FabledSteward/steward/core/reports.py

"""steward/core/reports.py

Weekly digest report: uptime, active alerts, alert events, top metrics.
Called by the scheduler (hourly check) or triggered manually from Settings.
"""
from __future__ import annotations
import logging
from datetime import datetime, timedelta, timezone

from sqlalchemy import and_, case, func, select

from steward.alerts import service as alert_svc
from steward.core.formatting import zone
from steward.core.mail import message, recipients, report_email, send
from steward.core.settings import get_setting
from steward.models.alerts import AlertEvent
from steward.models.metrics import PluginMetric
from steward.models.monitors import Monitor, MonitorResult

logger = logging.getLogger(__name__)

async def build_report_data(app) -> dict:
    """Collect all data for the weekly digest."""
    now = datetime.now(timezone.utc)
    cutoff_7d = now - timedelta(days=7)
    cutoff_24h = now - timedelta(hours=24)

    async with app.db_sessionmaker() as db:
        # ── Uptime summary (7d) — per enabled monitor of any type ─────────────
        monitors = (await db.execute(
            select(Monitor).where(Monitor.enabled.is_(True)).order_by(Monitor.name)
        )).scalars().all()

        uptime_rows = await db.execute(
            select(
                MonitorResult.monitor_id,
                func.count(MonitorResult.id).label("total"),
                func.sum(case((MonitorResult.is_up.is_(True), 1), else_=0)).label("up"),
            )
            .where(MonitorResult.checked_at >= cutoff_7d)
            .group_by(MonitorResult.monitor_id)
        )
        uptime_map: dict[str, float | None] = {}
        for row in uptime_rows:
            pct = round(float(row.up) / float(row.total) * 100, 2) if row.total else None
            uptime_map[row.monitor_id] = pct

        uptime_summary = [
            {"name": m.name, "pct_7d": uptime_map.get(m.id)} for m in monitors
        ]

        # ── Active alerts ─────────────────────────────────────────────────────
        active_rows = await alert_svc.active_alerts(db)
        active_alerts = [
            {
                "state": alert_svc.alert_label(state),
                "name": rule.name,
                "resource": rule.resource_name,
                "condition": alert_svc.rule_condition(rule),
            }
            for state, rule in active_rows
        ]

        # ── Alert event counts (7d) ───────────────────────────────────────────
        events_result = await db.execute(
            select(
                func.count(case((AlertEvent.to_state == "firing", 1), else_=None)).label("fired"),
                func.count(case((AlertEvent.to_state == "resolved", 1), else_=None)).label("resolved"),
            )
            .where(AlertEvent.transitioned_at >= cutoff_7d)
        )
        event_row = events_result.one()
        alert_events = {
            "fired": int(event_row.fired or 0),
            "resolved": int(event_row.resolved or 0),
        }

        # ── Top Traefik routers by avg request_rate (last 24h) ────────────────
        top_routers_result = await db.execute(
            select(
                PluginMetric.resource_name,
                func.avg(PluginMetric.value).label("avg_rate"),
            )
            .where(
                and_(
                    PluginMetric.source_module == "traefik",
                    PluginMetric.metric_name == "request_rate",
                    PluginMetric.recorded_at >= cutoff_24h,
                )
            )
            .group_by(PluginMetric.resource_name)
            .order_by(func.avg(PluginMetric.value).desc())
            .limit(10)
        )
        top_routers = [
            {"name": row.resource_name, "avg_rate": float(row.avg_rate)}
            for row in top_routers_result
        ]

        # ── Monitors currently down (latest result is_up = false) ─────────────
        from steward.core.status import _last_n_results
        enabled = (await db.execute(
            select(Monitor.id, Monitor.name).where(Monitor.enabled.is_(True))
        )).all()
        latest = await _last_n_results(db, [m.id for m in enabled], n=1)
        hosts_down = sorted(name for mid, name in enabled
                            if latest.get(mid) and not latest[mid][-1].is_up)

    return {
        "generated_at": now,
        "uptime_summary": uptime_summary,
        "active_alerts": active_alerts,
        "alert_events": alert_events,
        "top_routers": top_routers,
        "hosts_down": hosts_down,
    }


async def send_report(app) -> tuple[bool, str]:
    """Email the weekly digest to each account that gets it, and the "Also
    send to" addresses, each in its own zone. Returns (success, message)."""
    smtp_cfg = app.config.get("SMTP", {})
    if not smtp_cfg.get("host"):
        return False, "No mail server is set. Set one in Settings → Notifications."
    async with app.db_sessionmaker() as db:
        to = await recipients(db, "report", smtp_cfg)
    if not to:
        return False, ("Nobody gets the weekly report: no account has it on with a real email "
                       "address, and there are no Also send to addresses.")

    try:
        data = await build_report_data(app)
    except Exception as exc:
        logger.exception("Failed to build report data")
        return False, f"Data collection failed: {exc}"

    try:
        await send(smtp_cfg, [message(smtp_cfg, r.address, *report_email(smtp_cfg, data, r)) for r in to])
    except Exception as exc:
        logger.error("Failed to send weekly report: %s", exc)
        return False, f"Send failed: {exc}"
    logger.info("Weekly report sent to %d address(es)", len(to))
    return True, f"Report sent to {', '.join(r.address for r in to)}."


def report_due(now: datetime, day: int, hour: int, tz) -> bool:
    """Whether `now` falls in the scheduled hour, read in the schedule's zone."""
    local = now.astimezone(tz)
    return local.weekday() == day and local.hour == hour


def schedule_in(day: int, hour: int, saved_tz, view_tz, now: datetime | None = None) -> tuple[int, int]:
    """The schedule's (weekday, hour) as a reader in `view_tz` sees it: the next
    time it falls due in `saved_tz`, read on their clock."""
    local = (now or datetime.now(timezone.utc)).astimezone(saved_tz)
    due = (local + timedelta(days=(day - local.weekday()) % 7)).replace(
        hour=hour, minute=0, second=0, microsecond=0)
    seen = due.astimezone(view_tz)
    return seen.weekday(), seen.hour


async def check_and_send(app) -> None:
    """Hourly scheduler hook: send if day/hour match and not sent recently."""
    from steward.core.settings import set_setting

    async with app.db_sessionmaker() as db:
        enabled = await get_setting(db, "reports.enabled")
        if not enabled:
            return

        schedule_day = int(await get_setting(db, "reports.schedule_day") or 6)
        schedule_hour = int(await get_setting(db, "reports.schedule_hour") or 8)
        schedule_tz = zone(await get_setting(db, "reports.schedule_tz"))
        last_sent_str = await get_setting(db, "reports.last_sent_at") or ""

    now = datetime.now(timezone.utc)
    if not report_due(now, schedule_day, schedule_hour, schedule_tz):
        return

    if last_sent_str:
        try:
            last_sent = datetime.fromisoformat(last_sent_str)
            if (now - last_sent).total_seconds() < 23 * 3600:
                return  # already sent this window
        except ValueError:
            pass

    ok, msg = await send_report(app)
    if ok:
        async with app.db_sessionmaker() as db:
            async with db.begin():
                await set_setting(db, "reports.last_sent_at", now.isoformat())
    else:
        logger.warning("Weekly report send failed: %s", msg)