#!/usr/bin/env python3
"""
Service Bus for Personal Internet Cell
Event-driven service communication and orchestration
"""

import asyncio
import json
import logging
from datetime import datetime
from typing import Dict, List, Callable, Any, Optional
from collections import defaultdict
import threading
import queue
from dataclasses import dataclass
from enum import Enum

logger = logging.getLogger(__name__)

class EventType(Enum):
    """Event types for service communication"""
    SERVICE_STARTED = "service_started"
    SERVICE_STOPPED = "service_stopped"
    SERVICE_RESTARTED = "service_restarted"
    CONFIG_CHANGED = "config_changed"
    HEALTH_CHECK = "health_check"
    ERROR_OCCURRED = "error_occurred"
    PEER_CONNECTED = "peer_connected"
    PEER_DISCONNECTED = "peer_disconnected"
    SECRET_ROTATED = "secret_rotated"
    CERTIFICATE_EXPIRING = "certificate_expiring"
    BACKUP_CREATED = "backup_created"
    RESTORE_COMPLETED = "restore_completed"

@dataclass
class Event:
    """Event data structure"""
    event_type: EventType
    source: str
    data: Dict[str, Any]
    timestamp: datetime
    event_id: str

class ServiceBus:
    """Event-driven service communication bus"""
    
    def __init__(self):
        self.event_handlers: Dict[EventType, List[Callable]] = defaultdict(list)
        self.service_registry: Dict[str, Any] = {}
        self.event_queue = queue.Queue()
        self.running = False
        self.event_loop_thread = None
        self.event_history: List[Event] = []
        self.max_history = 1000
        
        # Service dependency mapping
        self.service_dependencies: Dict[str, List[str]] = {
            'wireguard': ['network'],
            'email': ['network', 'vault'],
            'calendar': ['network', 'vault'],
            'files': ['network', 'vault'],
            'routing': ['network', 'wireguard'],
            'vault': ['network']
        }
        
        # Service lifecycle hooks
        self.lifecycle_hooks: Dict[str, Dict[str, Callable]] = defaultdict(dict)
    
    def start(self):
        """Start the service bus"""
        if self.running:
            return
        
        self.running = True
        self.event_loop_thread = threading.Thread(target=self._event_loop, daemon=True)
        self.event_loop_thread.start()
        logger.info("Service bus started")
    
    def stop(self):
        """Stop the service bus"""
        self.running = False
        if self.event_loop_thread:
            self.event_loop_thread.join(timeout=5)
        logger.info("Service bus stopped")
    
    def register_service(self, name: str, service: Any):
        """Register a service with the bus"""
        self.service_registry[name] = service
        logger.info(f"Registered service: {name}")
        
        # Publish service started event
        self.publish_event(EventType.SERVICE_STARTED, name, {
            "service": name,
            "timestamp": datetime.utcnow().isoformat()
        })
    
    def unregister_service(self, name: str):
        """Unregister a service from the bus"""
        if name in self.service_registry:
            del self.service_registry[name]
            logger.info(f"Unregistered service: {name}")
            
            # Publish service stopped event
            self.publish_event(EventType.SERVICE_STOPPED, name, {
                "service": name,
                "timestamp": datetime.utcnow().isoformat()
            })
    
    def publish_event(self, event_type: EventType, source: str, data: Dict[str, Any]):
        """Publish an event to the bus"""
        import uuid
        
        event = Event(
            event_type=event_type,
            source=source,
            data=data,
            timestamp=datetime.utcnow(),
            event_id=str(uuid.uuid4())
        )
        
        self.event_queue.put(event)
        logger.debug(f"Published event: {event_type.value} from {source}")
    
    def subscribe_to_event(self, event_type: EventType, handler: Callable[[Event], None]):
        """Subscribe to an event type"""
        self.event_handlers[event_type].append(handler)
        logger.info(f"Subscribed to event: {event_type.value}")
    
    def unsubscribe_from_event(self, event_type: EventType, handler: Callable[[Event], None]):
        """Unsubscribe from an event type"""
        if event_type in self.event_handlers:
            try:
                self.event_handlers[event_type].remove(handler)
                logger.info(f"Unsubscribed from event: {event_type.value}")
            except ValueError:
                logger.warning(f"Handler not found for event: {event_type.value}")
    
