"""
health.py

Bot health monitoring. Tracks task execution status, WebSocket connectivity,
and game processing metrics. Writes periodic heartbeat to STORAGE/bot_health.json.
"""

# Standard Library Imports
import json
import logging
import time
from collections import deque
from pathlib import Path

# Third-Party Library Imports
import aiofiles
import aiosqlite

# Local Module Imports
from .utils import STORAGE_DIR, SQ_BATTLES_DB_PATH, get_bot

HEALTH_PATH = STORAGE_DIR / "bot_health.json"

# Rolling window for games-processed counters
_games_timestamps: deque[float] = deque()

_health_state: dict = {
    "bot_started_at": None,
    "guild_count": 0,
    "last_heartbeat": 0,
    "tasks": {},
    "websocket": {},
    "games_processed_1h": 0,
    "games_processed_24h": 0,
}


def init_health(started_at: float, guild_count: int) -> None:
    """Initialize health state on bot startup."""
    _health_state["bot_started_at"] = started_at
    _health_state["guild_count"] = guild_count


async def record_task_run(task_name: str, success: bool, error: str = "") -> None:
    """Record a task execution result."""
    entry = _health_state["tasks"].setdefault(task_name, {
        "status": "unknown",
        "last_run": 0,
        "run_count": 0,
        "error_count": 0,
        "last_error": "",
    })
    entry["last_run"] = time.time()
    entry["run_count"] += 1
    if success:
        entry["status"] = "ok"
    else:
        entry["status"] = "error"
        entry["error_count"] += 1
        entry["last_error"] = str(error)[:200]


async def record_ws_message(ws_name: str) -> None:
    """Record a WebSocket message receipt."""
    entry = _health_state["websocket"].setdefault(ws_name, {
        "connected": True,
        "last_message_at": 0,
        "messages_processed": 0,
    })
    entry["connected"] = True
    entry["last_message_at"] = time.time()
    entry["messages_processed"] += 1


def record_ws_disconnect(ws_name: str) -> None:
    """Mark a WebSocket as disconnected."""
    entry = _health_state["websocket"].get(ws_name)
    if entry:
        entry["connected"] = False


def record_game_processed() -> None:
    """Record that a game was processed (for hourly/daily counters)."""
    _games_timestamps.append(time.time())


def _prune_games_window() -> tuple[int, int]:
    """Count games in the last 1h and 24h, pruning old entries."""
    now = time.time()
    cutoff_24h = now - 86400
    while _games_timestamps and _games_timestamps[0] < cutoff_24h:
        _games_timestamps.popleft()

    cutoff_1h = now - 3600
    count_1h = sum(1 for ts in _games_timestamps if ts >= cutoff_1h)
    return count_1h, len(_games_timestamps)


async def write_heartbeat() -> None:
    """Dump current health state to HEALTH_PATH as JSON."""
    try:
        bot = get_bot()
        _health_state["guild_count"] = len(bot.guilds)
    except Exception:
        pass

    _health_state["last_heartbeat"] = time.time()
    games_1h, games_24h = _prune_games_window()
    _health_state["games_processed_1h"] = games_1h
    _health_state["games_processed_24h"] = games_24h

    try:
        HEALTH_PATH.parent.mkdir(parents=True, exist_ok=True)
        async with aiofiles.open(HEALTH_PATH, "w", encoding="utf-8") as f:
            await f.write(json.dumps(_health_state, indent=2, default=str))
    except Exception as e:
        logging.error(f"[HEALTH] Failed to write heartbeat: {e}")


async def get_health_snapshot() -> dict:
    """Return current health state dict (live, not from file)."""
    try:
        bot = get_bot()
        _health_state["guild_count"] = len(bot.guilds)
    except Exception:
        pass

    _health_state["last_heartbeat"] = time.time()
    games_1h, games_24h = _prune_games_window()
    _health_state["games_processed_1h"] = games_1h
    _health_state["games_processed_24h"] = games_24h

    return dict(_health_state)


async def get_recent_ttl_stats(limit: int = 30) -> dict:
    """Return receive-delay stats for the most recent completed games."""
    async with aiosqlite.connect(SQ_BATTLES_DB_PATH, timeout=10.0) as db:
        rows = list(await db.execute_fetchall(
            "SELECT endtime_unix, received_unix FROM match_summary "
            "WHERE received_unix IS NOT NULL AND endtime_unix IS NOT NULL "
            "ORDER BY endtime_unix DESC LIMIT ?",
            (limit,),
        ))

    if not rows:
        return {
            "sample_size": 0,
            "avg_delay": None,
            "min_delay": None,
            "max_delay": None,
            "last_received_ts": None,
        }

    delays = [max(int(received) - int(ended), 0) for ended, received in rows]
    return {
        "sample_size": len(delays),
        "avg_delay": int(sum(delays) / len(delays)),
        "min_delay": min(delays),
        "max_delay": max(delays),
        "last_received_ts": max(int(received) for _, received in rows),
    }