from __future__ import annotations
from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.orm import Session

from app.db.session import get_db
from app.core.security import get_current_user, require_roles, UserClaims
from app.schemas.pair import PairCreate, PairUpdate, PairRead
from app.services.pair_service import PairService

router = APIRouter(prefix="/v1/pairs", tags=["pairs"])

@router.post("", response_model=PairRead, status_code=201)
def create_pair(payload: PairCreate, db: Session = Depends(get_db),
                user: UserClaims = Depends(require_roles("ADMIN","MATCHMAKER"))):
    svc = PairService(db)
    return svc.create(user_id_a=payload.user_id_a, user_id_b=payload.user_id_b,
                      score=payload.score, notes=payload.notes, created_by=user.sub)

@router.get("", response_model=list[PairRead])
def list_pairs(for_user_id: str | None = None, status: str | None = None,
               offset: int = 0, limit: int = Query(50, le=200),
               db: Session = Depends(get_db),
               _: UserClaims = Depends(get_current_user)):
    return PairService(db).list(for_user_id=for_user_id, status=status, offset=offset, limit=limit)

@router.get("/{pair_id}", response_model=PairRead)
def get_pair(pair_id: str, db: Session = Depends(get_db), _: UserClaims = Depends(get_current_user)):
    obj = PairService(db).get(pair_id)
    if not obj:
        raise HTTPException(status_code=404, detail="Not found")
    return obj

@router.patch("/{pair_id}", response_model=PairRead)
def update_pair(pair_id: str, payload: PairUpdate, db: Session = Depends(get_db),
                _: UserClaims = Depends(require_roles("ADMIN","MATCHMAKER"))):
    svc = PairService(db)
    obj = svc.get(pair_id)
    if not obj:
        raise HTTPException(status_code=404, detail="Not found")
    return svc.update(obj, **payload.model_dump(exclude_none=True))

@router.post("/{pair_id}/accept", response_model=PairRead)
def accept(pair_id: str, db: Session = Depends(get_db), user: UserClaims = Depends(get_current_user)):
    svc = PairService(db)
    obj = svc.get(pair_id)
    if not obj:
        raise HTTPException(status_code=404, detail="Not found")
    # Validate that current user participates
    if user.sub not in (str(obj.user_id_a), str(obj.user_id_b)):
        raise HTTPException(status_code=403, detail="Not allowed")
    return svc.set_status(obj, "accepted")

@router.post("/{pair_id}/reject", response_model=PairRead)
def reject(pair_id: str, db: Session = Depends(get_db), user: UserClaims = Depends(get_current_user)):
    svc = PairService(db)
    obj = svc.get(pair_id)
    if not obj:
        raise HTTPException(status_code=404, detail="Not found")
    if user.sub not in (str(obj.user_id_a), str(obj.user_id_b)):
        raise HTTPException(status_code=403, detail="Not allowed")
    return svc.set_status(obj, "rejected")

@router.delete("/{pair_id}", status_code=204)
def delete_pair(pair_id: str, db: Session = Depends(get_db),
                _: UserClaims = Depends(require_roles("ADMIN","MATCHMAKER"))):
    svc = PairService(db)
    obj = svc.get(pair_id)
    if not obj:
        return
    svc.delete(obj)