import os
import json
import socket
import subprocess
import platform
import netifaces
import requests
from datetime import datetime
import logging

class NetworkConfig:
    """Verwaltet die Netzwerkkonfiguration für das MYP-System."""
    
    CONFIG_FILE = 'instance/network_config.json'
    DEFAULT_CONFIG = {
        'backend_hostname': '192.168.0.5',
        'backend_port': 5000,
        'frontend_hostname': '192.168.0.106',
        'frontend_port': 3000
    }
    
    def __init__(self, app=None):
        """Initialisierung der Netzwerkkonfiguration."""
        self.logger = logging.getLogger('myp.network')
        self.config = self.DEFAULT_CONFIG.copy()
        self.last_check = None
        self.backend_status = "Nicht überprüft"
        self.frontend_status = "Nicht überprüft"
        
        # Stelle sicher, dass das Verzeichnis existiert
        os.makedirs(os.path.dirname(self.CONFIG_FILE), exist_ok=True)
        
        # Lade gespeicherte Konfiguration, falls vorhanden
        self.load_config()
        
        if app:
            self.init_app(app)
    
    def init_app(self, app):
        """Initialisiert die Anwendung mit dieser Konfiguration."""
        app.network_config = self
        
        # Registriere Route für Netzwerkkonfiguration
        @app.route('/admin/network-config', methods=['GET', 'POST'])
        def network_config():
            from flask import request, render_template, flash, redirect, url_for
            
            # Prüfe aktuelle Status
            self.check_connection_statuses()
            
            if request.method == 'POST':
                # Aktualisiere Konfiguration
                self.config['backend_hostname'] = request.form.get('backend_hostname', self.DEFAULT_CONFIG['backend_hostname'])
                self.config['backend_port'] = int(request.form.get('backend_port', self.DEFAULT_CONFIG['backend_port']))
                self.config['frontend_hostname'] = request.form.get('frontend_hostname', self.DEFAULT_CONFIG['frontend_hostname'])
                self.config['frontend_port'] = int(request.form.get('frontend_port', self.DEFAULT_CONFIG['frontend_port']))
                
                # Speichere Konfiguration
                self.save_config()
                
                # Teste die neue Konfiguration
                self.check_connection_statuses()
                
                flash('Netzwerkkonfiguration erfolgreich gespeichert!', 'success')
                return redirect(url_for('network_config'))
            
            # Ermittle Netzwerkschnittstellen
            network_interfaces = self.get_network_interfaces()
            
            return render_template('network_config.html', 
                                 config=self.config,
                                 backend_status=self.backend_status,
                                 frontend_status=self.frontend_status,
                                 last_check=self.last_check,
                                 network_interfaces=network_interfaces,
                                 message=request.args.get('message'),
                                 message_type=request.args.get('message_type', 'info'))
    
    def load_config(self):
        """Lädt die gespeicherte Konfiguration."""
        try:
            if os.path.exists(self.CONFIG_FILE):
                with open(self.CONFIG_FILE, 'r') as f:
                    saved_config = json.load(f)
                    self.config.update(saved_config)
                    self.logger.info(f"Netzwerkkonfiguration geladen: {self.config}")
            else:
                self.logger.info(f"Keine gespeicherte Konfiguration gefunden, verwende Standardwerte: {self.config}")
        except Exception as e:
            self.logger.error(f"Fehler beim Laden der Netzwerkkonfiguration: {e}")
    
    def save_config(self):
        """Speichert die aktuelle Konfiguration."""
        try:
            with open(self.CONFIG_FILE, 'w') as f:
                json.dump(self.config, f, indent=4)
            self.logger.info(f"Netzwerkkonfiguration gespeichert: {self.config}")
            return True
        except Exception as e:
            self.logger.error(f"Fehler beim Speichern der Netzwerkkonfiguration: {e}")
            return False
    
    def get_backend_url(self):
        """Gibt die Backend-URL zurück."""
        return f"http://{self.config['backend_hostname']}:{self.config['backend_port']}"
    
    def get_frontend_url(self):
        """Gibt die Frontend-URL zurück."""
        return f"http://{self.config['frontend_hostname']}:{self.config['frontend_port']}"
    
    def check_connection_statuses(self):
        """Überprüft den Verbindungsstatus zu Backend und Frontend."""
        self.last_check = datetime.now().strftime("%d.%m.%Y %H:%M:%S")
        
        # Prüfe Backend-Verbindung
        backend_url = self.get_backend_url()
        try:
            response = requests.get(f"{backend_url}/api/test", timeout=3)
            if response.status_code == 200:
                self.backend_status = "Verbunden"
            else:
                self.backend_status = f"Fehler: HTTP {response.status_code}"
        except requests.exceptions.RequestException as e:
            self.backend_status = f"Nicht erreichbar: {str(e)}"
        
        # Prüfe Frontend-Verbindung
        frontend_url = self.get_frontend_url()
        try:
            response = requests.get(frontend_url, timeout=3)
            if response.status_code == 200:
                self.frontend_status = "Verbunden"
            else:
                self.frontend_status = f"Fehler: HTTP {response.status_code}"
        except requests.exceptions.RequestException as e:
            self.frontend_status = f"Nicht erreichbar: {str(e)}"
        
        self.logger.info(f"Verbindungsstatus - Backend: {self.backend_status}, Frontend: {self.frontend_status}")
    
    def get_network_interfaces(self):
        """Gibt Informationen zu allen Netzwerkschnittstellen zurück."""
        interfaces = []
        
        try:
            for interface in netifaces.interfaces():
                if interface.startswith(('lo', 'docker', 'br-')):
                    continue  # Ignoriere Loopback und Docker-Interfaces
                
                addresses = []
                try:
                    addrs = netifaces.ifaddresses(interface)
                    if netifaces.AF_INET in addrs:
                        for addr in addrs[netifaces.AF_INET]:
                            if 'addr' in addr:
                                addresses.append(addr['addr'])
                except Exception as e:
                    self.logger.error(f"Fehler beim Ermitteln der Adresse für Interface {interface}: {e}")
                
                if addresses:
                    interfaces.append({
                        'name': interface,
                        'address': ', '.join(addresses)
                    })
        except Exception as e:
            self.logger.error(f"Fehler beim Ermitteln der Netzwerkschnittstellen: {e}")
        
        return interfaces

# Helper-Funktion zum Testen von Netzwerkverbindungen
def test_connection(host, port, timeout=2):
    """Testet eine TCP-Verbindung zu einem Host und Port."""
    try:
        socket.setdefaulttimeout(timeout)
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.connect((host, port))
        s.close()
        return True
    except Exception as e:
        return False

# Helper-Funktion zum Ping eines Hosts
def ping_host(host, count=1):
    """Pingt einen Host an."""
    param = '-n' if platform.system().lower() == 'windows' else '-c'
    command = ['ping', param, str(count), host]
    return subprocess.call(command, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL) == 0