from datetime import datetime, timedelta, timezone

from fastapi import APIRouter, Depends
from pydantic import BaseModel
from sqlalchemy import func, select
from sqlalchemy.orm import Session, joinedload

from app.auth.jwt_auth import get_current_user
from app.database import get_db
from app.models import Event, Host, Problem
from app.schemas.list_models import EventSummary

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


class DashboardSummary(BaseModel):
    events_last_24h: int
    hosts_total: int
    problems_open: int
    severity_24h: dict[str, int]
    recent_events: list[EventSummary]


@router.get("/summary", response_model=DashboardSummary)
def dashboard_summary(
    db: Session = Depends(get_db),
    _user: str = Depends(get_current_user),
) -> DashboardSummary:
    since = datetime.now(timezone.utc) - timedelta(hours=24)

    events_24h = db.scalar(
        select(func.count()).select_from(Event).where(Event.received_at >= since)
    ) or 0
    hosts_total = db.scalar(select(func.count()).select_from(Host)) or 0
    problems_open = (
        db.scalar(select(func.count()).select_from(Problem).where(Problem.status == "open")) or 0
    )

    severity_rows = db.execute(
        select(Event.severity, func.count())
        .where(Event.received_at >= since)
        .group_by(Event.severity)
    ).all()
    severity_24h = {row[0]: row[1] for row in severity_rows}

    recent = db.scalars(
        select(Event)
        .join(Host)
        .options(joinedload(Event.host))
        .order_by(Event.received_at.desc())
        .limit(8)
    ).all()

    recent_events = [
        EventSummary(
            id=e.id,
            event_id=e.event_id,
            host_id=e.host_id,
            hostname=e.host.hostname,
            occurred_at=e.occurred_at,
            received_at=e.received_at,
            category=e.category,
            type=e.type,
            severity=e.severity,
            title=e.title,
            summary=e.summary,
        )
        for e in recent
    ]

    return DashboardSummary(
        events_last_24h=events_24h,
        hosts_total=hosts_total,
        problems_open=problems_open,
        severity_24h=severity_24h,
        recent_events=recent_events,
    )