# -*- coding: utf-8 -*-
"""
Metriken-Collector für Satellites.

Sammelt verschiedene Metriken wie Latenz, Durchsatz,
Fehler und Ressourcennutzung.
"""

from __future__ import annotations

import logging
from collections import deque
from dataclasses import dataclass, field
from datetime import datetime, timedelta
from enum import Enum, auto
from typing import Any, Callable


class MetricType(Enum):
    """Typ der Metrik."""
    COUNTER = auto()     # Zähler (nur steigend)
    GAUGE = auto()       # Momentanwert
    HISTOGRAM = auto()   # Verteilung
    TIMING = auto()      # Zeitmessung


@dataclass
class MetricValue:
    """Ein einzelner Metrik-Wert."""
    name: str
    value: float
    timestamp: datetime = field(default_factory=datetime.now)
    metric_type: MetricType = MetricType.GAUGE
    labels: dict[str, str] = field(default_factory=dict)
    unit: str = ""

    def to_dict(self) -> dict[str, Any]:
        """Konvertiert zu Dictionary."""
        return {
            "name": self.name,
            "value": self.value,
            "timestamp": self.timestamp.isoformat(),
            "type": self.metric_type.name,
            "labels": self.labels,
            "unit": self.unit,
        }


@dataclass
class SatelliteMetrics:
    """
    Gesammelte Metriken für einen Satellite.

    Enthält verschiedene Metrik-Kategorien und
    deren historische Werte.
    """
    satellite_id: str
    last_updated: datetime = field(default_factory=datetime.now)

    # Netzwerk
    latency_ms: float = 0.0           # Aktuelle Latenz
    packet_loss_percent: float = 0.0   # Paketverlusr
    bandwidth_kbps: float = 0.0        # Bandbreite
    messages_sent: int = 0             # Gesendete Nachrichten
    messages_received: int = 0         # Empfangene Nachrichten
    bytes_sent: int = 0                # Gesendete Bytes
    bytes_received: int = 0            # Empfangene Bytes

    # Verbindung
    connection_uptime_seconds: float = 0.0
    reconnect_count: int = 0
    last_heartbeat: datetime | None = None

    # Audio (falls relevant)
    audio_level_db: float = 0.0
    audio_samples_processed: int = 0

    # Errors
    error_count: int = 0
    last_error: str = ""
    last_error_time: datetime | None = None

    # Historische Daten (für Trends)
    latency_history: list[tuple[datetime, float]] = field(default_factory=list)

    def record_latency(self, latency_ms: float) -> None:
        """Zeichnet Latenz-Messung auf."""
        self.latency_ms = latency_ms
        self.last_updated = datetime.now()
        self.latency_history.append((self.last_updated, latency_ms))

        # Alte Einträge entfernen (max 1000)
        if len(self.latency_history) > 1000:
            self.latency_history = self.latency_history[-1000:]

    def record_error(self, error: str) -> None:
        """Zeichnet Fehler auf."""
        self.error_count += 1
        self.last_error = error
        self.last_error_time = datetime.now()
        self.last_updated = datetime.now()

    def get_avg_latency(self, seconds: int = 300) -> float:
        """Berechnet durchschnittliche Latenz der letzten Sekunden."""
        cutoff = datetime.now() - timedelta(seconds=seconds)
        recent = [v for t, v in self.latency_history if t >= cutoff]
        return sum(recent) / len(recent) if recent else 0.0

    def to_dict(self) -> dict[str, Any]:
        """Konvertiert zu Dictionary."""
        return {
            "satellite_id": self.satellite_id,
            "last_updated": self.last_updated.isoformat(),
            "network": {
                "latency_ms": self.latency_ms,
                "packet_loss_percent": self.packet_loss_percent,
                "bandwidth_kbps": self.bandwidth_kbps,
                "messages_sent": self.messages_sent,
                "messages_received": self.messages_received,
                "bytes_sent": self.bytes_sent,
                "bytes_received": self.bytes_received,
            },
            "connection": {
                "uptime_seconds": self.connection_uptime_seconds,
                "reconnect_count": self.reconnect_count,
                "last_heartbeat": (
                    self.last_heartbeat.isoformat()
                    if self.last_heartbeat else None
                ),
            },
            "errors": {
                "count": self.error_count,
                "last_error": self.last_error,
                "last_error_time": (
                    self.last_error_time.isoformat()
                    if self.last_error_time else None
                ),
            },
        }


class SatelliteMetricsCollector:
    """
    Sammelt Metriken von Satellites.

