"""统一配置：从 .env / 环境变量读 MySQL、调度器、数据源开关等参数。"""
from __future__ import annotations

import os
from pathlib import Path
from typing import Optional

from pydantic_settings import BaseSettings, SettingsConfigDict

try:
    from dotenv import load_dotenv
    _HAS_DOTENV = True
except ImportError:
    _HAS_DOTENV = False


_PROJECT_ROOT = Path(__file__).resolve().parent.parent.parent

# 启动时自动把 .env 加载到 os.environ，使下游 `os.environ.get(...)` 代码
# （如 app/sources/mairui.py / xueqiu.py）能拿到 credentials。
if _HAS_DOTENV:
    _env_file = _PROJECT_ROOT / ".env"
    if _env_file.exists():
        load_dotenv(_env_file, override=False)


class Settings(BaseSettings):
    """应用配置。所有字段都可以通过环境变量或 .env 文件覆盖。"""

    # MySQL
    mysql_host: str = "127.0.0.1"
    mysql_port: int = 3306
    mysql_user: str = "root"
    mysql_password: str = ""
    # 同步任务写入的目标库（原始市场数据）
    mysql_database: str = "market_data_sync_db"
    # 简版库（对照测试，可选）
    mysql_database_lite: str = "grid_seeker"
    # 业务主库（保留— 同步任务不再写入）
    mysql_database_business: str = "grid_seeker_model_base"

    # Scheduler
    scheduler_tick_seconds: int = 5
    scheduler_timezone: str = "Asia/Shanghai"
    scheduler_auto_seed: bool = True

    # API
    api_host: str = "0.0.0.0"
    api_port: int = 8100

    # Logging
    log_level: str = "INFO"
    log_dir: str = "./logs"

    # Datasources
    ds_baostock_enabled: bool = True
    ds_sina_enabled: bool = True
    xueqiu_token: str = ""

    # Trading calendar
    trading_holidays: str = ""

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

    @property
    def project_root(self) -> Path:
        return _PROJECT_ROOT

    @property
    def log_path(self) -> Path:
        p = Path(self.log_dir)
        if not p.is_absolute():
            p = _PROJECT_ROOT / p
        p.mkdir(parents=True, exist_ok=True)
        return p

    @property
    def holidays_list(self) -> list[str]:
        if not self.trading_holidays:
            return []
        return [d.strip() for d in self.trading_holidays.split(",") if d.strip()]

    def mysql_url(self, database: Optional[str] = None) -> str:
        """构造 SQLAlchemy URL。"""
        db = database or self.mysql_database
        return (
            f"mysql+pymysql://{self.mysql_user}:{self.mysql_password}"
            f"@{self.mysql_host}:{self.mysql_port}/{db}?charset=utf8mb4"
        )

    def pymysql_connect_kwargs(self, database: Optional[str] = None) -> dict:
        """构造 pymysql.connect 的关键字参数。

        内网自签名证书场景自动禁用 SSL。
        """
        db = database or self.mysql_database
        return {
            "host": self.mysql_host,
            "port": self.mysql_port,
            "user": self.mysql_user,
            "password": self.mysql_password,
            "database": db,
            "charset": "utf8mb4",
            "autocommit": False,
            # 兼容自签名证书的内网 MySQL — 禁用 SSL
            "ssl": None,
        }


_settings: Optional[Settings] = None


def get_settings() -> Settings:
    """全局单例。"""
    global _settings
    if _settings is None:
        _settings = Settings()
    return _settings


settings = get_settings()