from dataclasses import dataclass, field
from pathlib import Path

PROJECT_ROOT = Path(__file__).resolve().parents[2]


@dataclass(frozen=True)
class AppSettings:
    """FastAPI 基础配置。"""

    title: str = "Raspberry Pi Camera API"
    version: str = "0.1.0"
    description: str = "用于树莓派相机抓拍的 FastAPI 服务。"
    host: str = "0.0.0.0"
    port: int = 8002


@dataclass(frozen=True)
class CameraSettings:
    """树莓派相机配置。"""

    camera_index: int = 0
    width: int = 2048
    height: int = 2048
    frame_format: str = "RGB888"
    jpeg_quality: int = 95
    warmup_seconds: float = 0.05
    enable_continuous_autofocus: bool = True
    enable_auto_white_balance: bool = True


@dataclass(frozen=True)
class MqttSettings:
    """MQTT 配置。"""

    broker: str = "192.168.77.132"
    port: int = 1883
    keep_alive_interval: int = 60
    client_id_prefix: str = "arm_camera_api_"
    request_timeout_seconds: float = 40.0
    connect_timeout_seconds: float = 5.0
    default_cycles: int = 1
    command_topic: str = "arm_card_dealer/command"
    camera_response_topic: str = "arm_card_dealer/camera/response"
    status_topic: str = "arm_card_dealer/status"
    error_topic: str = "arm_card_dealer/error"
    camera_command_topic: str = "arm_card_dealer/camera/command"


@dataclass(frozen=True)
class StaticSettings:
    """静态目录配置。"""

    root_dir: Path = field(default_factory=lambda: PROJECT_ROOT / "static")
    capture_dir_name: str = "captures"
    front_filename: str = "1.jpg"
    back_filename: str = "2.jpg"
    index_filename: str = "index.html"

    @property
    def capture_dir(self) -> Path:
        return self.root_dir / self.capture_dir_name

    @property
    def front_image_path(self) -> Path:
        return self.capture_dir / self.front_filename

    @property
    def back_image_path(self) -> Path:
        return self.capture_dir / self.back_filename

    @property
    def front_relative_path(self) -> Path:
        return Path(self.capture_dir_name) / self.front_filename

    @property
    def back_relative_path(self) -> Path:
        return Path(self.capture_dir_name) / self.back_filename

    @property
    def index_path(self) -> Path:
        return self.root_dir / self.index_filename

    def ensure_directories(self) -> None:
        self.capture_dir.mkdir(parents=True, exist_ok=True)


@dataclass(frozen=True)
class Settings:
    """项目总配置。"""

    app: AppSettings = field(default_factory=AppSettings)
    camera: CameraSettings = field(default_factory=CameraSettings)
    mqtt: MqttSettings = field(default_factory=MqttSettings)
    static: StaticSettings = field(default_factory=StaticSettings)


settings = Settings()