from fastapi import APIRouter, HTTPException
from pydantic import BaseModel
from typing import Optional
import uuid

from bd import Settings
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

from bd.tables.choice import Choice
from bd.tables.question import Question

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


class ChoiceCreate(BaseModel):
    question_id: str
    text: str
    position: Optional[int]


class ChoiceUpdate(BaseModel):
    text: Optional[str]
    position: Optional[int]


def get_session():
    settings = Settings()
    engine = create_engine(settings.DATABASE_URL_syncpg, future=True)
    return sessionmaker(bind=engine, future=True)


@router.post("/", status_code=201)
def create_choice(payload: ChoiceCreate):
    Session = get_session()
    try:
        qid = uuid.UUID(payload.question_id)
    except Exception:
        raise HTTPException(status_code=400, detail="Invalid question UUID")
    with Session() as session:
        question = session.get(Question, qid)
        if not question:
            raise HTTPException(status_code=404, detail="Question not found")
        ch = Choice(question_id=qid, text=payload.text, position=payload.position)
        session.add(ch)
        session.commit()
        session.refresh(ch)
        return {"id": str(ch.id)}


@router.put("/{choice_id}")
def update_choice(choice_id: str, payload: ChoiceUpdate):
    Session = get_session()
    try:
        cid = uuid.UUID(choice_id)
    except Exception:
        raise HTTPException(status_code=400, detail="Invalid UUID")
    with Session() as session:
        ch = session.get(Choice, cid)
        if not ch:
            raise HTTPException(status_code=404, detail="Choice not found")
        if payload.text is not None:
            ch.text = payload.text
        if payload.position is not None:
            ch.position = payload.position
        session.add(ch)
        session.commit()
        session.refresh(ch)
        return {"id": str(ch.id)}


@router.delete("/{choice_id}", status_code=204)
def delete_choice(choice_id: str):
    Session = get_session()
    try:
        cid = uuid.UUID(choice_id)
    except Exception:
        raise HTTPException(status_code=400, detail="Invalid UUID")
    with Session() as session:
        ch = session.get(Choice, cid)
        if not ch:
            raise HTTPException(status_code=404, detail="Choice not found")
        session.delete(ch)
        session.commit()
        return {}


@router.get("/")
def list_choices(question_id: Optional[str] = None):
    Session = get_session()
    with Session() as session:
        q = session.query(Choice)
        if question_id:
            try:
                qid = uuid.UUID(question_id)
                q = q.filter(Choice.question_id == qid)
            except Exception:
                raise HTTPException(status_code=400, detail="Invalid question_id UUID")
        rows = q.all()
        return [{"id": str(r.id), "text": r.text, "question_id": str(r.question_id)} for r in rows]


@router.get("/{choice_id}")
def get_choice(choice_id: str):
    Session = get_session()
    try:
        cid = uuid.UUID(choice_id)
    except Exception:
        raise HTTPException(status_code=400, detail="Invalid UUID")
    with Session() as session:
        ch = session.get(Choice, cid)
        if not ch:
            raise HTTPException(status_code=404, detail="Choice not found")
        return {"id": str(ch.id), "text": ch.text, "question_id": str(ch.question_id)}