import uuid
from decimal import Decimal
from typing import Optional

from fastapi import APIRouter, HTTPException, status, Depends, Security
from sqlalchemy.exc import SQLAlchemyError
from sqlalchemy.orm import Session

from .save import do_save
from ...schemas.auth import UserToken
import barker.schemas.voucher as schemas
from ...core.security import get_current_active_user as get_user
from ...db.session import SessionLocal
from ...models import Voucher, SettleOption, Overview, Reprint
from ...routers.voucher import (
    do_update_settlements,
    get_guest_book,
)
from barker.schemas.receive_payment import ReceivePaymentItem as SettleSchema

router = APIRouter()


# Dependency
def get_db():
    try:
        db = SessionLocal()
        yield db
    finally:
        db.close()


@router.put("/change/{id_}")
def change(
    id_: uuid.UUID,
    data: schemas.VoucherIn,
    u: bool,  # Update table?
    g: Optional[uuid.UUID] = None,  # Guest book id
    db: Session = Depends(get_db),
    user: UserToken = Security(get_user),
):
    try:
        old: Voucher = db.query(Voucher).filter(Voucher.id == id_).first()
        amount_changed: bool = old.amount != round(
            sum(
                Decimal((0 if i.is_happy_hour else i.price) * i.quantity * (1 - i.discount) * (1 + i.tax_rate))
                for k in data.kots
                for i in k.inventories
            ),
            2,
        )
        items_changed: bool = len([i for k in old.kots for i in k.inventories]) != len(
            [i for k in data.kots for i in k.inventories]
        )
        if amount_changed or items_changed:
            void_and_issue_new_bill(data, u, g, old, db, user)
        else:
            reprint_bill(id_, user.id_, db)
        db.commit()
    except SQLAlchemyError as e:
        db.rollback()
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail=str(e),
        )
    except Exception:
        db.rollback()
        raise


def reprint_bill(voucher_id: uuid.UUID, user_id: uuid.UUID, db: Session):
    item = Reprint(voucher_id=voucher_id, user_id=user_id)
    db.add(item)


def void_and_issue_new_bill(
    data: schemas.VoucherIn, u: bool, g: Optional[uuid.UUID], old: Voucher, db: Session, user: UserToken
):
    update_table = u
    guest_book = get_guest_book(g, db)
    item = do_save(data, old.voucher_type, guest_book, db, user)
    db.flush()
    old.void = True
    old.void_reason = f"Bill Discounted / Changed. New Bill ID is {item.full_bill_id}"
    do_update_settlements(old, [SettleSchema(id=SettleOption.VOID(), amount=round(old.amount))], db)

    if update_table:
        if old.status is None:
            item.status = Overview(voucher_id=None, food_table_id=item.food_table_id, status="printed")
            db.add(item.status)
        else:
            db.query(Overview).filter(Overview.voucher_id == old.id).update({Overview.voucher_id: item.id})