# Copyright (C) 2018-2024 by BDE ENS Paris-Saclay
# SPDX-License-Identifier: GPL-3.0-or-later

import os
import shutil
import subprocess
from tempfile import mkdtemp

from crispy_forms.helper import FormHelper
from django.contrib.auth.mixins import LoginRequiredMixin
from django.core.exceptions import ValidationError, PermissionDenied
from django.db import transaction
from django.db.models import Q
from django.forms import Form
from django.http import HttpResponse
from django.shortcuts import redirect
from django.urls import reverse_lazy
from django.utils.translation import gettext_lazy as _
from django.views.generic import UpdateView, DetailView
from django.views.generic.base import View, TemplateView
from django.views.generic.edit import BaseFormView, DeleteView
from django_tables2 import MultiTableMixin, SingleTableMixin, SingleTableView
from note.models import SpecialTransaction, NoteSpecial, Alias
from note_kfet.settings.base import BASE_DIR
from permission.backends import PermissionBackend
from permission.views import ProtectQuerysetMixin, ProtectedCreateView

from .forms import InvoiceForm, ProductFormSet, ProductFormSetHelper, RemittanceForm, \
    LinkTransactionToRemittanceForm, SogeCreditForm
from .models import Invoice, Product, Remittance, SpecialTransactionProxy, SogeCredit
from .tables import InvoiceTable, RemittanceTable, SpecialTransactionTable, SogeCreditTable


class InvoiceCreateView(ProtectQuerysetMixin, ProtectedCreateView):
    """
    Create Invoice
    """
    model = Invoice
    form_class = InvoiceForm
    extra_context = {"title": _("Create new invoice")}

    def get_sample_object(self):
        return Invoice(
            id=0,
            object="",
            description="",
            name="",
            address="",
        )

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

        form = context['form']
        form.helper = FormHelper()
        # Remove form tag on the generation of the form in the template (already present on the template)
        form.helper.form_tag = False
        # The formset handles the set of the products
        form_set = ProductFormSet(instance=form.instance)
        context['formset'] = form_set
        context['helper'] = ProductFormSetHelper()

        return context

    def get_form(self, form_class=None):
        form = super().get_form(form_class)
        del form.fields["locked"]
        return form

    @transaction.atomic
    def form_valid(self, form):
        ret = super().form_valid(form)

        # For each product, we save it
        formset = ProductFormSet(self.request.POST, instance=form.instance)
        if formset.is_valid():
            for f in formset:
                # We don't save the product if the designation is not entered, ie. if the line is empty
                if f.is_valid() and f.instance.designation:
                    f.save()
                    f.instance.save()
                else:
                    f.instance = None

        return ret

    def get_success_url(self):
        return reverse_lazy('treasury:invoice_list')


class InvoiceListView(LoginRequiredMixin, SingleTableView):
    """
    List existing Invoices
    """
    model = Invoice
    table_class = InvoiceTable
    extra_context = {"title": _("Invoices list")}

    def dispatch(self, request, *args, **kwargs):
        # Check that the user is authenticated
        if not request.user.is_authenticated:
            return self.handle_no_permission()

        if not PermissionBackend.has_model_perm(self.request, Invoice(), "view"):
            raise PermissionDenied(_("You are not able to see the treasury interface."))
        return super().dispatch(request, *args, **kwargs)


class InvoiceUpdateView(ProtectQuerysetMixin, LoginRequiredMixin, UpdateView):
    """
    Create Invoice
    """
    model = Invoice
    form_class = InvoiceForm
    extra_context = {"title": _("Update an invoice")}

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

        form = context['form']
        form.helper = FormHelper()
        # Remove form tag on the generation of the form in the template (already present on the template)
        form.helper.form_tag = False
        # The formset handles the set of the products
        form_set = ProductFormSet(instance=self.object)
        context['formset'] = form_set
        context['helper'] = ProductFormSetHelper()

        if self.object.locked:
            for field_name in form.fields:
                form.fields[field_name].disabled = True
            for f in form_set.forms:
                for field_name in f.fields:
                    f.fields[field_name].disabled = True

        return context

    def get_form(self, form_class=None):
        form = super().get_form(form_class)
        del form.fields["id"]
        return form

