"""
User views for KeepItGoing.
"""

from django.contrib.auth import get_user_model, login, logout
from django.shortcuts import render, redirect
from django.views import View
from rest_framework import generics, permissions, status
from rest_framework.response import Response
from rest_framework.views import APIView
from rest_framework_simplejwt.tokens import RefreshToken

from .serializers import (
    UserSerializer,
    UserRegistrationSerializer,
    ChangePasswordSerializer,
    DeviceTokenSerializer,
)
from .models import DeviceToken

User = get_user_model()


# =============================================================================
# API Views
# =============================================================================

class RegisterAPIView(generics.CreateAPIView):
    """API endpoint for user registration."""

    queryset = User.objects.all()
    serializer_class = UserRegistrationSerializer
    permission_classes = [permissions.AllowAny]

    def create(self, request, *args, **kwargs):
        serializer = self.get_serializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        user = serializer.save()

        # Generate tokens
        refresh = RefreshToken.for_user(user)

        return Response({
            'user': UserSerializer(user).data,
            'tokens': {
                'refresh': str(refresh),
                'access': str(refresh.access_token),
            }
        }, status=status.HTTP_201_CREATED)


class UserProfileAPIView(generics.RetrieveUpdateAPIView):
    """API endpoint for user profile."""

    serializer_class = UserSerializer
    permission_classes = [permissions.IsAuthenticated]

    def get_object(self):
        return self.request.user


class ChangePasswordAPIView(APIView):
    """API endpoint for changing password."""

    permission_classes = [permissions.IsAuthenticated]

    def post(self, request):
        serializer = ChangePasswordSerializer(
            data=request.data,
            context={'request': request}
        )
        serializer.is_valid(raise_exception=True)

        request.user.set_password(serializer.validated_data['new_password'])
        request.user.save()

        return Response({'message': 'Password changed successfully.'})


class DeviceTokenAPIView(generics.ListCreateAPIView):
    """API endpoint for managing device tokens."""

    serializer_class = DeviceTokenSerializer
    permission_classes = [permissions.IsAuthenticated]

    def get_queryset(self):
        return DeviceToken.objects.filter(user=self.request.user)


class DeviceTokenDeleteAPIView(generics.DestroyAPIView):
    """API endpoint for deleting a device token."""

    serializer_class = DeviceTokenSerializer
    permission_classes = [permissions.IsAuthenticated]

    def get_queryset(self):
        return DeviceToken.objects.filter(user=self.request.user)


# =============================================================================
# Web Views (Django Templates)
# =============================================================================

class LoginView(View):
    """Web login page."""

    def get(self, request):
        if request.user.is_authenticated:
            return redirect('dashboard')
        return render(request, 'users/login.html')

    def post(self, request):
        from django.contrib.auth import authenticate

        email = request.POST.get('email')
        password = request.POST.get('password')

        user = authenticate(request, username=email, password=password)

        if user is not None:
            login(request, user)
            next_url = request.GET.get('next', 'dashboard')
            return redirect(next_url)

        return render(request, 'users/login.html', {
            'error': 'Invalid email or password.'
        })


class LogoutView(View):
    """Web logout."""

    def get(self, request):
        logout(request)
        return redirect('login')

    def post(self, request):
        logout(request)
        return redirect('login')


class RegisterView(View):
    """Web registration page."""

    def get(self, request):
        if request.user.is_authenticated:
            return redirect('dashboard')
        return render(request, 'users/register.html')

    def post(self, request):
        email = request.POST.get('email')
        username = request.POST.get('username')
        password = request.POST.get('password')
        password_confirm = request.POST.get('password_confirm')

        errors = {}

        if password != password_confirm:
            errors['password_confirm'] = 'Passwords do not match.'

        if User.objects.filter(email=email).exists():
            errors['email'] = 'Email already registered.'

        if User.objects.filter(username=username).exists():
            errors['username'] = 'Username already taken.'

        if errors:
            return render(request, 'users/register.html', {'errors': errors})

        user = User.objects.create_user(
            email=email,
            username=username,
            password=password
        )
        login(request, user)
        return redirect('dashboard')


class ProfileView(View):
    """Web profile page."""

    def get(self, request):
        if not request.user.is_authenticated:
            return redirect('login')
        return render(request, 'users/profile.html')

    def post(self, request):
        if not request.user.is_authenticated:
            return redirect('login')

        user = request.user
        user.first_name = request.POST.get('first_name', '')
        user.last_name = request.POST.get('last_name', '')
        user.timezone = request.POST.get('timezone', 'UTC')
        user.default_reminder_minutes = int(request.POST.get('default_reminder_minutes', 30))
        user.email_notifications = request.POST.get('email_notifications') == 'on'
        user.push_notifications = request.POST.get('push_notifications') == 'on'
        user.save()

        return render(request, 'users/profile.html', {
            'success': 'Profile updated successfully.'
        })