from fastapi import APIRouter, Depends, HTTPException, status
from sqlmodel import Session, select

from app.connection import get_session
from app.models.hackathon import Hackathon
from app.models.hackathon_participant import HackathonParticipant
from app.models.user import User
from app.schemas.hackathon import (
    HackathonCreate,
    HackathonRead,
    HackathonReadWithOrganizer,
    ParticipantRegistration,
    ParticipantRead,
    ParticipantConfirm,
)
from app.auth.dependencies import get_current_user, get_current_organizer

router = APIRouter(prefix="/hackathons", tags=["Hackathons"])


# ── CRUD ────────────────────────────────────────────────────────────────────


@router.post("/", response_model=HackathonRead, status_code=status.HTTP_201_CREATED)
def create_hackathon(
    data: HackathonCreate,
    session: Session = Depends(get_session),
    organizer: User = Depends(get_current_organizer),
) -> Hackathon:
    hackathon = Hackathon(**data.model_dump(), organizer_id=organizer.id)
    session.add(hackathon)
    session.commit()
    session.refresh(hackathon)
    return hackathon


@router.get("/", response_model=list[HackathonRead])
def list_hackathons(session: Session = Depends(get_session)) -> list[Hackathon]:
    return list(session.exec(select(Hackathon)).all())


@router.get("/{hackathon_id}", response_model=HackathonReadWithOrganizer)
def get_hackathon(hackathon_id: int, session: Session = Depends(get_session)) -> Hackathon:
    hackathon = session.get(Hackathon, hackathon_id)
    if not hackathon:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Хакатон не найден")
    return hackathon


@router.delete("/{hackathon_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_hackathon(
    hackathon_id: int,
    session: Session = Depends(get_session),
    organizer: User = Depends(get_current_organizer),
) -> None:
    hackathon = session.get(Hackathon, hackathon_id)
    if not hackathon:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Хакатон не найден")
    session.delete(hackathon)
    session.commit()


# ── Регистрация участников ──────────────────────────────────────────────────


@router.post("/{hackathon_id}/register", response_model=ParticipantRead, status_code=status.HTTP_201_CREATED)
def register_for_hackathon(
    hackathon_id: int,
    session: Session = Depends(get_session),
    current_user: User = Depends(get_current_user),
) -> HackathonParticipant:
    hackathon = session.get(Hackathon, hackathon_id)
    if not hackathon:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Хакатон не найден")

    existing = session.exec(
        select(HackathonParticipant).where(
            HackathonParticipant.user_id == current_user.id,
            HackathonParticipant.hackathon_id == hackathon_id,
        )
    ).first()
    if existing:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Вы уже зарегистрированы")

    participant = HackathonParticipant(
        user_id=current_user.id,
        hackathon_id=hackathon_id,
    )
    session.add(participant)
    session.commit()
    session.refresh(participant)
    return participant


@router.get("/{hackathon_id}/participants", response_model=list[ParticipantRead])
def list_participants(
    hackathon_id: int,
    session: Session = Depends(get_session),
) -> list[HackathonParticipant]:
    return list(
        session.exec(
            select(HackathonParticipant).where(HackathonParticipant.hackathon_id == hackathon_id)
        ).all()
    )


@router.patch("/{hackathon_id}/confirm", response_model=ParticipantRead)
def confirm_participant(
    hackathon_id: int,
    data: ParticipantConfirm,
    session: Session = Depends(get_session),
    organizer: User = Depends(get_current_organizer),
) -> HackathonParticipant:
    """Организатор подтверждает регистрацию участника."""
    participant = session.exec(
        select(HackathonParticipant).where(
            HackathonParticipant.user_id == data.user_id,
            HackathonParticipant.hackathon_id == hackathon_id,
        )
    ).first()
    if not participant:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Регистрация не найдена")
    participant.is_confirmed = True
    session.add(participant)
    session.commit()
    session.refresh(participant)
    return participant