hw6, hw7

- Redis / Celery / Celery Beat
- кэширование популярных тегов и лучших участников
- асинхронные уведомления в Centrifugo
- отправка email-уведомлений через Celery
- полнотекстовый поиск и подсказки
- Docker Compose инфраструктура

questions/context_processors.py

@@ -0,0 +1,55 @@
+from datetime import timedelta
+from django.utils import timezone
+from django.core.cache import cache
+from django.contrib.auth.models import User
+from django.db.models import Count, Q
+
+from .models import Tag
+
+
+def sidebar_data(request):
+    popular_tags = cache.get('popular_tags')
+    best_members = cache.get('best_members')
+
+    if popular_tags is None:
+        three_months_ago = timezone.now() - timedelta(days=90)
+        popular_qs = Tag.objects.annotate(
+            q_count=Count('question', filter=Q(question__created_at__gte=three_months_ago))
+        ).order_by('-q_count')[:10]
+        popular_tags = [
+            {'name': tag.name, 'count': tag.q_count}
+            for tag in popular_qs
+        ]
+        cache.set('popular_tags', popular_tags, timeout=60 * 60)
+
+    if best_members is None:
+        week_ago = timezone.now() - timedelta(days=7)
+        users_q = User.objects.annotate(
+            q_count=Count('question', filter=Q(question__created_at__gte=week_ago))
+        )
+        users_a = User.objects.annotate(
+            a_count=Count('answer', filter=Q(answer__created_at__gte=week_ago)))
+
+        scores = {}
+        for u in users_q:
+            scores[u.id] = scores.get(u.id, 0) + (u.q_count or 0)
+        for u in users_a:
+            scores[u.id] = scores.get(u.id, 0) + (u.a_count or 0)
+
+        best_members_list = User.objects.filter(id__in=list(scores.keys()))
+        best_members = [
+            {
+                'id': u.id,
+                'username': u.username,
+                'score': scores.get(u.id, 0)
+            }
+            for u in best_members_list
+        ]
+        best_members.sort(key=lambda x: x['score'], reverse=True)
+        best_members = best_members[:10]
+        cache.set('best_members', best_members, timeout=60 * 60)
+
+    return {
+        'popular_tags': popular_tags,
+        'best_members': best_members,
+    }

questions/migrations/0004_answer_created_at_and_search_index.py

@@ -0,0 +1,18 @@
+from django.db import migrations, models
+import django.utils.timezone
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('questions', '0003_question_correct_answer'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='answer',
+            name='created_at',
+            field=models.DateTimeField(auto_now_add=True, default=django.utils.timezone.now),
+            preserve_default=False,
+        ),
+    ]

questions/models.py

@@ -1,5 +1,7 @@
 from django.db import models
 from django.contrib.auth.models import User
+from django.contrib.postgres.indexes import GinIndex
+from django.contrib.postgres.search import SearchVector
 
 import uuid
 import os
@@ -85,6 +87,11 @@ class Question(models.Model):
     def __str__(self):
         return self.title
 
+    class Meta:
+        indexes = [
+            GinIndex(SearchVector('title', 'body'), name='question_search_idx')
+        ]
+
 
 class QuestionReaction(models.Model):
 
@@ -130,6 +137,7 @@ class Answer(models.Model):
     body = models.TextField()
 
     rating = models.IntegerField(default=0)
+    created_at = models.DateTimeField(auto_now_add=True)
 
     def __str__(self):
 

questions/static/core/css/style.css

@@ -58,6 +58,7 @@ a:hover {
     gap: 0.6rem;
     flex: 1;
     min-width: 40%;
+    position: relative;
 }
 
 .search input {
@@ -218,6 +219,41 @@ a:hover {
     margin-bottom: 1.5rem;
 }
 
+.search-suggestions {
+    position: absolute;
+    background: #ffffff;
+    border: 1px solid #1f2d3a;
+    border-radius: 0.5rem;
+    width: calc(100% - 2rem);
+    max-height: 18rem;
+    overflow: auto;
+    display: none;
+    z-index: 100;
+    margin-top: 0.4rem;
+}
+
+.search-suggestion {
+    display: block;
+    padding: 0.6rem 0.9rem;
+    color: #1f2d3a;
+    text-decoration: none;
+    border-bottom: 1px solid #e8f0f7;
+}
+
+.search-suggestion:hover {
+    background: #f0f7ff;
+}
+
+.best-members {
+    list-style: none;
+    padding: 0;
+    margin: 0;
+}
+
+.best-members li {
+    margin-bottom: 0.5rem;
+}
+
 .tag-cloud {
     display: flex;
     flex-wrap: wrap;

questions/static/core/js/script.js

@@ -5,9 +5,7 @@ function getCookie(name) {
         for (let cookie of cookies) {
             cookie = cookie.trim();
             if (cookie.startsWith(name + '=')) {
-                cookieValue = decodeURIComponent(
-                    cookie.substring(name.length + 1)
-                );
+                cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
                 break;
             }
         }
@@ -16,29 +14,56 @@ function getCookie(name) {
 }
 
 const csrftoken = getCookie('csrftoken');
+const searchInput = document.getElementById('search-input');
+const searchSuggestions = document.getElementById('search-suggestions');
+let searchTimeout = null;
 
