"""全局配置：路径、数据库、并发参数等。"""
from __future__ import annotations

import os
from pathlib import Path
from pydantic import Field
from pydantic_settings import BaseSettings, SettingsConfigDict


# 默认数据目录：放在 backend/.data 下，便于零配置启动
_BACKEND_ROOT = Path(__file__).resolve().parents[2]
_DEFAULT_DATA_DIR = _BACKEND_ROOT / ".data"


class Settings(BaseSettings):
    """读取 .env 与环境变量的全局配置。"""

    model_config = SettingsConfigDict(
        env_file=str(_BACKEND_ROOT / ".env"),
        env_file_encoding="utf-8",
        extra="ignore",
    )

    # 应用基础
    app_name: str = "snapAna"
    debug: bool = False
    host: str = "127.0.0.1"
    port: int = 8765

    # 数据目录
    data_dir: Path = Field(default=_DEFAULT_DATA_DIR)

    # 任务并发
    analyze_concurrency: int = 4
    max_retries: int = 3

    # 缩略图
    thumb_size: int = 320
    vlm_max_side: int = 1280  # 上传 VLM 前压缩的长边像素

    # CORS
    cors_origins: list[str] = ["http://localhost:5173", "http://127.0.0.1:5173"]

    @property
    def db_path(self) -> Path:
        """SQLite 数据库文件路径。"""
        return self.data_dir / "snapana.db"

    @property
    def db_url(self) -> str:
        """SQLAlchemy 连接串。"""
        return f"sqlite:///{self.db_path.as_posix()}"

    @property
    def thumb_dir(self) -> Path:
        """缩略图缓存目录。"""
        return self.data_dir / "thumbs"

    def ensure_dirs(self) -> None:
        """确保所有运行期目录存在。"""
        self.data_dir.mkdir(parents=True, exist_ok=True)
        self.thumb_dir.mkdir(parents=True, exist_ok=True)


settings = Settings()
settings.ensure_dirs()