"""
Integrations Celery tasks for external system communication.

This module contains tasks for NPHIES (insurance), ZATCA (e-invoicing),
Lab, and Radiology integrations.
"""

import logging
from typing import Dict, Optional, List

from celery import shared_task
from django.conf import settings
from django.utils import timezone

logger = logging.getLogger(__name__)


# ============================================================================
# NPHIES Integration Tasks (Saudi Insurance)
# ============================================================================


@shared_task(bind=True, max_retries=3)
def submit_nphies_eligibility(self, patient_id: str, insurance_id: str) -> Dict:
    """
    Submit eligibility check to NPHIES.
    
    Args:
        patient_id: UUID of the patient
        insurance_id: Insurance policy ID
        
    Returns:
        dict: Eligibility response
    """
    try:
        from core.models import Patient
        
        patient = Patient.objects.get(id=patient_id)
        
        # TODO: Implement actual NPHIES API call
        # This is a placeholder for the integration
        
        logger.info(f"NPHIES eligibility check for patient {patient.mrn}")
        
        # Placeholder response
        response = {
            'status': 'success',
            'eligible': True,
            'coverage_type': 'FULL',
            'message': 'Patient is eligible for coverage',
            'timestamp': str(timezone.now()),
        }
        
        return response
        
    except Exception as exc:
        logger.error(f"NPHIES eligibility check failed: {exc}")
        raise self.retry(exc=exc, countdown=300)


@shared_task(bind=True, max_retries=3)
def submit_nphies_prior_auth(self, appointment_id: str, services: list) -> Dict:
    """
    Submit prior authorization request to NPHIES.
    
    Args:
        appointment_id: UUID of the appointment
        services: List of services requiring authorization
        
    Returns:
        dict: Prior authorization response
    """
    try:
        from appointments.models import Appointment
        
        appointment = Appointment.objects.select_related('patient').get(id=appointment_id)
        
        # TODO: Implement actual NPHIES API call
        
        logger.info(f"NPHIES prior auth for appointment {appointment_id}")
        
        # Placeholder response
        response = {
            'status': 'success',
            'authorization_number': f"AUTH-{timezone.now().strftime('%Y%m%d%H%M%S')}",
            'approved': True,
            'services': services,
            'valid_until': str(timezone.now().date()),
            'timestamp': str(timezone.now()),
        }
        
        return response
        
    except Exception as exc:
        logger.error(f"NPHIES prior auth failed: {exc}")
        raise self.retry(exc=exc, countdown=300)


@shared_task(bind=True, max_retries=3)
def submit_nphies_claim(self, invoice_id: str) -> Dict:
    """
    Submit insurance claim to NPHIES.
    
    Args:
        invoice_id: UUID of the invoice
        
    Returns:
        dict: Claim submission response
    """
    try:
        from finance.models import Invoice
        
        invoice = Invoice.objects.select_related('patient', 'appointment').get(id=invoice_id)
        
        # TODO: Implement actual NPHIES API call
        
        logger.info(f"NPHIES claim submission for invoice {invoice.invoice_number}")
        
        # Placeholder response
        response = {
            'status': 'success',
            'claim_number': f"CLM-{timezone.now().strftime('%Y%m%d%H%M%S')}",
            'submitted': True,
            'amount_claimed': str(invoice.total_amount),
            'timestamp': str(timezone.now()),
        }
        
        return response
        
    except Exception as exc:
        logger.error(f"NPHIES claim submission failed: {exc}")
        raise self.retry(exc=exc, countdown=300)


# ============================================================================
# ZATCA Integration Tasks (Saudi E-Invoicing)
# ============================================================================


@shared_task(bind=True, max_retries=3)
def submit_zatca_invoice(self, invoice_id: str) -> Dict:
    """
    Submit e-invoice to ZATCA (Saudi Tax Authority).
    
