import datetime

import brewman.schemas.reports as schemas

from fastapi import APIRouter, Depends, Request, Security
from sqlalchemy.orm import Session
from sqlalchemy.sql.expression import desc, 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, VoucherType
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.Purchases)
def report_blank(
    request: Request,
    user: UserToken = Security(get_user, scopes=["purchases"]),
):
    return schemas.Purchases(
        startDate=get_start_date(request.session),
        finishDate=get_finish_date(request.session),
        body=[],
        footer=None,
    )


@router.get("/{start}/{finish}", response_model=schemas.Purchases)
def report_data(
    start: str,
    finish: str,
    request: Request,
    db: Session = Depends(get_db),
    user: UserToken = Security(get_user, scopes=["purchases"]),
):
    body, footer = build_report(start, finish, db)
    set_period(start, finish, request.session)
    return schemas.Purchases(
        startDate=start,
        finishDate=finish,
        body=body,
        footer=footer,
    )


def build_report(start_date, finish_date, db):
    body = []
    quantity_sum = func.sum(Journal.debit * Inventory.quantity).label("quantity")
    amount_sum = func.sum(
        Journal.debit * Inventory.quantity * Inventory.rate * (1 + Inventory.tax)
    ).label("amount")
    query = (
        db.query(Product, quantity_sum, amount_sum)
        .join(Product.inventories)
        .join(Inventory.voucher)
        .join(Voucher.journals)
        .filter(Voucher.date >= datetime.datetime.strptime(start_date, "%d-%b-%Y"))
        .filter(Voucher.date <= datetime.datetime.strptime(finish_date, "%d-%b-%Y"))
        .filter(Voucher.type != VoucherType.by_name("Issue").id)
        .filter(Journal.cost_centre_id == CostCentre.cost_centre_purchase())
        .group_by(Product)
        .order_by(desc(amount_sum))
        .all()
    )

    total_amount = 0
    for product, quantity, amount in query:
        rate = amount / quantity if quantity != 0 else 0
        total_amount += amount
        row = schemas.PurchasesItem(
            name=product.full_name,
            quantity=quantity,
            rate=rate,
            amount=amount,
            url=["/", "product-ledger", str(product.id)],
        )
        body.append(row)
    return (
        body,
        schemas.PurchasesItem(
            name="Total", quantity=0, rate=0, url=[], amount=total_amount
        ),
    )