using System.Collections.Generic;
using System;
using System.Diagnostics;
using System.Text;
using mRemoteNG.App;
using mRemoteNG.Tools.Cmdline;

namespace mRemoteNG.Tools
{
	public class ProcessController
	{
        #region Public Methods
		public bool Start(string fileName, CommandLineArguments arguments = null)
		{
			Process.StartInfo.UseShellExecute = false;
			Process.StartInfo.FileName = fileName;
			if (arguments != null)
				Process.StartInfo.Arguments = arguments.ToString();
				
			if (!Process.Start())
				return false;
			GetMainWindowHandle();
				
			return true;
		}
			
		public bool SetControlVisible(string className, string text, bool visible = true)
		{
			if (Process == null || Process.HasExited)
				return false;
			if (Handle == IntPtr.Zero)
				return false;
				
			var controlHandle = GetControlHandle(className, text);
			if (controlHandle == IntPtr.Zero)
				return false;

		    var nCmdShow = visible ? NativeMethods.SW_SHOW : NativeMethods.SW_HIDE;
            NativeMethods.ShowWindow(controlHandle, (int)nCmdShow);
			return true;
		}
			
		public bool SetControlText(string className, string oldText, string newText)
		{
			if (Process == null || Process.HasExited || Handle == IntPtr.Zero)
				return false;

			var controlHandle = GetControlHandle(className, oldText);
			if (controlHandle == IntPtr.Zero)
				return false;
				
			var result = NativeMethods.SendMessage(controlHandle, NativeMethods.WM_SETTEXT, (IntPtr)0, new StringBuilder(newText));
			return result.ToInt32() == NativeMethods.TRUE;
		}
			
		public bool SelectListBoxItem(string itemText)
		{
			if (Process == null || Process.HasExited || Handle == IntPtr.Zero)
				return false;
				
			var listBoxHandle = GetControlHandle("ListBox");
			if (listBoxHandle == IntPtr.Zero)
				return false;
				
			var result = NativeMethods.SendMessage(listBoxHandle, NativeMethods.LB_SELECTSTRING, (IntPtr)(-1), new StringBuilder(itemText));
			return result.ToInt32() != NativeMethods.LB_ERR;
		}
			
		public bool ClickButton(string text)
		{
			if (Process == null || Process.HasExited || Handle == IntPtr.Zero)
				return false;
				
			var buttonHandle = GetControlHandle("Button", text);
			if (buttonHandle == IntPtr.Zero)
				return false;

            var buttonControlId = NativeMethods.GetDlgCtrlID(buttonHandle);
            NativeMethods.SendMessage(Handle, NativeMethods.WM_COMMAND, (IntPtr)buttonControlId, buttonHandle);
				
			return true;
		}
			
		public void WaitForExit()
		{
			if (Process == null || Process.HasExited)
				return;
			Process.WaitForExit();
		}
#endregion
			
        #region Protected Fields

	    private readonly Process Process = new Process();
        private IntPtr Handle = IntPtr.Zero;
        private List<IntPtr> Controls = new List<IntPtr>();
        #endregion

        #region Protected Methods
	    // ReSharper disable once UnusedMethodReturnValue.Local
        private IntPtr GetMainWindowHandle()
		{
			if (Process == null || Process.HasExited)
				return IntPtr.Zero;
			
			Process.WaitForInputIdle(Settings.Default.MaxPuttyWaitTime * 1000);
			
			Handle = IntPtr.Zero;
			var startTicks = Environment.TickCount;
            while (Handle == IntPtr.Zero && Environment.TickCount < startTicks + (Settings.Default.MaxPuttyWaitTime * 1000))
			{
				Process.Refresh();
				Handle = Process.MainWindowHandle;
				if (Handle == IntPtr.Zero)
				{
					System.Threading.Thread.Sleep(0);
				}
			}
				
			return Handle;
		}

        private IntPtr GetControlHandle(string className, string text = "")
		{
			if (Process == null || Process.HasExited || Handle == IntPtr.Zero)
				return IntPtr.Zero;
				
			if (Controls.Count == 0)
			{
                var windowEnumerator = new EnumWindows();
                Controls = windowEnumerator.EnumChildWindows(Handle);
			}

            var stringBuilder = new StringBuilder();
			var controlHandle = IntPtr.Zero;
			foreach (var control in Controls)
			{
				NativeMethods.GetClassName(control, stringBuilder, stringBuilder.Capacity);
			    if (stringBuilder.ToString() != className) continue;
			    if (string.IsNullOrEmpty(text))
			    {
			        controlHandle = control;
			        break;
			    }
			    else
			    {
			        NativeMethods.SendMessage(control, NativeMethods.WM_GETTEXT, new IntPtr(stringBuilder.Capacity), stringBuilder);
			        if (stringBuilder.ToString() != text) continue;
			        controlHandle = control;
			        break;
			    }
			}
				
			return controlHandle;
		}
        #endregion
	}
}