    def call_service(self, service_name: str, method: str, **kwargs) -> Any:
        """Call a method on a registered service"""
        if service_name not in self.service_registry:
            raise ValueError(f"Service {service_name} not registered")
        
        service = self.service_registry[service_name]
        if not hasattr(service, method):
            raise ValueError(f"Method {method} not found on service {service_name}")
        
        try:
            result = getattr(service, method)(**kwargs)
            logger.debug(f"Called {service_name}.{method}")
            return result
        except Exception as e:
            logger.error(f"Error calling {service_name}.{method}: {e}")
            self.publish_event(EventType.ERROR_OCCURRED, service_name, {
                "error": str(e),
                "method": method,
                "service": service_name
            })
            raise
    
    def get_service(self, service_name: str) -> Any:
        """Get a registered service"""
        return self.service_registry.get(service_name)
    
    def list_services(self) -> List[str]:
        """List all registered services"""
        return list(self.service_registry.keys())
    
    def add_lifecycle_hook(self, service_name: str, hook_type: str, hook: Callable):
        """Add a lifecycle hook for a service"""
        self.lifecycle_hooks[service_name][hook_type] = hook
        logger.info(f"Added {hook_type} hook for {service_name}")
    
    def remove_lifecycle_hook(self, service_name: str, hook_type: str):
        """Remove a lifecycle hook for a service"""
        if service_name in self.lifecycle_hooks and hook_type in self.lifecycle_hooks[service_name]:
            del self.lifecycle_hooks[service_name][hook_type]
            logger.info(f"Removed {hook_type} hook for {service_name}")
    
    def orchestrate_service_start(self, service_name: str) -> bool:
        """Orchestrate starting a service with its dependencies"""
        try:
            # Map service names to Docker container names and their dependencies
            service_to_containers = {
                'wireguard': ['cell-wireguard'],
                'email': ['cell-mail', 'cell-rainloop'],  # Email service includes both mail server and web client
                'calendar': ['cell-radicale'],
                'files': ['cell-webdav', 'cell-filegator'],  # Files service includes both webdav and file manager
                'network': ['cell-dns', 'cell-dhcp', 'cell-ntp'],  # Network service includes all network components
                'routing': None,  # Routing is a system service, not a container
                'vault': None,  # Vault is part of API, not a separate container
                'container': None  # Container manager doesn't have its own container
            }
            
            containers = service_to_containers.get(service_name)
            
            if containers is None:
                # For services without containers (routing, vault, container), just call their start method
                if hasattr(self.service_registry[service_name], 'start'):
                    self.service_registry[service_name].start()
                logger.info(f"Started service (no container): {service_name}")
                return True
            
            # For services with containers, start all required Docker containers
            if 'container' in self.service_registry:
                container_manager = self.service_registry['container']
                all_success = True
                
                for container_name in containers:
                    success = container_manager.start_container(container_name)
                    if success:
                        logger.info(f"Started container {container_name} for service {service_name}")
                    else:
                        logger.error(f"Failed to start container {container_name} for service {service_name}")
                        all_success = False
                
                if all_success:
                    logger.info(f"Started all containers for service {service_name}: {containers}")
                    return True
                else:
                    logger.error(f"Failed to start some containers for service {service_name}")
                    return False
            else:
                logger.error("Container manager not available")
                return False
            
        except Exception as e:
            logger.error(f"Error orchestrating start of {service_name}: {e}")
            return False
    
    def orchestrate_service_stop(self, service_name: str) -> bool:
        """Orchestrate stopping a service"""
        try:
            # Map service names to Docker container names and their dependencies
            service_to_containers = {
                'wireguard': ['cell-wireguard'],
                'email': ['cell-mail', 'cell-rainloop'],  # Email service includes both mail server and web client
                'calendar': ['cell-radicale'],
                'files': ['cell-webdav', 'cell-filegator'],  # Files service includes both webdav and file manager
                'network': ['cell-dns', 'cell-dhcp', 'cell-ntp'],  # Network service includes all network components
                'routing': None,  # Routing is a system service, not a container
                'vault': None,  # Vault is part of API, not a separate container
                'container': None  # Container manager doesn't have its own container
            }
            
            containers = service_to_containers.get(service_name)
            
            if containers is None:
                # For services without containers (routing, vault, container), just call their stop method
                if hasattr(self.service_registry[service_name], 'stop'):
                    self.service_registry[service_name].stop()
                logger.info(f"Stopped service (no container): {service_name}")
                return True
            
