from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.orm import Session
from app.auth.dependencies import get_current_user
from app.database import get_db
from app.models.operation import Operation, OperationRelation
from app.models.user import User
from app.schemas.operation import OperationRelationCreate, OperationRelationOut

router = APIRouter(prefix="/operation-relations", tags=["operation-relations"])


@router.get("/{operation_id}", response_model=list[OperationRelationOut])
def list_relations(
    operation_id: int, db: Session = Depends(get_db), current_user: User = Depends(get_current_user)
):
    op = db.get(Operation, operation_id)
    if not op or op.user_id != current_user.id:
        raise HTTPException(status_code=404, detail="Operation not found")
    return db.query(OperationRelation).filter(
        (OperationRelation.operation_from_id == operation_id) |
        (OperationRelation.operation_to_id == operation_id)
    ).all()


@router.post("", response_model=OperationRelationOut, status_code=status.HTTP_201_CREATED)
def create_relation(
    body: OperationRelationCreate, db: Session = Depends(get_db), current_user: User = Depends(get_current_user)
):
    for op_id in (body.operation_from_id, body.operation_to_id):
        op = db.get(Operation, op_id)
        if not op or op.user_id != current_user.id:
            raise HTTPException(status_code=404, detail=f"Operation {op_id} not found")
    obj = OperationRelation(**body.model_dump())
    db.add(obj)
    db.commit()
    db.refresh(obj)
    return obj


@router.delete("/{relation_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_relation(
    relation_id: int, db: Session = Depends(get_db), current_user: User = Depends(get_current_user)
):
    obj = db.get(OperationRelation, relation_id)
    if not obj:
        raise HTTPException(status_code=404, detail="Relation not found")
    op = db.get(Operation, obj.operation_from_id)
    if not op or op.user_id != current_user.id:
        raise HTTPException(status_code=403, detail="Access denied")
    db.delete(obj)
    db.commit()