"""
Example subscription function for System Errors.
This is a template that can be used as a reference for creating other subscription functions.
"""

from typing import List
from modules.datamodels.datamodelMessaging import (
    MessagingEventParameters,
    MessagingSubscriptionExecutionResult,
    MessagingSubscriptionRegistration,
    MessagingChannel
)


def execute(
    eventParameters: MessagingEventParameters,
    registrations: List[MessagingSubscriptionRegistration],
    messagingService
) -> MessagingSubscriptionExecutionResult:
    """
    Subscription-Funktion für System-Errors.
    Erhält eventParameters vom Trigger und registrations bereits geholt.
    
    Args:
        eventParameters: Event-Parameter vom Trigger
        registrations: Liste der aktiven Registrierungen für diese Subscription
        messagingService: MessagingService-Instanz
    
    Returns:
        MessagingSubscriptionExecutionResult mit Status und Anzahl gesendeter Nachrichten
    """
    # Gruppiere nach Channel
    emailRegistrations = [r for r in registrations if r.channel == MessagingChannel.EMAIL]
    smsRegistrations = [r for r in registrations if r.channel == MessagingChannel.SMS]
    
    # Bereite Nachrichten vor (können pro Channel unterschiedlich sein)
    triggerData = eventParameters.triggerData
    errors = triggerData.get('errors', [])
    timestamp = triggerData.get('timestamp', 'Unknown')
    
    emailSubject = "System Error Report"
    emailMessage = f"System errors detected at {timestamp}:\n\n{errors}"
    
    smsMessage = f"System Error: {len(errors)} errors detected at {timestamp}"
    
    messagesSent = 0
    
    # Versende über sendMessage
    for reg in emailRegistrations:
        sendResult = messagingService.sendMessage(
            subject=emailSubject,
            message=emailMessage,
            registration=reg
        )
        if sendResult.success:
            messagesSent += 1
    
    for reg in smsRegistrations:
        sendResult = messagingService.sendMessage(
            subject="",  # SMS hat kein Subject
            message=smsMessage,
            registration=reg
        )
        if sendResult.success:
            messagesSent += 1
    
    return MessagingSubscriptionExecutionResult(
        success=True,
        messagesSent=messagesSent
    )