    Args:
        invoice_id: UUID of the invoice
        
    Returns:
        dict: ZATCA submission response
    """
    try:
        from finance.models import Invoice
        
        invoice = Invoice.objects.select_related('patient').get(id=invoice_id)
        
        # Only submit issued or paid invoices
        if invoice.status not in ['ISSUED', 'PAID']:
            logger.warning(f"Invoice {invoice.invoice_number} not ready for ZATCA submission")
            return {'status': 'skipped', 'reason': 'Invoice not issued'}
        
        # TODO: Implement actual ZATCA API call
        # This should include:
        # 1. Generate XML invoice in ZATCA format
        # 2. Sign invoice with digital certificate
        # 3. Generate QR code
        # 4. Submit to ZATCA API
        # 5. Store ZATCA UUID and hash
        
        logger.info(f"ZATCA e-invoice submission for {invoice.invoice_number}")
        
        # Placeholder response
        response = {
            'status': 'success',
            'zatca_uuid': f"ZATCA-{timezone.now().strftime('%Y%m%d%H%M%S')}",
            'invoice_hash': 'placeholder_hash',
            'qr_code': 'placeholder_qr_code_data',
            'submitted': True,
            'timestamp': str(timezone.now()),
        }
        
        return response
        
    except Exception as exc:
        logger.error(f"ZATCA submission failed: {exc}")
        raise self.retry(exc=exc, countdown=300)


@shared_task
def submit_pending_zatca_invoices() -> Dict:
    """
    Submit all pending invoices to ZATCA.
    
    This task runs daily at 11:00 PM to submit invoices
    that haven't been submitted to ZATCA yet.
    
    Returns:
        dict: Submission statistics
    """
    from finance.models import Invoice
    
    # Get invoices that need ZATCA submission
    pending_invoices = Invoice.objects.filter(
        status__in=['ISSUED', 'PAID'],
        # Add field to track ZATCA submission status
        # zatca_submitted=False
    )
    
    stats = {
        'total': pending_invoices.count(),
        'submitted': 0,
        'failed': 0,
        'errors': []
    }
    
    for invoice in pending_invoices:
        try:
            result = submit_zatca_invoice.delay(str(invoice.id)).get()
            if result.get('status') == 'success':
                stats['submitted'] += 1
            else:
                stats['failed'] += 1
                stats['errors'].append(f"Invoice {invoice.invoice_number}: {result.get('reason')}")
        except Exception as exc:
            stats['failed'] += 1
            stats['errors'].append(f"Invoice {invoice.invoice_number}: {str(exc)}")
    
    logger.info(f"ZATCA batch submission: {stats['submitted']} submitted, {stats['failed']} failed")
    
    return stats


# ============================================================================
# Lab Integration Tasks
# ============================================================================


@shared_task(bind=True, max_retries=3)
def sync_lab_results(self) -> Dict:
    """
    Sync lab results from external lab system.
    
    This task runs every 30 minutes to fetch new lab results.
    
    Returns:
        dict: Sync statistics
    """
    try:
        # TODO: Implement actual lab API integration
        # This should:
        # 1. Connect to lab API
        # 2. Fetch new results since last sync
        # 3. Match results to patients by MRN or order ID
        # 4. Store results in database
        # 5. Notify providers of new results
        
        logger.info("Lab results sync started")
        
        # Placeholder response
        stats = {
            'status': 'success',
            'new_results': 0,
            'updated_results': 0,
            'errors': 0,
            'timestamp': str(timezone.now()),
        }
        
        logger.info(f"Lab results sync completed: {stats}")
        
        return stats
        
    except Exception as exc:
        logger.error(f"Lab results sync failed: {exc}")
        raise self.retry(exc=exc, countdown=600)


@shared_task(bind=True, max_retries=3)
def send_lab_order(self, order_id: str) -> Dict:
    """
    Send lab order to external lab system.
    
