from io import BytesIO
import urllib.request
import urllib.error
import urllib.parse

from django.contrib.staticfiles.storage import staticfiles_storage
from django.core.mail import EmailMessage, EmailMultiAlternatives
from django.views import generic
from django.urls import reverse_lazy
from django.shortcuts import get_object_or_404
from django.template import RequestContext
from django.template.loader import get_template
from django.conf import settings
from django.urls import reverse
from django.core import signing
from django.http import HttpResponse
from django.core.exceptions import SuspiciousOperation
from django.db.models import Q
from django.contrib import messages
from django.utils.decorators import method_decorator
from django.views.decorators.csrf import csrf_exempt
from z3c.rml import rml2pdf
from PyPDF2 import PdfFileMerger, PdfFileReader
import simplejson
import premailer

from RIGS import models, forms
from PyRIGS import decorators
import datetime
import re
import copy

__author__ = 'ghost'


class RigboardIndex(generic.TemplateView):
    template_name = 'RIGS/rigboard.html'

    def get_context_data(self, **kwargs):
        # get super context
        context = super(RigboardIndex, self).get_context_data(**kwargs)

        # call out method to get current events
        context['events'] = models.Event.objects.current_events()
        return context


class WebCalendar(generic.TemplateView):
    template_name = 'RIGS/calendar.html'

    def get_context_data(self, **kwargs):
        context = super(WebCalendar, self).get_context_data(**kwargs)
        context['view'] = kwargs.get('view', '')
        context['date'] = kwargs.get('date', '')
        return context


class EventDetail(generic.DetailView):
    model = models.Event


class EventOembed(generic.View):
    model = models.Event

    def get(self, request, pk=None):
        embed_url = reverse('event_embed', args=[pk])
        full_url = "{0}://{1}{2}".format(request.scheme, request.META['HTTP_HOST'], embed_url)

        data = {
            'html': '<iframe src="{0}" frameborder="0" width="100%" height="250"></iframe>'.format(full_url),
            'version': '1.0',
            'type': 'rich',
            'height': '250'
        }

        json = simplejson.JSONEncoderForHTML().encode(data)
        return HttpResponse(json, content_type="application/json")


class EventEmbed(EventDetail):
    template_name = 'RIGS/event_embed.html'


class EventRA(generic.base.RedirectView):
    permanent = False

    def get_redirect_url(self, *args, **kwargs):
        event = get_object_or_404(models.Event, pk=kwargs['pk'])

        if event.risk_assessment_edit_url:
            return event.risk_assessment_edit_url

        params = {
            'entry.708610078': f'N{event.pk:05}',
            'entry.905899507': event.name,
            'entry.139491562': event.venue.name if event.venue else '',
            'entry.1689826056': event.start_date.strftime('%Y-%m-%d') + ((' - ' + event.end_date.strftime('%Y-%m-%d')) if event.end_date else ''),
            'entry.902421165': event.mic.name if event.mic else ''
        }
        return settings.RISK_ASSESSMENT_URL + "?" + urllib.parse.urlencode(params)


class EventCreate(generic.CreateView):
    model = models.Event
    form_class = forms.EventForm

    def get_context_data(self, **kwargs):
        context = super(EventCreate, self).get_context_data(**kwargs)
        context['edit'] = True
        context['currentVAT'] = models.VatRate.objects.current_rate()

        form = context['form']
        if re.search('"-\d+"', form['items_json'].value()):
            messages.info(self.request, "Your item changes have been saved. Please fix the errors and save the event.")

        # Get some other objects to include in the form. Used when there are errors but also nice and quick.
        for field, model in form.related_models.items():
            value = form[field].value()
            if value is not None and value != '':
                context[field] = model.objects.get(pk=value)
        return context

    def get_success_url(self):
        return reverse_lazy('event_detail', kwargs={'pk': self.object.pk})


class EventUpdate(generic.UpdateView):
    model = models.Event
    form_class = forms.EventForm

    def get_context_data(self, **kwargs):
        context = super(EventUpdate, self).get_context_data(**kwargs)
        context['edit'] = True

        form = context['form']

        # Get some other objects to include in the form. Used when there are errors but also nice and quick.
        for field, model in form.related_models.items():
            value = form[field].value()
            if value is not None and value != '':
                context[field] = model.objects.get(pk=value)

        return context

    def render_to_response(self, context, **response_kwargs):
        if not hasattr(context, 'duplicate'):
            # If this event has already been emailed to a client, show a warning
            if self.object.auth_request_at is not None:
                messages.info(self.request, 'This event has already been sent to the client for authorisation, any changes you make will be visible to them immediately.')

            if hasattr(self.object, 'authorised'):
                messages.warning(self.request, 'This event has already been authorised by client, any changes to price will require reauthorisation.')
        return super(EventUpdate, self).render_to_response(context, **response_kwargs)

    def get_success_url(self):
        return reverse_lazy('event_detail', kwargs={'pk': self.object.pk})


class EventDuplicate(EventUpdate):
    def get_object(self, queryset=None):
        old = super(EventDuplicate, self).get_object(queryset)  # Get the object (the event you're duplicating)
        new = copy.copy(old)  # Make a copy of the object in memory
        new.based_on = old  # Make the new event based on the old event
        new.purchase_order = None  # Remove old PO

