feat: 保存当前使用的 Android 设备 (#22)

client/src/selected_android_device_service.py

@@ -0,0 +1,50 @@
+"""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