# monitor.py - Real-time monitoring stats with Redis persistence
import time
import json
import asyncio
from typing import Dict, List, Optional
from datetime import datetime, timezone
from collections import deque
from redis import asyncio as aioredis
from utils import get_container_memory_percent
import psutil
import logging

logger = logging.getLogger(__name__)

class MonitorStats:
    """Tracks real-time server stats with Redis persistence."""

    def __init__(self, redis: aioredis.Redis):
        self.redis = redis
        self.start_time = time.time()

        # In-memory queues (fast reads, Redis backup)
        self.active_requests: Dict[str, Dict] = {}  # id -> request info
        self.completed_requests: deque = deque(maxlen=100)  # Last 100
        self.janitor_events: deque = deque(maxlen=100)
        self.errors: deque = deque(maxlen=100)

        # Endpoint stats (persisted in Redis)
        self.endpoint_stats: Dict[str, Dict] = {}  # endpoint -> {count, total_time, errors, ...}

        # Timeline data (5min window, 5s resolution = 60 points)
        self.memory_timeline: deque = deque(maxlen=60)
        self.requests_timeline: deque = deque(maxlen=60)
        self.browser_timeline: deque = deque(maxlen=60)

    async def track_request_start(self, request_id: str, endpoint: str, url: str, config: Dict = None):
        """Track new request start."""
        req_info = {
            "id": request_id,
            "endpoint": endpoint,
            "url": url[:100],  # Truncate long URLs
            "start_time": time.time(),
            "config_sig": config.get("sig", "default") if config else "default",
            "mem_start": psutil.Process().memory_info().rss / (1024 * 1024)
        }
        self.active_requests[request_id] = req_info

        # Increment endpoint counter
        if endpoint not in self.endpoint_stats:
            self.endpoint_stats[endpoint] = {
                "count": 0, "total_time": 0, "errors": 0,
                "pool_hits": 0, "success": 0
            }
        self.endpoint_stats[endpoint]["count"] += 1

        # Persist to Redis (fire and forget)
        asyncio.create_task(self._persist_endpoint_stats())

    async def track_request_end(self, request_id: str, success: bool, error: str = None,
                               pool_hit: bool = True, status_code: int = 200):
        """Track request completion."""
        if request_id not in self.active_requests:
            return

        req_info = self.active_requests.pop(request_id)
        end_time = time.time()
        elapsed = end_time - req_info["start_time"]
        mem_end = psutil.Process().memory_info().rss / (1024 * 1024)
        mem_delta = mem_end - req_info["mem_start"]

        # Update stats
        endpoint = req_info["endpoint"]
        if endpoint in self.endpoint_stats:
            self.endpoint_stats[endpoint]["total_time"] += elapsed
            if success:
                self.endpoint_stats[endpoint]["success"] += 1
            else:
                self.endpoint_stats[endpoint]["errors"] += 1
            if pool_hit:
                self.endpoint_stats[endpoint]["pool_hits"] += 1

        # Add to completed queue
        completed = {
            **req_info,
            "end_time": end_time,
            "elapsed": round(elapsed, 2),
            "mem_delta": round(mem_delta, 1),
            "success": success,
            "error": error,
            "status_code": status_code,
            "pool_hit": pool_hit
        }
        self.completed_requests.append(completed)

        # Track errors
        if not success and error:
            self.errors.append({
                "timestamp": end_time,
                "endpoint": endpoint,
                "url": req_info["url"],
                "error": error,
                "request_id": request_id
            })

        await self._persist_endpoint_stats()

    def track_janitor_event(self, event_type: str, sig: str, details: Dict):
        """Track janitor cleanup events."""
        self.janitor_events.append({
            "timestamp": time.time(),
            "type": event_type,  # "close_cold", "close_hot", "promote"
            "sig": sig[:8],
            "details": details
        })

    async def update_timeline(self):
        """Update timeline data points (called every 5s)."""
        now = time.time()
        mem_pct = get_container_memory_percent()

        # Count requests in last 5s
        recent_reqs = sum(1 for req in self.completed_requests
                         if now - req.get("end_time", 0) < 5)

        # Browser counts (need to import from crawler_pool)
        from crawler_pool import PERMANENT, HOT_POOL, COLD_POOL
        browser_count = {
            "permanent": 1 if PERMANENT else 0,
            "hot": len(HOT_POOL),
            "cold": len(COLD_POOL)
        }

        self.memory_timeline.append({"time": now, "value": mem_pct})
        self.requests_timeline.append({"time": now, "value": recent_reqs})
        self.browser_timeline.append({"time": now, "browsers": browser_count})

    async def _persist_endpoint_stats(self):
        """Persist endpoint stats to Redis."""
        try:
            await self.redis.set(
                "monitor:endpoint_stats",
                json.dumps(self.endpoint_stats),
                ex=86400  # 24h TTL
            )
        except Exception as e:
            logger.warning(f"Failed to persist endpoint stats: {e}")

    async def load_from_redis(self):
        """Load persisted stats from Redis."""
        try:
            data = await self.redis.get("monitor:endpoint_stats")
            if data:
                self.endpoint_stats = json.loads(data)
                logger.info("Loaded endpoint stats from Redis")
        except Exception as e:
            logger.warning(f"Failed to load from Redis: {e}")

    def get_health_summary(self) -> Dict:
        """Get current system health snapshot."""
        mem_pct = get_container_memory_percent()
        cpu_pct = psutil.cpu_percent(interval=0.1)

