from pythonapp.Instance.Instance import Instance


class InstanceHandler:
    def __init__(self):
        self._loaded_instances: dict[str, Instance] = {}
        self._active_instance: Instance | None = None
        pass

    def _unknown_command(self, command: list[str]):
        command_str = ''
        for word in command: command_str += word + ' '
        raise ValueError(f"Unknown INSTANCE subcommand: {command_str}")

    def _create_handler(self, command: list[str]):
        if len(command) < 4: raise ValueError("CREATE INSTANCE: missing arguments")
        if command[1].upper() == "VENV":
            Instance(path=command[3], env=command[1].lower(), python=command[2]).create()

    def _activate_handler(self, command: list[str]):
        if len(command) != 2: raise ValueError("ACTIVATE INSTANCE: missing arguments")
        i = self._loaded_instances.get(command[1], None)
        if i: self._active_instance = i
        else: raise ValueError("ACTIVATE INSTANCE: instance not exists")

    def _load_handler(self, command: list[str]):
        if len(command) != 3: raise ValueError("LOAD INSTANCE: missing arguments")
        name = command[1]
        path = command[2]
        i = Instance(path)
        if not i.config.created:  raise ValueError("ACTIVATE INSTANCE: instance not exists")
        self._loaded_instances[name] = i
        self._active_instance = i
        print(f"instance {path} loaded and activated. identified by {name}")

    def _show_handler(self, command: list[str]):
        print("Environment type:", self._active_instance.config.env_type)

    def _install_handler(self, command: list[str]):
        if len(command) <= 2: raise ValueError("missing arguments")
        verb = command[1].lower()
        if verb == "package":
            args = command[2:]
            pkgs = []
            repo = None
            for arg in args:
                if arg.lower().startswith("repo:"): repo = arg[5:]
                else: pkgs.append(arg)
            self._active_instance.install_packages(pkgs, repo)

        if verb == "gitapp":
            app_extensions_dir: str = None
            app_models_dir: str = None
            app_output_dir: str = None
            app_input_dir: str = None
            app_user_dir: str = None
            req_file: str = 'requirements.txt'
            url = command[2]
            args = command[3:]

            for arg in args:
                if arg.lower().startswith("ext:"): app_extensions_dir = arg[4:]
                elif arg.lower().startswith("mod:"): app_models_dir = arg[4:]
                elif arg.lower().startswith("out:"): app_output_dir = arg[4:]
                elif arg.lower().startswith("inp:"): app_input_dir = arg[4:]
                elif arg.lower().startswith("usr:"): app_user_dir = arg[4:]
                elif arg.lower().startswith("req:"): req_file = arg[4:]

            self._active_instance.install_git_app(url, req_file, app_extensions_dir, app_models_dir, app_output_dir,
                                                  app_input_dir, app_user_dir)


    def handle(self, command: list[str]):
        if len(command) == 0: return

        verb = command[0].upper()

        if verb == "CREATE": self._create_handler(command)
        elif verb == "LOAD": self._load_handler(command)
        elif verb == "ACTIVATE": self._activate_handler(command)
        elif verb == "SHOW": self._show_handler(command)
        elif verb == "INSTALL": self._install_handler(command)

        else:
            self._unknown_command(command)
            return

        pass