    @transaction.atomic
    def form_valid(self, form):
        ret = super().form_valid(form)

        formset = ProductFormSet(self.request.POST, instance=form.instance)
        saved = []
        # For each product, we save it
        if formset.is_valid():
            for f in formset:
                # We don't save the product if the designation is not entered, ie. if the line is empty
                if f.is_valid() and f.instance.designation:
                    f.save()
                    f.instance.save()
                    saved.append(f.instance.pk)
                else:
                    f.instance = None
            # Remove old products that weren't given in the form
            Product.objects.filter(~Q(pk__in=saved), invoice=form.instance).delete()

        return ret

    def get_success_url(self):
        return reverse_lazy('treasury:invoice_list')


class InvoiceDeleteView(ProtectQuerysetMixin, LoginRequiredMixin, DeleteView):
    """
    Delete a non-validated WEI registration
    """
    model = Invoice
    extra_context = {"title": _("Delete invoice")}

    def delete(self, request, *args, **kwargs):
        if self.get_object().locked:
            raise PermissionDenied(_("This invoice is locked and can't be deleted."))
        return super().delete(request, *args, **kwargs)

    def get_success_url(self):
        return reverse_lazy('treasury:invoice_list')


class InvoiceRenderView(LoginRequiredMixin, View):
    """
    Render Invoice as a generated PDF with the given information and a LaTeX template
    """

    def get(self, request, **kwargs):
        pk = kwargs["pk"]
        invoice = Invoice.objects.filter(PermissionBackend.filter_queryset(request, Invoice, "view")).get(pk=pk)
        tex = invoice.tex

        try:
            os.mkdir(BASE_DIR + "/tmp")
        except FileExistsError:
            pass
        # We render the file in a temporary directory
        tmp_dir = mkdtemp(prefix=BASE_DIR + "/tmp/")

        try:
            with open("{}/invoice-{:d}.tex".format(tmp_dir, pk), "wb") as f:
                f.write(tex.encode("UTF-8"))
            del tex

            # The file has to be rendered twice
            for _ignored in range(2):
                error = subprocess.Popen(
                    ["/usr/bin/xelatex", "-interaction=nonstopmode", "invoice-{}.tex".format(pk)],
                    cwd=tmp_dir,
                    stdin=open(os.devnull, "r"),
                    stderr=open(os.devnull, "wb"),
                    stdout=open(os.devnull, "wb"),
                ).wait()

                if error:
                    with open("{}/invoice-{:d}.log".format(tmp_dir, pk), "r") as f:
                        log = f.read()
                    raise IOError("An error attempted while generating a invoice (code=" + str(error) + ")\n\n" + log)

            # Display the generated pdf as a HTTP Response
            pdf = open("{}/invoice-{}.pdf".format(tmp_dir, pk), 'rb').read()
            response = HttpResponse(pdf, content_type="application/pdf")
            response['Content-Disposition'] = "inline;filename=Facture%20n°{:d}.pdf".format(pk)
        except IOError as e:
            raise e
        finally:
            # Delete all temporary files
            shutil.rmtree(tmp_dir)

        return response


class RemittanceCreateView(ProtectQuerysetMixin, ProtectedCreateView):
    """
    Create Remittance
    """
    model = Remittance
    form_class = RemittanceForm
    extra_context = {"title": _("Create a new remittance")}

    def get_sample_object(self):
        return Remittance(
            remittance_type_id=1,
            comment="",
        )

    def get_success_url(self):
        return reverse_lazy('treasury:remittance_list')

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

        context["table"] = RemittanceTable(
            data=Remittance.objects.filter(
                PermissionBackend.filter_queryset(self.request, Remittance, "view")).all())
        context["special_transactions"] = SpecialTransactionTable(data=SpecialTransaction.objects.none())

        return context


class RemittanceListView(LoginRequiredMixin, MultiTableMixin, TemplateView):
    """
    List existing Remittances
    """
    template_name = "treasury/remittance_list.html"
    extra_context = {"title": _("Remittances list")}

    tables = [
        lambda data: RemittanceTable(data, prefix="opened-remittances-"),
        lambda data: RemittanceTable(data, prefix="closed-remittances-"),
        lambda data: SpecialTransactionTable(data, prefix="no-remittance-", exclude=('remittance_remove', )),
        lambda data: SpecialTransactionTable(data, prefix="with-remittance-", exclude=('remittance_add', )),
    ]
    paginate_by = 10     # number of rows in tables

    def dispatch(self, request, *args, **kwargs):
        # Check that the user is authenticated
        if not request.user.is_authenticated:
            return self.handle_no_permission()

        if not PermissionBackend.has_model_perm(self.request, Remittance(), "view"):
            raise PermissionDenied(_("You are not able to see the treasury interface."))
        return super().dispatch(request, *args, **kwargs)

    def get_tables_data(self):
        return [
            Remittance.objects.filter(closed=False).filter(
                PermissionBackend.filter_queryset(self.request, Remittance, "view")),
            Remittance.objects.filter(closed=True).filter(
                PermissionBackend.filter_queryset(self.request, Remittance, "view")),
            SpecialTransaction.objects.filter(source__in=NoteSpecial.objects.filter(~Q(remittancetype=None)),
                                              specialtransactionproxy__remittance=None).filter(
                PermissionBackend.filter_queryset(self.request, Remittance, "view")),
            SpecialTransaction.objects.filter(source__in=NoteSpecial.objects.filter(~Q(remittancetype=None)),
                                              specialtransactionproxy__remittance__closed=False).filter(
                PermissionBackend.filter_queryset(self.request, Remittance, "view")),
        ]

