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

import json

from django.conf import settings
from django.contrib.auth.mixins import LoginRequiredMixin
from django.contrib.contenttypes.models import ContentType
from django.core.exceptions import PermissionDenied
from django.db.models import Q, F
from django.utils.translation import gettext_lazy as _
from django.views.generic import CreateView, UpdateView, DetailView
from django.urls import reverse_lazy
from django_tables2 import SingleTableView
from activity.models import Entry
from permission.backends import PermissionBackend
from permission.views import ProtectQuerysetMixin
from note_kfet.inputs import AmountInput

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


class TransactionCreateView(ProtectQuerysetMixin, 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"
    # SingleTableView creates `context["table"]` we will  load it with transaction history
    model = Transaction
    # Transaction history table
    table_class = HistoryTable
    extra_context = {"title": _("Transfer money")}

    def get_queryset(self, **kwargs):
        # retrieves only Transaction that user has the right to see.
        return Transaction.objects.filter(
            PermissionBackend.filter_queryset(self.request, Transaction, "view")
        ).order_by("-created_at").all()[:20]

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['amount_widget'] = AmountInput(attrs={"id": "amount"})
        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\
            .filter(PermissionBackend.filter_queryset(self.request, NoteSpecial, "view"))\
            .order_by("special_type").all()

        # Add a shortcut for entry page for open activities
        if "activity" in settings.INSTALLED_APPS:
            from activity.models import Activity
            activities_open = Activity.objects.filter(open=True, activity_type__manage_entries=True).filter(
                PermissionBackend.filter_queryset(self.request, Activity, "view")).distinct().all()
            context["activities_open"] = [a for a in activities_open
                                          if PermissionBackend.check_perm(self.request,
                                                                          "activity.add_entry",
                                                                          Entry(activity=a,
                                                                                note=self.request.user.note, ))]

        return context


class TransactionTemplateCreateView(ProtectQuerysetMixin, LoginRequiredMixin, CreateView):
    """
    Create Transaction template
    """
    model = TransactionTemplate
    form_class = TransactionTemplateForm
    success_url = reverse_lazy('note:template_list')
    extra_context = {"title": _("Create new button")}


class TransactionTemplateListView(ProtectQuerysetMixin, LoginRequiredMixin, SingleTableView):
    """
    List Transaction templates
    """
    model = TransactionTemplate
    table_class = ButtonTable
    extra_context = {"title": _("Search button")}

    def get_queryset(self, **kwargs):
        """
        Filter the user list with the given pattern.
        """
        qs = super().get_queryset().distinct()
        if "search" in self.request.GET:
            pattern = self.request.GET["search"]
            qs = qs.filter(
                Q(name__iregex=pattern)
                | Q(destination__club__name__iregex=pattern)
                | Q(category__name__iregex=pattern)
                | Q(description__iregex=pattern)
            )

        qs = qs.order_by('-display', 'category__name', 'destination__club__name', 'name')

        return qs


class TransactionTemplateUpdateView(ProtectQuerysetMixin, LoginRequiredMixin, UpdateView):
    """
    Update Transaction template
    """
    model = TransactionTemplate
    form_class = TransactionTemplateForm
    success_url = reverse_lazy('note:template_list')
    extra_context = {"title": _("Update button")}

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

        if "logs" in settings.INSTALLED_APPS:
            from logs.models import Changelog
            update_logs = Changelog.objects.filter(
                model=ContentType.objects.get_for_model(TransactionTemplate),
                instance_pk=self.object.pk,
                action="edit",
            )
            price_history = []
            for log in update_logs.all():
                old_dict = json.loads(log.previous)
                new_dict = json.loads(log.data)
                if "amount" not in old_dict:
                    # The amount price of the button was not modified in this changelog
                    continue
                old_price = old_dict["amount"]
                new_price = new_dict["amount"]
                if old_price != new_price:
                    price_history.append(dict(price=old_price, time=log.timestamp))

            price_history.append(dict(price=self.object.amount, time=None))

            price_history.reverse()

            context["price_history"] = price_history

        return context


class ConsoView(ProtectQuerysetMixin, 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 `static/note/js/consos.js`)
    """
    model = Transaction
    template_name = "note/conso_form.html"
    extra_context = {"title": _("Consumptions")}

    # Transaction history table
    table_class = HistoryTable

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

        templates = TransactionTemplate.objects.filter(
            PermissionBackend().filter_queryset(self.request, TransactionTemplate, "view")
        )
        if not templates.exists():
            raise PermissionDenied(_("You can't see any button."))
        return super().dispatch(request, *args, **kwargs)

    def get_queryset(self, **kwargs):
        """
        restrict to the transaction history the user can see.
        """
        return Transaction.objects.filter(
            PermissionBackend.filter_queryset(self.request, Transaction, "view")
        ).order_by("-created_at").all()[:20]

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

        categories = TemplateCategory.objects.order_by('name').all()
        # for each category, find which transaction templates the user can see.
        for category in categories:
            category.templates_filtered = category.templates.filter(
                PermissionBackend().filter_queryset(self.request, TransactionTemplate, "view")
            ).filter(display=True).order_by('name').all()

        context['categories'] = [cat for cat in categories if cat.templates_filtered]
        # some transactiontemplate are put forward to find them easily
        context['highlighted'] = TransactionTemplate.objects.filter(highlighted=True).filter(
            PermissionBackend().filter_queryset(self.request, TransactionTemplate, "view")
        ).order_by('name').all()
        context['polymorphic_ctype'] = ContentType.objects.get_for_model(RecurrentTransaction).pk

        context['all_buttons'] = TransactionTemplate.objects.filter(
            PermissionBackend.filter_queryset(self.request, TransactionTemplate, "view")
        ).filter(display=True).order_by('name').all()

        return context


class TransactionSearchView(ProtectQuerysetMixin, LoginRequiredMixin, DetailView):
    model = Note
    context_object_name = "note"
    template_name = "note/search_transactions.html"
    extra_context = {"title": _("Search transactions")}

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

        form = SearchTransactionForm(data=self.request.GET if self.request.GET else None)
        context["form"] = form

        form.full_clean()
        data = form.cleaned_data if form.is_valid() else {}

        transactions = Transaction.objects.annotate(total_amount=F("quantity") * F("amount")).filter(
            PermissionBackend.filter_queryset(self.request, Transaction, "view"))\
            .filter(Q(source=self.object) | Q(destination=self.object)).order_by('-created_at')

        if "source" in data and data["source"]:
            transactions = transactions.filter(source_id=data["source"].note_id)
        if "destination" in data and data["destination"]:
            transactions = transactions.filter(destination_id=data["destination"].note_id)
        if "type" in data and data["type"]:
            transactions = transactions.filter(polymorphic_ctype__in=data["type"])
        if "reason" in data and data["reason"]:
            transactions = transactions.filter(reason__iregex=data["reason"])
        if "valid" in data and data["valid"]:
            transactions = transactions.filter(valid=data["valid"])
        if "amount_gte" in data and data["amount_gte"]:
            transactions = transactions.filter(total_amount__gte=data["amount_gte"])
        if "amount_lte" in data and data["amount_lte"]:
            transactions = transactions.filter(total_amount__lte=data["amount_lte"])
        if "created_after" in data and data["created_after"]:
            transactions = transactions.filter(created_at__gte=data["created_after"])
        if "created_before" in data and data["created_before"]:
            transactions = transactions.filter(created_at__lte=data["created_before"])

        table = HistoryTable(transactions)
        table.paginate(per_page=100, page=self.request.GET.get("page", 1))
        context["table"] = table

        return context