            # For services with containers, stop all required Docker containers
            if 'container' in self.service_registry:
                container_manager = self.service_registry['container']
                all_success = True
                
                for container_name in containers:
                    success = container_manager.stop_container(container_name)
                    if success:
                        logger.info(f"Stopped container {container_name} for service {service_name}")
                    else:
                        logger.error(f"Failed to stop container {container_name} for service {service_name}")
                        all_success = False
                
                if all_success:
                    logger.info(f"Stopped all containers for service {service_name}: {containers}")
                    return True
                else:
                    logger.error(f"Failed to stop some containers for service {service_name}")
                    return False
            else:
                logger.error("Container manager not available")
                return False
            
        except Exception as e:
            logger.error(f"Error orchestrating stop of {service_name}: {e}")
            return False
    
    def orchestrate_service_restart(self, service_name: str) -> bool:
        """Orchestrate restarting a service"""
        try:
            if self.orchestrate_service_stop(service_name):
                return self.orchestrate_service_start(service_name)
            return False
        except Exception as e:
            logger.error(f"Error orchestrating restart of {service_name}: {e}")
            return False
    
    def get_event_history(self, event_type: Optional[EventType] = None, 
                         source: Optional[str] = None, limit: int = 100) -> List[Event]:
        """Get event history with optional filtering"""
        events = self.event_history
        
        if event_type:
            events = [e for e in events if e.event_type == event_type]
        
        if source:
            events = [e for e in events if e.source == source]
        
        return events[-limit:]
    
    def clear_event_history(self):
        """Clear event history"""
        self.event_history.clear()
        logger.info("Event history cleared")
    
    def _event_loop(self):
        """Main event processing loop"""
        while self.running:
            try:
                # Get event from queue with timeout
                event = self.event_queue.get(timeout=1)
                
                # Add to history
                self.event_history.append(event)
                if len(self.event_history) > self.max_history:
                    self.event_history.pop(0)
                
                # Process event handlers
                handlers = self.event_handlers.get(event.event_type, [])
                for handler in handlers:
                    try:
                        handler(event)
                    except Exception as e:
                        logger.error(f"Error in event handler for {event.event_type.value}: {e}")
                
                # Mark task as done
                self.event_queue.task_done()
                
            except queue.Empty:
                continue
            except Exception as e:
                logger.error(f"Error in event loop: {e}")
    
    def get_service_dependencies(self, service_name: str) -> List[str]:
        """Get dependencies for a service"""
        return self.service_dependencies.get(service_name, [])
    
    def add_service_dependency(self, service_name: str, dependency: str):
        """Add a dependency for a service"""
        if service_name not in self.service_dependencies:
            self.service_dependencies[service_name] = []
        self.service_dependencies[service_name].append(dependency)
        logger.info(f"Added dependency {dependency} for service {service_name}")
    
    def remove_service_dependency(self, service_name: str, dependency: str):
        """Remove a dependency for a service"""
        if service_name in self.service_dependencies:
            try:
                self.service_dependencies[service_name].remove(dependency)
                logger.info(f"Removed dependency {dependency} for service {service_name}")
            except ValueError:
                logger.warning(f"Dependency {dependency} not found for service {service_name}")
    
    def get_service_status_summary(self) -> Dict[str, Any]:
        """Get summary of all service statuses"""
        summary = {
            "total_services": len(self.service_registry),
            "services": {},
            "event_count": len(self.event_history),
            "timestamp": datetime.utcnow().isoformat()
        }
        
        for service_name, service in self.service_registry.items():
            try:
                if hasattr(service, 'get_status'):
                    status = service.get_status()
                else:
                    status = {"status": "unknown"}
                
                summary["services"][service_name] = {
                    "status": status,
                    "dependencies": self.service_dependencies.get(service_name, [])
                }
            except Exception as e:
                summary["services"][service_name] = {
                    "status": {"error": str(e)},
                    "dependencies": self.service_dependencies.get(service_name, [])
                }
        
        return summary