"""backend/api/daemon_status.py — Live status of the Telegram session daemon.

Espone lo stato del session-daemon (scripts/session-daemon.mjs) leggendo
le sessioni attive da Supabase agent_tasks (status = "__session__").

Endpoint:
  GET /api/daemon/status  — sessioni attive, ultimo heartbeat, uptime, task corrente
"""
from __future__ import annotations

import asyncio
import json
import logging
import time
from typing import Any

from fastapi import APIRouter

_logger = logging.getLogger("api.daemon_status")

router = APIRouter(prefix="/api/daemon", tags=["daemon-status"])

# ACTIVE_TTL: allineato a session-daemon.mjs (5 * 60_000 ms)
_ACTIVE_TTL_MS = 5 * 60 * 1000  # 5 minuti


def _parse_context(raw: Any) -> dict:
    """Decodifica il campo context (può essere str JSON o dict)."""
    if isinstance(raw, dict):
        return raw
    if isinstance(raw, str):
        try:
            return json.loads(raw)
        except Exception:
            return {}
    return {}


def _fmt_uptime(started_at_ms: int | None) -> str:
    if not started_at_ms:
        return "unknown"
    elapsed_s = int((time.time() * 1000 - started_at_ms) / 1000)
    h, rem = divmod(elapsed_s, 3600)
    m, s = divmod(rem, 60)
    if h:
        return f"{h}h {m}m"
    if m:
        return f"{m}m {s}s"
    return f"{s}s"


@router.get("/status")
async def daemon_status() -> dict:
    """
    Ritorna lo stato live del session-daemon leggendo Supabase agent_tasks.

    Una sessione è ATTIVA se updated_at < 5 minuti fa (ACTIVE_TTL del daemon).
    Il daemon fa heartbeat ogni 30s — se non si vede da >5min è stale/crashato.

    Response:
      ok              — False se Supabase non raggiungibile
      supabase_ok     — True se query OK
      active_sessions — conteggio sessioni con heartbeat < 5min
      sessions[]      — lista sessioni con: session_name, active, last_heartbeat,
                        uptime, current_task, pid, head_sha, claimed_files
      checked_at      — timestamp UTC della verifica
    """
    from .state import _sb

    checked_at = time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime())
    now_ms = int(time.time() * 1000)

    if not _sb:
        return {
            "ok": False,
            "supabase_ok": False,
            "error": "Supabase non configurato (SUPABASE_URL / SUPABASE_KEY mancanti)",
            "sessions": [],
            "active_sessions": 0,
            "checked_at": checked_at,
        }

    try:
        result = await asyncio.to_thread(
            lambda: _sb.table("agent_tasks")
            .select("task_id, goal, context, updated_at, created_at")
            .eq("status", "__session__")
            .order("updated_at", desc=True)
            .limit(10)
            .execute()
        )
        rows = result.data or []
    except Exception as exc:
        _logger.warning("daemon_status: Supabase query failed: %s", exc)
        return {
            "ok": False,
            "supabase_ok": False,
            "error": str(exc),
            "sessions": [],
            "active_sessions": 0,
            "checked_at": checked_at,
        }

    sessions = []
    for row in rows:
        ctx = _parse_context(row.get("context"))
        updated_ms: int = row.get("updated_at") or 0
        age_ms = now_ms - updated_ms
        # CLOCK-SKEW-FIX: Railway clock può essere leggermente avanti di HF Space.
        # age_ms negativo = heartbeat *appena* avvenuto → trattare come attivo.
        # Tolleriamo fino a 60s di skew (ben oltre il tipico 1-2s osservato).
        is_active = -60_000 < age_ms < _ACTIVE_TTL_MS

        ago_s = int(age_ms / 1000)
        if ago_s < 0:
            last_seen = "appena ora"
        elif ago_s < 60:
            last_seen = f"{ago_s}s fa"
        elif ago_s < 3600:
            last_seen = f"{ago_s // 60}m {ago_s % 60}s fa"
        else:
            last_seen = f"{ago_s // 3600}h {(ago_s % 3600) // 60}m fa"

        head = (ctx.get("headSha") or "")
        sessions.append({
            "session_id":    row.get("task_id", ""),
            "session_name":  row.get("goal") or ctx.get("sessionName", ""),
            "active":        is_active,
            "last_heartbeat": last_seen,
            "uptime":        _fmt_uptime(ctx.get("startedAt")),
            "current_task":  ctx.get("sprint") or "idle",
            "pid":           ctx.get("pid"),
            "head_sha":      head[:10] if head else None,
            "claimed_files": ctx.get("claimedFiles", []),
            "updated_at_ms": updated_ms,
        })

    active_count = sum(1 for s in sessions if s["active"])

    return {
        "ok": True,
        "supabase_ok": True,
        "active_sessions": active_count,
        "total_sessions":  len(sessions),
        "sessions":        sessions,
        "active_ttl_s":    _ACTIVE_TTL_MS // 1000,
        "checked_at":      checked_at,
    }