
            {
                lock (sessions)
                {
                    Session session = this.sessions[sessionID];
                    session.Touch();
                    return session;
                }
            }
            else
            {
                Session session = CreateSession();
                lock (this.sessions)
                {
                    this.sessions.Add(session.SessionID, session);
                }
                return session;
            }
        }

    }
}