    Args:
        order_id: UUID of the lab order
        
    Returns:
        dict: Order submission response
    """
    try:
        # TODO: Implement actual lab order submission
        # This should:
        # 1. Get order details from database
        # 2. Format order in lab system format
        # 3. Submit to lab API
        # 4. Store lab reference number
        
        logger.info(f"Lab order submission: {order_id}")
        
        # Placeholder response
        response = {
            'status': 'success',
            'lab_reference': f"LAB-{timezone.now().strftime('%Y%m%d%H%M%S')}",
            'submitted': True,
            'estimated_completion': str(timezone.now().date()),
            'timestamp': str(timezone.now()),
        }
        
        return response
        
    except Exception as exc:
        logger.error(f"Lab order submission failed: {exc}")
        raise self.retry(exc=exc, countdown=300)


# ============================================================================
# Radiology Integration Tasks
# ============================================================================


@shared_task(bind=True, max_retries=3)
def sync_radiology_results(self) -> Dict:
    """
    Sync radiology results from PACS/RIS system.
    
    This task runs every 30 minutes to fetch new radiology results.
    
    Returns:
        dict: Sync statistics
    """
    try:
        # TODO: Implement actual radiology system integration
        # This should:
        # 1. Connect to PACS/RIS API
        # 2. Fetch new studies and reports
        # 3. Match to patients and orders
        # 4. Store results and images
        # 5. Notify providers of new results
        
        logger.info("Radiology results sync started")
        
        # Placeholder response
        stats = {
            'status': 'success',
            'new_studies': 0,
            'new_reports': 0,
            'errors': 0,
            'timestamp': str(timezone.now()),
        }
        
        logger.info(f"Radiology results sync completed: {stats}")
        
        return stats
        
    except Exception as exc:
        logger.error(f"Radiology results sync failed: {exc}")
        raise self.retry(exc=exc, countdown=600)


@shared_task(bind=True, max_retries=3)
def send_radiology_order(self, order_id: str) -> Dict:
    """
    Send radiology order to PACS/RIS system.
    
    Args:
        order_id: UUID of the radiology order
        
    Returns:
        dict: Order submission response
    """
    try:
        # TODO: Implement actual radiology order submission
        # This should:
        # 1. Get order details from database
        # 2. Format order in DICOM/HL7 format
        # 3. Submit to PACS/RIS
        # 4. Store accession number
        
        logger.info(f"Radiology order submission: {order_id}")
        
        # Placeholder response
        response = {
            'status': 'success',
            'accession_number': f"RAD-{timezone.now().strftime('%Y%m%d%H%M%S')}",
            'submitted': True,
            'scheduled_date': str(timezone.now().date()),
            'timestamp': str(timezone.now()),
        }
        
        return response
        
    except Exception as exc:
        logger.error(f"Radiology order submission failed: {exc}")
        raise self.retry(exc=exc, countdown=300)


# ============================================================================
# SMS/WhatsApp Integration Tasks
# ============================================================================


@shared_task(bind=True, max_retries=3)
def send_sms_async(
    self,
    to: str,
    message: str,
    tenant_id: str,
    template_code: Optional[str] = None,
    context: Optional[Dict] = None
) -> Dict:
    """
    Send SMS message asynchronously.
    
    Args:
        to: Recipient phone number
        message: Message body (if not using template)
        tenant_id: Tenant UUID
        template_code: Template code (optional)
        context: Template context variables (optional)
    
    Returns:
        dict: Send result
    """
    try:
        from integrations.messaging_service import MessagingService
        
        service = MessagingService()
        
        if template_code and context:
            result = service.send_from_template(
                template_code=template_code,
                recipient_phone=to,
                channel='SMS',
                context=context,
                tenant_id=tenant_id
            )
        else:
            result = service.send_message(
                to=to,
                message=message,
                channel='SMS',
                tenant_id=tenant_id
            )
        
        if not result['success']:
            logger.warning(f"SMS send failed: {result.get('error')}")
            # Retry on failure
            raise self.retry(exc=Exception(result.get('error')), countdown=300)
        
        logger.info(f"SMS sent successfully to {to}")
        return result
        
    except Exception as exc:
        logger.error(f"SMS async send failed: {exc}")
        raise self.retry(exc=exc, countdown=300)


@shared_task(bind=True, max_retries=3)
def send_whatsapp_async(
    self,
    to: str,
    message: str,
    tenant_id: str,
    template_code: Optional[str] = None,
    context: Optional[Dict] = None
) -> Dict:
    """
    Send WhatsApp message asynchronously.
    
