from __future__ import annotations
from quart import Blueprint, current_app, render_template
from sqlalchemy import select, func
from steward.auth.middleware import require_role
from steward.models.users import UserRole
from steward.models.hosts import Host
from steward.models.monitors import DnsResult

dns_bp = Blueprint("dns", __name__, url_prefix="/dns")


async def _latest_dns(db, host_ids: list[str]) -> dict:
    if not host_ids:
        return {}
    subq = (
        select(DnsResult.host_id, func.max(DnsResult.resolved_at).label("max_at"))
        .where(DnsResult.host_id.in_(host_ids))
        .group_by(DnsResult.host_id)
        .subquery()
    )
    pr = await db.execute(
        select(DnsResult).join(
            subq,
            (DnsResult.host_id == subq.c.host_id) & (DnsResult.resolved_at == subq.c.max_at),
        )
    )
    return {r.host_id: r for r in pr.scalars()}


@dns_bp.get("/")
@require_role(UserRole.viewer)
async def index():
    async with current_app.db_sessionmaker() as db:
        result = await db.execute(
            select(Host).where(Host.dns_enabled.is_(True)).order_by(Host.name)
        )
        hosts = result.scalars().all()
        latest = await _latest_dns(db, [h.id for h in hosts])
    poll_interval = current_app.config.get("MONITORS_POLL_INTERVAL", 60)
    return await render_template("dns/index.html", hosts=hosts, latest=latest, poll_interval=poll_interval)


@dns_bp.get("/rows")
@require_role(UserRole.viewer)
async def rows():
    async with current_app.db_sessionmaker() as db:
        result = await db.execute(
            select(Host).where(Host.dns_enabled.is_(True)).order_by(Host.name)
        )
        hosts = result.scalars().all()
        latest = await _latest_dns(db, [h.id for h in hosts])
    return await render_template("dns/rows.html", hosts=hosts, latest=latest)