Add comment system with models, forms, and UI integration for lessons

courses/views.py

@@ -1,12 +1,102 @@
-from django.shortcuts import render, get_object_or_404
+from django.shortcuts import render, get_object_or_404, redirect
+from django.urls import reverse
 from django.views import generic
-from .models import Course, Lesson
+from django.db.models import Prefetch
+from .models import Course, Lesson, Module, Comment
+from .forms import CommentForm
 
 def list(request):
     courses = Course.objects.all()
     return render(request, 'courses/list.html', {'courses': courses})
 
 def show(request, course_name, course_id):
-    course = get_object_or_404(Course, pk=course_id)
-    lessons = Lesson.objects.filter(course_id=course_id)
-    return render(request, 'courses/show.html', {'course' : course, 'lessons': lessons})
+    # Optimized course fetch with related author and profile (if present)
+    course = get_object_or_404(
+        Course.objects.select_related('author', 'author__profile'),
+        pk=course_id,
+    )
+
+    # Fetch lessons through module -> course relation and keep a stable order
+    lessons = (
+        Lesson.objects.filter(module__course_id=course_id)
+        .select_related('module')
+        .order_by('order')
+    )
+
+    context = {
+        'course': course,
+        'lessons': lessons,
+    }
+    return render(request, 'courses/show.html', context)
+
+
+def lesson_detail(request, course_slug, module_slug, lesson_slug):
+    # Fetch course by slug
+    course = get_object_or_404(
+        Course.objects.select_related('author', 'author__profile'),
+        slug=course_slug,
+    )
+
+    # Fetch module within course
+    module = get_object_or_404(
+        Module.objects.filter(course=course),
+        slug=module_slug,
+    )
+
+    # Fetch lesson within module
+    lesson = get_object_or_404(
+        Lesson.objects.select_related('module').filter(module=module),
+        slug=lesson_slug,
+    )
+
+    # Handle comment submission
+    if request.method == 'POST':
+        if not request.user.is_authenticated:
+            login_url = reverse('login')
+            return redirect(f"{login_url}?next={request.path}")
+        form = CommentForm(request.POST)
+        if form.is_valid():
+            parent = None
+            parent_id = form.cleaned_data.get('parent')
+            if parent_id:
+                try:
+                    parent = Comment.objects.get(id=parent_id, lesson=lesson, is_active=True)
+                except Comment.DoesNotExist:
+                    parent = None
+
+            Comment.objects.create(
+                lesson=lesson,
+                user=request.user,
+                content=form.cleaned_data['content'],
+                parent=parent,
+            )
+            # Redirect to anchor to show the new comment
+            return redirect(request.path + "#comments")
+    else:
+        form = CommentForm()
+
+    # Lessons list for TOC (entire course ordered)
+    lessons = (
+        Lesson.objects.filter(module__course=course)
+        .select_related('module')
+        .order_by('order')
+    )
+
+    # Public comments for the current lesson (top-level) and their replies
+    replies_qs = Comment.objects.filter(is_active=True).select_related('user').order_by('created_at')
+    comments = (
+        Comment.objects.filter(lesson=lesson, is_active=True, parent__isnull=True)
+        .select_related('user')
+        .prefetch_related(Prefetch('replies', queryset=replies_qs))
+        .order_by('created_at')
+    )
+
+    context = {
+        'course': course,
+        'module': module,
+        'lesson': lesson,
+        'lessons': lessons,
+        'comments': comments,
+        'comment_form': form,
+    }
+    return render(request, 'courses/lesson.html', context)