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.group import Group
from bd.tables.users import User

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


class GroupCreate(BaseModel):
    name_group: str
    user_id: str


class GroupUpdate(BaseModel):
    name_group: Optional[str]
    user_id: Optional[str]


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_group(payload: GroupCreate):
    Session = get_session()
    try:
        uid = uuid.UUID(payload.user_id)
    except Exception:
        raise HTTPException(status_code=400, detail="Invalid user_id UUID")
    with Session() as session:
        user = session.get(User, uid)
        if not user:
            raise HTTPException(status_code=404, detail="User not found")
        grp = Group(name_group=payload.name_group, user_id=uid)
        session.add(grp)
        session.commit()
        session.refresh(grp)
        return {"id": str(grp.id), "name_group": grp.name_group, "user_id": str(grp.user_id)}


@router.get("/")
def list_groups():
    Session = get_session()
    with Session() as session:
        rows = session.query(Group).all()
        return [{"id": str(g.id), "name_group": g.name_group, "user_id": str(g.user_id)} for g in rows]


@router.get("/{group_id}")
def get_group(group_id: str):
    Session = get_session()
    try:
        gid = uuid.UUID(group_id)
    except Exception:
        raise HTTPException(status_code=400, detail="Invalid UUID")
    with Session() as session:
        grp = session.get(Group, gid)
        if not grp:
            raise HTTPException(status_code=404, detail="Group not found")
        return {"id": str(grp.id), "name_group": grp.name_group, "user_id": str(grp.user_id)}


@router.put("/{group_id}")
def update_group(group_id: str, payload: GroupUpdate):
    Session = get_session()
    try:
        gid = uuid.UUID(group_id)
    except Exception:
        raise HTTPException(status_code=400, detail="Invalid UUID")
    with Session() as session:
        grp = session.get(Group, gid)
        if not grp:
            raise HTTPException(status_code=404, detail="Group not found")
        if payload.name_group is not None:
            grp.name_group = payload.name_group
        if payload.user_id is not None:
            try:
                new_uid = uuid.UUID(payload.user_id)
            except Exception:
                raise HTTPException(status_code=400, detail="Invalid user_id UUID")
            user = session.get(User, new_uid)
            if not user:
                raise HTTPException(status_code=404, detail="User not found")
            grp.user_id = new_uid
        session.add(grp)
        session.commit()
        session.refresh(grp)
        return {"id": str(grp.id), "name_group": grp.name_group, "user_id": str(grp.user_id)}


@router.delete("/{group_id}", status_code=204)
def delete_group(group_id: str):
    Session = get_session()
    try:
        gid = uuid.UUID(group_id)
    except Exception:
        raise HTTPException(status_code=400, detail="Invalid UUID")
    with Session() as session:
        grp = session.get(Group, gid)
        if not grp:
            raise HTTPException(status_code=404, detail="Group not found")
        session.delete(grp)
        session.commit()
        return {}