"""MeshSafe 定时任务调度器 — 零依赖，Docker 容器前台常驻。

和 api 共享同一个镜像，容器 entrypoint 换成本脚本即可。
用法: docker run meshsafe:latest python3 scripts/cron_entrypoint.py

支持的任务:
  每天 03:00 归档 + 清理 DB (archive_old_tasks.py --apply)
  每周一 03:10 VACUUM ANALYZE (维护表统计信息)
"""
from __future__ import annotations

import logging
import os
import subprocess
import sys
import time
from datetime import datetime, timedelta

sys.path.insert(0, "/app")

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(message)s",
)
log = logging.getLogger("scheduler")


def run(cmd: list[str], label: str) -> None:
    """跑一个命令，捕获输出并记日志。"""
    log.info(f"[{label}] 开始执行: {' '.join(cmd)}")
    try:
        proc = subprocess.run(cmd, capture_output=True, text=True, timeout=1800)
        if proc.stdout:
            for line in proc.stdout.strip().splitlines():
                log.info(f"[{label}] {line}")
        if proc.stderr:
            for line in proc.stderr.strip().splitlines():
                log.warning(f"[{label}] {line}")
        if proc.returncode == 0:
            log.info(f"[{label}] ✅ 完成")
        else:
            log.error(f"[{label}] ❌ 返回码 {proc.returncode}")
    except subprocess.TimeoutExpired:
        log.error(f"[{label}] ❌ 超时 (30min)")
    except Exception as e:
        log.error(f"[{label}] ❌ 异常: {e}")


def run_vacuum() -> None:
    """VACUUM ANALYZE — 维护表统计信息。"""
    try:
        from app.db import engine
        from sqlalchemy import text

        tables = [
            "scan_tasks", "scan_tasks_archive",
            "scan_findings", "idempotency_records",
            "policy_versions", "audit_logs",
        ]
        with engine.begin() as conn:
            for tbl in tables:
                log.info(f"[VACUUM] {tbl} ...")
                conn.execute(text(f"VACUUM ANALYZE {tbl}"))
        log.info("[VACUUM] ✅ 全部完成")
    except Exception as e:
        log.error(f"[VACUUM] ❌ 异常: {e}")


def seconds_until(target_hour: int, target_minute: int, weekday: int | None = None) -> float:
    """计算到下次目标时间的秒数。

    weekday: 0=周一...6=周日, None=每天
    """
    now = datetime.now()
    candidate = now.replace(hour=target_hour, minute=target_minute, second=0, microsecond=0)

    if weekday is not None:
        # 找到本周目标日
        days_ahead = weekday - now.weekday()
        if days_ahead < 0 or (days_ahead == 0 and now >= candidate):
            days_ahead += 7
        candidate += timedelta(days=days_ahead)
    else:
        if candidate <= now:
            candidate += timedelta(days=1)

    return (candidate - now).total_seconds()


def main() -> None:
    log.info("=" * 60)
    log.info("MeshSafe 定时任务调度器启动")
    log.info(f"PID={os.getpid()}  TZ=Asia/Shanghai")
    log.info("任务:")
    log.info("  - 每天 03:00  archive_old_tasks.py --apply")
    log.info("  - 每周一 03:10 VACUUM ANALYZE")
    log.info("=" * 60)

    while True:
        # 计算两个任务下次执行时间，取更早的那个
        secs_archive = seconds_until(3, 0, weekday=None)      # 每天 03:00
        secs_vacuum = seconds_until(3, 10, weekday=0)          # 周一 03:10

        if secs_archive <= secs_vacuum:
            log.info(f"下一个任务: 归档 → {secs_archive/3600:.1f}h 后")
            time.sleep(secs_archive)
            run(
                [sys.executable, "/app/scripts/archive_old_tasks.py", "--apply"],
                "ARCHIVE",
            )
            # 跑完后清下一次时间 (避免在 03:00 这一刻两个任务重叠)
            continue
        else:
            log.info(f"下一个任务: VACUUM → {secs_vacuum/3600:.1f}h 后")
            time.sleep(secs_vacuum)
            run_vacuum()
            continue


if __name__ == "__main__":
    main()