"""
公司定时调度服务 — 基于 APScheduler 周期执行公司项目
"""
from __future__ import annotations

import logging
from datetime import datetime
from typing import Optional

from apscheduler.schedulers.background import BackgroundScheduler
from apscheduler.triggers.cron import CronTrigger
from sqlalchemy.orm import Session

from app.models.company_schedule import CompanySchedule

logger = logging.getLogger(__name__)

# Global scheduler instance
_scheduler: Optional[BackgroundScheduler] = None


def get_scheduler() -> BackgroundScheduler:
    """获取全局调度器实例（懒初始化）。"""
    global _scheduler
    if _scheduler is None:
        _scheduler = BackgroundScheduler()
        _scheduler.start()
        logger.info("CompanyScheduler started")
    return _scheduler


def load_schedules(db: Session):
    """从数据库加载所有启用的调度并注册到调度器。"""
    sched = get_scheduler()
    schedules = db.query(CompanySchedule).filter(CompanySchedule.enabled.is_(True)).all()

    for cs in schedules:
        register_schedule(cs)

    logger.info("Loaded %d company schedules from database", len(schedules))


def register_schedule(cs: CompanySchedule):
    """将单个调度注册到 APScheduler。"""
    if not cs.cron_expression:
        logger.warning("Schedule %s has no cron expression, skipping", cs.id)
        return

    sched = get_scheduler()
    job_id = f"company_schedule_{cs.id}"

    # Remove existing job if any
    if sched.get_job(job_id):
        sched.remove_job(job_id)

    try:
        trigger = CronTrigger.from_crontab(cs.cron_expression)
        sched.add_job(
            _execute_scheduled_project,
            trigger=trigger,
            id=job_id,
            args=[cs.id],
            name=cs.name,
            replace_existing=True,
        )
        # Update next run time
        job = sched.get_job(job_id)
        if job and job.next_run_time:
            cs.next_run_at = job.next_run_time
        logger.info("Registered schedule: %s (cron: %s, next: %s)", cs.name, cs.cron_expression, cs.next_run_at)
    except Exception as e:
        logger.error("Failed to register schedule %s: %s", cs.id, e)


def unregister_schedule(schedule_id: str):
    """从调度器移除单个调度。"""
    sched = get_scheduler()
    job_id = f"company_schedule_{schedule_id}"
    if sched.get_job(job_id):
        sched.remove_job(job_id)
        logger.info("Unregistered schedule: %s", schedule_id)


def shutdown_scheduler():
    """关闭调度器。"""
    global _scheduler
    if _scheduler:
        _scheduler.shutdown(wait=False)
        _scheduler = None
        logger.info("CompanyScheduler shut down")


async def _execute_scheduled_project(schedule_id: str):
    """调度器回调：执行公司的定时项目。"""
    from app.core.database import SessionLocal
    from app.services.company_orchestrator import CompanyOrchestrator

    db = SessionLocal()
    try:
        cs = db.query(CompanySchedule).filter(CompanySchedule.id == schedule_id).first()
        if not cs or not cs.enabled:
            return

        logger.info("CompanyScheduler: Executing schedule '%s' for company %s", cs.name, cs.company_id)
        orchestrator = CompanyOrchestrator(db, cs.company_id, "system")
        result = await orchestrator.execute(cs.project_goal)

        cs.last_run_at = datetime.utcnow()
        db.commit()

        logger.info("CompanyScheduler: Schedule '%s' completed, success=%s", cs.name, result.get("success"))
    except Exception as e:
        logger.error("CompanyScheduler: Schedule '%s' failed: %s", schedule_id, e)
    finally:
        db.close()