# mysite/views.py
from django.views.generic import ListView, CreateView, UpdateView, DeleteView, DetailView
from django.contrib.auth.mixins import LoginRequiredMixin, UserPassesTestMixin
from django.contrib.auth import logout
from django.shortcuts import render, redirect, get_object_or_404
from django.urls import reverse_lazy
from django.db.models import Avg, Count
from django.contrib import messages
from .models import Musician, Song, Meloman, Rating, Album, Genre
from .forms import MusicianForm, SongForm, RatingForm, RegistrationForm
from django.views.generic import TemplateView


# Регистрация
def register(request):
    if request.method == 'POST':
        form = RegistrationForm(request.POST)
        if form.is_valid():
            form.save()
            messages.success(request, 'Регистрация прошла успешно! Теперь вы можете войти в систему.')
            return redirect('mysite:login')
    else:
        form = RegistrationForm()
    return render(request, 'mysite/register.html', {'form': form})

# Выход из системы
def custom_logout(request):
    logout(request)
    messages.success(request, 'Вы успешно вышли из системы')
    return redirect('mysite:login')

# Главная страница со списком песен
class SongListView(ListView):
    model = Song
    template_name = 'mysite/song_list.html'
    context_object_name = 'songs'
    
    def get_queryset(self):
        return Song.objects.select_related('album__musician', 'genre').annotate(
            avg_rating=Avg('rating__score'),
            ratings_count=Count('rating')
        )
    
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        search_query = self.request.GET.get('search', '')
        if search_query:
            context['songs'] = context['songs'].filter(
                title__icontains=search_query
            ) | context['songs'].filter(
                album__musician__name__icontains=search_query
            )
            context['search_query'] = search_query
        return context

# Список исполнителей
class MusicianListView(LoginRequiredMixin, ListView):
    model = Musician
    template_name = 'mysite/musician_list.html'
    context_object_name = 'musicians'
    paginate_by = 10
    
    def get_queryset(self):
        return Musician.objects.annotate(albums_count=Count('album'))

class MusicianCreateView(LoginRequiredMixin, CreateView):
    model = Musician
    form_class = MusicianForm
    template_name = 'mysite/musician_form.html'
    success_url = reverse_lazy('mysite:musician_list')
    
    def form_valid(self, form):
        messages.success(self.request, 'Исполнитель успешно добавлен')
        return super().form_valid(form)

class MusicianUpdateView(LoginRequiredMixin, UpdateView):
    model = Musician
    form_class = MusicianForm
    template_name = 'mysite/musician_form.html'
    success_url = reverse_lazy('mysite:musician_list')
    
    def form_valid(self, form):
        messages.success(self.request, 'Данные исполнителя обновлены')
        return super().form_valid(form)

class MusicianDeleteView(LoginRequiredMixin, UserPassesTestMixin, DeleteView):
    model = Musician
    template_name = 'mysite/musician_confirm_delete.html'
    success_url = reverse_lazy('mysite:musician_list')
    
    def test_func(self):
        return self.request.user.is_superuser
    
    def delete(self, request, *args, **kwargs):
        messages.success(request, 'Исполнитель удален')
        return super().delete(request, *args, **kwargs)

# Список песен для CRUD
class SongListDataView(LoginRequiredMixin, ListView):
    model = Song
    template_name = 'mysite/song_list_data.html'
    context_object_name = 'songs'
    
    def get_queryset(self):
        return Song.objects.select_related('album__musician', 'genre').annotate(
            avg_rating=Avg('rating__score')
        )

class SongCreateView(LoginRequiredMixin, CreateView):
    model = Song
    form_class = SongForm
    template_name = 'mysite/song_form.html'
    success_url = reverse_lazy('mysite:song_list_data')
    
    def form_valid(self, form):
        messages.success(self.request, 'Песня успешно добавлена')
        return super().form_valid(form)

class SongUpdateView(LoginRequiredMixin, UpdateView):
    model = Song
    form_class = SongForm
    template_name = 'mysite/song_form.html'
    success_url = reverse_lazy('mysite:song_list_data')
    
