from dataclasses import dataclass
from typing import ClassVar

from fansifter_common.auth.requests import AuthRequest
from fansifter_common.auth.services import AuthService
from fansifter_common.auth.types import Permission

from email_campaigns.adapters.db import Repository
from email_campaigns.emails.cache import EmailPublicPreviewCache
from email_campaigns.emails.exceptions import EmailNotFoundError
from email_campaigns.emails.models import BaseEmail
from email_campaigns.emails.types import EmailPreview


@dataclass(kw_only=True)
class UpdateEmailContentRequest(AuthRequest):
    email_id: str
    html: str | None = None
    css: str | None = None


class UpdateEmailContentHandler[T: BaseEmail]:
    permission: ClassVar[Permission]

    def __init__(
        self,
        auth_service: AuthService,
        email_repository: Repository[T],
        preview_cache: EmailPublicPreviewCache,
    ) -> None:
        self.auth_service = auth_service
        self.email_repository = email_repository
        self.preview_cache = preview_cache

    def validate_email(self, email: T) -> None:
        """Additional validation of email before content update"""

    def validate_updated_email(self, email: T) -> None:
        """Additional validation of email after content update"""

    def handle(self, request: UpdateEmailContentRequest) -> EmailPreview:
        email = self.email_repository.get(request.email_id)
        if email is None:
            raise EmailNotFoundError

        self.auth_service.authorize_account(
            request.identity_id,
            account=email.account,
            permission=self.permission,
        )

        self.validate_email(email)

        if request.html is not None:
            email.html_content = request.html

        if request.css is not None:
            email.css_content = request.css

        self.validate_updated_email(email)

        self.email_repository.save(email)

        # Invalidate cache after content update
        self.preview_cache.delete(email.id, email.email_type)

        return email.preview