from django.shortcuts import render, redirect, get_object_or_404
from django.contrib import messages
from django.http import HttpResponseRedirect
from django.urls import reverse_lazy
from django.contrib.auth.decorators import login_required
from django.contrib.auth import update_session_auth_hash
from django.views.generic import CreateView, ListView
from django.core.paginator import Paginator
from django.conf import settings
from django.utils.decorators import method_decorator

from accounts.decorators import lecturer_required, student_required
from .forms import SessionForm, SemesterForm, NewsAndEventsForm
from .models import *

User = settings.AUTH_USER_MODEL

# ########################################################
# News & Events
# ########################################################
@login_required
def home_view(request):
    items = NewsAndEvents.objects.all().order_by('-updated_date')
    context = {
        'title': "News & Events | DjangoSMS",
        'items': items,
    }
    return render(request, 'app/index.html', context)


@login_required
def post_add(request):
    if request.method == 'POST':
        form = NewsAndEventsForm(request.POST)
        title = request.POST.get('title')
        if form.is_valid():
            form.save()

            messages.success(request, (title + ' has been uploaded.'))
            return redirect('home')
        else:
            messages.error(request, 'Please correct the error(s) below.')
    else:
        form = NewsAndEventsForm()
    return render(request, 'app/post_add.html', {
        'title': 'Add Post | DjangoSMS',
        'form': form,
    })


@login_required
@lecturer_required
def edit_post(request, pk):
    instance = get_object_or_404(NewsAndEvents, pk=pk)
    if request.method == 'POST':
        form = NewsAndEventsForm(request.POST, instance=instance)
        title = request.POST.get('title')
        if form.is_valid():
            form.save()

            messages.success(request, (title + ' has been updated.'))
            return redirect('home')
        else:
            messages.error(request, 'Please correct the error(s) below.')
    else:
        form = NewsAndEventsForm(instance=instance)
    return render(request, 'app/post_add.html', {
        'title': 'Edit Post | DjangoSMS',
        'form': form,
    })


@login_required
@lecturer_required
def delete_post(request, pk):
    post = get_object_or_404(NewsAndEvents, pk=pk)
    title = post.title
    post.delete()
    messages.success(request, (title + ' has been deleted.'))
    return redirect('home')

# ########################################################
# Session
# ########################################################
@login_required
@lecturer_required
def session_list_view(request):
    """ Show list of all sessions """
    sessions = Session.objects.all().order_by('-is_current_session', '-session')
    return render(request, 'app/session_list.html', {"sessions": sessions})


@login_required
@lecturer_required
def session_add_view(request):
    """ check request method, if POST we add session otherwise show empty form """
    if request.method == 'POST':
        form = SessionForm(request.POST)
        if form.is_valid():
            data = form.data.get('is_current_session')  # returns string of 'True' if the user selected Yes
            print(data)
            if data == 'true':
                sessions = Session.objects.all()
                if sessions:
                    for session in sessions:
                        if session.is_current_session == True:
                            unset = Session.objects.get(is_current_session=True)
                            unset.is_current_session = False
                            unset.save()
                    form.save()
                else:
                    form.save()
            else:
                form.save()
            messages.success(request, 'Session added successfully. ')
            return redirect('session_list')

    else:
        form = SessionForm()
    return render(request, 'app/session_update.html', {'form': form})


@login_required
@lecturer_required
def session_update_view(request, pk):
    session = Session.objects.get(pk=pk)
    if request.method == 'POST':
        form = SessionForm(request.POST, instance=session)
        data = form.data.get('is_current_session')
        if data == 'true':
            sessions = Session.objects.all()
            if sessions:
                for session in sessions:
                    if session.is_current_session == True:
                        unset = Session.objects.get(is_current_session=True)
                        unset.is_current_session = False
                        unset.save()
            
            if form.is_valid():
                form.save()
                messages.success(request, 'Session updated successfully. ')
                return redirect('session_list')
        else:
            form = SessionForm(request.POST, instance=session)
            if form.is_valid():
                form.save()
                messages.success(request, 'Session updated successfully. ')
                return redirect('session_list')

    else:
        form = SessionForm(instance=session)
    return render(request, 'app/session_update.html', {'form': form})


