import datetime
import re

import reversion
from django import forms
from django.contrib import messages
from django.db import transaction
from django.db.models import Q
from django.http import Http404, HttpResponseRedirect
from django.http import HttpResponse
from django.shortcuts import get_object_or_404
from django.template.loader import get_template
from django.urls import reverse
from django.views import generic
from z3c.rml import rml2pdf

from RIGS import models

forms.DateField.widget = forms.DateInput(attrs={'type': 'date'})


class InvoiceIndex(generic.ListView):
    model = models.Invoice
    template_name = 'invoice_list.html'

    def get_context_data(self, **kwargs):
        context = super(InvoiceIndex, self).get_context_data(**kwargs)
        total = 0
        for i in context['object_list']:
            total += i.balance
        context['page_title'] = "Outstanding Invoices ({} Events, £{:.2f})".format(len(list(context['object_list'])), total)
        context['description'] = "Paperwork for these events has been sent to treasury, but the full balance has not yet appeared on a ledger"
        return context

    def get_queryset(self):
        return self.model.objects.outstanding_invoices()


class InvoiceDetail(generic.DetailView):
    model = models.Invoice
    template_name = 'invoice_detail.html'

    def get_context_data(self, **kwargs):
        context = super(InvoiceDetail, self).get_context_data(**kwargs)
        context['page_title'] = "Invoice {} ({}) ".format(self.object.display_id, self.object.invoice_date.strftime("%d/%m/%Y"))
        if self.object.void:
            context['page_title'] += "<span class='badge badge-warning float-right'>VOID</span>"
        elif self.object.is_closed:
            context['page_title'] += "<span class='badge badge-success float-right'>PAID</span>"
        else:
            context['page_title'] += "<span class='badge badge-info float-right'>OUTSTANDING</span>"
        return context


class InvoicePrint(generic.View):
    def get(self, request, pk):
        invoice = get_object_or_404(models.Invoice, pk=pk)
        object = invoice.event
        template = get_template('event_print.xml')

        context = {
            'object': object,
            'invoice': invoice,
            'current_user': request.user,
            'filename': 'Invoice {} for {} {}.pdf'.format(invoice.display_id, object.display_id, re.sub(r'[^a-zA-Z0-9 \n\.]', '', object.name))
        }

        rml = template.render(context)

        buffer = rml2pdf.parseString(rml)

        pdfData = buffer.read()

        response = HttpResponse(content_type='application/pdf')
        response['Content-Disposition'] = 'filename="{}"'.format(context['filename'])
        response.write(pdfData)
        return response


class InvoiceVoid(generic.View):
    def get(self, *args, **kwargs):
        pk = kwargs.get('pk')
        object = get_object_or_404(models.Invoice, pk=pk)
        object.void = not object.void
        object.save()

        if object.void:
            return HttpResponseRedirect(reverse('invoice_list'))
        return HttpResponseRedirect(reverse('invoice_detail', kwargs={'pk': object.pk}))


class InvoiceDelete(generic.DeleteView):
    model = models.Invoice
    template_name = 'invoice_confirm_delete.html'

    def get(self, request, pk):
        obj = self.get_object()
        if obj.payment_set.all().count() > 0:
            messages.info(self.request, 'To delete an invoice, delete the payments first.')
            return HttpResponseRedirect(reverse('invoice_detail', kwargs={'pk': obj.pk}))
        return super(InvoiceDelete, self).get(pk)

    def post(self, request, pk):
        obj = self.get_object()
        if obj.payment_set.all().count() > 0:
            messages.info(self.request, 'To delete an invoice, delete the payments first.')
            return HttpResponseRedirect(reverse('invoice_detail', kwargs={'pk': obj.pk}))
        return super(InvoiceDelete, self).post(pk)

    def get_success_url(self):
        return self.request.POST.get('next')


class InvoiceArchive(generic.ListView):
    model = models.Invoice
    template_name = 'invoice_list_archive.html'
    paginate_by = 25

    def get_context_data(self, **kwargs):
        context = super(InvoiceArchive, self).get_context_data(**kwargs)
        context['page_title'] = "Invoice Archive"
        context['description'] = "This page displays all invoices: outstanding, paid, and void"
        return context

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

        filter = Q(event__name__icontains=q)

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

        try:
            if q[0] == "N":
                val = int(q[1:])
                filter = Q(event__pk=val)  # If string is Nxxxxx then filter by event number
            elif q[0] == "#":
                val = int(q[1:])
                filter = Q(pk=val)  # If string is #xxxxx then filter by invoice number
        except:  # noqa
            pass

        object_list = self.model.objects.filter(filter).order_by('-invoice_date')

        return object_list


class InvoiceWaiting(generic.ListView):
    model = models.Event
    paginate_by = 25
    template_name = 'invoice_list_waiting.html'

    def get_context_data(self, **kwargs):
        context = super(InvoiceWaiting, self).get_context_data(**kwargs)
        total = 0
        objects = self.get_queryset()
        for obj in objects:
            total += obj.sum_total
        context['page_title'] = "Events for Invoice ({} Events, £{:.2f})".format(len(objects), total)
        return context

    def get_queryset(self):
        return self.model.objects.waiting_invoices()


class InvoiceEvent(generic.View):
    @transaction.atomic()
    @reversion.create_revision()
    def get(self, *args, **kwargs):
        reversion.set_user(self.request.user)
        epk = kwargs.get('pk')
        event = models.Event.objects.get(pk=epk)
        invoice, created = models.Invoice.objects.get_or_create(event=event)

        if created:
            invoice.invoice_date = datetime.date.today()
            messages.success(self.request, 'Invoice created successfully')

        if kwargs.get('void'):
            invoice.void = not invoice.void
            invoice.save()
            messages.warning(self.request, 'Invoice voided')

        return HttpResponseRedirect(reverse('invoice_detail', kwargs={'pk': invoice.pk}))


class PaymentCreate(generic.CreateView):
    model = models.Payment
    fields = ['invoice', 'date', 'amount', 'method']
    template_name = 'payment_form.html'

    def get_initial(self):
        initial = super(generic.CreateView, self).get_initial()
        invoicepk = self.request.GET.get('invoice', self.request.POST.get('invoice', None))
        if invoicepk is None:
            raise Http404()
        invoice = get_object_or_404(models.Invoice, pk=invoicepk)
        initial.update({'invoice': invoice})
        return initial

    @transaction.atomic()
    @reversion.create_revision()
    def form_valid(self, form, *args, **kwargs):
        reversion.add_to_revision(form.cleaned_data['invoice'])
        reversion.set_comment("Payment added")
        return super().form_valid(form, *args, **kwargs)

    def get_success_url(self):
        messages.info(self.request, "location.reload()")
        return reverse('closemodal')


class PaymentDelete(generic.DeleteView):
    model = models.Payment
    template_name = 'payment_confirm_delete.html'

    @transaction.atomic()
    @reversion.create_revision()
    def delete(self, *args, **kwargs):
        reversion.add_to_revision(self.get_object().invoice)
        reversion.set_comment("Payment removed")
        return super().delete(*args, **kwargs)

    def get_success_url(self):
        return self.request.POST.get('next')