from contextlib import suppress
from datetime import date, timedelta

from constance import config
from django.db.models import Count, F, QuerySet, Sum
from django.db.models.functions import Coalesce, TruncDate
from django.utils.timezone import now

from engine.core.models import Order, OrderProduct


def get_period_order_products(
    period: timedelta = timedelta(days=30), statuses: list[str] | None = None
) -> QuerySet[OrderProduct]:
    if statuses is None:
        statuses = ["FINISHED"]
    current = now()
    perioded = current - period
    orders = Order.objects.filter(status="FINISHED", buy_time__lte=current, buy_time__gte=perioded)
    return OrderProduct.objects.filter(status__in=statuses, order__in=orders)


def get_revenue(clear: bool = True, period: timedelta = timedelta(days=30)) -> float:
    order_products = get_period_order_products(period)
    total: float = (
        order_products.aggregate(total=Coalesce(Sum(F("buy_price") * F("quantity")), 0.0)).get("total") or 0.0
    )
    try:
        total = float(total)
    except (TypeError, ValueError):
        total = 0.0

    if not clear:
        return round(float(total), 2)

    try:
        tax_rate = float(config.TAX_RATE or 0)
    except (TypeError, ValueError):
        tax_rate = 0.0

    tax_included = False
    with suppress(Exception):
        tax_included = bool(getattr(config, "TAX_INCLUDED", False))

    if tax_rate <= 0:
        net = total
    else:
        if tax_included:
            divisor = 1.0 + (tax_rate / 100.0)
            if divisor <= 0:
                net = total
            else:
                net = total / divisor
        else:
            net = total

    return round(float(net or 0.0), 2)


def get_returns(period: timedelta = timedelta(days=30)) -> float:
    order_products = get_period_order_products(period, ["RETURNED"])
    total_returns: float = (
        order_products.aggregate(total=Coalesce(Sum(F("buy_price") * F("quantity")), 0.0)).get("total") or 0.0
    )
    try:
        return round(float(total_returns), 2)
    except (TypeError, ValueError):
        return 0.0


def get_total_processed_orders(period: timedelta = timedelta(days=30)) -> int:
    return get_period_order_products(period, ["RETURNED", "FINISHED"]).count()


def get_daily_finished_orders_count(period: timedelta = timedelta(days=30)) -> dict[date, int]:
    current = now()
    period_start = current - period
    qs = (
        Order.objects.filter(status="FINISHED", buy_time__lte=current, buy_time__gte=period_start)
        .annotate(day=TruncDate("buy_time"))
        .values("day")
        .annotate(cnt=Count("id"))
        .order_by("day")
    )
    result: dict[date, int] = {}
    for row in qs:
        d = row.get("day")
        c = int(row.get("cnt", 0) or 0)
        if d:
            result[d] = c
    return result


def get_daily_gross_revenue(period: timedelta = timedelta(days=30)) -> dict[date, float]:
    qs = (
        get_period_order_products(period, ["FINISHED"])  # OrderProduct queryset
        .annotate(day=TruncDate("order__buy_time"))
        .values("day")
        .annotate(total=Coalesce(Sum(F("buy_price") * F("quantity")), 0.0))
        .order_by("day")
    )
    result: dict[date, float] = {}
    for row in qs:
        d = row.get("day")
        total = row.get("total") or 0.0
        try:
            total_f = round(float(total), 2)
        except (TypeError, ValueError):
            total_f = 0.0
        if d:
            result[d] = total_f
    return result