using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;

//weird callback method, like pointers in C#, pretty cool stuff!
public delegate bool CallBack(int hWnd, int lParam);

namespace KillOneNote
{
    /* Thanks to:
     *   http://www.codeproject.com/csharp/cskillapp.asp
     * & http://www.c-sharpcorner.com/Code/2002/Nov/win32api.asp
     * & http://www.vbaccelerator.com/home/net/code/Libraries/Windows/Enumerating_Windows/article.asp
     * & http://www.codeproject.com/csharp/runninginstanceie.asp <-- good!
     */

    class OneNoteWindowFinder
    {
        //delcare the external methods that are imported from the user32.dll library
        [DllImport("user32.Dll")]
        public static extern int EnumWindows(CallBack x, int y);
        [DllImport("User32.Dll")]
        public static extern void GetWindowText(int h, StringBuilder s, int nMaxCount);
        [DllImport("User32.Dll")]
        public static extern void GetClassName(int h, StringBuilder s, int nMaxCount);
        [DllImport("User32.Dll")]
        public static extern IntPtr PostMessage(IntPtr hWnd, int msg, int wParam, int lParam);

        //a list for all of my windows..see my 'class' (actually a struct below)
        //static because I need to have other methods access this
        private static List<ONWindow> all_windows;

        public List<ONWindow> All_windows
        {
            get
            {
                return all_windows;
            }
        }


        public OneNoteWindowFinder()
        {
            all_windows = new List<ONWindow>();
            getWindows();
        }

        public void getWindows()
        {
            //calls the user32.dll EnumWindows and goes to my CallBack method (delcared @ the top)
            EnumWindows(new CallBack(OneNoteWindowFinder.EnumWindowCallBack), 0);
        }

        //now this is called by the EunmWindows and it needs to be static and so it the all_windows above
        private static bool EnumWindowCallBack(int hWnd, int lParam)
        {
            StringBuilder sWText = new StringBuilder(1024);
            StringBuilder sWClass = new StringBuilder(256);
            
            //get the window text & window class type
            GetWindowText(hWnd, sWText, sWText.Capacity);
            GetClassName(hWnd, sWClass, sWClass.Capacity);

            //look for OneNote in the title and also our type which is Framework::CFrame
            if (sWText.ToString().Contains("Microsoft Office OneNote") && sWClass.ToString().Equals("Framework::CFrame"))
            {
                OneNoteWindowFinder.all_windows.Add(new ONWindow(hWnd, sWText.ToString()));
            }

            return true;
        }

        public void Kill(int hWnd)
        {
            int kill_msg = 0x0010;  /* WM_CLOSE */
            //call the user32.dll method for this
            PostMessage((IntPtr)hWnd, kill_msg, 0, 0);
        }

    }

    //my basic class to hold the hWnd & title
    class ONWindow 
    {
        String title;
        int hWnd;

        public int HWnd
        {
            get
            {
                return hWnd;
            }
        }

        public String Title
        {
            get
            {
                return title;
            }
        }

        public ONWindow(int in_hWnd, String sb)
        {
            hWnd = in_hWnd;
            title = sb;
        }

        //just in case you want it!
        public string toString()
        {
            return ("hWnd: " + hWnd + "\tTitle: " + title);
        }
    }

    

    class Program
    {
        static void Main(string[] args)
        {
            OneNoteWindowFinder onFinder = new OneNoteWindowFinder();
            foreach (ONWindow onw in onFinder.All_windows)
            {
                System.Console.WriteLine(onw.toString());
                onFinder.Kill(onw.HWnd);
            }  
        }
    }
}