from __future__ import annotations

import asyncio
import logging
import os
from datetime import datetime, timedelta, timezone

from apscheduler.schedulers.asyncio import AsyncIOScheduler
from apscheduler.triggers.interval import IntervalTrigger

from app.db import get_pool
from app.services.scraper import ScraperService

logger = logging.getLogger(__name__)
_scheduler = AsyncIOScheduler()
_scraper = ScraperService()
JOB_ID = "auto_scrape"


async def _run_auto_scrape() -> None:
    """爬取所有已注册模型。"""
    pool = get_pool()
    async with pool.acquire() as conn:
        cfg = await conn.fetchrow("SELECT * FROM scrape_schedule WHERE id = 1")

    if not cfg or not cfg["enabled"]:
        return

    async with pool.acquire() as conn:
        rows = await conn.fetch("SELECT url FROM models ORDER BY created_at")

    urls = [r["url"] for r in rows]
    if not urls:
        logger.info("[scheduler] 没有已注册的模型，跳过")
        return

    logger.info(f"[scheduler] 开始自动爬取 {len(urls)} 个模型")
    job_id_row = await pool.fetchrow(
        "INSERT INTO scrape_jobs (urls, status) VALUES ($1, 'pending') RETURNING id",
        urls,
    )
    asyncio.create_task(_scraper.run_job(str(job_id_row["id"]), urls, pool))


def _reschedule(interval_days: int, start_hour: int) -> None:
    if _scheduler.get_job(JOB_ID):
        _scheduler.remove_job(JOB_ID)
    # start_hour 是用户输入的本地时间（UTC+8），转换为 UTC
    tz_offset = int(os.environ.get("TZ_OFFSET_HOURS", "8"))
    start_hour_utc = (start_hour - tz_offset) % 24
    now = datetime.now(timezone.utc)
    next_run = now.replace(hour=start_hour_utc, minute=0, second=0, microsecond=0)
    if next_run <= now:
        next_run += timedelta(days=1)
    _scheduler.add_job(
        _run_auto_scrape,
        trigger=IntervalTrigger(days=interval_days, start_date=next_run),
        id=JOB_ID,
        replace_existing=True,
    )
    logger.info(f"[scheduler] 已设置每 {interval_days} 天本地 {start_hour}:00 (UTC {start_hour_utc}:00) 执行，下次: {next_run}")


async def start_scheduler() -> None:
    pool = get_pool()
    async with pool.acquire() as conn:
        cfg = await conn.fetchrow("SELECT * FROM scrape_schedule WHERE id = 1")
    interval = cfg["interval_days"] if cfg else 1
    start_hour = cfg["start_hour"] if cfg else 2
    _reschedule(interval, start_hour)
    _scheduler.start()
    logger.info("[scheduler] 调度器已启动")


async def stop_scheduler() -> None:
    if _scheduler.running:
        _scheduler.shutdown(wait=False)


def get_scheduler() -> AsyncIOScheduler:
    return _scheduler


def reschedule(interval_days: int, start_hour: int) -> None:
    _reschedule(interval_days, start_hour)