from django.shortcuts import render, reverse
from django.db.models import Avg, Count, Min, Sum
from django.db.models.functions import Round
from django.urls import reverse_lazy
from django.views.generic.base import TemplateView
from django.views.generic.edit import FormView, CreateView, UpdateView, DeleteView
from django.views.generic.detail import DetailView
from django.views.generic.list import ListView
from django.core.paginator import Paginator
from django.contrib.auth.decorators import login_required
from django.contrib.auth.mixins import LoginRequiredMixin, PermissionRequiredMixin
from django.utils import timezone
from django.contrib import messages
from django.contrib.auth.models import User
from django.shortcuts import get_object_or_404
from accounts.models import Instructor, Student
from .models import Code, Period
from .forms import AttendanceUpdateForm, PeriodForm


# OVERVIEW
class AttendanceOverview(LoginRequiredMixin, TemplateView):
    template_name = 'attendance/attendance_overview.html'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['user'] = self.request.user
        if hasattr(self.request.user, 'instructor'):
            instructor = self.request.user.instructor
            context['student_list'] = Student.objects.filter(
                department=instructor.department
            ).annotate(total_hours=Sum('period__duration'))

            context['period_list'] = Period.objects.filter(
                student__department=instructor.department
            ).filter(
                clocked_in__year=timezone.now().year
            ).filter(
                clocked_in__month=timezone.now().month
            )

        elif hasattr(self.request.user, 'student'):
            student = self.request.user.student

            # sum all duration fields for student
            context['monthly_total'] = Period.objects.filter(
                student = student
                ).filter(
                    clocked_in__year=timezone.now().year
                ).filter(
                    clocked_in__month=timezone.now().month
                ).aggregate(duration=Sum('duration'))

            context['period_list'] = Period.objects.filter(
                student=student
                ).filter(
                    clocked_in__year=timezone.now().year
                ).filter(
                    clocked_in__month=timezone.now().month
                )
            if student.current_period_id != None:
                context['current_period'] = Period.objects.get(pk=student.current_period_id)
        return context

class AttendanceUpdateView(LoginRequiredMixin, FormView):
    template_name = 'attendance/attendance_form.html'
    form_class = AttendanceUpdateForm

    def form_valid(self, form):
        student_number = form.cleaned_data['qr_string'].split(':')[0]
        station_number = form.cleaned_data['qr_string'].split(':')[1]
        student = Student.objects.get(student_number=student_number)
        if student.is_clocked_in:
            period = student.period_set.get(pk=student.current_period_id)
            period.clocked_out=timezone.now()
            period.save()
            messages.add_message(self.request, messages.INFO, f'{student.user.first_name} {student.user.last_name} clocked out.')
        else:
            period = student.period_set.create(student=student, clocked_in=timezone.now(), station_number=station_number)
            messages.add_message(self.request, messages.INFO, f'{student.user.first_name} {student.user.last_name} clocked in.')
        return super().form_valid(form)

    def get_success_url(self):
        return reverse('attendance-update')




# PERIODS
class PeriodListView(LoginRequiredMixin, ListView):
    model = Period
    paginate_by = 25
    template_name = 'attendance/period_list.html'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        if hasattr(self.request.user, 'student'):
            period_list = Period.objects.filter(
                student = self.request.user.student
            )
            paginator = Paginator(period_list, 25)
            page_number = self.request.GET.get('page')
            page_obj = paginator.get_page(page_number)

            context['page_obj'] = page_obj
        return context

class PeriodCreateView(LoginRequiredMixin, CreateView):
    model = Period
    form_class = PeriodForm
    template_name = 'attendance/period_form.html'

class PeriodDetailView(LoginRequiredMixin, DetailView):
    model = Period
    template_name = 'attendance/period_detail.html'

class PeriodUpdateView(LoginRequiredMixin, UpdateView):
    model = Period
    form_class = PeriodForm
    template_name = 'attendance/period_form.html'

    def get_success_url(self):
        pk = self.kwargs["pk"]
        return reverse('period-detail', kwargs={'pk': pk})

class PeriodDeleteView(LoginRequiredMixin, DeleteView):
    model = Period
    success_url = '/attendance'



# CODES
class CodeCreateView(LoginRequiredMixin, CreateView):
    model = Code
    fields = ['station_number']
    template_name = 'attendance/code_form.html'

    def form_valid(self, form):
        form.instance.student = self.request.user.student
        return super().form_valid(form)

class CodeDetailView(LoginRequiredMixin, DetailView):
    model = Code
    template_name = 'attendance/code_detail.html'

class CodeUpdateView(LoginRequiredMixin, UpdateView):
    model = Code
    fields = ['station_number']
    template_name = 'attendance/code_form.html'

    def get_success_url(self):
        pk = self.kwargs["pk"]
        return reverse('code-detail', kwargs={'pk': pk})