from typing import Union

from fastapi import HTTPException, status

from app.models import Book as BookDB, Author as AuthorDB

from app.services.common import TRGMSearchService
from app.serializers.book import CreateBook, CreateRemoteBook


class BookTGRMSearchService(TRGMSearchService):
    MODEL_CLASS = BookDB
    FIELDS = [
        BookDB.Meta.table.c.title
    ]
    PREFETCH_RELATED = ["source", "authors"]
    FILTERS = [
        BookDB.Meta.table.c.is_deleted == False,
    ]


class BookCreator:
    @classmethod
    def _raise_bad_request(cls):
        raise HTTPException(status.HTTP_404_NOT_FOUND)

    @classmethod
    async def _create_book(cls, data: CreateBook) -> BookDB:
        data_dict = data.dict()

        author_ids = data_dict.pop("authors", [])
        authors = await AuthorDB.objects.filter(id__in=author_ids).all()

        if len(author_ids) != len(authors):
            cls._raise_bad_request()

        book = await BookDB.objects.create(
            **data_dict
        )

        for author in authors:
            await book.authors.add(author)

        return book

    @classmethod
    async def _create_remote_book(cls, data: CreateRemoteBook) -> BookDB:
        data_dict = data.dict()

        author_ids = data_dict.pop("remote_authors", [])
        authors = await AuthorDB.objects.filter(source__id=data.source, remote_id__in=author_ids).all()

        if len(author_ids) != len(authors):
            cls._raise_bad_request()

        book = await BookDB.objects.create(
            **data_dict
        )

        for author in authors:
            await book.authors.add(author)

        return book

    @classmethod
    async def create(cls, data: Union[CreateBook, CreateRemoteBook]) -> BookDB:
        if isinstance(data, CreateBook):
            return await cls._create_book(data)
        if isinstance(data, CreateRemoteBook):
            return await cls._create_remote_book(data)