    Args:
        to: Recipient phone number
        message: Message body (if not using template)
        tenant_id: Tenant UUID
        template_code: Template code (optional)
        context: Template context variables (optional)
    
    Returns:
        dict: Send result
    """
    try:
        from integrations.messaging_service import MessagingService
        
        service = MessagingService()
        
        if template_code and context:
            result = service.send_from_template(
                template_code=template_code,
                recipient_phone=to,
                channel='WHATSAPP',
                context=context,
                tenant_id=tenant_id
            )
        else:
            result = service.send_message(
                to=to,
                message=message,
                channel='WHATSAPP',
                tenant_id=tenant_id
            )
        
        if not result['success']:
            logger.warning(f"WhatsApp send failed: {result.get('error')}")
            # Retry on failure
            raise self.retry(exc=Exception(result.get('error')), countdown=300)
        
        logger.info(f"WhatsApp sent successfully to {to}")
        return result
        
    except Exception as exc:
        logger.error(f"WhatsApp async send failed: {exc}")
        raise self.retry(exc=exc, countdown=300)


@shared_task
def update_message_statuses() -> Dict:
    """
    Update status of all pending messages by checking with providers.
    
    This task runs every 5 minutes to update message delivery status.
    
    Returns:
        dict: Update statistics
    """
    from notifications.models import Message
    from integrations.messaging_service import MessagingService
    from datetime import timedelta
    
    # Get messages sent in last 24 hours that aren't delivered/failed
    cutoff = timezone.now() - timedelta(hours=24)
    pending_messages = Message.objects.filter(
        created_at__gte=cutoff,
        status__in=[Message.Status.QUEUED, Message.Status.SENT],
        provider_message_id__isnull=False
    )
    
    service = MessagingService()
    stats = {
        'total': pending_messages.count(),
        'updated': 0,
        'errors': 0
    }
    
    for message in pending_messages:
        try:
            result = service.update_message_status(str(message.id))
            if result['success'] and result.get('updated'):
                stats['updated'] += 1
        except Exception as exc:
            logger.error(f"Failed to update message {message.id}: {exc}")
            stats['errors'] += 1
    
    logger.info(f"Message status update: {stats['updated']}/{stats['total']} updated")
    
    return stats


@shared_task
def retry_failed_messages() -> Dict:
    """
    Retry sending failed messages that can be retried.
    
    This task runs every hour to retry failed messages.
    
    Returns:
        dict: Retry statistics
    """
    from notifications.models import Message
    from integrations.messaging_service import MessagingService
    from datetime import timedelta
    
    # Get failed messages from last 24 hours that can be retried
    cutoff = timezone.now() - timedelta(hours=24)
    failed_messages = Message.objects.filter(
        created_at__gte=cutoff,
        status=Message.Status.FAILED,
        retry_count__lt=3
    )
    
    service = MessagingService()
    stats = {
        'total': failed_messages.count(),
        'retried': 0,
        'succeeded': 0,
        'failed': 0
    }
    
    for message in failed_messages:
        try:
            result = service.retry_failed_message(str(message.id))
            stats['retried'] += 1
            
            if result['success']:
                stats['succeeded'] += 1
            else:
                stats['failed'] += 1
                
        except Exception as exc:
            logger.error(f"Failed to retry message {message.id}: {exc}")
            stats['failed'] += 1
    
    logger.info(f"Message retry: {stats['succeeded']}/{stats['retried']} succeeded")
    
    return stats


@shared_task
def cleanup_old_messages() -> Dict:
    """
    Clean up old message records to prevent database bloat.
    
