from django import forms
from django.contrib import messages
from django.contrib.messages.views import SuccessMessageMixin
from django.http import HttpResponse, HttpResponseRedirect
from django.template import engines
from django.template.response import TemplateResponse
from django.urls import path, re_path, reverse
from django.views.decorators.cache import never_cache
from django.views.generic.edit import FormView

TEMPLATE = """{% if messages %}
<ul class="messages">
    {% for message in messages %}
    <li{% if message.tags %} class="{{ message.tags }}"{% endif %}>
        {{ message }}
    </li>
    {% endfor %}
</ul>
{% endif %}
"""


@never_cache
def add(request, message_type):
    # Don't default to False here to test that it defaults to False if
    # unspecified.
    fail_silently = request.POST.get('fail_silently', None)
    for msg in request.POST.getlist('messages'):
        if fail_silently is not None:
            getattr(messages, message_type)(request, msg, fail_silently=fail_silently)
        else:
            getattr(messages, message_type)(request, msg)
    return HttpResponseRedirect(reverse('show_message'))


@never_cache
def add_template_response(request, message_type):
    for msg in request.POST.getlist('messages'):
        getattr(messages, message_type)(request, msg)
    return HttpResponseRedirect(reverse('show_template_response'))


@never_cache
def show(request):
    template = engines['django'].from_string(TEMPLATE)
    return HttpResponse(template.render(request=request))


@never_cache
def show_template_response(request):
    template = engines['django'].from_string(TEMPLATE)
    return TemplateResponse(request, template)


class ContactForm(forms.Form):
    name = forms.CharField(required=True)
    slug = forms.SlugField(required=True)


class ContactFormViewWithMsg(SuccessMessageMixin, FormView):
    form_class = ContactForm
    success_url = show
    success_message = "%(name)s was created successfully"


urlpatterns = [
    re_path('^add/(debug|info|success|warning|error)/$', add, name='add_message'),
    path('add/msg/', ContactFormViewWithMsg.as_view(), name='add_success_msg'),
    path('show/', show, name='show_message'),
    re_path(
        '^template_response/add/(debug|info|success|warning|error)/$',
        add_template_response, name='add_template_response',
    ),
    path('template_response/show/', show_template_response, name='show_template_response'),
]