"""Mehrere Chargen auf einmal: komplett ausbuchen, Teilmenge, löschen."""

from datetime import date, timedelta

import pytest
from fastapi import HTTPException

from app.models import BaseUnit, Lot, Movement, MovementType, Product, Role, User
from app.routers.stock import bulk_lot_checkout, bulk_lot_delete
from app.schemas import BulkLotCheckout, BulkLotDelete
from app.services.stock import current_stock


@pytest.fixture()
def user(db):
    person = User(username="tester", password_hash="x", role=Role.admin)
    db.add(person)
    db.commit()
    db.refresh(person)
    return person


@pytest.fixture()
def milch(db):
    product = Product(
        name="Vollmilch", base_unit=BaseUnit.milliliter, package_size=1000,
        source="manual",
    )
    db.add(product)
    db.commit()
    db.refresh(product)
    return product


def _lot(db, product, menge, tage=None):
    lot = Lot(
        product_id=product.id, quantity=menge,
        best_before=(date.today() + timedelta(days=tage)) if tage is not None else None,
    )
    db.add(lot)
    db.commit()
    db.refresh(lot)
    return lot


# --------------------------------------------------------------------------
# Komplett ausbuchen
# --------------------------------------------------------------------------
def test_mehrere_chargen_komplett_ausbuchen(db, user, milch):
    a = _lot(db, milch, 1000, 5)
    b = _lot(db, milch, 2000, 9)

    anzahl = bulk_lot_checkout(BulkLotCheckout(lot_ids=[a.id, b.id]), db=db, user=user)

    assert anzahl == 2
    assert db.query(Lot).count() == 0
    assert current_stock(db, milch.id) == 0


def test_je_charge_eine_bewegung(db, user, milch):
    a = _lot(db, milch, 1000, 5)
    b = _lot(db, milch, 2000, 9)

    bulk_lot_checkout(BulkLotCheckout(lot_ids=[a.id, b.id]), db=db, user=user)

    bewegungen = db.query(Movement).all()
    assert len(bewegungen) == 2
    assert {m.quantity for m in bewegungen} == {1000, 2000}
    assert all(m.type == MovementType.out for m in bewegungen)


def test_notiz_landet_an_der_bewegung(db, user, milch):
    a = _lot(db, milch, 1000, 5)

    bulk_lot_checkout(
        BulkLotCheckout(lot_ids=[a.id], note="Grossputz"), db=db, user=user
    )

    assert db.query(Movement).one().note == "Grossputz"


def test_leere_auswahl_tut_nichts(db, user, milch):
    _lot(db, milch, 1000, 5)
    assert bulk_lot_checkout(BulkLotCheckout(lot_ids=[]), db=db, user=user) == 0
    assert current_stock(db, milch.id) == 1000


def test_unbekannte_ids_werden_uebergangen(db, user, milch):
    a = _lot(db, milch, 1000, 5)

    anzahl = bulk_lot_checkout(BulkLotCheckout(lot_ids=[a.id, 999]), db=db, user=user)

    assert anzahl == 1
    assert current_stock(db, milch.id) == 0


# --------------------------------------------------------------------------
# Teilmenge je Charge
# --------------------------------------------------------------------------
def test_teilmenge_je_charge(db, user, milch):
    a = _lot(db, milch, 1000, 5)
    b = _lot(db, milch, 2000, 9)

    bulk_lot_checkout(
        BulkLotCheckout(lot_ids=[a.id, b.id], quantity=200, unit="ml"), db=db, user=user
    )

    assert db.get(Lot, a.id).quantity == 800
    assert db.get(Lot, b.id).quantity == 1800


def test_teilmenge_bei_gemischten_artikeln_wird_abgelehnt(db, user, milch):
    """„1 Packung" bei Milch und Brötchen sind verschiedene Dinge."""
    broetchen = Product(name="Brötchen", base_unit=BaseUnit.piece, package_size=6,
                        source="manual")
    db.add(broetchen)
    db.commit()
    a = _lot(db, milch, 1000, 5)
    b = _lot(db, broetchen, 6, 2)

    with pytest.raises(HTTPException) as fehler:
        bulk_lot_checkout(
            BulkLotCheckout(lot_ids=[a.id, b.id], quantity=1, unit="package"),
            db=db, user=user,
        )

    assert fehler.value.status_code == 400
    assert db.get(Lot, a.id).quantity == 1000      # nichts gebucht
    assert db.get(Lot, b.id).quantity == 6


def test_zu_wenig_bestand_rollt_alles_zurueck(db, user, milch):
    """Ein halb gebuchter Stand wäre schlimmer als gar keiner."""
    viel = _lot(db, milch, 1000, 5)
    wenig = _lot(db, milch, 100, 9)

    with pytest.raises(HTTPException) as fehler:
        bulk_lot_checkout(
            BulkLotCheckout(lot_ids=[viel.id, wenig.id], quantity=500, unit="ml"),
            db=db, user=user,
        )

    assert fehler.value.status_code == 409
    assert current_stock(db, milch.id) == 1100     # unverändert
    assert db.query(Movement).count() == 0


def test_unbekannte_einheit_bucht_nichts(db, user, milch):
    a = _lot(db, milch, 1000, 5)

    with pytest.raises(HTTPException) as fehler:
        bulk_lot_checkout(
            BulkLotCheckout(lot_ids=[a.id], quantity=1, unit="furlong"), db=db, user=user
        )

    assert fehler.value.status_code == 400
    assert current_stock(db, milch.id) == 1000


def test_teilmenge_leert_und_entfernt_die_charge(db, user, milch):
    a = _lot(db, milch, 500, 5)

    bulk_lot_checkout(
        BulkLotCheckout(lot_ids=[a.id], quantity=500, unit="ml"), db=db, user=user
    )

    assert db.get(Lot, a.id) is None


# --------------------------------------------------------------------------
# Löschen als Korrektur
# --------------------------------------------------------------------------
def test_mehrere_chargen_loeschen(db, user, milch):
    a = _lot(db, milch, 1000, 5)
    b = _lot(db, milch, 2000, 9)

    anzahl = bulk_lot_delete(BulkLotDelete(lot_ids=[a.id, b.id]), db=db, user=user)

    assert anzahl == 2
    assert db.query(Lot).count() == 0


def test_loeschen_schreibt_korrektur_nicht_verbrauch(db, user, milch):
    a = _lot(db, milch, 1000, 5)

    bulk_lot_delete(BulkLotDelete(lot_ids=[a.id]), db=db, user=user)

    bewegung = db.query(Movement).one()
    assert bewegung.type == MovementType.adjust
    assert bewegung.quantity == -1000
    assert bewegung.note == "Charge gelöscht"
    # Keine Charge mehr, an der die Bewegung haengen koennte.
    assert bewegung.lot_id is None


def test_loeschen_mit_leerer_auswahl(db, user, milch):
    _lot(db, milch, 1000, 5)
    assert bulk_lot_delete(BulkLotDelete(lot_ids=[]), db=db, user=user) == 0
    assert current_stock(db, milch.id) == 1000