"""
Email and notification utilities for appointments app.
"""
from django.core.mail import send_mail, EmailMultiAlternatives
from django.template.loader import render_to_string
from django.conf import settings
from django.utils import timezone
from core.utils import AuditLogger


class AppointmentNotifications:
    """
    Handle email notifications for appointment-related events.
    """
    
    @staticmethod
    def send_appointment_confirmation(appointment):
        """
        Send confirmation email when appointment request is created.
        """
        try:
            subject = f'Appointment Request Confirmation - {appointment.request_id}'
            
            # Render HTML email
            html_content = render_to_string('appointments/emails/appointment_confirmation.html', {
                'appointment': appointment,
                'patient': appointment.patient,
                'provider': appointment.provider,
            })
            
            # Render plain text email
            text_content = render_to_string('appointments/emails/appointment_confirmation.txt', {
                'appointment': appointment,
                'patient': appointment.patient,
                'provider': appointment.provider,
            })
            
            # Send email
            email = EmailMultiAlternatives(
                subject=subject,
                body=text_content,
                from_email=settings.DEFAULT_FROM_EMAIL,
                to=[appointment.patient.user.email],
            )
            email.attach_alternative(html_content, "text/html")
            email.send()
            
            # Log notification
            AuditLogger.log_event(
                tenant=appointment.tenant,
                event_type='NOTIFICATION',
                event_category='APPOINTMENT_MANAGEMENT',
                action='Send Appointment Confirmation Email',
                description=f'Sent confirmation email to {appointment.patient.user.email}',
                user=None,
                content_object=appointment,
                request=None
            )
            
            return True
        except Exception as e:
            print(f"Error sending appointment confirmation email: {e}")
            return False
    
    @staticmethod
    def send_appointment_reminder(appointment, hours_before=24):
        """
        Send reminder email before appointment.
        """
        try:
            subject = f'Appointment Reminder - {appointment.scheduled_datetime.strftime("%B %d, %Y")}'
            
            html_content = render_to_string('appointments/emails/appointment_reminder.html', {
                'appointment': appointment,
                'patient': appointment.patient,
                'provider': appointment.provider,
                'hours_before': hours_before,
            })
            
            text_content = render_to_string('appointments/emails/appointment_reminder.txt', {
                'appointment': appointment,
                'patient': appointment.patient,
                'provider': appointment.provider,
                'hours_before': hours_before,
            })
            
            email = EmailMultiAlternatives(
                subject=subject,
                body=text_content,
                from_email=settings.DEFAULT_FROM_EMAIL,
                to=[appointment.patient.user.email],
            )
            email.attach_alternative(html_content, "text/html")
            email.send()
            
            # Log notification
            AuditLogger.log_event(
                tenant=appointment.tenant,
                event_type='NOTIFICATION',
                event_category='APPOINTMENT_MANAGEMENT',
                action='Send Appointment Reminder Email',
                description=f'Sent {hours_before}h reminder to {appointment.patient.user.email}',
                user=None,
                content_object=appointment,
                request=None
            )
            
            return True
        except Exception as e:
            print(f"Error sending appointment reminder email: {e}")
            return False
    
    @staticmethod
    def send_appointment_cancelled(appointment):
        """
        Send notification when appointment is cancelled.
        """
        try:
            subject = f'Appointment Cancelled - {appointment.request_id}'
            
            html_content = render_to_string('appointments/emails/appointment_cancelled.html', {
                'appointment': appointment,
                'patient': appointment.patient,
                'provider': appointment.provider,
            })
            
            text_content = render_to_string('appointments/emails/appointment_cancelled.txt', {
                'appointment': appointment,
                'patient': appointment.patient,
                'provider': appointment.provider,
            })
            
            email = EmailMultiAlternatives(
                subject=subject,
                body=text_content,
                from_email=settings.DEFAULT_FROM_EMAIL,
                to=[appointment.patient.user.email],
            )
            email.attach_alternative(html_content, "text/html")
            email.send()
            
            # Log notification
            AuditLogger.log_event(
                tenant=appointment.tenant,
                event_type='NOTIFICATION',
                event_category='APPOINTMENT_MANAGEMENT',
                action='Send Appointment Cancellation Email',
                description=f'Sent cancellation email to {appointment.patient.user.email}',
                user=None,
                content_object=appointment,
                request=None
            )
            
            return True
        except Exception as e:
            print(f"Error sending appointment cancellation email: {e}")
            return False
    
