import platform
import subprocess
import time
import pyautogui
from PIL import Image

def get_window_list():
    """OSごとのウィンドウ一覧を取得"""
    os_type = platform.system()
    windows = []

    if os_type == "Windows":
        import pygetwindow as gw
        windows = [w.title for w in gw.getAllWindows() if w.title.strip()]
    
    elif os_type == "Darwin":  # macOS
        # AppleScriptを使って実行中のアプリケーション名を取得
        script = 'tell application "System Events" to get name of every process whose background only is false'
        proc = subprocess.run(['osascript', '-e', script], capture_output=True, text=True)
        windows = [name.strip() for name in proc.stdout.split(',')]

    elif os_type == "Linux":
        # wmctrlコマンドを利用するのが最も一般的
        try:
            res = subprocess.run(['wmctrl', '-l'], capture_output=True, text=True)
            for line in res.stdout.splitlines():
                parts = line.split(None, 3)
                if len(parts) >= 4:
                    windows.append(parts[3])
        except FileNotFoundError:
            print("Linuxで実行するには 'sudo apt-get install wmctrl' が必要です。")
            
    return windows

def focus_and_capture(target_title):
    os_type = platform.system()
    
    try:
        if os_type == "Windows":
            import pygetwindow as gw
            win = gw.getWindowsWithTitle(target_title)[0]
            win.activate()
            time.sleep(1)
            region = (win.left, win.top, win.width, win.height)

        elif os_type == "Darwin": # macOS
            # AppleScriptでアプリを前面に出す
            subprocess.run(['osascript', '-e', f'tell application "{target_title}" to activate'])
            time.sleep(1)
            # macOSはウィンドウ単位の座標取得が複雑なため、全画面を撮ってから手動で切り抜くか、
            # スクリーン全体をターゲットにするのが一般的です。
            print("macOSでは画面全体を撮影します。")
            region = None 

        elif os_type == "Linux":
            # wmctrlでウィンドウをアクティブ化
            subprocess.run(['wmctrl', '-a', target_title])
            time.sleep(1)
            # xwininfoなどで座標取得可能だが、ここでは簡易的に全体撮影を例示
            region = None

        # 撮影
        ss = pyautogui.screenshot(region=region)
        filename = f"ss_{int(time.time())}.png"
        ss.save(filename)
        print(f"保存成功: {filename}")

    except Exception as e:
        print(f"エラーが発生しました: {e}")

if __name__ == "__main__":
    titles = get_window_list()
    for i, t in enumerate(titles):
        print(f"[{i+1}] {t}")
    
    idx = int(input("\n番号を選んでください: ")) - 1
    focus_and_capture(titles[idx])