import uuid

from datetime import date, timedelta

import barker.schemas.product as schemas

from fastapi import APIRouter, Depends, HTTPException, Security, status
from sqlalchemy import and_, insert, or_, select, update
from sqlalchemy.exc import SQLAlchemyError
from sqlalchemy.orm import Session, joinedload
from sqlalchemy.sql.functions import count, func

from ..core.config import settings
from ..core.security import get_current_active_user as get_user
from ..db.session import SessionFuture
from ..models.inventory import Inventory
from ..models.kot import Kot
from ..models.menu_category import MenuCategory
from ..models.modifier_category import ModifierCategory
from ..models.modifier_category_product import ModifierCategoryProduct
from ..models.product import Product
from ..models.product_version import ProductVersion
from ..models.sale_category import SaleCategory
from ..models.voucher import Voucher
from ..schemas.user_token import UserToken
from . import effective_date


router = APIRouter()


@router.post("/list", response_model=list[schemas.Product])
def sort_order(
    data: list[schemas.Product],
    date_: date = Depends(effective_date),
    user: UserToken = Security(get_user, scopes=["products"]),
):
    try:
        with SessionFuture() as db:
            indexes: dict[uuid.UUID, int] = {}
            for item in data:
                if item.menu_category.id_ in indexes:
                    indexes[item.menu_category.id_] += 1
                else:
                    indexes[item.menu_category.id_] = 0
                db.execute(
                    update(ProductVersion)
                    .where(
                        and_(
                            ProductVersion.product_id == item.id_,
                            or_(
                                ProductVersion.valid_from == None,  # noqa: E711
                                ProductVersion.valid_from <= date_,
                            ),
                            or_(
                                ProductVersion.valid_till == None,  # noqa: E711
                                ProductVersion.valid_till >= date_,
                            ),
                        )
                    )
                    .values(sort_order=indexes[item.menu_category.id_])
                )
            db.commit()
            return product_list(date_, db)
    except SQLAlchemyError as e:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=str(e),
        )


@router.post("", response_model=None)
def save(
    data: schemas.ProductIn,
    date_: date = Depends(effective_date),
    user: UserToken = Security(get_user, scopes=["products"]),
) -> None:
    try:
        with SessionFuture() as db:
            item = Product()
            db.add(item)
            db.flush()
            product_version = ProductVersion(
                product_id=item.id,
                name=data.name,
                units=data.units,
                menu_category_id=data.menu_category.id_,
                sale_category_id=data.sale_category.id_,
                price=data.price,
                has_happy_hour=data.has_happy_hour,
                is_not_available=data.is_not_available,
                quantity=data.quantity,
                valid_from=date_,
                valid_till=None,
            )
            db.add(product_version)
            add_modifiers(item.id, product_version.menu_category_id, date_, db)
            db.commit()
            return
    except SQLAlchemyError as e:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=str(e),
        )


def add_modifiers(product_id: uuid.UUID, menu_category_id: uuid.UUID, date_: date, db: Session):
    products_in_category = db.execute(
        select(count(ProductVersion.id)).where(
            and_(
                ProductVersion.menu_category_id == menu_category_id,
                ProductVersion.product_id != product_id,
                or_(
                    ProductVersion.valid_from == None,  # noqa: E711
                    ProductVersion.valid_from <= date_,
                ),
                or_(
                    ProductVersion.valid_till == None,  # noqa: E711
                    ProductVersion.valid_till >= date_,
                ),
            )
        )
    ).scalar()
    categories = db.execute(
        select(count(ProductVersion.id), ModifierCategory.id)
        .join(Product.versions)
        .join(ModifierCategoryProduct, Product.id == ModifierCategoryProduct.product_id)
        .join(ModifierCategory, ModifierCategory.id == ModifierCategoryProduct.modifier_category_id)
        .where(
            and_(
                ProductVersion.menu_category_id == menu_category_id,
                or_(
                    ProductVersion.valid_from == None,  # noqa: E711
                    ProductVersion.valid_from <= date_,
                ),
                or_(
                    ProductVersion.valid_till == None,  # noqa: E711
                    ProductVersion.valid_till >= date_,
                ),
            )
        )
        .group_by(ModifierCategory.id)
    ).all()
    for c, mc in categories:
        if c == products_in_category:
            db.execute(insert(ModifierCategoryProduct).values(product_id=product_id, modifier_category_id=mc))


