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 fansifter_common.constants import PROD_ENVIRONMENT

from email_campaigns.adapters.db import Repository
from email_campaigns.config import settings
from email_campaigns.emails import tokens
from email_campaigns.emails.exceptions import EmailNotFoundError
from email_campaigns.emails.models import BaseEmail


@dataclass
class GenerateEmailPublicPreviewUrlRequest(AuthRequest):
    email_id: str
    domain: str


@dataclass
class GenerateEmailPublicPreviewUrlResponse:
    url: str


class GenerateEmailPublicPreviewUrlHandler[T: BaseEmail]:
    """Base handler for generating public preview URLs for emails."""

    permission: ClassVar[Permission]
    path_prefix: ClassVar[str] = ""

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

    def _get_domain(self, requested_domain: str) -> str:
        if settings.environment == PROD_ENVIRONMENT:
            if requested_domain in settings.email_public_preview_available_domains:
                return requested_domain
            return settings.email_public_preview_available_domains[0]
        return settings.qa_email_public_preview_domain

    def handle(
        self, request: GenerateEmailPublicPreviewUrlRequest
    ) -> GenerateEmailPublicPreviewUrlResponse:
        """Generate public preview URL for an email."""
        email_id = request.email_id
        email = self.email_repository.get(email_id)
        if email is None:
            raise EmailNotFoundError

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

        token = tokens.encrypt_email_id(email_id)
        domain = self._get_domain(request.domain)
        public_preview_url = f"https://fansifter-emails.{domain}/{self.path_prefix}{email_id}?pwd={token}"

        return GenerateEmailPublicPreviewUrlResponse(url=public_preview_url)