from django.conf import settings
from django.contrib import messages
from django.core.mail import EmailMultiAlternatives
from django.http import HttpRequest
from django.db.models.query import QuerySet
from django.utils.safestring import SafeText
from django.template.loader import render_to_string

from ..models.students import Student

from smtplib import SMTPException
from email.mime.image import MIMEImage

import os

def send_mail_password(request: HttpRequest, queryset: QuerySet[Student]) -> None:
    img: MIMEImage | None = None
    try:
        for d in settings.STATICFILES_DIRS:
            filename = os.path.join(d, "cantorair.png")
            if not os.path.exists(filename):
                continue
            with open(filename, "rb") as f:
                img = MIMEImage(f.read())
                img.add_header("Content-ID", "logo_image")
                img.add_header("Content-Disposition", "inline", filename="cantorair.png")
                break
    except:
        messages.error(request=request, message="Cannot Load CantorAir Logo")
        return

    for student in queryset:
        if not student.user or not student.email: # skip student if has not an associated user
            continue
        try:
            username: str = student.user.username
            password: str = student.default_password()
            address: str = student.email

            text_message: str = f"Cantor Air Flight Scheduler\nUsername:{username}\nPassword:{password}\n"

            html_message: SafeText = render_to_string(
                template_name="email/mail.html",
                context={"username": username, "password": password}
            )

            mail: EmailMultiAlternatives = EmailMultiAlternatives(
                subject="CantorAir Flight Scheduler 🛫",
                from_email="ema.trabattoni@gmail.com",
                body=text_message, 
                to = [ address ]
            )
            mail.attach(filename=img)
            mail.attach_alternative(content=html_message, mimetype="text/html")
            mail.send()
        except SMTPException as e:
            messages.error(request=request, message=f"Send Mail error: {e.strerror}")
        except Exception as e:
            messages.error(request=request, message=f"General Error: {e}")
        else:
            messages.success(request=request, message=f"Email sent to {student.surname} {student.name[0].upper()}. -> {mail.to.pop()}")
    return