using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

/*
ListSelection: (By Shining Ying)
  * v0.1: (2022.05.01) list selected item in top most explorer

use with python:
import subprocess
app = r"D:\Projects\Dev\ListSelection\ListSelection\bin\Release\ListSelection.exe"
info=subprocess.Popen( '{0}'.format(app),stdout=subprocess.PIPE, stdin=subprocess.PIPE, stderr=subprocess.PIPE )
out, err = info.communicate()
result_list = [x.strip() for x in out.split('\n') if x.strip()!='' and not x.strip().startswith('#') ]

 */
namespace ListSelection
{
    
    class Program
    {
        // need user32 to use get foreground window
        [System.Runtime.InteropServices.DllImport("user32.dll")]
        private static extern IntPtr GetForegroundWindow();

        [System.Runtime.InteropServices.DllImport("user32.dll")]
        private static extern IntPtr GetTopWindow(IntPtr hWnd);

        [System.Runtime.InteropServices.DllImport("user32.dll")]
        private static extern bool IsWindowVisible(IntPtr hWnd);

        [System.Runtime.InteropServices.DllImport("user32.dll")]
        static extern IntPtr GetWindow(IntPtr hWnd, uint uCmd);

        enum GetWindow_Cmd : uint
        {
            GW_HWNDFIRST = 0,
            GW_HWNDLAST = 1,
            GW_HWNDNEXT = 2,
            GW_HWNDPREV = 3,
            GW_OWNER = 4,
            GW_CHILD = 5,
            GW_ENABLEDPOPUP = 6
        }

        // stathread needed to fix unable to cast com object error, as it needs sta thread to use shell object
        // https://stackoverflow.com/questions/31403956/exception-when-using-shell32-to-get-file-extended-properties
        [STAThread]
        static void Main(string[] args)
        {
            List<IntPtr> order_list = new List<IntPtr>();
            /*IntPtr fg_handle = GetForegroundWindow();*/
            IntPtr top_handle = GetTopWindow((IntPtr)null);
            if (top_handle != IntPtr.Zero)
            {
                //Console.WriteLine((int)top_handle);
                if (IsWindowVisible(top_handle))
                {
                    order_list.Add(top_handle);
                }
            }

            IntPtr top_next = GetWindow(top_handle, 2);
            while (top_next != IntPtr.Zero) {
                //Console.WriteLine((int)top_next);
                if (IsWindowVisible(top_next)) { 
                    order_list.Add(top_next);
                }
                top_next = GetWindow(top_next, 2);
            }
            /*
            Console.WriteLine("===========================");
            Console.WriteLine("Order:");
            for (int i = 0; i < order_list.Count; i++)
            {
                Console.WriteLine((int)order_list[i]);
            }
            */
            

            Shell32.Shell shell = new Shell32.Shell();
            // fix reference: right click project, Add > Reference; in COM, check on Microsoft Shell Controls and Automation
            List<int> win_list = new List<int>();
            foreach (SHDocVw.InternetExplorer window in shell.Windows())
            {
                win_list.Add(window.HWND);
            }
            /*
            Console.WriteLine("===========================");
            Console.WriteLine("win:");
            for (int i = 0; i < win_list.Count; i++)
            {
                Console.WriteLine(win_list[i]);
            }
            */

            // top most explorer
            int top_explorer = 0;
            for (int i = 0; i < order_list.Count; i++)
            {
                if (win_list.Contains((int)order_list[i])) {
                    top_explorer = (int)order_list[i];
                    break;
                }
            }

            List<string> selected = new List<string>();
            foreach (SHDocVw.InternetExplorer window in shell.Windows())
            {
                // fix SHDocVw: right click project, Add > Reference; in COM, check on Microsoft Internet Controls
                if (window.HWND == top_explorer)
                {
                    Shell32.FolderItems items = ((Shell32.IShellFolderViewDual2)window.Document).SelectedItems();
                    foreach (Shell32.FolderItem item in items)
                    {
                        selected.Add(item.Path);
                        Console.WriteLine(item.Path);
                    }
                }
            }

            Console.WriteLine("# By Shining Ying. - 2022/05/01");
            //return (string.Join(", ", selected.ToArray()));

        }
    }
}