"""
Notification services for emails, alerts, and reminders.
"""
from typing import Dict, Any
from datetime import timedelta
from django.utils import timezone
from django.core.mail import send_mail
from django.template.loader import render_to_string
from django.conf import settings
from backend.core.repositories.services.services import ServiceRepository
from backend.core.repositories.invoices.invoices import InvoiceRepository


class NotificationService:
    """
    Service for sending notifications and alerts.
    """

    @staticmethod
    def send_email(
            recipient_email: str,
            subject: str,
            template_name: str,
            context: Dict[str, Any]
    ) -> bool:
        """
        Send an email using a template.

        Args:
            recipient_email: Recipient email address
            subject: Email subject
            template_name: Template name
            context: Template context

        Returns:
            True if email was sent successfully, False otherwise
        """
        try:
            html_content = render_to_string(f"emails/{template_name}.html", context)
            text_content = render_to_string(f"emails/{template_name}.txt", context)

            send_mail(
                subject=subject,
                message=text_content,
                from_email=settings.DEFAULT_FROM_EMAIL,
                recipient_list=[recipient_email],
                html_message=html_content,
                fail_silently=False
            )

            return True
        except Exception as e:
            # Log the error
            print(f"Error sending email: {str(e)}")
            return False

    @staticmethod
    def send_service_reminders() -> int:
        """
        Send service reminders for tomorrow's services.

        Returns:
            Number of reminders sent
        """
        tomorrow = timezone.now().date() + timedelta(days=1)

        # Get services scheduled for tomorrow
        services = ServiceRepository.get_all(date=tomorrow)

        reminder_count = 0

        for service in services:
            # Get the account
            account = service.account

            # Skip if no account (shouldn't happen)
            if not account:
                continue

            # Get team members
            team_members = service.team_members.all()

            # Send reminder to each team member
            for member in team_members:
                # Skip if no email
                if not member.email:
                    continue

                # Prepare context
                context = {
                    'service': service,
                    'account': account,
                    'team_member': member,
                    'service_time': f"{service.deadline_start.strftime('%I:%M %p')} - {service.deadline_end.strftime('%I:%M %p')}" if service.deadline_start and service.deadline_end else "All day"
                }

                # Send email
                success = NotificationService.send_email(
                    recipient_email=member.email,
                    subject=f"Service Reminder: {account.name} - {tomorrow.strftime('%m/%d/%Y')}",
                    template_name="service_reminder",
                    context=context
                )

                if success:
                    reminder_count += 1

        return reminder_count

    @staticmethod
    def send_overdue_invoice_reminders() -> int:
        """
        Send reminders for overdue invoices.

        Returns:
            Number of reminders sent
        """
        # Get overdue invoices
        overdue_invoices = InvoiceRepository.get_overdue()

        reminder_count = 0

        for invoice in overdue_invoices:
            # Get the customer
            customer = invoice.customer

            # Skip if no customer (shouldn't happen)
            if not customer:
                continue

            # Skip if no billing email
            if not customer.billing_email:
                continue

            # Calculate days overdue
            days_overdue = (timezone.now().date() - invoice.date).days - 30

            # Prepare context
            context = {
                'invoice': invoice,
                'customer': customer,
                'days_overdue': days_overdue,
                'total_amount': invoice.total_amount
            }

            # Send email
            success = NotificationService.send_email(
                recipient_email=customer.billing_email,
                subject=f"Overdue Invoice Reminder: {invoice.id}",
                template_name="overdue_invoice_reminder",
                context=context
            )

            if success:
                reminder_count += 1

        return reminder_count