        # Clear checked in by if it's a dry hire
        if new.dry_hire is True:
            new.checked_in_by = None

        # Remove all the authorisation information from the new event
        new.auth_request_to = None
        new.auth_request_by = None
        new.auth_request_at = None

        if self.request.method in (
                'POST', 'PUT'):  # This only happens on save (otherwise items won't display in editor)
            new.pk = None  # This means a new event will be created on save, and all items will be re-created
        else:
            messages.info(self.request, 'Event data duplicated but not yet saved. Click save to complete operation.')

        return new

    def get_context_data(self, **kwargs):
        context = super(EventDuplicate, self).get_context_data(**kwargs)
        context["duplicate"] = True
        return context


class EventPrint(generic.View):
    def get(self, request, pk):
        object = get_object_or_404(models.Event, pk=pk)
        template = get_template('RIGS/event_print.xml')

        merger = PdfFileMerger()

        context = {
            'object': object,
            'fonts': {
                'opensans': {
                    'regular': 'RIGS/static/fonts/OPENSANS-REGULAR.TTF',
                    'bold': 'RIGS/static/fonts/OPENSANS-BOLD.TTF',
                }
            },
            'quote': True,
            'current_user': request.user,
        }

        rml = template.render(context)

        buffer = rml2pdf.parseString(rml)
        merger.append(PdfFileReader(buffer))
        buffer.close()

        terms = urllib.request.urlopen(settings.TERMS_OF_HIRE_URL)
        merger.append(BytesIO(terms.read()))

        merged = BytesIO()
        merger.write(merged)

        response = HttpResponse(content_type='application/pdf')

        escapedEventName = re.sub('[^a-zA-Z0-9 \n\.]', '', object.name)

        response['Content-Disposition'] = "filename=N%05d | %s.pdf" % (object.pk, escapedEventName)
        response.write(merged.getvalue())
        return response


class EventArchive(generic.ListView):
    model = models.Event
    paginate_by = 25
    template_name = "RIGS/event_archive.html"

    def get_context_data(self, **kwargs):
        # get super context
        context = super(EventArchive, self).get_context_data(**kwargs)

        context['start'] = self.request.GET.get('start', None)
        context['end'] = self.request.GET.get('end', datetime.date.today().strftime('%Y-%m-%d'))
        return context

    def get_queryset(self):
        start = self.request.GET.get('start', None)
        end = self.request.GET.get('end', datetime.date.today())

        # Assume idiots, always check
        if start and start > end:
            messages.add_message(self.request, messages.INFO,
                                 "Muppet! Check the dates, it has been fixed for you.")
            start, end = end, start  # Stop the impending fail

        filter = Q()
        if end != "":
            filter &= Q(start_date__lte=end)
        if start:
            filter &= Q(start_date__gte=start)

        q = self.request.GET.get('q', "")

        if q is not "":
            qfilter = Q(name__icontains=q) | Q(description__icontains=q) | Q(notes__icontains=q)

            # try and parse an int
            try:
                val = int(q)
                qfilter = qfilter | Q(pk=val)
            except:  # noqa not an integer
                pass

            try:
                if q[0] == "N":
                    val = int(q[1:])
                    qfilter = Q(pk=val)  # If string is N###### then do a simple PK filter
            except:  # noqa
                pass

            filter &= qfilter

        qs = self.model.objects.filter(filter).order_by('-start_date')

        # Preselect related for efficiency
        qs.select_related('person', 'organisation', 'venue', 'mic')

        if len(qs) == 0:
            messages.add_message(self.request, messages.WARNING, "No events have been found matching those criteria.")

        return qs


class EventAuthorise(generic.UpdateView):
    template_name = 'RIGS/eventauthorisation_form.html'
    success_template = 'RIGS/eventauthorisation_success.html'

    def form_valid(self, form):
        self.object = form.save()

        self.template_name = self.success_template
        messages.add_message(self.request, messages.SUCCESS,
                             'Success! Your event has been authorised. ' +
                             'You will also receive email confirmation to %s.' % (self.object.email))
        return self.render_to_response(self.get_context_data())