    @staticmethod
    def send_appointment_rescheduled(appointment):
        """
        Send notification when appointment is rescheduled.
        """
        try:
            subject = f'Appointment Rescheduled - {appointment.request_id}'
            
            html_content = render_to_string('appointments/emails/appointment_rescheduled.html', {
                'appointment': appointment,
                'patient': appointment.patient,
                'provider': appointment.provider,
            })
            
            text_content = render_to_string('appointments/emails/appointment_rescheduled.txt', {
                'appointment': appointment,
                'patient': appointment.patient,
                'provider': appointment.provider,
            })
            
            email = EmailMultiAlternatives(
                subject=subject,
                body=text_content,
                from_email=settings.DEFAULT_FROM_EMAIL,
                to=[appointment.patient.user.email],
            )
            email.attach_alternative(html_content, "text/html")
            email.send()
            
            # Log notification
            AuditLogger.log_event(
                tenant=appointment.tenant,
                event_type='NOTIFICATION',
                event_category='APPOINTMENT_MANAGEMENT',
                action='Send Appointment Rescheduled Email',
                description=f'Sent rescheduled email to {appointment.patient.user.email}',
                user=None,
                content_object=appointment,
                request=None
            )
            
            return True
        except Exception as e:
            print(f"Error sending appointment rescheduled email: {e}")
            return False
    
    @staticmethod
    def send_queue_position_update(queue_entry):
        """
        Send notification when patient's queue position changes significantly.
        """
        try:
            subject = f'Queue Update - You are #{queue_entry.queue_position}'
            
            html_content = render_to_string('appointments/emails/queue_position_update.html', {
                'queue_entry': queue_entry,
                'patient': queue_entry.patient,
                'queue': queue_entry.queue,
            })
            
            text_content = render_to_string('appointments/emails/queue_position_update.txt', {
                'queue_entry': queue_entry,
                'patient': queue_entry.patient,
                'queue': queue_entry.queue,
            })
            
            email = EmailMultiAlternatives(
                subject=subject,
                body=text_content,
                from_email=settings.DEFAULT_FROM_EMAIL,
                to=[queue_entry.patient.user.email],
            )
            email.attach_alternative(html_content, "text/html")
            email.send()
            
            return True
        except Exception as e:
            print(f"Error sending queue position update email: {e}")
            return False
    
    @staticmethod
    def send_patient_called(queue_entry):
        """
        Send notification when patient is called from queue.
        """
        try:
            subject = f'You are being called - {queue_entry.queue.name}'
            
            html_content = render_to_string('appointments/emails/patient_called.html', {
                'queue_entry': queue_entry,
                'patient': queue_entry.patient,
                'queue': queue_entry.queue,
            })
            
            text_content = render_to_string('appointments/emails/patient_called.txt', {
                'queue_entry': queue_entry,
                'patient': queue_entry.patient,
                'queue': queue_entry.queue,
            })
            
            email = EmailMultiAlternatives(
                subject=subject,
                body=text_content,
                from_email=settings.DEFAULT_FROM_EMAIL,
                to=[queue_entry.patient.user.email],
            )
            email.attach_alternative(html_content, "text/html")
            email.send()
            
            return True
        except Exception as e:
            print(f"Error sending patient called email: {e}")
            return False


class QueueAudioNotifications:
    """
    Handle audio notifications for queue management.
    """
    
    @staticmethod
    def get_notification_sound(notification_type='default'):
        """
        Get the appropriate notification sound file.
        """
        sounds = {
            'default': 'sounds/notification.mp3',
            'patient_called': 'sounds/patient_called.mp3',
            'urgent': 'sounds/urgent.mp3',
            'emergency': 'sounds/emergency.mp3',
        }
        return sounds.get(notification_type, sounds['default'])
    
    @staticmethod
    def should_play_sound(queue_entry):
        """
        Determine if sound should be played based on priority.
        """
        priority_sounds = {
            'EMERGENCY': 'emergency',
            'STAT': 'emergency',
            'URGENT': 'urgent',
            'ROUTINE': 'patient_called',
        }
        return priority_sounds.get(queue_entry.priority, 'default')