    def form_valid(self, form):
        messages.success(self.request, 'Данные песни обновлены')
        return super().form_valid(form)

class SongDeleteView(LoginRequiredMixin, UserPassesTestMixin, DeleteView):
    model = Song
    template_name = 'mysite/song_confirm_delete.html'
    success_url = reverse_lazy('mysite:song_list_data')
    
    def test_func(self):
        return self.request.user.is_superuser

# Список меломанов
class MelomanListView(LoginRequiredMixin, ListView):
    model = Meloman
    template_name = 'mysite/meloman_list.html'
    context_object_name = 'melomans'
    
    def get_queryset(self):
        return Meloman.objects.annotate(
            ratings_count=Count('rating'),
            avg_score=Avg('rating__score')
        )
    
    def dispatch(self, request, *args, **kwargs):
        if not request.user.is_superuser:
            return redirect('mysite:song_list')
        return super().dispatch(request, *args, **kwargs)

# Профиль меломана
class MelomanProfileView(LoginRequiredMixin, DetailView):
    model = Meloman
    template_name = 'mysite/profile.html'
    context_object_name = 'meloman'
    
    def get_object(self):
        try:
            return Meloman.objects.get(user=self.request.user)
        except Meloman.DoesNotExist:
            return None
    
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        meloman = self.get_object()
        if meloman:
            context['total_ratings'] = meloman.rating_set.count()
            context['avg_user_rating'] = meloman.rating_set.aggregate(Avg('score'))['score__avg']
            context['favorite_genres'] = meloman.preference_set.select_related('genre').all()
            context['age'] = meloman.age
            context['recent_ratings'] = meloman.rating_set.select_related('song').order_by('-rating_date')[:5]
        return context

# Оценка песни
def rate_song(request, song_id):
    if not request.user.is_authenticated:
        return redirect('mysite:login')
    
    song = get_object_or_404(Song, pk=song_id)
    
    try:
        meloman = Meloman.objects.get(user=request.user)
    except Meloman.DoesNotExist:
        messages.error(request, 'У вас нет профиля меломана. Обратитесь к администратору.')
        return redirect('mysite:song_list')
    
    rating, created = Rating.objects.get_or_create(
        meloman=meloman,
        song=song,
        defaults={'score': 5}
    )
    
    if request.method == 'POST':
        form = RatingForm(request.POST, instance=rating)
        if form.is_valid():
            form.save()
            messages.success(request, f'Оценка для "{song.title}" сохранена!')
            return redirect('mysite:song_list')
    else:
        form = RatingForm(instance=rating)
    
    return render(request, 'mysite/rate_song.html', {'form': form, 'song': song})


from django.db import connection

class SongDetailsView(ListView):
    """Использование представления song_details_view"""
    template_name = 'mysite/song_details.html'
    context_object_name = 'songs'
    
    def get_queryset(self):
        with connection.cursor() as cursor:
            cursor.execute("""
                SELECT song_id, title, musician_name, album_name, 
                       genre_name, duration_sec, avg_rating, ratings_count
                FROM song_details_view
                ORDER BY avg_rating DESC NULLS LAST
            """)
            columns = [col[0] for col in cursor.description]
            return [dict(zip(columns, row)) for row in cursor.fetchall()]
        

class RecommendationsView(LoginRequiredMixin, TemplateView):
    """Использование функции recommend_songs"""
    template_name = 'mysite/recommendations.html'
    
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        
        try:
            meloman = Meloman.objects.get(user=self.request.user)
            meloman_id = meloman.meloman_id
        except Meloman.DoesNotExist:
            context['recommendations'] = []
            context['error'] = 'Профиль меломана не найден'
            return context
        
        with connection.cursor() as cursor:
            cursor.execute("""
                SELECT * FROM recommend_songs(%s, %s)
            """, [meloman_id, 10])
            
            columns = [col[0] for col in cursor.description]
            recommendations = [dict(zip(columns, row)) for row in cursor.fetchall()]
        
        context['recommendations'] = recommendations
        return context