        # Network I/O (delta since last call)
        net = psutil.net_io_counters()

        # Pool status
        from crawler_pool import PERMANENT, HOT_POOL, COLD_POOL, LAST_USED
        permanent_mem = 270 if PERMANENT else 0  # Estimate
        hot_mem = len(HOT_POOL) * 180  # Estimate 180MB per browser
        cold_mem = len(COLD_POOL) * 180

        return {
            "container": {
                "memory_percent": round(mem_pct, 1),
                "cpu_percent": round(cpu_pct, 1),
                "network_sent_mb": round(net.bytes_sent / (1024**2), 2),
                "network_recv_mb": round(net.bytes_recv / (1024**2), 2),
                "uptime_seconds": int(time.time() - self.start_time)
            },
            "pool": {
                "permanent": {"active": PERMANENT is not None, "memory_mb": permanent_mem},
                "hot": {"count": len(HOT_POOL), "memory_mb": hot_mem},
                "cold": {"count": len(COLD_POOL), "memory_mb": cold_mem},
                "total_memory_mb": permanent_mem + hot_mem + cold_mem
            },
            "janitor": {
                "next_cleanup_estimate": "adaptive",  # Would need janitor state
                "memory_pressure": "LOW" if mem_pct < 60 else "MEDIUM" if mem_pct < 80 else "HIGH"
            }
        }

    def get_active_requests(self) -> List[Dict]:
        """Get list of currently active requests."""
        now = time.time()
        return [
            {
                **req,
                "elapsed": round(now - req["start_time"], 1),
                "status": "running"
            }
            for req in self.active_requests.values()
        ]

    def get_completed_requests(self, limit: int = 50, filter_status: str = "all") -> List[Dict]:
        """Get recent completed requests."""
        requests = list(self.completed_requests)[-limit:]
        if filter_status == "success":
            requests = [r for r in requests if r.get("success")]
        elif filter_status == "error":
            requests = [r for r in requests if not r.get("success")]
        return requests

    def get_browser_list(self) -> List[Dict]:
        """Get detailed browser pool information."""
        from crawler_pool import PERMANENT, HOT_POOL, COLD_POOL, LAST_USED, USAGE_COUNT, DEFAULT_CONFIG_SIG

        browsers = []
        now = time.time()

        if PERMANENT:
            browsers.append({
                "type": "permanent",
                "sig": DEFAULT_CONFIG_SIG[:8] if DEFAULT_CONFIG_SIG else "unknown",
                "age_seconds": int(now - self.start_time),
                "last_used_seconds": int(now - LAST_USED.get(DEFAULT_CONFIG_SIG, now)),
                "memory_mb": 270,
                "hits": USAGE_COUNT.get(DEFAULT_CONFIG_SIG, 0),
                "killable": False
            })

        for sig, crawler in HOT_POOL.items():
            browsers.append({
                "type": "hot",
                "sig": sig[:8],
                "age_seconds": int(now - self.start_time),  # Approximation
                "last_used_seconds": int(now - LAST_USED.get(sig, now)),
                "memory_mb": 180,  # Estimate
                "hits": USAGE_COUNT.get(sig, 0),
                "killable": True
            })

        for sig, crawler in COLD_POOL.items():
            browsers.append({
                "type": "cold",
                "sig": sig[:8],
                "age_seconds": int(now - self.start_time),
                "last_used_seconds": int(now - LAST_USED.get(sig, now)),
                "memory_mb": 180,
                "hits": USAGE_COUNT.get(sig, 0),
                "killable": True
            })

        return browsers

    def get_endpoint_stats_summary(self) -> Dict[str, Dict]:
        """Get aggregated endpoint statistics."""
        summary = {}
        for endpoint, stats in self.endpoint_stats.items():
            count = stats["count"]
            avg_time = (stats["total_time"] / count) if count > 0 else 0
            success_rate = (stats["success"] / count * 100) if count > 0 else 0
            pool_hit_rate = (stats["pool_hits"] / count * 100) if count > 0 else 0

            summary[endpoint] = {
                "count": count,
                "avg_latency_ms": round(avg_time * 1000, 1),
                "success_rate_percent": round(success_rate, 1),
                "pool_hit_rate_percent": round(pool_hit_rate, 1),
                "errors": stats["errors"]
            }
        return summary

    def get_timeline_data(self, metric: str, window: str = "5m") -> Dict:
        """Get timeline data for charts."""
        # For now, only 5m window supported
        if metric == "memory":
            data = list(self.memory_timeline)
        elif metric == "requests":
            data = list(self.requests_timeline)
        elif metric == "browsers":
            data = list(self.browser_timeline)
        else:
            return {"timestamps": [], "values": []}

        return {
            "timestamps": [int(d["time"]) for d in data],
            "values": [d.get("value", d.get("browsers")) for d in data]
        }

    def get_janitor_log(self, limit: int = 100) -> List[Dict]:
        """Get recent janitor events."""
        return list(self.janitor_events)[-limit:]

    def get_errors_log(self, limit: int = 100) -> List[Dict]:
        """Get recent errors."""
        return list(self.errors)[-limit:]

# Global instance (initialized in server.py)
monitor_stats: Optional[MonitorStats] = None

def get_monitor() -> MonitorStats:
    """Get global monitor instance."""
    if monitor_stats is None:
        raise RuntimeError("Monitor not initialized")
    return monitor_stats