def classify_command(command: str) -> str:
    """
    Classifies a user's command into categories for action or AI response.

    Args:
        command (str): User's input text.

    Returns:
        str: Command type (e.g. 'open_app', 'screenshot', 'create_file', etc.)
    """
    command = command.lower()

    # --- Application control ---
    if "open" in command and any(app in command for app in ["chrome", "firefox", "notepad", "calculator", "edge", "terminal", "vscode"]):
        return "open_app"
    elif "close" in command and any(app in command for app in ["chrome", "firefox", "notepad", "calculator", "edge", "terminal", "vscode"]):
        return "close_app"

    # --- File system operations ---
    if "create" in command and "file" in command:
        return "create_file"
    elif "delete" in command and "file" in command:
        return "delete_file"
    elif "read" in command and "file" in command:
        return "read_file"
    elif "write" in command and "file" in command:
        return "write_file"

    # --- System commands ---
    if "screenshot" in command or "screen shot" in command:
        return "screenshot"
    if "shutdown" in command:
        return "shutdown"
    if "restart" in command:
        return "restart"
    if "lock" in command:
        return "lock_computer"

    # --- Internet-related ---
    if "search" in command or "what is" in command or "who is" in command:
        return "web_search"
    if "open" in command and ".com" in command:
        return "open_website"

    # --- AI Assistant Query ---
    return "chat"