import os
import sys
import time

import pygame
import screen_brightness_control as sbc

# Windows-only calls are guarded so the module still imports on other OSes.
try:
    import ctypes
    from ctypes import wintypes
except Exception:
    ctypes = None


def resource_path(rel):
    """Absolute path to a bundled resource, works both from source and from a
    PyInstaller-frozen exe (sys._MEIPASS)."""
    base = getattr(sys, "_MEIPASS", os.path.dirname(os.path.abspath(__file__)))
    return os.path.join(base, rel)


# ---------------------------------------------------------------------------
# Brightness — handle EVERY monitor, not just the first one
# ---------------------------------------------------------------------------
def get_all_brightness():
    """Return a list with one brightness value per monitor, or None on failure."""
    try:
        vals = sbc.get_brightness()
    except Exception:
        return None
    if isinstance(vals, list):
        return list(vals) if vals else None
    return [vals]


def set_all_brightness(value):
    """Set brightness on ALL monitors at once."""
    try:
        sbc.set_brightness(int(value))
        return True
    except Exception:
        return False


def restore_all_brightness(original):
    """Restore each monitor to its previously saved brightness."""
    if not original:
        return
    for i, b in enumerate(original):
        try:
            sbc.set_brightness(int(b), display=i)
        except Exception:
            pass


# ---------------------------------------------------------------------------
# Window geometry — cover the whole virtual desktop (all monitors)
# ---------------------------------------------------------------------------
def get_virtual_screen_rect():
    """Bounding rectangle of all monitors combined (may start at negative x/y)."""
    user32 = ctypes.windll.user32
    try:
        user32.SetProcessDPIAware()
    except Exception:
        pass
    SM_XVIRTUALSCREEN = 76
    SM_YVIRTUALSCREEN = 77
    SM_CXVIRTUALSCREEN = 78
    SM_CYVIRTUALSCREEN = 79
    x = user32.GetSystemMetrics(SM_XVIRTUALSCREEN)
    y = user32.GetSystemMetrics(SM_YVIRTUALSCREEN)
    w = user32.GetSystemMetrics(SM_CXVIRTUALSCREEN)
    h = user32.GetSystemMetrics(SM_CYVIRTUALSCREEN)
    if w <= 0 or h <= 0:  # fallback to primary monitor
        w = user32.GetSystemMetrics(0)  # SM_CXSCREEN
        h = user32.GetSystemMetrics(1)  # SM_CYSCREEN
        x = y = 0
    return x, y, w, h


def make_window_cover_all_monitors(hwnd, rect):
    """Move/resize the window to the virtual-screen rect and pin it topmost so it
    sits above the taskbar and every monitor."""
    user32 = ctypes.windll.user32
    HWND_TOPMOST = -1
    x, y, w, h = rect
    user32.SetWindowPos(int(hwnd), HWND_TOPMOST, x, y, w, h, 0)
    try:
        user32.SetForegroundWindow(int(hwnd))
    except Exception:
        pass


def main():
    # --- brightness: save every monitor, then dim them all to 0 ---
    original_brightness = get_all_brightness()
    if original_brightness is not None:
        set_all_brightness(0)

    # --- black screen over the whole virtual desktop ---
    pygame.init()

    if sys.platform == "win32" and ctypes is not None:
        x, y, w, h = get_virtual_screen_rect()
    else:
        info = pygame.display.Info()
        x, y, w, h = 0, 0, info.current_w, info.current_h

    screen = pygame.display.set_mode((w, h), pygame.NOFRAME)
    pygame.display.set_caption("Black Screen Dim")

    try:
        icon = pygame.image.load(resource_path("icon.ico"))
        pygame.display.set_icon(icon)
    except Exception:
        pass

    pygame.mouse.set_visible(False)

    # Pin the borderless window across all monitors and bring it to front.
    if sys.platform == "win32" and ctypes is not None:
        try:
            hwnd = pygame.display.get_wm_info().get("window")
            if hwnd:
                make_window_cover_all_monitors(hwnd, (x, y, w, h))
        except Exception:
            pass

    font = pygame.font.SysFont(None, 48)
    hint_text = "ESC - exit"
    text_surf = font.render(hint_text, True, (255, 255, 255))
    text_rect = text_surf.get_rect(center=(w // 2, h // 2))
    show_hint_until = time.time() + 1.0  # ~1 second

    running = True
    while running:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
            if event.type == pygame.KEYDOWN and event.key == pygame.K_ESCAPE:
                running = False

        screen.fill((0, 0, 0))
        if time.time() < show_hint_until:
            screen.blit(text_surf, text_rect)

        pygame.display.flip()

    # --- exit: restore every monitor's brightness and the cursor ---
    if original_brightness is not None:
        restore_all_brightness(original_brightness)

    try:
        pygame.mouse.set_visible(True)
    except Exception:
        pass

    pygame.quit()
    sys.exit()


if __name__ == "__main__":
    main()