from datetime import date, datetime

import brewman.schemas.reports as schemas

from fastapi import APIRouter, Depends, Request, Security
from sqlalchemy.orm import Session
from sqlalchemy.sql.expression import func

from ...core.security import get_current_active_user as get_user
from ...core.session import get_finish_date, get_start_date, set_period
from ...db.session import SessionLocal
from ...models.master import CostCentre, Product
from ...models.voucher import Inventory, Journal, Voucher
from ...schemas.auth import UserToken


router = APIRouter()


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


@router.get("", response_model=schemas.ClosingStock)
def report_blank(
    request: Request,
    user: UserToken = Security(get_user, scopes=["closing-stock"]),
):
    return {"date": get_finish_date(request.session), "body": []}


@router.get("/{date_}", response_model=schemas.ClosingStock)
def report_data(
    date_: str,
    request: Request,
    db: Session = Depends(get_db),
    user: UserToken = Security(get_user, scopes=["closing-stock"]),
):
    set_period(get_start_date(request.session), date_, request.session)
    return {
        "date": date_,
        "body": build_report(datetime.strptime(date_, "%d-%b-%Y").date(), db),
    }


def build_report(date_: date, db: Session):
    amount_sum = func.sum(
        Journal.debit * Inventory.quantity * Inventory.rate * (1 + Inventory.tax)
    ).label("amount")
    quantity_sum = func.sum(Journal.debit * Inventory.quantity).label("quantity")
    query = (
        db.query(Product, quantity_sum, amount_sum)
        .join(Product.inventories)
        .join(Inventory.voucher)
        .join(Voucher.journals)
        .filter(Voucher.date <= date_)
        .filter(Journal.cost_centre_id == CostCentre.cost_centre_purchase())
        .group_by(Product)
        .order_by(amount_sum.desc())
        .all()
    )

    body = []
    for product, quantity, amount in query:
        if quantity != 0 and amount != 0:
            body.append(
                {
                    "product": product.full_name,
                    "group": product.product_group.name,
                    "quantity": quantity,
                    "amount": amount,
                }
            )
    return body


def get_opening_stock(date_: date, db: Session):
    opening_stock = (
        db.query(
            func.sum(
                Inventory.quantity
                * Inventory.rate
                * (1 + Inventory.tax)
                * Journal.debit
            )
        )
        .join(Journal.voucher)
        .join(Journal.account)
        .join(Voucher.inventories)
        .filter(Voucher.date < date_)
        .filter(Journal.cost_centre_id == CostCentre.cost_centre_purchase())
        .scalar()
    )
    return 0 if opening_stock is None else opening_stock


def get_closing_stock(date_, db: Session):
    closing_stock = (
        db.query(
            func.sum(
                Inventory.quantity
                * Inventory.rate
                * (1 + Inventory.tax)
                * Journal.debit
            )
        )
        .join(Journal.voucher)
        .join(Journal.account)
        .join(Voucher.inventories)
        .filter(Voucher.date <= date_)
        .filter(Journal.cost_centre_id == CostCentre.cost_centre_purchase())
        .scalar()
    )
    return 0 if closing_stock is None else closing_stock