    @property
    def event(self):
        return models.Event.objects.select_related('organisation', 'person', 'venue').get(pk=self.kwargs['pk'])

    def get_object(self, queryset=None):
        return getattr(self.event, 'authorisation', None)

    def get_form_class(self):
        return forms.InternalClientEventAuthorisationForm

    def get_context_data(self, **kwargs):
        context = super(EventAuthorise, self).get_context_data(**kwargs)
        context['event'] = self.event

        context['tos_url'] = settings.TERMS_OF_HIRE_URL
        return context

    def get(self, request, *args, **kwargs):
        if self.get_object() is not None and self.get_object().pk is not None:
            if self.event.authorised:
                messages.add_message(self.request, messages.WARNING,
                                     "This event has already been authorised. "
                                     "Reauthorising is not necessary at this time.")
            else:
                messages.add_message(self.request, messages.WARNING,
                                     "This event has already been authorised, but the amount has changed. " +
                                     "Please check the amount and reauthorise.")
        return super(EventAuthorise, self).get(request, *args, **kwargs)

    def get_form(self, **kwargs):
        form = super(EventAuthorise, self).get_form(**kwargs)
        form.instance.event = self.event
        form.instance.email = self.request.email
        form.instance.sent_by = self.request.sent_by
        return form

    def dispatch(self, request, *args, **kwargs):
        # Verify our signature matches up and all is well with the integrity of the URL
        try:
            data = signing.loads(kwargs.get('hmac'))
            assert int(kwargs.get('pk')) == int(data.get('pk'))
            request.email = data['email']
            request.sent_by = models.Profile.objects.get(pk=data['sent_by'])
        except (signing.BadSignature, AssertionError, KeyError, models.Profile.DoesNotExist):
            raise SuspiciousOperation(
                "This URL is invalid. Please ask your TEC contact for a new URL")
        return super(EventAuthorise, self).dispatch(request, *args, **kwargs)


class EventAuthorisationRequest(generic.FormView, generic.detail.SingleObjectMixin):
    model = models.Event
    form_class = forms.EventAuthorisationRequestForm
    template_name = 'RIGS/eventauthorisation_request.html'

    @method_decorator(decorators.nottinghamtec_address_required)
    def dispatch(self, *args, **kwargs):
        return super(EventAuthorisationRequest, self).dispatch(*args, **kwargs)

    @property
    def object(self):
        return self.get_object()

    def get_success_url(self):
        if self.request.is_ajax():
            url = reverse_lazy('closemodal')
            messages.info(self.request, "location.reload()")
        else:
            url = reverse_lazy('event_detail', kwargs={
                'pk': self.object.pk,
            })
            messages.add_message(self.request, messages.SUCCESS, "Authorisation request successfully sent.")
        return url

    def form_valid(self, form):
        email = form.cleaned_data['email']
        event = self.object
        event.auth_request_by = self.request.user
        event.auth_request_at = datetime.datetime.now()
        event.auth_request_to = email
        event.save()

        context = {
            'object': self.object,
            'request': self.request,
            'hmac': signing.dumps({
                'pk': self.object.pk,
                'email': email,
                'sent_by': self.request.user.pk,
            }),
        }
        if event.person is not None and email == event.person.email:
            context['to_name'] = event.person.name
        elif event.organisation is not None and email == event.organisation.email:
            context['to_name'] = event.organisation.name

        msg = EmailMultiAlternatives(
            "N%05d | %s - Event Authorisation Request" % (self.object.pk, self.object.name),
            get_template("RIGS/eventauthorisation_client_request.txt").render(context),
            to=[email],
            reply_to=[self.request.user.email],
        )
        css = staticfiles_storage.path('css/email.css')
        html = premailer.Premailer(get_template("RIGS/eventauthorisation_client_request.html").render(context),
                                   external_styles=css).transform()
        msg.attach_alternative(html, 'text/html')

        msg.send()

        return super(EventAuthorisationRequest, self).form_valid(form)


class EventAuthoriseRequestEmailPreview(generic.DetailView):
    template_name = "RIGS/eventauthorisation_client_request.html"
    model = models.Event

    def render_to_response(self, context, **response_kwargs):
        from django.contrib.staticfiles.storage import staticfiles_storage
        css = staticfiles_storage.path('css/email.css')
        response = super(EventAuthoriseRequestEmailPreview, self).render_to_response(context, **response_kwargs)
        assert isinstance(response, HttpResponse)
        response.content = premailer.Premailer(response.rendered_content, external_styles=css).transform()
        return response

    def get_context_data(self, **kwargs):
        context = super(EventAuthoriseRequestEmailPreview, self).get_context_data(**kwargs)
        context['hmac'] = signing.dumps({
            'pk': self.object.pk,
            'email': self.request.GET.get('email', 'hello@world.test'),
            'sent_by': self.request.user.pk,
        })
        context['to_name'] = self.request.GET.get('to_name', None)
        return context


@method_decorator(csrf_exempt, name='dispatch')
class LogRiskAssessment(generic.View):
    http_method_names = ["post"]

    def post(self, request, **kwargs):
        data = request.POST
        shared_secret = data.get("secret")
        edit_url = data.get("editUrl")
        rig_number = data.get("rigNum")
        if shared_secret is None or edit_url is None or rig_number is None:
            return HttpResponse(status=422)

        if shared_secret != settings.RISK_ASSESSMENT_SECRET:
            return HttpResponse(status=403)

        rig_number = int(re.sub("[^0-9]", "", rig_number))

        event = get_object_or_404(models.Event, pk=rig_number)
        event.risk_assessment_edit_url = edit_url
        event.save()

        return HttpResponse(status=200)