# Copyright (C) 2018-2022 by BDE ENS Paris-Saclay
# SPDX-License-Identifier: GPL-3.0-or-later
from datetime import timedelta

from crispy_forms.bootstrap import Accordion, AccordionGroup, FormActions
from crispy_forms.helper import FormHelper
from crispy_forms.layout import Fieldset, Submit, Row, Field
from django import forms
from django.contrib.auth.mixins import LoginRequiredMixin
from django.db import transaction
from django.forms import Form
from django.urls import reverse_lazy
from django.utils import timezone
from django.utils.translation import gettext_lazy as _
from django.views.generic import DetailView, UpdateView, FormView
from django_tables2 import SingleTableView

from note.models import Alias, Note
from note.templatetags.pretty_money import pretty_money
from note_kfet.inputs import AmountInput, Autocomplete
from permission.backends import PermissionBackend
from permission.views import ProtectQuerysetMixin, ProtectedCreateView

from .forms import FoodForm, MealForm, SheetForm, FoodOptionsFormSet, FoodOptionFormSetHelper
from .models import Sheet, Food, Meal, Order, OrderedMeal, OrderedFood, SheetOrderTransaction
from .tables import SheetTable


class SheetListView(ProtectQuerysetMixin, LoginRequiredMixin, SingleTableView):
    model = Sheet
    table_class = SheetTable
    ordering = '-date'
    extra_context = {"title": _("Search note sheet")}

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["can_create_sheet"] = PermissionBackend.check_perm(self.request, "sheets.add_sheet", Sheet(
            name="Test",
            date=timezone.now(),
            description="Test sheet",
        ))
        return context


class SheetCreateView(ProtectQuerysetMixin, ProtectedCreateView):
    model = Sheet
    form_class = SheetForm
    extra_context = {"title": _("Create note sheet")}

    def get_sample_object(self):
        return Sheet(
            name="Test",
            date=timezone.now(),
            description="Test",
        )


class SheetUpdateView(ProtectQuerysetMixin, LoginRequiredMixin, UpdateView):
    model = Sheet
    form_class = SheetForm
    extra_context = {"title": _("Update note sheet")}


class SheetDetailView(ProtectQuerysetMixin, LoginRequiredMixin, DetailView):
    model = Sheet

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

        context['can_change_sheet'] = PermissionBackend.check_perm(self.request, 'sheets.change_sheet', self.object)
        context['can_add_meal'] = PermissionBackend.check_perm(self.request,
                                                               'sheets.add_meal',
                                                               Meal(sheet=self.object, name="Test", price=500))
        context['can_add_food'] = PermissionBackend.check_perm(self.request,
                                                               'sheets.add_food',
                                                               Food(sheet=self.object, name="Test", price=500))

        return context


class FoodCreateView(ProtectQuerysetMixin, ProtectedCreateView):
    model = Food
    form_class = FoodForm
    extra_context = {"title": _("Create new food")}

    def get_sample_object(self):
        return Food(
            sheet_id=self.kwargs['pk'],
            name="Test",
            price=500,
        )

    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 = FoodOptionsFormSet(instance=form.instance)
        context['formset'] = form_set
        context['helper'] = FoodOptionFormSetHelper()

        return context

    def form_valid(self, form):
        form.instance.sheet_id = self.kwargs['pk']

        # For each product, we save it
        formset = FoodOptionsFormSet(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.name:
                    f.save()
                    f.instance.save()
                else:
                    f.instance = None

        return super().form_valid(form)

    def get_success_url(self):
        return reverse_lazy('sheets:sheet_detail', args=(self.kwargs['pk'],))


class FoodUpdateView(ProtectQuerysetMixin, LoginRequiredMixin, UpdateView):
    model = Food
    form_class = FoodForm
    extra_context = {"title": _("Update food")}

    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 = FoodOptionsFormSet(instance=form.instance)
        context['formset'] = form_set
        context['helper'] = FoodOptionFormSetHelper()

        return context

    def form_valid(self, form):
        # For each product, we save it
        formset = FoodOptionsFormSet(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.name:
                    f.save()
                    f.instance.save()
                else:
                    f.instance = None

        return super().form_valid(form)

    def get_success_url(self):
        return reverse_lazy('sheets:sheet_detail', args=(self.object.sheet_id,))


class MealCreateView(ProtectQuerysetMixin, ProtectedCreateView):
    model = Meal
    form_class = MealForm
    extra_context = {"title": _("Create new meal")}

    def get_sample_object(self):
        return Meal(
            sheet_id=self.kwargs['pk'],
            name="Test",
            price=500,
        )

    def get_form(self, form_class=None):
        form = super().get_form(form_class)
        form.fields['content'].queryset = form.fields['content'].queryset.filter(sheet_id=self.kwargs['pk'])
        return form

    def form_valid(self, form):
        form.instance.sheet_id = self.kwargs['pk']
        return super().form_valid(form)

    def get_success_url(self):
        return reverse_lazy('sheets:sheet_detail', args=(self.object.sheet_id,))


