using System;
using System.Web;

using CMS.CMSHelper;
using CMS.SettingsProvider;

public class CMSHttpApplication : HttpApplication
{
    #region "Variables"

    /// <summary>
    /// True if handlers were already initialized
    /// </summary>
    private static bool mHandlersInitialized = false;

    /// <summary>
    /// Lock object
    /// </summary>
    private static object mLock = new object();

    #endregion


    #region "Application events"

    /// <summary>
    /// Application start event handler.
    /// </summary>
    public void Application_Start(object sender, EventArgs e)
    {
        // Azure Application start init
        AzureInit.Current.ApplicationStartInit();

        CMSAppBase.CMSApplicationStart();
    }


    /// <summary>
    /// Application error event handler.
    /// </summary>
    public void Application_Error(object sender, EventArgs e)
    {
        CMSAppBase.CMSApplicationError(sender, e);
    }


    /// <summary>
    /// Application end event handler.
    /// </summary>
    public void Application_End(object sender, EventArgs e)
    {
        CMSAppBase.CMSApplicationEnd(sender, e);
    }

    #endregion


    #region "Session events"

    /// <summary>
    /// Session start event handler.
    /// </summary>
    public void Session_Start(object sender, EventArgs e)
    {
        CMSAppBase.CMSSessionStart(sender, e);
    }


    /// <summary>
    /// Session end event handler.
    /// </summary>
    public void Session_End(object sender, EventArgs e)
    {
        CMSAppBase.CMSSessionEnd(sender, e);
    }

    #endregion


    #region "Request events"

    /// <summary>
    /// Constructor
    /// </summary>
    public CMSHttpApplication()
    {
        InitHandlers();
    }


    /// <summary>
    /// Initializes the handlers
    /// </summary>
    private void InitHandlers()
    {
        if (mHandlersInitialized)
        {
            return;
        }

        lock (mLock)
        {
            if (mHandlersInitialized)
            {
                return;
            }

            // Map the request handlers
            CMSApplicationModule.BeginRequest += CMSAppBase.CMSBeginRequest;
            CMSApplicationModule.AuthenticateRequest += CMSAppBase.CMSAuthenticateRequest;
            CMSApplicationModule.AuthorizeRequest += CMSAppBase.CMSAuthorizeRequest;
            CMSApplicationModule.MapRequestHandler += CMSAppBase.CMSMapRequestHandler;
            CMSApplicationModule.PostMapRequestHandler += CMSAppBase.CMSPostMapRequestHandler;
            CMSApplicationModule.AcquireRequestState += CMSAppBase.CMSAcquireRequestState;
            CMSApplicationModule.EndRequest += CMSAppBase.CMSEndRequest;
            CMSApplicationModule.PreSendRequestHeaders += CMSAppBase.CMSPreSendRequestHeaders;

            mHandlersInitialized = true;
        }
    }

    #endregion


    #region "Overridden methods"

    /// <summary>
    /// Custom cache parameters processing.
    /// </summary>
    public override string GetVaryByCustomString(HttpContext context, string custom)
    {
        return CMSAppBase.CMSGetVaryByCustomString(context, custom);
    }

    #endregion
}