from datetime import date
from fastapi import APIRouter, Depends, HTTPException, Query, status
from sqlalchemy.orm import Session
from app.auth.dependencies import get_current_user, require_role
from app.database import get_db
from app.models.currency import ExchangeRate
from app.schemas.currency import ExchangeRateCreate, ExchangeRateOut

router = APIRouter(prefix="/exchange-rates", tags=["exchange-rates"])

require_accountant = require_role("accountant")


@router.get("", response_model=list[ExchangeRateOut])
def list_rates(
    currency_from_id: int | None = None,
    currency_to_id: int | None = None,
    rate_date: date | None = None,
    limit: int = Query(50, le=500),
    db: Session = Depends(get_db),
    _=Depends(get_current_user),
):
    q = db.query(ExchangeRate)
    if currency_from_id:
        q = q.filter(ExchangeRate.currency_from_id == currency_from_id)
    if currency_to_id:
        q = q.filter(ExchangeRate.currency_to_id == currency_to_id)
    if rate_date:
        q = q.filter(ExchangeRate.rate_date == rate_date)
    return q.order_by(ExchangeRate.rate_date.desc()).limit(limit).all()


@router.post("", response_model=ExchangeRateOut, status_code=status.HTTP_201_CREATED)
def create_rate(body: ExchangeRateCreate, db: Session = Depends(get_db), _=Depends(require_accountant)):
    if body.currency_from_id == body.currency_to_id:
        raise HTTPException(status_code=400, detail="Cannot set rate between the same currency")
    existing = db.query(ExchangeRate).filter(
        ExchangeRate.currency_from_id == body.currency_from_id,
        ExchangeRate.currency_to_id == body.currency_to_id,
        ExchangeRate.rate_date == body.rate_date,
    ).first()
    if existing:
        for field, value in body.model_dump(exclude_none=True).items():
            setattr(existing, field, value)
        db.commit()
        db.refresh(existing)
        return existing
    obj = ExchangeRate(**body.model_dump())
    db.add(obj)
    db.commit()
    db.refresh(obj)
    return obj


@router.delete("/{rate_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_rate(rate_id: int, db: Session = Depends(get_db), _=Depends(require_accountant)):
    obj = db.get(ExchangeRate, rate_id)
    if not obj:
        raise HTTPException(status_code=404, detail="Exchange rate not found")
    db.delete(obj)
    db.commit()