class MealUpdateView(ProtectQuerysetMixin, LoginRequiredMixin, UpdateView):
    model = Meal
    form_class = MealForm
    extra_context = {"title": _("Update meal")}

    def get_form(self, form_class=None):
        form = super().get_form(form_class)
        form.fields['content'].queryset = form.fields['content'].queryset.filter(sheet=self.object.sheet)
        return form

    def get_success_url(self):
        return reverse_lazy('sheets:sheet_detail', args=(self.object.sheet_id,))


class OrderView(LoginRequiredMixin, FormView, DetailView):
    model = Sheet
    template_name = 'sheets/order.html'
    extra_context = {'title': _("Order now")}

    def get_form(self, form_class=None):
        form = Form()
        form.helper = FormHelper()
        layout_fields = []

        self.object = self.get_object()

        form.fields['note'] = forms.ModelChoiceField(
            queryset=Note.objects.filter(PermissionBackend.filter_queryset(self.request, Note, 'note.view_note')),
            label=_("Orderer"),
            initial=self.request.user.note,
            widget=Autocomplete(
                model=Note,
                attrs={
                    "api_url": "/api/note/note/",
                    'placeholder': _("Who orders")
                },
            ),
        )
        layout_fields.append(Field('note', css_class='is-valid'))

        for meal in self.object.meal_set.filter(available=True).all():
            form.fields[f'meal_{meal.id}_quantity'] = forms.IntegerField(
                label=_("Quantity"),
                initial=0,
            )
            form.fields[f'meal_{meal.id}_gift'] = forms.IntegerField(
                label=_("gift").capitalize(),
                initial=0,
                widget=AmountInput(),
                help_text=_("Be careful: this gift will be multiplied for each order."),
            )
            form.fields[f'meal_{meal.id}_remark'] = forms.CharField(
                max_length=255,
                required=False,
                label=_("remark").capitalize(),
                help_text=_("Allergies,…"),
            )
            form.fields[f'meal_{meal.id}_priority'] = forms.CharField(
                max_length=64,
                required=False,
                label=_("priority request").capitalize(),
                help_text=_("Lesson at 13h30,…"),
            )

            ag = AccordionGroup(f"{meal} ({pretty_money(meal.price)})",
                                Row(Field(f'meal_{meal.id}_quantity', wrapper_class='col-sm-9'),
                                    Field(f'meal_{meal.id}_gift', wrapper_class='col-sm-3')),
                                Row(Field(f'meal_{meal.id}_remark', wrapper_class='col-sm-9'),
                                    Field(f'meal_{meal.id}_priority', wrapper_class='col-sm-3')))

            for food in meal.content.filter(available=True).all():
                if food.foodoption_set.count():
                    options_fieldset = Fieldset(_("Options for ") + str(food))
                    options_row = Row(css_class='ml-0')
                    for option in food.foodoption_set.filter(available=True).all():
                        form.fields[f'meal_{meal.id}_food_{food.id}_option_{option.id}'] = forms.BooleanField(
                            label=f"{option}{f' ({pretty_money(option.extra_cost)})' if option.extra_cost else ''}",
                            required=False,
                        )
                        options_row.fields.append(
                            Field(f'meal_{meal.id}_food_{food.id}_option_{option.id}', wrapper_class='col-sm-12'))
                    options_fieldset.fields.append(options_row)
                    ag.fields.append(options_fieldset)

            layout_fields.append(ag)

        for food in self.object.food_set.filter(available=True).all():
            form.fields[f'food_{food.id}_quantity'] = forms.IntegerField(
                label=_("quantity").capitalize(),
                initial=0,
            )
            form.fields[f'food_{food.id}_gift'] = forms.IntegerField(
                label=_("gift").capitalize(),
                initial=0,
                widget=AmountInput(),
                help_text=_("Be careful: this gift will be multiplied for each order."),
            )
            form.fields[f'food_{food.id}_remark'] = forms.CharField(
                max_length=255,
                required=False,
                label=_("remark").capitalize(),
                help_text=_("Allergies,…"),
            )
            form.fields[f'food_{food.id}_priority'] = forms.CharField(
                max_length=255,
                required=False,
                label=_("priority request").capitalize(),
                help_text=_("Lesson at 13h30,…"),
            )

            ag = AccordionGroup(f"{food} ({pretty_money(food.price)})",
                                Row(Field(f'food_{food.id}_quantity', wrapper_class='col-sm-9'),
                                    Field(f'food_{food.id}_gift', wrapper_class='col-sm-3')),
                                Row(Field(f'food_{food.id}_remark', wrapper_class='col-sm-9'),
                                    Field(f'food_{food.id}_priority', wrapper_class='col-sm-3')))

            if food.foodoption_set.count():
                options_fieldset = Fieldset(_("Options"))
                options_row = Row(css_class='ml-0')
                for option in food.foodoption_set.all():
                    form.fields[f'food_{food.id}_option_{option.id}'] = forms.BooleanField(
                        label=f"{option}{f' ({pretty_money(option.extra_cost)})' if option.extra_cost else ''}",
                        required=False,
                    )
                    options_row.fields.append(Field(f'food_{food.id}_option_{option.id}', wrapper_class='col-sm-12'))
                options_fieldset.fields.append(options_row)
                ag.fields.append(options_fieldset)

