import win32gui
import win32process
import win32con
import win32api
import threading
from typing import Callable
import psutil


def get_active_window() -> str:
    """Returns a string like 'YouTube - Chrome (chrome.exe)'"""
    try:
        hwnd = win32gui.GetForegroundWindow()
        title = win32gui.GetWindowText(hwnd) or "Unknown Window"

        # Get process name
        _, pid = win32process.GetWindowThreadProcessId(hwnd)
        try:
            proc = psutil.Process(pid)
            exe_name = proc.name()
        except (psutil.NoSuchProcess, psutil.AccessDenied, psutil.ZombieProcess):
            exe_name = "unknown.exe"

        return f"{title} ({exe_name})"
    except Exception:
        return "Error getting window info"


def register_session_listener(callback: Callable[[str], None]) -> None:
    """Register a callback for Windows session lock/unlock events"""

    def session_event_handler(hwnd, msg, wparam, lparam):
        # Fallback numeric constants
        WM_WTSSESSION_CHANGE = 0x02B1
        WTS_SESSION_LOCK = 0x1
        WTS_SESSION_UNLOCK = 0x2

        if msg == WM_WTSSESSION_CHANGE:
            if wparam == WTS_SESSION_LOCK:
                callback("locked")
            elif wparam == WTS_SESSION_UNLOCK:
                callback("unlocked")

        return win32gui.DefWindowProc(hwnd, msg, wparam, lparam)

    def run_message_loop():
        hinst = win32api.GetModuleHandle(None)
        wndclass = win32gui.WNDCLASS()
        wndclass.hInstance = hinst
        wndclass.lpszClassName = "SessionWatcher"
        wndclass.lpfnWndProc = session_event_handler

        try:
            win32gui.RegisterClass(wndclass)
        except:
            pass  # Already registered

        hwnd = win32gui.CreateWindow(
            wndclass.lpszClassName,
            "Session Watcher",
            0, 0, 0, 0, 0,
            0, 0, hinst, None
        )

        # Register for session notifications
        try:
            from win32ts import WTSRegisterSessionNotification
            WTSRegisterSessionNotification(hwnd, 1)
        except ImportError:
            pass

        win32gui.PumpMessages()

    thread = threading.Thread(target=run_message_loop, daemon=True)
    thread.start()


def get_idle_time() -> int:
    """Get the system idle time in seconds on Windows"""
    from ctypes import Structure, windll, c_uint, sizeof, byref

    class LASTINPUTINFO(Structure):
        _fields_ = [('cbSize', c_uint), ('dwTime', c_uint)]

    lastInputInfo = LASTINPUTINFO()
    lastInputInfo.cbSize = sizeof(lastInputInfo)
    windll.user32.GetLastInputInfo(byref(lastInputInfo))

    millis = windll.kernel32.GetTickCount() - lastInputInfo.dwTime
    return millis // 1000