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 asyncio
import logging
import smtplib
import ssl
from datetime import datetime, timedelta, timezone
from email.message import EmailMessage

from sqlalchemy import and_, case, func, select

from steward.models.alerts import AlertRule, AlertState, AlertStateEnum, AlertEvent
from steward.models.hosts import Host
from steward.models.metrics import PluginMetric
from steward.models.monitors import PingResult, PingStatus

logger = logging.getLogger(__name__)

_DAYS = ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"]


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) ───────────────────────────────────────────────
        host_result = await db.execute(
            select(Host).where(Host.ping_enabled.is_(True)).order_by(Host.name)
        )
        hosts = host_result.scalars().all()

        uptime_rows = await db.execute(
            select(
                PingResult.host_id,
                func.count(PingResult.id).label("total"),
                func.sum(case((PingResult.status == PingStatus.up, 1), else_=0)).label("up"),
            )
            .where(PingResult.probed_at >= cutoff_7d)
            .group_by(PingResult.host_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.host_id] = pct

        uptime_summary = []
        for h in hosts:
            uptime_summary.append({
                "name": h.name,
                "pct_7d": uptime_map.get(h.id),
            })

        # ── Active alerts ─────────────────────────────────────────────────────
        active_result = await db.execute(
            select(AlertState, AlertRule)
            .join(AlertRule, AlertState.rule_id == AlertRule.id)
            .where(AlertState.state.in_([
                AlertStateEnum.firing, AlertStateEnum.acknowledged, AlertStateEnum.pending,
            ]))
            .order_by(AlertState.last_transition_at.desc())
        )
        active_alerts = [
            {
                "state": state.state.value.upper(),
                "name": rule.name,
                "resource": rule.resource_name,
                "metric": rule.metric_name,
                "operator": rule.operator.value,
                "threshold": rule.threshold,
            }
            for state, rule in active_result.all()
        ]

        # ── 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
        ]

        # ── Hosts currently down ──────────────────────────────────────────────
        latest_ping_subq = (
            select(PingResult.host_id, func.max(PingResult.probed_at).label("max_at"))
            .group_by(PingResult.host_id)
            .subquery()
        )
        down_result = await db.execute(
            select(Host.name)
            .join(PingResult, PingResult.host_id == Host.id)
            .join(
                latest_ping_subq,
                and_(
                    PingResult.host_id == latest_ping_subq.c.host_id,
                    PingResult.probed_at == latest_ping_subq.c.max_at,
                ),
            )
            .where(
                Host.ping_enabled.is_(True),
                PingResult.status == PingStatus.down,
            )
            .order_by(Host.name)
        )
        hosts_down = [row.name for row in down_result]

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


def _render_report_text(data: dict) -> str:
    now = data["generated_at"]
    lines: list[str] = []

    lines.append("Steward — Weekly Report")
    lines.append(f"Generated: {now.strftime('%Y-%m-%d %H:%M UTC')}")
    lines.append("")

    # ── Hosts currently down ──────────────────────────────────────────────────
    down = data["hosts_down"]
    if down:
        lines.append(f"⚠  {len(down)} host(s) currently DOWN: {', '.join(down)}")
        lines.append("")

    # ── Uptime summary ────────────────────────────────────────────────────────
    lines.append("UPTIME SUMMARY (7-day)")
    lines.append("─" * 40)
    for entry in data["uptime_summary"]:
        pct = entry["pct_7d"]
        pct_str = f"{pct:.2f}%" if pct is not None else "no data"
        lines.append(f"  {entry['name']:<32} {pct_str}")
    if not data["uptime_summary"]:
        lines.append("  (no ping-enabled hosts)")
    lines.append("")

    # ── Active alerts ─────────────────────────────────────────────────────────
    alerts = data["active_alerts"]
    lines.append(f"ACTIVE ALERTS ({len(alerts)})")
    lines.append("─" * 40)
    if alerts:
        for a in alerts:
            lines.append(
                f"  [{a['state']}] {a['name']} — {a['resource']}:"
                f"{a['metric']} {a['operator']} {a['threshold']}"
            )
    else:
        lines.append("  None — all clear.")
    lines.append("")

    # ── Alert events this week ────────────────────────────────────────────────
    ev = data["alert_events"]
    lines.append("ALERT EVENTS THIS WEEK")
    lines.append("─" * 40)
    lines.append(f"  Fired:    {ev['fired']}")
    lines.append(f"  Resolved: {ev['resolved']}")
    lines.append("")

    # ── Top Traefik routers ───────────────────────────────────────────────────
    if data["top_routers"]:
        lines.append("TOP TRAEFIK ROUTERS (avg req/s, last 24h)")
        lines.append("─" * 40)
        for r in data["top_routers"]:
            lines.append(f"  {r['name']:<40} {r['avg_rate']:.2f} req/s")
        lines.append("")

    lines.append("─" * 40)
    lines.append("Steward — https://git.fabledsword.com/bvandeusen/Steward")
    return "\n".join(lines)


async def send_report(app) -> tuple[bool, str]:
    """Build and email the weekly digest. Returns (success, message)."""
    smtp_cfg = app.config.get("SMTP", {})
    if not smtp_cfg.get("host") or not smtp_cfg.get("recipients"):
        return False, "SMTP not configured — set host and recipients in Settings → Notifications."

    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}"

    body = _render_report_text(data)
    date_str = data["generated_at"].strftime("%Y-%m-%d")
    subject = f"[Steward] Weekly Report — {date_str}"

    msg = EmailMessage()
    msg["Subject"] = subject
    msg["From"] = smtp_cfg.get("username", "steward@localhost")
    msg["To"] = ", ".join(smtp_cfg["recipients"])
    msg.set_content(body)

    try:
        loop = asyncio.get_running_loop()
        from steward.core.notifications import _smtp_send_sync
        await loop.run_in_executor(None, _smtp_send_sync, smtp_cfg, msg)
        logger.info("Weekly report sent to %s", smtp_cfg["recipients"])
        return True, f"Report sent to {', '.join(smtp_cfg['recipients'])}."
    except Exception as exc:
        logger.error("Failed to send weekly report: %s", exc)
        return False, f"Send failed: {exc}"


async def check_and_send(app) -> None:
    """Hourly scheduler hook: send if day/hour match and not sent recently."""
    from steward.core.settings import get_setting, 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)
        last_sent_str = await get_setting(db, "reports.last_sent_at") or ""

    now = datetime.now(timezone.utc)
    if now.weekday() != schedule_day or now.hour != schedule_hour:
        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)