from typing import List
from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session
from sqlalchemy import desc, func
from app.db.session import get_db
from app.models.monitor import Monitor, UptimeCheck
from app.models.schemas import (
    MonitorCreate,
    MonitorUpdate,
    MonitorResponse,
    UptimeCheckResponse,
    MonitorStats,
)

router = APIRouter(prefix="/monitors", tags=["monitors"])


@router.post("/", response_model=MonitorResponse)
def create_monitor(monitor: MonitorCreate, db: Session = Depends(get_db)):
    db_monitor = Monitor(**monitor.dict())
    db.add(db_monitor)
    db.commit()
    db.refresh(db_monitor)
    return db_monitor


@router.get("/", response_model=List[MonitorResponse])
def get_monitors(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
    monitors = db.query(Monitor).offset(skip).limit(limit).all()
    return monitors


@router.get("/{monitor_id}", response_model=MonitorResponse)
def get_monitor(monitor_id: int, db: Session = Depends(get_db)):
    monitor = db.query(Monitor).filter(Monitor.id == monitor_id).first()
    if not monitor:
        raise HTTPException(status_code=404, detail="Monitor not found")
    return monitor


@router.put("/{monitor_id}", response_model=MonitorResponse)
def update_monitor(
    monitor_id: int, monitor: MonitorUpdate, db: Session = Depends(get_db)
):
    db_monitor = db.query(Monitor).filter(Monitor.id == monitor_id).first()
    if not db_monitor:
        raise HTTPException(status_code=404, detail="Monitor not found")

    update_data = monitor.dict(exclude_unset=True)
    for field, value in update_data.items():
        setattr(db_monitor, field, value)

    db.commit()
    db.refresh(db_monitor)
    return db_monitor


@router.delete("/{monitor_id}")
def delete_monitor(monitor_id: int, db: Session = Depends(get_db)):
    monitor = db.query(Monitor).filter(Monitor.id == monitor_id).first()
    if not monitor:
        raise HTTPException(status_code=404, detail="Monitor not found")

    db.delete(monitor)
    db.commit()
    return {"message": "Monitor deleted successfully"}


@router.get("/{monitor_id}/checks", response_model=List[UptimeCheckResponse])
def get_monitor_checks(
    monitor_id: int, skip: int = 0, limit: int = 100, db: Session = Depends(get_db)
):
    monitor = db.query(Monitor).filter(Monitor.id == monitor_id).first()
    if not monitor:
        raise HTTPException(status_code=404, detail="Monitor not found")

    checks = (
        db.query(UptimeCheck)
        .filter(UptimeCheck.monitor_id == monitor_id)
        .order_by(desc(UptimeCheck.checked_at))
        .offset(skip)
        .limit(limit)
        .all()
    )
    return checks


@router.get("/{monitor_id}/stats", response_model=MonitorStats)
def get_monitor_stats(monitor_id: int, db: Session = Depends(get_db)):
    monitor = db.query(Monitor).filter(Monitor.id == monitor_id).first()
    if not monitor:
        raise HTTPException(status_code=404, detail="Monitor not found")

    total_checks = (
        db.query(UptimeCheck).filter(UptimeCheck.monitor_id == monitor_id).count()
    )
    successful_checks = (
        db.query(UptimeCheck)
        .filter(UptimeCheck.monitor_id == monitor_id, UptimeCheck.is_up)
        .count()
    )

    uptime_percentage = (
        (successful_checks / total_checks * 100) if total_checks > 0 else 0
    )

    avg_response_time = (
        db.query(func.avg(UptimeCheck.response_time))
        .filter(
            UptimeCheck.monitor_id == monitor_id,
            UptimeCheck.is_up,
            UptimeCheck.response_time.isnot(None),
        )
        .scalar()
    )

    last_check = (
        db.query(UptimeCheck)
        .filter(UptimeCheck.monitor_id == monitor_id)
        .order_by(desc(UptimeCheck.checked_at))
        .first()
    )

    return MonitorStats(
        monitor_id=monitor_id,
        uptime_percentage=round(uptime_percentage, 2),
        total_checks=total_checks,
        successful_checks=successful_checks,
        average_response_time=round(avg_response_time, 2)
        if avg_response_time
        else None,
        last_check=last_check.checked_at if last_check else None,
    )