            layout_fields.append(ag)

        layout_fields.append(FormActions(Submit('submit', _("Order now"))))

        form.helper.layout = Accordion(*layout_fields)

        if self.request.method in ['PUT', 'POST']:
            form.data = self.request.POST
            form.files = self.request.FILES
            form.is_bound = not form.data or not form.files

        return form

    def form_valid(self, form):
        data = form.cleaned_data
        sheet = self.get_object()

        with transaction.atomic():
            order = Order.objects.create(sheet_id=self.kwargs['pk'], note=data['note'])

            total_quantity = 0

            for meal in sheet.meal_set.filter(available=True).all():
                quantity = data[f'meal_{meal.id}_quantity']
                if not quantity:
                    continue

                total_quantity += quantity
                gift = data[f'meal_{meal.id}_gift']
                remark = data[f'meal_{meal.id}_remark'] or ''
                priority = data[f'meal_{meal.id}_priority'] or ''
                ordered_meal = OrderedMeal.objects.create(order=order, meal=meal, gift=gift)

                for ignored in range(quantity):
                    for food in meal.content.filter(available=True).all():
                        n = OrderedFood.objects.filter(order__sheet_id=self.kwargs['pk'],
                                                       order__note=order.note,
                                                       order__date__gte=timezone.now() - timedelta(hours=6),
                                                       food=food).exclude(status='CANCELED').count()
                        of = OrderedFood.objects.create(order=order, meal=ordered_meal, food=food,
                                                        remark=remark, priority=priority, number=n + 1, gift=0)

                        for option in food.foodoption_set.filter(available=True).all():
                            if data[f'meal_{meal.id}_food_{food.id}_option_{option.id}']:
                                of.options.add(option)
                        of.save()

                first_food = ordered_meal.orderedfood_set.first()
                tr = SheetOrderTransaction(source_id=order.note_id, destination=first_food.food.club.note,
                                           source_alias=str(order.note), destination_alias=first_food.food.club.name,
                                           quantity=quantity, ordered_food=first_food,
                                           reason=f"{meal.name} - {sheet.name}")
                tr.amount = tr.get_price / tr.quantity
                tr.save()

            for food in sheet.food_set.filter(available=True).all():
                quantity = data[f'food_{food.id}_quantity']
                if not quantity:
                    continue

                total_quantity += quantity
                gift = data[f'food_{meal.id}_gift']
                remark = data[f'food_{meal.id}_remark'] or ''
                priority = data[f'food_{meal.id}_priority'] or ''

                for ignored in range(quantity):
                    n = OrderedFood.objects.filter(order__sheet_id=self.kwargs['pk'],
                                                   order__note=order.note,
                                                   order__date__gte=timezone.now() - timedelta(hours=6),
                                                   food=food).exclude(state='CANCELED').count()
                    of = OrderedFood.objects.create(order=order, food=food, gift=gift,
                                                    remark=remark, priority=priority, number=n + 1)

                    for option in food.foodoption_set.filter(available=True).all():
                        if data[f'meal_{meal.id}_food_{food.id}_option_{option.id}']:
                            of.options.add(option)
                    of.options.save()

                    tr = SheetOrderTransaction(source_id=order.note_id, destination_id=first_food.club.note,
                                               source_alias=str(order.note), destination_alias=first_food.club.name,
                                               quantity=quantity, ordered_food=of,
                                               reason=f"{food.name} - {sheet.name}")
                    tr.amount = tr.get_price / tr.quantity
                    tr.save()

        if total_quantity == 0:
            form.add_error(None, _("You didn't select anything."))
            transaction.rollback()
            return self.form_invalid(form)

        return super().form_valid(form)

    def get_success_url(self):
        return reverse_lazy('sheets:sheet_detail', args=(self.kwargs['pk'],))


class WaitingListView(ProtectQuerysetMixin, DetailView):
    model = Food
    template_name = 'sheets/waiting_list.html'
    extra_context = {'title': _("Waiting list")}

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

        content['queue'] = OrderedFood.objects.filter(food_id=self.kwargs['pk'], status='QUEUED')\
            .order_by('-priority', 'number', 'order__date').all()
        content['ready'] = OrderedFood.objects.filter(food_id=self.kwargs['pk'], status='READY')\
            .order_by('served_date').all()

        return content


class WaitingListDetailView(ProtectQuerysetMixin, DetailView):
    model = Food
    template_name = 'sheets/waiting_list_detail.html'

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

        list_type = 'CANCELED' if 'canceled' in self.request.path else \
            'SERVED' if 'served' in self.request.path else \
            'READY' if 'ready' in self.request.path else 'QUEUED'
        context['list_type'] = list_type
        context['orders'] = OrderedFood.objects.filter(food_id=self.kwargs['pk'], status=list_type)\
            .order_by('served_date', '-priority', 'number', 'order__date').all()
        context['title'] = self.object.name + " - " + _(list_type.lower()).capitalize()

        return context