"""当前使用 Android 设备的本地设置服务。"""

from .settings_repository import SettingsRepository


SELECTED_ANDROID_SERIAL_KEY = "android.selected_serial"
MAX_ANDROID_SERIAL_LENGTH = 255


class SelectedAndroidDeviceService:
    """只保存自动化应使用的设备号，不缓存 ADB 搜索结果。"""

    def __init__(self, repository: SettingsRepository):
        self._repository = repository

    def load(self) -> str:
        """读取已保存设备号；缺失或损坏时返回空字符串。"""

        value = self._repository.get(SELECTED_ANDROID_SERIAL_KEY, "")
        if not isinstance(value, str):
            return ""
        return value.strip()

    def save(self, serial: str) -> str:
        """校验并保存设备号，返回规范化后的值。"""

        normalized = self._normalize_serial(serial)
        self._repository.set(SELECTED_ANDROID_SERIAL_KEY, normalized)
        return normalized

    def delete(self) -> bool:
        """清除当前设备配置；配置不存在时也视为安全完成。"""

        return self._repository.delete(SELECTED_ANDROID_SERIAL_KEY)

    @staticmethod
    def _normalize_serial(serial: object) -> str:
        if not isinstance(serial, str):
            raise ValueError("Android 设备号必须是文本")

        normalized = serial.strip()
        if not normalized:
            raise ValueError("Android 设备号不能为空")
        if len(normalized) > MAX_ANDROID_SERIAL_LENGTH:
            raise ValueError(
                f"Android 设备号最多 {MAX_ANDROID_SERIAL_LENGTH} 个字符"
            )
        if any(character.isspace() for character in normalized):
            raise ValueError("Android 设备号不能包含空白字符")
        return normalized