# Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
# SPDX-License-Identifier: GPL-3.0-or-later

from dal import autocomplete
from django.contrib.auth.mixins import LoginRequiredMixin
from django.contrib.contenttypes.models import ContentType
from django.db.models import Q
from django.utils.translation import gettext_lazy as _
from django.views.generic import CreateView, UpdateView
from django_tables2 import SingleTableView
from django.urls import reverse_lazy
from permission.backends import PermissionBackend

from .forms import TransactionTemplateForm
from .models import Transaction, TransactionTemplate, Alias, RecurrentTransaction, NoteSpecial
from .models.transactions import SpecialTransaction
from .tables import HistoryTable, ButtonTable


class TransactionCreateView(LoginRequiredMixin, SingleTableView):
    """
    View for the creation of Transaction between two note which are not :models:`transactions.RecurrentTransaction`.
    e.g. for donation/transfer between people and clubs or for credit/debit with :models:`note.NoteSpecial`
    """
    template_name = "note/transaction_form.html"

    model = Transaction
    # Transaction history table
    table_class = HistoryTable
    table_pagination = {"per_page": 50}

    def get_queryset(self):
        return Transaction.objects.filter(PermissionBackend.filter_queryset(
            self.request.user, Transaction, "view")
        ).order_by("-id").all()[:50]

    def get_context_data(self, **kwargs):
        """
        Add some context variables in template such as page title
        """
        context = super().get_context_data(**kwargs)
        context['title'] = _('Transfer money')
        context['polymorphic_ctype'] = ContentType.objects.get_for_model(Transaction).pk
        context['special_polymorphic_ctype'] = ContentType.objects.get_for_model(SpecialTransaction).pk
        context['special_types'] = NoteSpecial.objects.order_by("special_type").all()

        return context


class NoteAutocomplete(autocomplete.Select2QuerySetView):
    """
    Auto complete note by aliases. Used in every search field for note
    ex: :view:`ConsoView`, :view:`TransactionCreateView`
    """

    def get_queryset(self):
        """
        When someone look for an :models:`note.Alias`, a query is sent to the dedicated API.
        This function handles the result and return a filtered list of aliases.
        """
        #  Un utilisateur non connecté n'a accès à aucune information
        if not self.request.user.is_authenticated:
            return Alias.objects.none()

        qs = Alias.objects.all()

        # self.q est le paramètre de la recherche
        if self.q:
            qs = qs.filter(Q(name__regex="^" + self.q) | Q(normalized_name__regex="^" + Alias.normalize(self.q))) \
                .order_by('normalized_name').distinct()

        # Filtrage par type de note (user, club, special)
        note_type = self.forwarded.get("note_type", None)
        if note_type:
            types = str(note_type).lower()
            if "user" in types:
                qs = qs.filter(note__polymorphic_ctype__model="noteuser")
            elif "club" in types:
                qs = qs.filter(note__polymorphic_ctype__model="noteclub")
            elif "special" in types:
                qs = qs.filter(note__polymorphic_ctype__model="notespecial")
            else:
                qs = qs.none()

        return qs

    def get_result_label(self, result):
        """
        Show the selected alias and the username associated
        <Alias> (aka. <Username> )
        """
        # Gère l'affichage de l'alias dans la recherche
        res = result.name
        note_name = str(result.note)
        if res != note_name:
            res += " (aka. " + note_name + ")"
        return res

    def get_result_value(self, result):
        """
        The value used for the transactions will be the id of the Note.
        """
        return str(result.note.pk)


class TransactionTemplateCreateView(LoginRequiredMixin, CreateView):
    """
    Create TransactionTemplate
    """
    model = TransactionTemplate
    form_class = TransactionTemplateForm
    success_url = reverse_lazy('note:template_list')


class TransactionTemplateListView(LoginRequiredMixin, SingleTableView):
    """
    List TransactionsTemplates
    """
    model = TransactionTemplate
    table_class = ButtonTable


class TransactionTemplateUpdateView(LoginRequiredMixin, UpdateView):
    """
    """
    model = TransactionTemplate
    form_class = TransactionTemplateForm
    success_url = reverse_lazy('note:template_list')


class ConsoView(LoginRequiredMixin, SingleTableView):
    """
    The Magic View that make people pay their beer and burgers.
    (Most of the magic happens in the dark world of Javascript see consos.js)
    """
    template_name = "note/conso_form.html"

    # Transaction history table
    table_class = HistoryTable
    table_pagination = {"per_page": 50}

    def get_queryset(self):
        return Transaction.objects.filter(
            PermissionBackend.filter_queryset(self.request.user, Transaction, "view")
        ).order_by("-id").all()[:50]

    def get_context_data(self, **kwargs):
        """
        Add some context variables in template such as page title
        """
        context = super().get_context_data(**kwargs)
        from django.db.models import Count
        buttons = TransactionTemplate.objects.filter(
            PermissionBackend().filter_queryset(self.request.user, TransactionTemplate, "view")
        ).filter(display=True).annotate(clicks=Count('recurrenttransaction')).order_by('category__name', 'name')
        context['transaction_templates'] = buttons
        context['most_used'] = buttons.order_by('-clicks', 'name')[:10]
        context['title'] = _("Consumptions")
        context['polymorphic_ctype'] = ContentType.objects.get_for_model(RecurrentTransaction).pk

        # select2 compatibility
        context['no_cache'] = True

        return context