import traceback
import uuid

from datetime import datetime, timedelta
from decimal import Decimal

import barker.schemas.voucher as schemas

from fastapi import APIRouter, HTTPException, Security, status
from sqlalchemy import and_, func, or_, select
from sqlalchemy.exc import SQLAlchemyError
from sqlalchemy.orm import Session

from ...core.config import settings
from ...core.security import get_current_active_user as get_user
from ...db.session import SessionFuture
from ...models.guest_book import GuestBook
from ...models.inventory import Inventory
from ...models.inventory_modifier import InventoryModifier
from ...models.kot import Kot
from ...models.product_version import ProductVersion
from ...models.voucher import Voucher
from ...models.voucher_type import VoucherType
from ...printing.bill import print_bill
from ...printing.kot import print_kot
from ...routers.voucher import (
    check_permissions,
    do_update_bill_numbers,
    do_update_settlements,
    do_update_table,
    get_guest_book,
    get_tax,
    happy_hour_has_discount,
    happy_hour_items_balanced,
)
from ...schemas.user_token import UserToken


router = APIRouter()


@router.post("/save")
def save(
    data: schemas.VoucherIn,
    u: bool,  # Update table?
    p: int,  # Print type
    g: uuid.UUID | None = None,  # Guest book id
    user: UserToken = Security(get_user),
):
    try:
        with SessionFuture() as db:
            update_table = u
            voucher_type = VoucherType(p)
            guest_book = get_guest_book(g, db)
            item: Voucher = do_save(data, voucher_type, guest_book, db, user)
            if update_table:
                do_update_table(item, guest_book, db)
            db.commit()
            voucher_id = item.id
        with SessionFuture() as db:
            print_kot(voucher_id, db)
            if item.voucher_type != VoucherType.KOT:
                print_bill(voucher_id, db)
    except SQLAlchemyError as e:
        traceback.print_exc()
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=str(e),
        )


def do_save(
    data: schemas.VoucherIn,
    voucher_type: VoucherType,
    guest_book: GuestBook | None,
    db: Session,
    user: UserToken,
):
    now = datetime.utcnow()
    product_date = (now + timedelta(minutes=settings.TIMEZONE_OFFSET_MINUTES - settings.NEW_DAY_OFFSET_MINUTES)).date()
    check_permissions(None, voucher_type, user.permissions)

    kot_id = db.execute(select(func.coalesce(func.max(Voucher.kot_id), 0) + 1)).scalar_one()

    item = Voucher(
        now,
        guest_book.pax if guest_book is not None else data.pax,
        kot_id,
        data.table.id_,
        data.customer.id_ if data.customer is not None else None,
        voucher_type,
        user.id_,
    )
    db.add(item)
    for dk in data.kots:
        # Filter out nil inventories
        dk.inventories = [dki for dki in dk.inventories if round(dki.quantity, 2) != 0]
    # Filter out nil kots
    data.kots = [k for k in data.kots if len(k.inventories) > 0]
    for k in data.kots:
        if not happy_hour_items_balanced(k.inventories):
            raise HTTPException(
                status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
                detail="Happy hour products are not balanced.",
            )
        if happy_hour_has_discount(k.inventories):
            raise HTTPException(
                status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
                detail="Discount is not allowed on happy hour products.",
            )
        code = db.execute(select(func.coalesce(func.max(Kot.code), 0) + 1)).scalar_one()
        kot = Kot(item.id, code, item.food_table_id, item.date, item.user_id)
        item.kots.append(kot)
        db.add(kot)
        for index, i in enumerate(k.inventories):
            if round(i.quantity, 2) == 0:
                continue
            total_quantity: Decimal = round(
                Decimal(
                    sum(inv.quantity for ko in data.kots for inv in ko.inventories if inv.product.id_ == i.product.id_)
                ),
                2,
            )
            product: ProductVersion = db.execute(
                select(ProductVersion).where(
                    and_(
                        ProductVersion.product_id == i.product.id_,
                        or_(
                            ProductVersion.valid_from == None,  # noqa: E711
                            ProductVersion.valid_from <= product_date,
                        ),
                        or_(
                            ProductVersion.valid_till == None,  # noqa: E711
                            ProductVersion.valid_till >= product_date,
                        ),
                    )
                )
            ).scalar_one()
            if total_quantity < 0:
                raise HTTPException(
                    status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
                    detail=f"Quantity of {product.full_name} cannot be less than 0",
                )
            if round(i.quantity, 2) < 0:
                if "edit-printed-product" not in user.permissions:
                    raise HTTPException(
                        status_code=status.HTTP_403_FORBIDDEN,
                        detail=f"You are not allowed to delete printed products."
                        f"\n In this case {product.full_name}",
                    )
            tax_rate = get_tax(product.sale_category.tax.rate, voucher_type)
            inv = Inventory(
                kot.id,
                product.product_id,
                round(i.quantity, 2),
                product.price,
                round(min(i.discount, product.sale_category.discount_limit), 5),
                i.is_happy_hour,
                product.sale_category.tax_id,
                tax_rate,
                index,
            )
            kot.inventories.append(inv)
            db.add(inv)
            for m in i.modifiers:
                mod = InventoryModifier(None, m.id_, Decimal(0))
                inv.modifiers.append(mod)
                db.add(mod)
            db.flush()
    do_update_settlements(item, [], db)
    do_update_bill_numbers(item, db)
    if len(item.kots) == 0 or len(item.kots[0].inventories) == 0:
        raise HTTPException(
            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
            detail="Please add some products",
        )
    return item