"""Send email to members, using templates and contexts for the emails.

* We keep everything as plain text for now.
* Notice that emails can be multilingual
* Generally, an email consists of templates (for body and subject) and a get_context() method.
"""

from accounting.models import Order
from django.contrib import messages
from django.contrib.auth.tokens import default_token_generator
from django.contrib.sites.shortcuts import get_current_site
from django.core.mail.message import EmailMessage
from django.http import HttpRequest
from django.template import loader
from django.utils import translation
from django.utils.translation import gettext_lazy as _

from .models import Membership


class BaseEmail(EmailMessage):
    """Send emails via templated body and subjects.

    This base class is extended for all email functionality.
    Because all emails are sent to the Member object, we can keep them gathered here, even when they are generated by
    other apps (like the accounting app).
    """

    template = "membership/email/base.txt"
    # Optional: Set to a template path for subject
    template_subject = None
    default_subject = "SET SUBJECT HERE"

    def __init__(self, request: HttpRequest, *args, **kwargs) -> None:
        self.context = kwargs.pop("context", {})
        self.user = kwargs.pop("user", None)
        if self.user:
            kwargs["to"] = [self.user.email]
            self.context["user"] = self.user
            self.context["recipient_name"] = self.user.get_display_name()

        # Necessary to set request before instantiating body and subject
        self.request = request
        kwargs.setdefault("subject", self.get_subject())
        kwargs.setdefault("body", self.get_body())

        super().__init__(*args, **kwargs)

    def get_context_data(self) -> dict:
        """Resolve common context for sending emails.

        When overwriting, remember to call this via super().
        """
        c = self.context
        site = get_current_site(self.request)
        c["request"] = self.request
        c["domain"] = site.domain
        c["site_name"] = site.name
        c["protocol"] = "http" if self.request and not self.request.is_secure() else "https"
        return c

    def get_body(self) -> str:
        """Build the email body from template and context."""
        if self.user and self.user.language_code:
            with translation.override(self.user.language_code):
                body = loader.render_to_string(self.template, self.get_context_data())
        else:
            body = loader.render_to_string(self.template, self.get_context_data())
        return body

    def get_subject(self) -> str:
        """Build the email subject from template or self.default_subject."""
        if self.user and self.user.language_code:
            with translation.override(self.user.language_code):
                if self.template_subject:
                    subject = loader.render_to_string(self.template_subject, self.get_context_data()).strip()
                else:
                    subject = str(self.default_subject)
        elif self.template_subject:
            subject = loader.render_to_string(self.template_subject, self.get_context_data()).strip()
        else:
            subject = str(self.default_subject)
        return subject

    def send_with_feedback(self, *, success_msg: str | None = None, no_message: bool = False) -> None:
        """Send email, possibly adding feedback via django.contrib.messages."""
        if not success_msg:
            success_msg = _("Email successfully sent to {}").format(", ".join(self.to))
        try:
            self.send(fail_silently=False)
            if not no_message:
                messages.success(self.request, success_msg)
        except RuntimeError:
            messages.error(self.request, _("Not sent, something wrong with the mail server."))


class InviteEmail(BaseEmail):
    template = "membership/emails/invite.txt"
    default_subject = _("Invite to data.coop membership")

    def __init__(self, membership: Membership, request: HttpRequest, *args, **kwargs) -> None:
        self.membership = membership
        kwargs["user"] = membership.user
        super().__init__(request, *args, **kwargs)

    def get_context_data(self) -> dict:
        c = super().get_context_data()
        c["membership"] = self.membership
        c["token"] = default_token_generator.make_token(self.membership.user)
        c["referral_code"] = self.membership.referral_code
        return c


class OrderEmail(BaseEmail):
    template = "membership/emails/order.txt"
    default_subject = _("Your data.coop order and payment")

    def __init__(self, order: Order, request: HttpRequest, *args, **kwargs) -> None:
        self.order = order
        kwargs["user"] = order.member
        super().__init__(request, *args, **kwargs)

    def get_context_data(self) -> dict:
        c = super().get_context_data()
        c["order"] = self.order
        return c