;; ウィンドウタイトルを部分一致で検索
SetTitleMatchMode, 2
;; Focus to Emacs
WinActivate, Emacs ahk_exe vcxsrv.exe

Focus(z){
   static past ; saves the last z parameter passed
   windows := AltTabWindows()

   if (z = "next") {
      static next, count

      if (z != past || next > windows.length()) {
         loop % windows.length()
            next := A_Index+1
         until (WinActive("A") = windows[A_Index])
         past := z
         WinActivate, % "ahk_id" windows[next]
         return windows[next]
      } else if (next < windows.length()) {
         next++, count++
         past := z
         WinActivate, % "ahk_id" windows[next]
         return windows[next]
      } else if (next = windows.length()) {
         count--
         past := z
         if (count = 0)
            past := "reset"
         WinActivate, % "ahk_id" windows[next]
         return windows[next]
      }
   }

   if (z = "recent") {
      loop % windows.length()
         recent := A_Index+1
      until (WinActive("A") == windows[A_Index])
      past := z
      return windows[recent]

      ; WinActivate, % "ahk_id" windows[recent]
      ; return windows[recent] 

   }

   if (z ~= "(?i)^bot") {
      past := z
      WinActivate, % "ahk_id" windows[windows.length()]
      return windows[windows.length()]
   }

   if (z is integer) {
      past := z
      WinActivate, % "ahk_id" windows[z]
      return windows[z]
   }
}

AltTabWindows() { ; modernized, original by ophthalmos https://www.autohotkey.com/boards/viewtopic.php?t=13288
   static WS_EX_APPWINDOW :=      0x40000 ; has a taskbar button
   static WS_EX_TOOLWINDOW :=        0x80 ; does not appear on the Alt-Tab list
   static GW_OWNER :=                   4 ; identifies as the owner window

   AltTabList := {}
   windowList := ""
   DetectHiddenWindows, Off ; makes DllCall("IsWindowVisible") unnecessary
   WinGet, windowList, List ; gather a list of running programs

   Loop, %windowList% {
      ownerID := windowID := windowList%A_Index% + 0 ; format as an unsigned integer
      Loop ; gets the hWnd of the top-most parent if the window is a child window.
         ownerID := DllCall("GetWindow", "uint", ownerID, "uint", GW_OWNER)
      Until !DllCall("GetWindow", "uint", ownerID, "uint", GW_OWNER)
      ownerID := ownerID ? ownerID : windowID

      If (DllCall("GetLastActivePopup", "uint", ownerID) = windowID) {
         WinGet, es, ExStyle, ahk_id %windowID%
         ; Must appear on the Alt+Tab list, have a taskbar button, and not be a Windows 10 background app.
         If (!((es & WS_EX_TOOLWINDOW) && !(es & WS_EX_APPWINDOW)) && !IsInvisibleWin10BackgroundAppWindow(windowID))
            AltTabList.Push(Format("0x{:x}", windowID))
      }
   }

   return AltTabList
}

IsInvisibleWin10BackgroundAppWindow(hWindow) {
   result := 0
   VarSetCapacity(cloakedVal, A_PtrSize) ; DWMWA_CLOAKED := 14
   hr := DllCall("DwmApi\DwmGetWindowAttribute", "ptr", hWindow, "uint", 14, "ptr", &cloakedVal, "uint", A_PtrSize)
   if !hr ; returns S_OK (which is zero) on success. Otherwise, it returns an HRESULT error code
      result := NumGet(cloakedVal) ; omitting the "&" performs better
   return result ? true : false
}

/*
DWMWA_CLOAKED: If the window is cloaked, the following values explain why:
1  The window was cloaked by its owner application (DWM_CLOAKED_APP)
2  The window was cloaked by the Shell (DWM_CLOAKED_SHELL)
4  The cloak value was inherited from its owner window (DWM_CLOAKED_INHERITED)
*/


out := 0 
stdout := FileOpen("*", "w", "UTF-8")
stdout.WriteLine(Focus("recent"))
FileAppend % var,  * ; StdOut
stdout.Close()
 
ExitApp % out