"""
Syslog Parser - Analizza log MikroTik e li salva in PostgreSQL
Legge da /var/log/mikrotik/raw.log e popola la tabella network_logs
"""

import re
import psycopg2
from datetime import datetime
from typing import Dict, Optional
import os
import time
from dotenv import load_dotenv


class SyslogParser:
    """
    Parser per log MikroTik in formato syslog
    Estrae informazioni di rete e salva in database
    """
    
    def __init__(self, db_config: Dict[str, str]):
        self.db_config = db_config
        self.conn = None
        self.cursor = None
        
        # Pattern regex per parsare log MikroTik
        # Formato: timestamp hostname tag: message
        self.patterns = {
            # Firewall connection
            'firewall': re.compile(
                r'(?P<action>accept|drop|reject).*'
                r'src-address=(?P<src_ip>[\d.]+):(?P<src_port>\d+).*'
                r'dst-address=(?P<dst_ip>[\d.]+):(?P<dst_port>\d+).*'
                r'proto=(?P<proto>\w+).*'
                r'(?:len=(?P<len>\d+))?'
            ),
            # Connection tracking
            'connection': re.compile(
                r'(?P<src_ip>[\d.]+):(?P<src_port>\d+)->(?P<dst_ip>[\d.]+):(?P<dst_port>\d+).*'
                r'proto (?P<proto>\w+).*'
                r'(?:packets: (?P<packets>\d+))?.*'
                r'(?:bytes: (?P<bytes>\d+))?'
            ),
        }
    
    def connect_db(self):
        """Connessione al database PostgreSQL"""
        try:
            self.conn = psycopg2.connect(**self.db_config)
            self.cursor = self.conn.cursor()
            print("[INFO] Connesso a PostgreSQL")
        except Exception as e:
            print(f"[ERROR] Connessione database fallita: {e}")
            raise
    
    def disconnect_db(self):
        """Chiusura connessione database"""
        if self.cursor:
            self.cursor.close()
        if self.conn:
            self.conn.close()
        print("[INFO] Disconnesso da PostgreSQL")
    
    def parse_log_line(self, line: str) -> Optional[Dict]:
        """
        Analizza una singola riga di log MikroTik
        Returns: Dict con dati parsati o None se non parsabile
        """
        # Estrai timestamp, hostname, tag e messaggio
        # Formato: Jan 15 10:30:45 router1 firewall,info: drop src-address=...
        parts = line.split(None, 4)
        if len(parts) < 5:
            return None
        
        month, day, time_str, hostname, message = parts
        
        # Parse timestamp (usa anno corrente)
        current_year = datetime.now().year
        try:
            timestamp = datetime.strptime(
                f"{current_year} {month} {day} {time_str}",
                "%Y %b %d %H:%M:%S"
            )
        except ValueError:
            return None
        
        # Prova pattern firewall
        for pattern_name, pattern in self.patterns.items():
            match = pattern.search(message)
            if match:
                data = match.groupdict()
                
                # Aggiungi metadati
                data['timestamp'] = timestamp
                data['router_name'] = hostname
                data['log_type'] = pattern_name
                data['raw_message'] = message.strip()
                
                # Converti numeri
                for key in ['src_port', 'dst_port', 'len', 'packets', 'bytes']:
                    if key in data and data[key]:
                        data[key] = int(data[key])
                
                return data
        
        return None
    
    def save_to_db(self, log_data: Dict):
        """Salva log parsato nel database"""
        try:
            query = """
                INSERT INTO network_logs 
                (timestamp, router_name, source_ip, source_port, destination_ip, 
                 destination_port, protocol, packet_length, action, raw_message)
                VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
                ON CONFLICT DO NOTHING
            """
            
            self.cursor.execute(query, (
                log_data.get('timestamp'),
                log_data.get('router_name'),
                log_data.get('src_ip'),
                log_data.get('src_port'),
                log_data.get('dst_ip'),
                log_data.get('dst_port'),
                log_data.get('proto', 'unknown').lower(),
                log_data.get('len') or log_data.get('bytes'),
                log_data.get('action', 'unknown'),
                log_data.get('raw_message')
            ))
            
        except Exception as e:
            print(f"[ERROR] Errore salvataggio log: {e}")
            self.conn.rollback()
    
    def process_log_file(self, log_file: str, follow: bool = False):
        """
        Processa file di log
        follow: se True, segue il file come 'tail -f'
        """
        print(f"[INFO] Processando {log_file} (follow={follow})")
        
        processed = 0
        saved = 0
        
        try:
            with open(log_file, 'r') as f:
                # Se follow, vai alla fine del file
                if follow:
                    f.seek(0, 2)  # Seek to end
                
                while True:
                    line = f.readline()
                    
                    if not line:
                        if follow:
                            time.sleep(0.1)  # Attendi nuove righe
                            self.conn.commit()  # Commit batch
                            continue
                        else:
                            break  # Fine file
                    
                    processed += 1
                    
                    # Parsa riga
                    log_data = self.parse_log_line(line.strip())
                    if log_data:
                        self.save_to_db(log_data)
                        saved += 1
                    
                    # Commit ogni 100 righe
                    if processed % 100 == 0:
                        self.conn.commit()
                        print(f"[INFO] Processate {processed} righe, salvate {saved} log")
        
        except KeyboardInterrupt:
            print("\n[INFO] Interrotto dall'utente")
        except Exception as e:
            print(f"[ERROR] Errore processamento file: {e}")
        finally:
            self.conn.commit()
            print(f"[INFO] Totale: {processed} righe processate, {saved} log salvati")


def main():
    """Main entry point"""
    # Carica variabili d'ambiente da .env
    load_dotenv("/opt/ids/.env")
    
    # Configurazione database da environment
    # IMPORTANTE: Usa 127.0.0.1 invece di localhost per forzare IPv4
    db_config = {
        'host': os.getenv('PGHOST', '127.0.0.1'),
        'port': os.getenv('PGPORT', '5432'),
        'database': os.getenv('PGDATABASE', 'ids_database'),
        'user': os.getenv('PGUSER', 'ids_user'),
        'password': os.getenv('PGPASSWORD', 'ids_password_change_me')
    }
    
    # File log da processare
    log_file = '/var/log/mikrotik/raw.log'
    
    # Crea parser
    parser = SyslogParser(db_config)
    
    try:
        # Connetti al database
        parser.connect_db()
        
        # Processa file in modalità follow (come tail -f)
        parser.process_log_file(log_file, follow=True)
        
    finally:
        parser.disconnect_db()


if __name__ == "__main__":
    print("=== SYSLOG PARSER PER ROUTER MIKROTIK ===")
    print("Pressione Ctrl+C per interrompere\n")
    main()