"""
Notification System
Email, SMS, Push notifications for IOM platform
"""

from typing import Dict, List, Optional
from dataclasses import dataclass
from enum import Enum
from datetime import datetime


class NotificationChannel(str, Enum):
    """Notification channels"""
    EMAIL = "email"
    SMS = "sms"
    PUSH = "push"
    WEBHOOK = "webhook"
    SLACK = "slack"


class NotificationPriority(str, Enum):
    """Notification priorities"""
    LOW = "low"
    MEDIUM = "medium"
    HIGH = "high"
    CRITICAL = "critical"


@dataclass
class Notification:
    """Notification message"""
    id: str
    channel: NotificationChannel
    recipient: str
    subject: str
    body: str
    priority: NotificationPriority
    timestamp: str
    metadata: Optional[Dict] = None


class NotificationEngine:
    """
    Multi-channel notification engine
    
    Supports:
    - Email (SMTP)
    - SMS (Twilio/simulated)
    - Push (Firebase/APNs)
    - Webhook (HTTP callbacks)
    - Slack (webhooks)
    """
    
    def __init__(self):
        self.providers: Dict[NotificationChannel, callable] = {
            NotificationChannel.EMAIL: self._send_email,
            NotificationChannel.SMS: self._send_sms,
            NotificationChannel.PUSH: self._send_push,
            NotificationChannel.WEBHOOK: self._send_webhook,
            NotificationChannel.SLACK: self._send_slack
        }
        self.history: List[Notification] = []
    
    def send(
        self,
        channel: NotificationChannel,
        recipient: str,
        subject: str,
        body: str,
        priority: NotificationPriority = NotificationPriority.MEDIUM,
        metadata: Optional[Dict] = None
    ) -> Dict:
        """Send notification"""
        notification = Notification(
            id=f"NOT-{datetime.utcnow().strftime('%Y%m%d%H%M%S')}",
            channel=channel,
            recipient=recipient,
            subject=subject,
            body=body,
            priority=priority,
            timestamp=datetime.utcnow().isoformat(),
            metadata=metadata
        )
        
        # Send via provider
        provider = self.providers.get(channel)
        if provider:
            result = provider(notification)
        else:
            result = {"status": "failed", "error": "Unknown channel"}
        
        # Store in history
        self.history.append(notification)
        
        return {
            "notification_id": notification.id,
            "channel": channel.value,
            "recipient": recipient,
            "status": result.get("status", "unknown"),
            "timestamp": notification.timestamp
        }
    
    def send_bulk(
        self,
        notifications: List[Dict]
    ) -> List[Dict]:
        """Send multiple notifications"""
        results = []
        for notif in notifications:
            result = self.send(
                channel=NotificationChannel(notif["channel"]),
                recipient=notif["recipient"],
                subject=notif["subject"],
                body=notif["body"],
                priority=NotificationPriority(notif.get("priority", "medium"))
            )
            results.append(result)
        return results
    
    def notify_stakeholder(
        self,
        stakeholder_type: str,
        event_type: str,
        data: Dict
    ) -> List[Dict]:
        """Notify stakeholder about event"""
        notifications = []
        
        if stakeholder_type == "municipality":
            if event_type == "critical_defect":
                notifications.append({
                    "channel": "email",
                    "recipient": "municipality@example.com",
                    "subject": f"Critical defect detected: {data.get('location', 'Unknown')}",
                    "body": f"A critical defect has been detected. Location: {data.get('location')}. Condition: {data.get('condition')}",
                    "priority": "critical"
                })
        
        elif stakeholder_type == "property_owner":
            if event_type == "maintenance_required":
                notifications.append({
                    "channel": "email",
                    "recipient": "owner@example.com",
                    "subject": "Maintenance required",
                    "body": f"Your property requires maintenance. Estimated cost: ${data.get('cost', 0)}",
                    "priority": "high"
                })
        
        return self.send_bulk(notifications)
    
    def _send_email(self, notification: Notification) -> Dict:
        """Send email notification"""
        # In production, use SMTP
        print(f"[EMAIL] To: {notification.recipient}")
        print(f"[EMAIL] Subject: {notification.subject}")
        print(f"[EMAIL] Body: {notification.body[:100]}...")
        return {"status": "sent"}
    
    def _send_sms(self, notification: Notification) -> Dict:
        """Send SMS notification"""
        # In production, use Twilio
        print(f"[SMS] To: {notification.recipient}")
        print(f"[SMS] Body: {notification.body[:160]}")
        return {"status": "sent"}
    
    def _send_push(self, notification: Notification) -> Dict:
        """Send push notification"""
        # In production, use Firebase/APNs
        print(f"[PUSH] To: {notification.recipient}")
        print(f"[PUSH] Title: {notification.subject}")
        return {"status": "sent"}
    
    def _send_webhook(self, notification: Notification) -> Dict:
        """Send webhook notification"""
        # In production, use HTTP client
        print(f"[WEBHOOK] URL: {notification.recipient}")
        print(f"[WEBHOOK] Payload: {notification.body[:100]}...")
        return {"status": "sent"}
    
    def _send_slack(self, notification: Notification) -> Dict:
        """Send Slack notification"""
        # In production, use Slack webhook
        print(f"[SLACK] Channel: {notification.recipient}")
        print(f"[SLACK] Message: {notification.body[:100]}...")
        return {"status": "sent"}
    
    def get_history(self, limit: int = 100) -> List[Dict]:
        """Get notification history"""
        return [
            {
                "id": n.id,
                "channel": n.channel.value,
                "recipient": n.recipient,
                "subject": n.subject,
                "priority": n.priority.value,
                "timestamp": n.timestamp
            }
            for n in self.history[-limit:]
        ]


# Example usage
def example_notifications():
    """Example: Notification system"""
    print("=== Notification Engine Demo ===\n")
    
    engine = NotificationEngine()
    
    # Send email
    print("Sending email...")
    result = engine.send(
        channel=NotificationChannel.EMAIL,
        recipient="admin@landvex.com",
        subject="Critical alert: Bridge condition",
        body="The bridge on Main Street has degraded to condition 4. Immediate action required.",
        priority=NotificationPriority.CRITICAL
    )
    print(f"Status: {result['status']}\n")
    
    # Send SMS
    print("Sending SMS...")
    result = engine.send(
        channel=NotificationChannel.SMS,
        recipient="+46701234567",
        subject="Alert",
        body="Critical defect detected near your location. Please check the app.",
        priority=NotificationPriority.HIGH
    )
    print(f"Status: {result['status']}\n")
    
    # Notify stakeholder
    print("Notifying municipality...")
    results = engine.notify_stakeholder(
        stakeholder_type="municipality",
        event_type="critical_defect",
        data={"location": "Main Street Bridge", "condition": 4}
    )
    print(f"Sent: {len(results)} notifications\n")
    
    # History
    print("Notification history:")
    history = engine.get_history()
    for h in history:
        print(f"  [{h['channel']}] {h['subject']} ({h['priority']})")
    
    return engine


if __name__ == '__main__':
    example_notifications()