# Copyright © 2022 Aravinth Manivannan <realaravinth@batsense.net>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
from datetime import datetime, timedelta, timezone

from django.shortcuts import get_object_or_404, redirect, render
from django.template.response import TemplateResponse
from django.contrib.auth.decorators import login_required
from django.http import HttpResponse
from django.urls import reverse

from payments import get_payment_model, RedirectNeeded, PaymentStatus
from dash.models import Instance
from django.db.models import Q
from infrastructure.utils import create_vm_if_not_exists


def default_ctx(title: str, username: str):
    """
    Default context for all dashboard
    """
    return {
        "title": title,
        "username": username,
    }


@login_required
def pending_invoices(request):
    PAGE_TITLE = "Pending Invoices"

    user = request.user
    Payment = get_payment_model()
    payments = Payment.objects.filter(~Q(status=PaymentStatus.CONFIRMED), paid_by=user)
    ctx = default_ctx(title=PAGE_TITLE, username=user.username)
    ctx["payments"] = payments
    return render(request, "billing/invoices/pending/index.html", context=ctx)


@login_required
def paid_invoices(request):
    PAGE_TITLE = "Payment Receipts"

    user = request.user
    Payment = get_payment_model()
    payments = Payment.objects.filter(status=PaymentStatus.CONFIRMED, paid_by=user)
    ctx = default_ctx(title=PAGE_TITLE, username=user.username)
    ctx["payments"] = payments
    return render(request, "billing/invoices/paid/index.html", context=ctx)


@login_required
def generate_invoice(request, instance_name: str):
    instance = get_object_or_404(Instance, name=instance_name, owned_by=request.user)

    Payment = get_payment_model()
    now = datetime.now(tz=timezone.utc)
    delta = now - timedelta(seconds=(60 * 60 * 24 * 30))  # one month

    payment = None
    for p in Payment.objects.filter(date__gt=(delta), instance_name=instance_name):
        if p.status == PaymentStatus.CONFIRMED:
            return HttpResponse("BAD REQUEST: Already paid", status=400)
        elif any([p.status == PaymentStatus.INPUT, p.status == PaymentStatus.WAITING]):
            if payment is None:
                payment = p
            else:
                print(f"Duplicate payment {p}, deleting in favor of {payment}")
                p.delete()

    if payment is None:
        print("Payment not found, generating new payment")
        payment = Payment.objects.create(
            variant="stripe",  # this is the variant from PAYMENT_VARIANTS
            instance=instance,
        )

    return redirect(reverse("billing.invoice.details", args=(payment.public_ref,)))


@login_required
def payment_details(request, payment_public_id):

    payment = get_object_or_404(
        get_payment_model(), public_ref=payment_public_id, paid_by=request.user
    )

    try:
        form = payment.get_form(data=request.POST or None)
    except RedirectNeeded as redirect_to:
        return redirect(str(redirect_to))

    PAGE_TITLE = f'Invoice for VM "{payment.instance_name}"'

    ctx = default_ctx(title=PAGE_TITLE, username=request.user.username)
    ctx["form"] = form
    ctx["payment"] = payment
    return render(request, "billing/index.html", ctx)


@login_required
def payment_success(request, payment_public_id):
    PAGE_TITLE = "Payment Success"
    ctx = default_ctx(title=PAGE_TITLE, username=request.user.username)
    payment = get_object_or_404(
        get_payment_model(), public_ref=payment_public_id, paid_by=request.user
    )
    return redirect(reverse("infra.create", args=(payment.instance_name,)))


@login_required
def payment_failure(request, payment_public_id):
    PAGE_TITLE = "Payment failure"
    payment = get_object_or_404(
        get_payment_model(), public_ref=payment_public_id, paid_by=request.user
    )
    ctx = default_ctx(title=PAGE_TITLE, username=request.user.username)
    return HttpResponse(f"{payment} failed")