    Deletes messages older than 90 days.
    This task runs daily at 2:00 AM.
    
    Returns:
        dict: Cleanup statistics
    """
    from notifications.models import Message
    from datetime import timedelta
    
    cutoff = timezone.now() - timedelta(days=90)
    
    old_messages = Message.objects.filter(created_at__lt=cutoff)
    count = old_messages.count()
    
    old_messages.delete()
    
    logger.info(f"Cleaned up {count} old messages")
    
    return {
        'deleted': count,
        'cutoff_date': str(cutoff.date())
    }


@shared_task
def send_bulk_sms(
    recipients: List[str],
    message: str,
    tenant_id: str
) -> Dict:
    """
    Send SMS to multiple recipients.
    
    Args:
        recipients: List of phone numbers
        message: Message body
        tenant_id: Tenant UUID
    
    Returns:
        dict: Bulk send statistics
    """
    from integrations.messaging_service import MessagingService
    
    service = MessagingService()
    
    result = service.send_bulk_messages(
        recipients=recipients,
        message=message,
        channel='SMS',
        tenant_id=tenant_id
    )
    
    logger.info(f"Bulk SMS: {result['sent']}/{result['total']} sent")
    
    return result


@shared_task
def send_bulk_whatsapp(
    recipients: List[str],
    message: str,
    tenant_id: str
) -> Dict:
    """
    Send WhatsApp message to multiple recipients.
    
    Args:
        recipients: List of phone numbers
        message: Message body
        tenant_id: Tenant UUID
    
    Returns:
        dict: Bulk send statistics
    """
    from integrations.messaging_service import MessagingService
    
    service = MessagingService()
    
    result = service.send_bulk_messages(
        recipients=recipients,
        message=message,
        channel='WHATSAPP',
        tenant_id=tenant_id
    )
    
    logger.info(f"Bulk WhatsApp: {result['sent']}/{result['total']} sent")
    
    return result


# ============================================================================
# Integration Health Check
# ============================================================================


@shared_task
def check_integration_health() -> Dict:
    """
    Check health status of all external integrations.
    
    Returns:
        dict: Health status of all integrations
    """
    health = {
        'nphies': {'status': 'unknown', 'last_check': str(timezone.now())},
        'zatca': {'status': 'unknown', 'last_check': str(timezone.now())},
        'lab': {'status': 'unknown', 'last_check': str(timezone.now())},
        'radiology': {'status': 'unknown', 'last_check': str(timezone.now())},
        'sms': {'status': 'unknown', 'last_check': str(timezone.now())},
        'whatsapp': {'status': 'unknown', 'last_check': str(timezone.now())},
    }
    
    # Check SMS/WhatsApp providers
    try:
        from integrations.sms_providers import ProviderFactory
        
        # Test SMS provider
        try:
            sms_provider = ProviderFactory.create_sms_provider()
            health['sms']['status'] = 'healthy'
            health['sms']['provider'] = getattr(settings, 'SMS_PROVIDER', 'mock')
        except Exception as exc:
            health['sms']['status'] = 'error'
            health['sms']['error'] = str(exc)
        
        # Test WhatsApp provider
        try:
            whatsapp_provider = ProviderFactory.create_whatsapp_provider()
            health['whatsapp']['status'] = 'healthy'
            health['whatsapp']['provider'] = getattr(settings, 'WHATSAPP_PROVIDER', 'mock')
        except Exception as exc:
            health['whatsapp']['status'] = 'error'
            health['whatsapp']['error'] = str(exc)
            
    except Exception as exc:
        logger.error(f"Health check failed: {exc}")
    
    # TODO: Implement actual health checks for other integrations
    # This should ping each API and verify connectivity
    
    logger.info(f"Integration health check: {health}")
    
    return health