from dataclasses import dataclass, replace
from typing import ClassVar

from fansifter_common.adapters.ows_account import OwsAccountClient
from fansifter_common.adapters.ows_users import OwsUsersClient
from fansifter_common.adapters.sendgrid import SendGridClient
from fansifter_common.auth.requests import AuthRequest
from fansifter_common.auth.services import AuthService
from fansifter_common.auth.types import Permission
from fansifter_common.legal_info.services import LegalInfoService
from fansifter_common.translation.services import TranslationService

from email_campaigns.adapters.db import Repository
from email_campaigns.emails.exceptions import EmailNotFoundError
from email_campaigns.emails.models import BaseEmail
from email_campaigns.emails.substitutions import apply_preview_substitutions
from email_campaigns.emails.types import EmailPreview
from email_campaigns.fonts.services.google_fonts import GoogleFontsService


@dataclass(kw_only=True)
class GetEmailPreviewRequest(AuthRequest):
    email_id: str
    apply_substitutions: bool = False
    with_unapplied_changes: bool = False


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

    def __init__(
        self,
        auth_service: AuthService,
        email_repository: Repository[T],
        sendgrid_client: SendGridClient,
        legal_info_service: LegalInfoService,
        translation_service: TranslationService,
        ows_account_client: OwsAccountClient,
        ows_users_client: OwsUsersClient,
        fonts_service: GoogleFontsService,
    ) -> None:
        self.auth_service = auth_service
        self.email_repository = email_repository
        self.sendgrid_client = sendgrid_client
        self.legal_info_service = legal_info_service
        self.translation_service = translation_service
        self.ows_account_client = ows_account_client
        self.ows_users_client = ows_users_client
        self.fonts_service = fonts_service

    def handle(self, request: GetEmailPreviewRequest) -> 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,
        )

        preview = replace(
            email.preview,
            favorite_fonts=self.fonts_service.get_favorite_fonts_for_email(email),
        )

        return self.apply_substitutions(preview, email=email, request=request)

    def apply_substitutions(
        self, preview: EmailPreview, *, email: T, request: GetEmailPreviewRequest
    ) -> EmailPreview:
        if not request.apply_substitutions or preview.html is None:
            return preview

        identity = self.ows_users_client.get_identity(request.identity_id)

        return replace(
            preview,
            html=apply_preview_substitutions(
                preview.html,
                email=email,
                user_email=identity.email,
                sendgrid_client=self.sendgrid_client,
                legal_info_service=self.legal_info_service,
                translation_service=self.translation_service,
                ows_account_client=self.ows_account_client,
            ),
        )