"""公共工具 — 消除各模块间的重复代码。"""

from __future__ import annotations

from datetime import datetime, timezone
from pathlib import Path
from zoneinfo import ZoneInfo

import httpx
from fastapi.templating import Jinja2Templates

from app.config import settings

# ── 路径常量 ──────────────────────────────────────────────────────────

DATA_DIR = Path("data")
PAPERS_DIR = DATA_DIR / "papers"
TMP_DIR = DATA_DIR / "tmp"

# ── 模板单例 ──────────────────────────────────────────────────────────

templates = Jinja2Templates(directory="app/templates")


# ── 时区工具 ──────────────────────────────────────────────────────────


def today_str() -> str:
    """当前日期字符串（按 APP_TIMEZONE）。"""
    tz = ZoneInfo(settings.APP_TIMEZONE)
    return datetime.now(tz).strftime("%Y-%m-%d")


# ── 锁释放 ────────────────────────────────────────────────────────────


def release_lock(db, lock) -> None:
    """释放 TaskLock。"""
    try:
        lock.status = "finished"
        lock.released_at = datetime.now(timezone.utc)
        db.commit()
    except Exception:
        db.rollback()


# ── HTTP 客户端工厂 ───────────────────────────────────────────────────


def make_http_client(*, sync: bool = False, follow_redirects: bool = False, **kwargs) -> httpx.AsyncClient | httpx.Client:
    """创建带 proxy 和默认配置的 httpx 客户端。

    Args:
        sync: True 返回同步 Client，False 返回 AsyncClient
        follow_redirects: 是否跟随重定向
        **kwargs: 覆盖默认参数
    """
    defaults: dict = {
        "timeout": settings.HTTP_TIMEOUT_SECONDS,
        "headers": {"User-Agent": settings.HTTP_USER_AGENT},
        "follow_redirects": follow_redirects,
    }
    if settings.http_proxy:
        defaults["transport"] = (
            httpx.HTTPTransport(proxy=settings.http_proxy)
            if sync
            else httpx.AsyncHTTPTransport(proxy=settings.http_proxy)
        )
    defaults.update(kwargs)

    if sync:
        return httpx.Client(**defaults)
    return httpx.AsyncClient(**defaults)