# 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 django.shortcuts import render, redirect, get_object_or_404
from django.utils.http import urlencode
from django.contrib.auth import authenticate, login, logout
from django.contrib.auth import get_user_model
from django.contrib.auth.decorators import login_required
from django.http import HttpResponse
from django.views.decorators.csrf import csrf_protect
from django.urls import reverse

from .models import Instance, InstanceConfiguration

from accounts.decorators import confirm_access


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


@login_required
def home(request):
    """
    Dashboard homepage view
    """
    PAGE_TITLE = "Home"
    user = request.user
    ctx = default_ctx(title=PAGE_TITLE, username=user.username)

    instances = Instance.objects.filter(owned_by=user)
    if instances:
        ctx["instances"] = instances

    return render(request, "dash/home/index.html", context=ctx)


@login_required
@csrf_protect
def create_instance(request):
    """
    Create instance view
    """
    PAGE_TITLE = "Create Instance"
    user = request.user

    def get_ctx():
        ctx = default_ctx(title=PAGE_TITLE, username=user.username)
        configurations = InstanceConfiguration.objects.all()
        ctx["configurations"] = InstanceConfiguration.objects.all()
        return ctx

    if request.method == "GET":
        ctx = get_ctx()
        return render(request, "dash/instances/new/index.html", context=ctx)

    name = request.POST["name"]
    if Instance.objects.filter(name=name).exists():
        ctx = get_ctx()
        ctx["error"] = {
            "title": "Can't create instance",
            "reason": "Instance name exists, please try again with a different name",
        }
        print(ctx["error"]["reason"])
        return render(request, "dash/instances/new/index.html", status=400, context=ctx)

    configuration = request.POST["configuration"]
    if not InstanceConfiguration.objects.filter(name=configuration).exists():
        ctx = get_ctx()
        ctx["error"] = {
            "title": "Can't create instance",
            "reason": "Configuration doesn't exist, please try again.",
        }
        print(ctx["error"]["reason"])
        return render(request, "dash/instances/new/index.html", status=400, context=ctx)

    configuration = get_object_or_404(InstanceConfiguration, name=configuration)
    instance = Instance(
        name=name, configuration_id=configuration, owned_by=request.user
    )
    instance.save()
    return redirect(reverse("billing.invoice.generate", args=(instance.name,)))


@login_required
def list_instances(request):
    PAGE_TITLE = "My Instances"
    user = request.user

    instances = Instance.objects.filter(owned_by=user)
    ctx = default_ctx(title=PAGE_TITLE, username=user.username)
    ctx["instances"] = instances
    return render(request, "dash/instances/list/index.html", context=ctx)


@login_required
def view_instance(request, name: str):
    PAGE_TITLE = f"Hostea Instance: {name}"
    user = request.user

    instance = get_object_or_404(Instance, owned_by=user, name=name)
    ctx = default_ctx(title=PAGE_TITLE, username=user.username)
    instance.configuration = instance.configuration_id
    ctx["instance"] = instance
    return render(request, "dash/instances/view/index.html", context=ctx)


@login_required
@csrf_protect
@confirm_access
def delete_instance(request, name):
    PAGE_TITLE = f"Delete Instance {name}"
    user = request.user

    instance = get_object_or_404(Instance, name=name, owned_by=user)
    if request.method == "GET":
        ctx = default_ctx(title=PAGE_TITLE, username=user.username)
        ctx["instance"] = instance
        return render(request, "dash/instances/delete/index.html", context=ctx)

    instance.delete()
    return redirect(reverse("dash.home"))