@router.put("/{id_}", response_model=None)
def update_route(
    id_: uuid.UUID,
    data: schemas.ProductIn,
    date_: date = Depends(effective_date),
    user: UserToken = Security(get_user, scopes=["products"]),
) -> None:
    try:
        with SessionFuture() as db:
            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.name == data.name
                and item.units == data.units
                and item.menu_category_id == data.menu_category.id_
                and item.sale_category_id == data.sale_category.id_
                and item.price == data.price
                and item.has_happy_hour == data.has_happy_hour
                and item.is_not_available == data.is_not_available
            ):
                if item.quantity != data.quantity or item.sort_order != data.sort_order:
                    item.quantity = data.quantity
                    item.sort_order = data.sort_order
                    db.commit()
                # The product is identical. No need for a new one
                return None
            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.name = data.name
                item.units = data.units
                item.menu_category_id = data.menu_category.id_
                item.sale_category_id = data.sale_category.id_
                item.price = data.price
                item.has_happy_hour = data.has_happy_hour
                item.is_not_available = data.is_not_available
                item.quantity = data.quantity
                item.sort_order = data.sort_order
                db.commit()
                return None
            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=data.name,
                    units=data.units,
                    menu_category_id=data.menu_category.id_,
                    sale_category_id=data.sale_category.id_,
                    price=data.price,
                    has_happy_hour=data.has_happy_hour,
                    is_not_available=data.is_not_available,
                    quantity=data.quantity,
                    valid_from=date_,
                    valid_till=None,
                    sort_order=item.sort_order,
                )
                db.add(product_version)
                db.commit()
                return None
    except SQLAlchemyError as e:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=str(e),
        )


@router.delete("/{id_}", response_model=None)
def delete_route(
    id_: uuid.UUID,
    date_: date = Depends(effective_date),
    user: UserToken = Security(get_user, scopes=["products"]),
) -> None:
    with SessionFuture() as db:
        item: ProductVersion = db.execute(
            select(ProductVersion).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()
        day = func.date_trunc(
            "day", Voucher.date + timedelta(minutes=settings.NEW_DAY_OFFSET_MINUTES - settings.TIMEZONE_OFFSET_MINUTES)
        ).label("day")
        billed = db.execute(
            select(count(Inventory.id))
            .join(Inventory.kot)
            .join(Kot.voucher)
            .where(Inventory.product_id == id_, day >= date_)
        ).scalar_one()
        if billed > 0:
            raise HTTPException(
                status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
                detail="The cannot delete this product as it was billed",
            )

        if item.valid_from == date_:
            db.delete(item)
        else:
            item.valid_till = date_ - timedelta(days=1)
        db.commit()


@router.get("", response_model=schemas.ProductBlank)
def show_blank(
    user: UserToken = Security(get_user, scopes=["products"]),
) -> schemas.ProductBlank:
    return schemas.ProductBlank(
        name="",
        units="",
        price=0,
        hasHappyHour=False,
        isNotAvailable=False,
        isActive=True,
        sortOrder=0,
        quantity=0,
    )


@router.get("/list", response_model=list[schemas.Product])
def show_list(date_: date = Depends(effective_date), user: UserToken = Depends(get_user)) -> list[schemas.Product]:
    with SessionFuture() as db:
        return product_list(date_, db)


def product_list(date_: date, db: Session) -> list[schemas.Product]:
    return [
        product_info(item)
        for item in db.execute(
            select(ProductVersion)
            .join(ProductVersion.menu_category)
            .join(ProductVersion.sale_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_,
                    ),
                )
            )
            .order_by(MenuCategory.sort_order)
            .order_by(MenuCategory.name)
            .order_by(ProductVersion.sort_order)
            .order_by(ProductVersion.name)
            .options(
                joinedload(ProductVersion.menu_category, innerjoin=True),
                joinedload(ProductVersion.sale_category, innerjoin=True),
            )
        )
        .scalars()
        .all()
    ]