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

        tables = context["tables"]
        names = [
            "opened_remittances",
            "closed_remittances",
            "special_transactions_no_remittance",
            "special_transactions_with_remittance",
        ]
        for name, table in zip(names, tables):
            context[name] = table

        return context


class RemittanceUpdateView(ProtectQuerysetMixin, LoginRequiredMixin, SingleTableMixin, UpdateView):
    """
    Update Remittance
    """
    model = Remittance
    form_class = RemittanceForm
    extra_context = {"title": _("Update a remittance")}

    table_class = SpecialTransactionTable
    context_table_name = "special_transactions"

    def get_success_url(self):
        return reverse_lazy('treasury:remittance_list')

    def get_table_data(self):
        return SpecialTransaction.objects.filter(specialtransactionproxy__remittance=self.object).filter(
            PermissionBackend.filter_queryset(self.request, Remittance, "view"))

    def get_table_kwargs(self):
        return {"exclude": ('remittance_add', 'remittance_remove', ) if self.object.closed else ('remittance_add', )}


class LinkTransactionToRemittanceView(ProtectQuerysetMixin, LoginRequiredMixin, UpdateView):
    """
    Attach a special transaction to a remittance
    """
    model = SpecialTransactionProxy
    form_class = LinkTransactionToRemittanceForm
    extra_context = {"title": _("Attach a transaction to a remittance")}

    def get_success_url(self):
        return reverse_lazy('treasury:remittance_list')

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

        form = context["form"]
        form.fields["last_name"].initial = self.object.transaction.last_name
        form.fields["first_name"].initial = self.object.transaction.first_name
        form.fields["bank"].initial = self.object.transaction.bank
        form.fields["amount"].initial = self.object.transaction.amount
        form.fields["remittance"].queryset = form.fields["remittance"] \
            .queryset.filter(remittance_type__note=self.object.transaction.source)

        return context


class UnlinkTransactionToRemittanceView(LoginRequiredMixin, View):
    """
    Unlink a special transaction and its remittance
    """

    def get(self, *args, **kwargs):
        pk = kwargs["pk"]
        transaction = SpecialTransactionProxy.objects.get(pk=pk)

        # The remittance must be open (or inexistant)
        if transaction.remittance and transaction.remittance.closed:
            raise ValidationError("Remittance is already closed.")

        transaction.remittance = None
        transaction.save()

        return redirect('treasury:remittance_list')


class SogeCreditListView(LoginRequiredMixin, ProtectQuerysetMixin, SingleTableView):
    """
    List all Société Générale credits
    """
    model = SogeCredit
    table_class = SogeCreditTable
    extra_context = {"title": _("List of credits from the Société générale")}

    def dispatch(self, request, *args, **kwargs):
        # Check that the user is authenticated
        if not request.user.is_authenticated:
            return self.handle_no_permission()

        if not PermissionBackend.has_model_perm(self.request, SogeCredit(), "view"):
            raise PermissionDenied(_("You are not able to see the treasury interface."))
        return super().dispatch(request, *args, **kwargs)

    def get_queryset(self, **kwargs):
        """
        Filter the table with the given parameter.
        :param kwargs:
        :return:
        """
        qs = super().get_queryset()
        if "search" in self.request.GET:
            pattern = self.request.GET["search"]
            if pattern:
                qs = qs.filter(
                    Q(user__first_name__iregex=pattern)
                    | Q(user__last_name__iregex=pattern)
                    | Q(user__note__alias__name__iregex="^" + pattern)
                    | Q(user__note__alias__normalized_name__iregex="^" + Alias.normalize(pattern))
                )

        if "valid" not in self.request.GET or not self.request.GET["valid"]:
            qs = qs.filter(credit_transaction__valid=False)

        return qs

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['form'] = SogeCreditForm(self.request.POST or None)
        return context


class SogeCreditManageView(LoginRequiredMixin, ProtectQuerysetMixin, BaseFormView, DetailView):
    """
    Manage credits from the Société générale.
    """
    model = SogeCredit
    form_class = Form
    extra_context = {"title": _("Manage credits from the Société générale")}

    @transaction.atomic
    def form_valid(self, form):
        if "validate" in form.data:
            self.get_object().validate(True)
        elif "delete" in form.data:
            self.get_object().delete()
        return super().form_valid(form)

    def get_success_url(self):
        if "validate" in self.request.POST:
            return reverse_lazy('treasury:manage_soge_credit', args=(self.get_object().pk,))
        return reverse_lazy('treasury:soge_credits')