from datetime import datetime, timedelta
from app.db import SessionLocal, RequestLog
from sqlalchemy import func

# 全局变量，记录启动时间
START_TIME = datetime.utcnow()

class SystemStats:
    def __init__(self):
        pass

    def get_uptime(self) -> str:
        delta = datetime.utcnow() - START_TIME
        days = delta.days
        hours, remainder = divmod(delta.seconds, 3600)
        minutes, seconds = divmod(remainder, 60)
        if days > 0:
            return f"{days}天 {hours}小时"
        elif hours > 0:
            return f"{hours}小时 {minutes}分"
        else:
            return f"{minutes}分 {seconds}秒"

    def get_today_count(self) -> int:
        session = SessionLocal()
        try:
            today_start = datetime.utcnow().replace(hour=0, minute=0, second=0, microsecond=0)
            count = session.query(func.count(RequestLog.id)).filter(RequestLog.received_at >= today_start).scalar()
            return count or 0
        finally:
            session.close()

    def get_latest_log_time(self) -> str:
        session = SessionLocal()
        try:
            log = session.query(RequestLog).order_by(RequestLog.received_at.desc()).first()
            if log:
                # 简单转为本地时间显示（+8）
                dt = log.received_at + timedelta(hours=8)
                return dt.strftime("%H:%M:%S")
            return "无"
        finally:
            session.close()

stats_service = SystemStats()