@router.get("/query")
def show_term(
    mc: uuid.UUID | None = None,
    sc: uuid.UUID | None = None,
    date_: date = Depends(effective_date),
    current_user: UserToken = Depends(get_user),
):
    list_ = []
    query = select(ProductVersion)
    if sc is not None:
        query = query.join(ProductVersion.menu_category)
    if mc is not None:
        query = query.join(ProductVersion.sale_category).join(SaleCategory.tax)
    query = query.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 mc is not None:
        query = query.where(ProductVersion.menu_category_id == mc).order_by(
            ProductVersion.sort_order, ProductVersion.name
        )
    if sc is not None:
        query = query.where(ProductVersion.sale_category_id == sc).order_by(
            MenuCategory.sort_order, ProductVersion.sort_order, ProductVersion.name
        )

    if mc is not None:
        query = query.options(
            joinedload(ProductVersion.sale_category, innerjoin=True),
            joinedload(ProductVersion.sale_category, SaleCategory.tax, innerjoin=True),
        )

    if sc is not None:
        query = query.options(
            joinedload(ProductVersion.menu_category, innerjoin=True),
        )

    with SessionFuture() as db:
        for item in db.execute(query).scalars().all():
            if sc is not None:
                list_.append(
                    {
                        "id": item.product_id,
                        "name": item.full_name,
                        "menuCategory": {
                            "id": item.menu_category_id,
                            "name": item.menu_category.name,
                        },
                        "price": item.price,
                    }
                )
            if mc is not None:
                list_.append(query_product_info(item, False))
                if item.has_happy_hour:
                    list_.append(query_product_info(item, True))
        return list_


def product_list_of_sale_category(date_: date, db: Session) -> list[schemas.Product]:
    return [
        product_info(item)
        for item in db.execute(
            select(ProductVersion)
            .join(ProductVersion.menu_category)
            .join(ProductVersion.sale_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_,
                    ),
                )
            )
            .order_by(MenuCategory.sort_order)
            .order_by(MenuCategory.name)
            .order_by(ProductVersion.sort_order)
            .order_by(ProductVersion.name)
            .options(
                joinedload(ProductVersion.menu_category, innerjoin=True),
                joinedload(ProductVersion.sale_category, innerjoin=True),
            )
        )
        .scalars()
        .all()
    ]


@router.get("/{id_}", response_model=schemas.Product)
def show_id(
    id_: uuid.UUID,
    date_: date = Depends(effective_date),
    user: UserToken = Security(get_user, scopes=["products"]),
) -> schemas.Product:
    with SessionFuture() as db:
        item: ProductVersion = db.execute(
            select(ProductVersion)
            .join(ProductVersion.sale_category)
            .join(SaleCategory.tax)
            .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_,
                    ),
                )
            )
            .order_by(ProductVersion.sort_order, ProductVersion.name)
            .options(
                joinedload(ProductVersion.sale_category, innerjoin=True),
                joinedload(ProductVersion.sale_category, SaleCategory.tax, innerjoin=True),
            )
        ).scalar_one()
        return product_info(item)


def query_product_info(item: ProductVersion, happy_hour: bool):
    return {
        "id": item.product_id,
        "name": ("H H " if happy_hour else "") + item.full_name,
        "saleCategory": {
            "id": item.sale_category_id,
            "name": item.sale_category.name,
        },
        "tax": {
            "id": item.sale_category.tax_id,
            "name": item.sale_category.tax.name,
            "rate": item.sale_category.tax.rate,
        },
        "price": item.price,
        "hasHappyHour": happy_hour,
        "isNotAvailable": item.is_not_available,
        "sortOrder": item.sort_order,
    }


def product_info(item: ProductVersion) -> schemas.Product:
    return schemas.Product(
        id=item.product_id,
        versionId=item.id,
        name=item.name,
        units=item.units,
        menuCategory=schemas.MenuCategoryLink(id=item.menu_category_id, name=item.menu_category.name, products=[]),
        saleCategory=schemas.SaleCategoryLink(
            id=item.sale_category_id,
            name=item.sale_category.name,
        ),
        price=item.price,
        hasHappyHour=item.has_happy_hour,
        isNotAvailable=item.is_not_available,
        quantity=item.quantity,
        isActive=True,
        sortOrder=item.sort_order,
        validFrom=item.valid_from,
        validTill=item.valid_till,
    )