import uuid

from datetime import date, timedelta
from decimal import Decimal
from typing import List, Optional

from fastapi import APIRouter, Depends, HTTPException, Security, status
from sqlalchemy import and_, or_, select
from sqlalchemy.orm import Session, contains_eager, joinedload

from ..core.security import get_current_active_user as get_user
from ..db.session import SessionFuture
from ..models.menu_category import MenuCategory
from ..models.product_version import ProductVersion
from ..schemas.update_product_prices import UpdateProductPrices, UpdateProductPricesItem
from ..schemas.user_token import UserToken
from . import optional_query_date


router = APIRouter()


@router.get("", response_model=UpdateProductPrices)
def get_update_product_prices(
    date_: Optional[date] = Depends(optional_query_date),
    user: UserToken = Security(get_user, scopes=["products"]),
) -> UpdateProductPrices:
    if date_ is None:
        return UpdateProductPrices(
            date=date.today(),
            items=[],
        )
    with SessionFuture() as db:
        return UpdateProductPrices(
            date=date_,
            items=update_product_prices_list(None, date_, db),
        )


@router.get("/{id_}", response_model=UpdateProductPrices)
def get_update_product_prices_id(
    id_: uuid.UUID,
    date_: Optional[date] = Depends(optional_query_date),
    user: UserToken = Security(get_user, scopes=["products"]),
) -> UpdateProductPrices:
    if date_ is None:
        return UpdateProductPrices(
            date=date.today(),
            menuCategoryId=id_,
            items=[],
        )
    with SessionFuture() as db:
        return UpdateProductPrices(
            date=date_,
            menuCategoryId=id_,
            items=update_product_prices_list(id_, date_, db),
        )


def update_product_prices_list(
    menu_category_id: Optional[uuid.UUID], date_: date, db: Session
) -> List[UpdateProductPricesItem]:
    list_ = (
        select(ProductVersion)
        .join(ProductVersion.menu_category)
        .where(
            and_(
                or_(
                    ProductVersion.valid_from == None,  # noqa: E711
                    ProductVersion.valid_from <= date_,
                ),
                or_(
                    ProductVersion.valid_till == None,  # noqa: E711
                    ProductVersion.valid_till >= date_,
                ),
            )
        )
    )
    if menu_category_id is not None:
        list_ = list_.where(ProductVersion.menu_category_id == menu_category_id)
    list_.order_by(
        MenuCategory.sort_order,
        MenuCategory.name,
        ProductVersion.sort_order,
        ProductVersion.name,
        ProductVersion.valid_from.nullsfirst(),
    ).options(
        joinedload(ProductVersion.menu_category, innerjoin=True),
        contains_eager(ProductVersion.menu_category),
    )

    return [
        UpdateProductPricesItem(id=item.product_id, name=item.full_name, oldPrice=item.price, newPrice=item.price)
        for item in db.execute(list_).scalars().all()
    ]


@router.post("", response_model=UpdateProductPrices)
def save_update_product_prices(
    data: UpdateProductPrices,
    user: UserToken = Security(get_user, scopes=["products"]),
) -> UpdateProductPrices:
    with SessionFuture() as db:
        for item in data.items:
            update_product(item.id, item.new_price, data.date_, db)
        db.commit()
        return UpdateProductPrices(
            date=data.date_,
            items=update_product_prices_list(None, data.date_, db),
        )


@router.post("/{id_}", response_model=UpdateProductPrices)
def save_update_product_prices_id(
    id_: uuid.UUID,
    data: UpdateProductPrices,
    user: UserToken = Security(get_user, scopes=["products"]),
) -> UpdateProductPrices:
    with SessionFuture() as db:
        for item in data.items:
            update_product(item.id, item.new_price, data.date_, db)
        db.commit()
        return UpdateProductPrices(
            date=data.date_,
            menuCategoryId=id_,
            items=update_product_prices_list(id_, data.date_, db),
        )


def update_product(id_: uuid.UUID, price: Decimal, date_: date, db: Session):
    item: ProductVersion = db.execute(
        select(ProductVersion)
        .join(ProductVersion.menu_category)
        .where(
            and_(
                ProductVersion.product_id == id_,
                or_(
                    ProductVersion.valid_from == None,  # noqa: E711
                    ProductVersion.valid_from <= date_,
                ),
                or_(
                    ProductVersion.valid_till == None,  # noqa: E711
                    ProductVersion.valid_till >= date_,
                ),
            )
        )
    ).scalar_one()
    if item.valid_till is not None:
        # Allow adding a product here splitting the valid from and to, but not implemented right now
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Product has been invalidated",
        )
    if item.valid_from == date_:  # Update the product as valid from the the same
        item.price = price
        db.commit()
    else:  # Create a new version of the product from the new details
        item.valid_till = date_ - timedelta(days=1)
        product_version = ProductVersion(
            product_id=item.product_id,
            name=item.name,
            units=item.units,
            menu_category_id=item.menu_category_id,
            sale_category_id=item.sale_category_id,
            price=price,
            has_happy_hour=item.has_happy_hour,
            is_not_available=item.is_not_available,
            quantity=item.quantity,
            valid_from=date_,
            valid_till=None,
            sort_order=item.sort_order,
        )
        db.add(product_version)