@login_required
@lecturer_required
def session_delete_view(request, pk):
    session = get_object_or_404(Session, pk=pk)

    if session.is_current_session:
        messages.error(request, "You cannot delete current session")
        return redirect('session_list')
    else:
        session.delete()
        messages.success(request, "Session successfully deleted")
    return redirect('session_list')
# ########################################################


# ########################################################
# Semester
# ########################################################
@login_required
@lecturer_required
def semester_list_view(request):
    semesters = Semester.objects.all().order_by('-is_current_semester', '-semester')
    return render(request, 'app/semester_list.html', {"semesters": semesters, })


@login_required
@lecturer_required
def semester_add_view(request):
    if request.method == 'POST':
        form = SemesterForm(request.POST)
        if form.is_valid():
            data = form.data.get('is_current_semester')  # returns string of 'True' if the user selected Yes
            if data == 'True':
                semester = form.data.get('semester')
                ss = form.data.get('session')
                session = Session.objects.get(pk=ss)
                try:
                    if Semester.objects.get(semester=semester, session=ss):
                        messages.error(request, semester + " semester in " + session.session + " session already exist")
                        return redirect('add_semester')
                except:
                    semesters = Semester.objects.all()
                    sessions = Session.objects.all()
                    if semesters:
                        for semester in semesters:
                            if semester.is_current_semester == True:
                                unset_semester = Semester.objects.get(is_current_semester=True)
                                unset_semester.is_current_semester = False
                                unset_semester.save()
                        for session in sessions:
                            if session.is_current_session == True:
                                unset_session = Session.objects.get(is_current_session=True)
                                unset_session.is_current_session = False
                                unset_session.save()

                    new_session = request.POST.get('session')
                    set_session = Session.objects.get(pk=new_session)
                    set_session.is_current_session = True
                    set_session.save()
                    form.save()
                    messages.success(request, 'Semester added successfully.')
                    return redirect('semester_list')

            form.save()
            messages.success(request, 'Semester added successfully. ')
            return redirect('semester_list')
    else:
        form = SemesterForm()
    return render(request, 'app/semester_update.html', {'form': form})


@login_required
@lecturer_required
def semester_update_view(request, pk):
    semester = Semester.objects.get(pk=pk)
    if request.method == 'POST':
        if request.POST.get('is_current_semester') == 'True': # returns string of 'True' if the user selected yes for 'is current semester'
            unset_semester = Semester.objects.get(is_current_semester=True)
            unset_semester.is_current_semester = False
            unset_semester.save()
            unset_session = Session.objects.get(is_current_session=True)
            unset_session.is_current_session = False
            unset_session.save()
            new_session = request.POST.get('session')
            form = SemesterForm(request.POST, instance=semester)
            if form.is_valid():
            	set_session = Session.objects.get(pk=new_session)
            	set_session.is_current_session = True
            	set_session.save()
            	form.save()
            	messages.success(request, 'Semester updated successfully !')
            	return redirect('semester_list')
        else:
            form = SemesterForm(request.POST, instance=semester)
            if form.is_valid():
                form.save()
                return redirect('semester_list')

    else:
        form = SemesterForm(instance=semester)
    return render(request, 'app/semester_update.html', {'form': form})


@login_required
@lecturer_required
def semester_delete_view(request, pk):
    semester = get_object_or_404(Semester, pk=pk)
    if semester.is_current_semester:
        messages.error(request, "You cannot delete current semester")
        return redirect('semester_list')
    else:
        semester.delete()
        messages.success(request, "Semester successfully deleted")
    return redirect('semester_list')
# ########################################################


# from django.shortcuts import render_to_response
# from django.template import RequestContext

# def handler404(request, exception, template_name="common/404.html"):
#     response = render_to_response("common/404.html")
#     response.status_code = 404
#     return response


# def handler500(request, *args, **argv):
#     response = render_to_response('common/500.html', {}, context_instance=RequestContext(request))
#     response.status_code = 500

#     return response


# def handler400(request, exception, template_name="common/400.html"):
#     response = render_to_response('common/400.html', context_instance=RequestContext(request))
#     response.status_code = 400

#     return response