"""
配置包：只读环境变量，组装 Settings。

本文件职责：集中声明 YTD_ENV、端口、企微与库变量名（对齐 prompt/13、09）。
禁止：在本包写业务 if/else；禁止把密钥默认值写进源码。
"""

from __future__ import annotations

from functools import lru_cache
from pathlib import Path

from pydantic import Field
from pydantic_settings import BaseSettings, SettingsConfigDict


def _find_dotenv() -> str:
    """自 agent 目录向上找仓库根 .env；找不到则返回空，由环境变量本身提供。"""
    here = Path(__file__).resolve()
    for parent in here.parents:
        candidate = parent / ".env"
        if candidate.is_file():
            return str(candidate)
    return ""


class Settings(BaseSettings):
    """
    进程级只读配置。

    调用时机：HTTP / Worker 启动时通过 get_settings() 加载一次。
    企微密钥必须来自环境/.env，源码中不得出现明文 Secret。
    """

    model_config = SettingsConfigDict(
        env_file=_find_dotenv() or None,
        env_file_encoding="utf-8",
        extra="ignore",
    )

    ytd_env: str = Field(default="test", alias="YTD_ENV")
    agent_http_port: int = Field(default=8910, alias="AGENT_HTTP_PORT")
    public_base_url: str = Field(default="", alias="PUBLIC_BASE_URL")
    biz_api_base_url: str = Field(default="http://127.0.0.1:8180", alias="BIZ_API_BASE_URL")
    agent_callback_token: str = Field(default="", alias="AGENT_CALLBACK_TOKEN")

    # 企微询价应用（与正式同一套应用 ID；密钥只从环境读）
    wecom_corp_id: str = Field(default="", alias="WECOM_CORP_ID")
    wecom_agent_id: str = Field(default="1000010", alias="WECOM_AGENT_ID")
    wecom_secret: str = Field(default="", alias="WECOM_SECRET")
    wecom_callback_token: str = Field(default="", alias="WECOM_CALLBACK_TOKEN")
    wecom_encoding_aes_key: str = Field(default="", alias="WECOM_ENCODING_AES_KEY")
    wecom_callback_reply_text: str = Field(
        default="询价智能体接通成功。已收到：{content}",
        alias="WECOM_CALLBACK_REPLY_TEXT",
    )
    # 本机注入开关：test 默认开；prod 默认关
    dev_inject_enabled: bool = Field(default=False, alias="DEV_INJECT_ENABLED")

    pg_host: str = Field(default="", alias="PG_HOST")
    pg_port: int = Field(default=5432, alias="PG_PORT")
    pg_database: str = Field(default="", alias="PG_DATABASE")
    pg_user: str = Field(default="", alias="PG_USER")
    pg_password: str = Field(default="", alias="PG_PASSWORD")
    redis_url: str = Field(default="", alias="REDIS_URL")
    redis_key_prefix: str = Field(default="inquiry_robot:", alias="REDIS_KEY_PREFIX")

    libreoffice_slots: int = Field(default=1, alias="LIBREOFFICE_SLOTS")
    http_job_slots: int = Field(default=3, alias="HTTP_JOB_SLOTS")


@lru_cache(maxsize=1)
def get_settings() -> Settings:
    """返回进程内单例 Settings。副作用：首次可能读 .env。"""
    return Settings()