    Verwaltet Metriken für mehrere Satellites und bietet
    Methoden für Aufzeichnung und Abfrage.

    Beispiel:
        collector = SatelliteMetricsCollector()

        # Latenz aufzeichnen
        collector.record_latency("sat-001", 15.5)

        # Nachricht aufzeichnen
        collector.record_message_sent("sat-001", 256)

        # Metriken abrufen
        metrics = collector.get_metrics("sat-001")
    """

    def __init__(
        self,
        history_size: int = 1000,
        logger: logging.Logger | None = None,
    ) -> None:
        """
        Initialisiert den Collector.

        Args:
            history_size: Maximale Anzahl historischer Werte
            logger: Logger-Instanz
        """
        self._history_size = history_size
        self.logger = logger or logging.getLogger(__name__)

        self._metrics: dict[str, SatelliteMetrics] = {}
        self._custom_metrics: dict[str, deque[MetricValue]] = {}
        self._callbacks: list[Callable[[str, MetricValue], None]] = []

    @property
    def satellite_count(self) -> int:
        """Anzahl überwachter Satellites."""
        return len(self._metrics)

    def _get_or_create(self, satellite_id: str) -> SatelliteMetrics:
        """Holt oder erstellt Metriken für Satellite."""
        if satellite_id not in self._metrics:
            self._metrics[satellite_id] = SatelliteMetrics(
                satellite_id=satellite_id
            )
        return self._metrics[satellite_id]

    def _notify(self, satellite_id: str, value: MetricValue) -> None:
        """Benachrichtigt registrierte Callbacks."""
        for callback in self._callbacks:
            try:
                callback(satellite_id, value)
            except Exception as e:
                self.logger.error(f"Callback-Fehler: {e}")

    def on_metric(
        self,
        callback: Callable[[str, MetricValue], None],
    ) -> None:
        """Registriert Callback für neue Metriken."""
        self._callbacks.append(callback)

    def record_latency(self, satellite_id: str, latency_ms: float) -> None:
        """
        Zeichnet Latenz-Messung auf.

        Args:
            satellite_id: Satellite-ID
            latency_ms: Latenz in Millisekunden
        """
        metrics = self._get_or_create(satellite_id)
        metrics.record_latency(latency_ms)

        value = MetricValue(
            name="latency",
            value=latency_ms,
            metric_type=MetricType.TIMING,
            unit="ms",
        )
        self._notify(satellite_id, value)

    def record_message_sent(
        self,
        satellite_id: str,
        bytes_count: int,
    ) -> None:
        """Zeichnet gesendete Nachricht auf."""
        metrics = self._get_or_create(satellite_id)
        metrics.messages_sent += 1
        metrics.bytes_sent += bytes_count
        metrics.last_updated = datetime.now()

    def record_message_received(
        self,
        satellite_id: str,
        bytes_count: int,
    ) -> None:
        """Zeichnet empfangene Nachricht auf."""
        metrics = self._get_or_create(satellite_id)
        metrics.messages_received += 1
        metrics.bytes_received += bytes_count
        metrics.last_updated = datetime.now()

    def record_heartbeat(self, satellite_id: str) -> None:
        """Zeichnet Heartbeat auf."""
        metrics = self._get_or_create(satellite_id)
        metrics.last_heartbeat = datetime.now()
        metrics.last_updated = datetime.now()

    def record_reconnect(self, satellite_id: str) -> None:
        """Zeichnet Reconnect auf."""
        metrics = self._get_or_create(satellite_id)
        metrics.reconnect_count += 1
        metrics.connection_uptime_seconds = 0.0
        metrics.last_updated = datetime.now()

