from collections.abc import Iterator
from logging import getLogger

import requests
import dataclasses

from .favro_data_model import Card, CardId, OrganizationId, SeqId
from .favro_markdown import CardContents

logger = getLogger(__name__)

# Endpoints
URL_API_ROOT = 'https://favro.com/api/v1'
URL_GET_ALL_CARDS = URL_API_ROOT + '/cards'
URL_UPDATE_CARD = URL_API_ROOT + '/cards/{card_id}'

class CardCache:

    def __init__(self):
        self.cards = []

    def add_card(self, card: Card) -> None:
        self.remove(card.card_id)
        self.cards.append(card)

    def get_card_by_card_id(self, card_id: CardId) -> Card | None:
        for card in reversed(self.cards):
            if card.card_id == card_id:
                return card

    def get_card_by_seq_id(self, seq_id: SeqId) -> Card | None:
        for card in reversed(self.cards):
            if card.seq_id == seq_id:
                return card

    def remove(self, card_id: CardId) -> Card | None:
        while card := self.get_card_by_card_id(card_id):
            self.cards.remove(card)
            return card

class FavroClient:
    def __init__(
        self,
        *,
        favro_org_id: OrganizationId,
        favro_username: str,
        favro_password: str,
        session: requests.Session | None = None,
        read_only=True,
    ):
        assert favro_org_id is not None
        assert favro_username is not None
        assert favro_password is not None

        # Setup session
        self.session = session or requests.Session()
        self.session.auth = (favro_username, favro_password)
        self.session.headers.update(
            {
                'organizationId': favro_org_id.raw_id,
                'content-type': 'application/json',
            },
        )
        self.read_only = read_only

        self.cache = CardCache()

    def check_logged_in(self) -> None:
        next(self.get_todo_list_cards())

    def get_todo_list_cards(self) -> Iterator[Card]:
        yield from self.get_cards(todo_list=True)

    def get_cards(
        self, *, seq_id: SeqId | None = None, todo_list=False,
    ) -> Iterator[Card]:
        # Determine params for get_cards
        request = self._get_cards_request(seq_id, todo_list)

        # Run query
        logger.warning('Sending request: %s', request.url)
        response = self.session.send(request)
        response.raise_for_status()
        json = response.json()

        # TODO: Add support for pageination
        for entity_json in json['entities']:
            print(entity_json)
            card = Card.from_json(entity_json)
            self.cache.add_card(card)
            yield card
            del entity_json

    def _get_cards_request(
        self, seq_id: SeqId | None = None, todo_list=False,
    ) -> requests.PreparedRequest:
        params = {'descriptionFormat': 'markdown'}
        if seq_id is not None:
            params['cardSequentialId'] = str(seq_id.raw_id)
        if todo_list is True:
            params['todoList'] = 'true'

        request = requests.Request('GET', URL_GET_ALL_CARDS, params=params)
        return self.session.prepare_request(request)

    def get_card(self, seq_id: SeqId) -> Card:
        if card := self.cache.get_card_by_seq_id(seq_id):
            return card
        return next(self.get_cards(seq_id=seq_id))

    def _invalidate_cache(self, card_id: CardId) -> None:
        card = self.cache.remove(card_id)
        if card:
            self.session.cache.delete(
                requests=[self._get_cards_request(seq_id=card.seq_id)],
            )

    def update_card_contents_locally(self, card_id: CardId, card_contents: CardContents) -> Card:
        if card := self.cache.remove(card_id):
            card = dataclasses.replace(card, detailed_description=card_contents.description,name=card_contents.name)
            self.cache.add_card(card)
        return card

    def update_card_contents(self, card_id: CardId, card_contents: CardContents) -> Card:
        """Returns updated Card."""
        if self.read_only == 'silent':
            logger.warning(
                'FavroClient is silent read only: Discarding card description update of length %d',
                len(description),
            )
            return None  # TODO
        elif self.read_only is True:
            raise Exception('FavroClient is read only')

        json_body = {
            'name': card_contents.name,
            'detailedDescription': card_contents.description,
            'descriptionFormat': 'markdown',
        }

        url = URL_UPDATE_CARD.format(card_id=card_id.raw_id)
        logger.warning('Sending request: %s', url)
        response = self.session.put(
            url, json=json_body,
        )
        response.raise_for_status()
        self._invalidate_cache(card_id)
        return self.update_card_contents_locally(card_id, card_contents)