    def record_error(self, satellite_id: str, error: str) -> None:
        """Zeichnet Fehler auf."""
        metrics = self._get_or_create(satellite_id)
        metrics.record_error(error)

        value = MetricValue(
            name="error",
            value=1,
            metric_type=MetricType.COUNTER,
            labels={"error": error[:100]},  # Begrenzen
        )
        self._notify(satellite_id, value)

    def record_packet_loss(
        self,
        satellite_id: str,
        loss_percent: float,
    ) -> None:
        """Zeichnet Paketverlust auf."""
        metrics = self._get_or_create(satellite_id)
        metrics.packet_loss_percent = loss_percent
        metrics.last_updated = datetime.now()

    def record_bandwidth(
        self,
        satellite_id: str,
        bandwidth_kbps: float,
    ) -> None:
        """Zeichnet Bandbreite auf."""
        metrics = self._get_or_create(satellite_id)
        metrics.bandwidth_kbps = bandwidth_kbps
        metrics.last_updated = datetime.now()

    def record_custom(
        self,
        satellite_id: str,
        name: str,
        value: float,
        metric_type: MetricType = MetricType.GAUGE,
        labels: dict[str, str] | None = None,
        unit: str = "",
    ) -> None:
        """
        Zeichnet benutzerdefinierte Metrik auf.

        Args:
            satellite_id: Satellite-ID
            name: Metrik-Name
            value: Wert
            metric_type: Metrik-Typ
            labels: Optionale Labels
            unit: Einheit
        """
        metric_value = MetricValue(
            name=name,
            value=value,
            metric_type=metric_type,
            labels=labels or {},
            unit=unit,
        )

        key = f"{satellite_id}:{name}"
        if key not in self._custom_metrics:
            self._custom_metrics[key] = deque(maxlen=self._history_size)

        self._custom_metrics[key].append(metric_value)
        self._notify(satellite_id, metric_value)

    def get_metrics(self, satellite_id: str) -> SatelliteMetrics | None:
        """Holt Metriken für Satellite."""
        return self._metrics.get(satellite_id)

    def get_all_metrics(self) -> dict[str, SatelliteMetrics]:
        """Holt alle Metriken."""
        return self._metrics.copy()

    def get_custom_metric(
        self,
        satellite_id: str,
        name: str,
    ) -> list[MetricValue]:
        """Holt benutzerdefinierte Metrik-Historie."""
        key = f"{satellite_id}:{name}"
        if key in self._custom_metrics:
            return list(self._custom_metrics[key])
        return []

    def remove_satellite(self, satellite_id: str) -> bool:
        """Entfernt Metriken für Satellite."""
        if satellite_id in self._metrics:
            del self._metrics[satellite_id]

            # Custom Metriken entfernen
            to_remove = [
                k for k in self._custom_metrics
                if k.startswith(f"{satellite_id}:")
            ]
            for key in to_remove:
                del self._custom_metrics[key]

            return True
        return False

    def get_summary(self) -> dict[str, Any]:
        """Liefert Zusammenfassung aller Metriken."""
        if not self._metrics:
            return {
                "satellite_count": 0,
                "avg_latency_ms": 0,
                "total_messages": 0,
                "total_errors": 0,
            }

        avg_latency = sum(
            m.latency_ms for m in self._metrics.values()
        ) / len(self._metrics)

        total_messages = sum(
            m.messages_sent + m.messages_received
            for m in self._metrics.values()
        )

        total_errors = sum(
            m.error_count for m in self._metrics.values()
        )

        return {
            "satellite_count": self.satellite_count,
            "avg_latency_ms": round(avg_latency, 2),
            "total_messages": total_messages,
            "total_errors": total_errors,
            "satellites": {
                sat_id: {
                    "latency_ms": m.latency_ms,
                    "messages": m.messages_sent + m.messages_received,
                    "errors": m.error_count,
                }
                for sat_id, m in self._metrics.items()
            },
        }

    def clear_all(self) -> None:
        """Löscht alle Metriken."""
        self._metrics.clear()
        self._custom_metrics.clear()