-$(document).on('click', '.question-like', function () {
-    const btn = $(this);
-    const questionId = btn.data('id');
+function setSearchSuggestions(results) {
+    if (!searchSuggestions) return;
+    if (!results.length) {
+        searchSuggestions.innerHTML = '';
+        searchSuggestions.style.display = 'none';
+        return;
+    }
+    searchSuggestions.innerHTML = results.map(item => `
+        <a class="search-suggestion" href="${item.url}">${item.title}</a>
+    `).join('');
+    searchSuggestions.style.display = 'block';
+}
+
+if (searchInput) {
+    searchInput.addEventListener('input', function () {
+        const query = this.value.trim();
+        clearTimeout(searchTimeout);
+        if (!query) {
+            setSearchSuggestions([]);
+            return;
+        }
+        searchTimeout = setTimeout(function () {
+            fetch(`/search?q=${encodeURIComponent(query)}`)
+                .then(response => response.json())
+                .then(data => {
+                    setSearchSuggestions(data.results || []);
+                })
+                .catch(() => setSearchSuggestions([]));
+        }, 250);
+    });
+    document.addEventListener('click', function (event) {
+        if (!searchSuggestions.contains(event.target) && event.target !== searchInput) {
+            searchSuggestions.style.display = 'none';
+        }
+    });
+}
+
+function postReaction(url, data, onSuccess) {
     $.ajax({
-        url: '/ajax/question/react/',
+        url,
         type: 'POST',
         headers: {
             'X-CSRFToken': csrftoken
         },
-        data: {
-            question_id: questionId,
-            type: 'like'
-        },
-        success: function (response) {
-            $('#question-rating-' + questionId)
-                .text(response.rating);
-            btn.remove();
-            $('.question-dislike[data-id="' + questionId + '"]')
-                .remove();
-            $('#question-rating-' + questionId)
-                .after('<span> voted </span>');
-        },
+        data,
+        success: onSuccess,
         error: function (xhr) {
             if (xhr.responseJSON) {
                 alert(xhr.responseJSON.error);
@@ -47,136 +72,98 @@ $(document).on('click', '.question-like', function () {
             }
         }
     });
+}
+
+$(document).on('click', '.question-like', function () {
+    const btn = $(this);
+    const questionId = btn.data('id');
+    postReaction('/ajax/question/react/', {question_id: questionId, type: 'like'}, function (response) {
+        $('#question-rating-' + questionId).text(response.rating);
+        btn.remove();
+        $('.question-dislike[data-id="' + questionId + '"]').remove();
+        $('#question-rating-' + questionId).after('<span> voted </span>');
+    });
 });
 
 $(document).on('click', '.question-dislike', function () {
     const btn = $(this);
     const questionId = btn.data('id');
-    $.ajax({
-        url: '/ajax/question/react/',
-        type: 'POST',
-        headers: {
-            'X-CSRFToken': csrftoken
-        },
-        data: {
-            question_id: questionId,
-            type: 'dislike'
-        },
-        success: function (response) {
-            $('#question-rating-' + questionId)
-                .text(response.rating);
-            btn.remove();
-            $('.question-like[data-id="' + questionId + '"]')
-                .remove();
-            $('#question-rating-' + questionId)
-                .after('<span> voted </span>');
-        }
-        error: function (xhr) {
-            if (xhr.responseJSON) {
-                alert(xhr.responseJSON.error);
-            } else {
-                alert('Server error');
-            }
-        }
+    postReaction('/ajax/question/react/', {question_id: questionId, type: 'dislike'}, function (response) {
+        $('#question-rating-' + questionId).text(response.rating);
+        btn.remove();
+        $('.question-like[data-id="' + questionId + '"]').remove();
+        $('#question-rating-' + questionId).after('<span> voted </span>');
     });
 });
 
 $(document).on('click', '.answer-like', function () {
     const btn = $(this);
     const answerId = btn.data('id');
-    $.ajax({
-        url: '/ajax/answer/react/',
-        type: 'POST',
-        headers: {
-            'X-CSRFToken': csrftoken
-        },
-        data: {
-            answer_id: answerId,
-            type: 'like'
-        }
-        success: function (response) {
-            $('#answer-rating-' + answerId)
-                .text(response.rating);
-            btn.remove();
-            $('.answer-dislike[data-id="' + answerId + '"]')
-                .remove();
-            $('#answer-rating-' + answerId)
-                .after('<span> voted </span>');
-        },
-        error: function (xhr) {
-            if (xhr.responseJSON) {
-                alert(xhr.responseJSON.error);
-            } else {
-                alert('Server error');
-            }
-        }
+    postReaction('/ajax/answer/react/', {answer_id: answerId, type: 'like'}, function (response) {
+        $('#answer-rating-' + answerId).text(response.rating);
+        btn.remove();
+        $('.answer-dislike[data-id="' + answerId + '"]').remove();
+        $('#answer-rating-' + answerId).after('<span> voted </span>');
     });
 });
 
 $(document).on('click', '.answer-dislike', function () {
     const btn = $(this);
     const answerId = btn.data('id');
-    $.ajax({
-        url: '/ajax/answer/react/',
-        type: 'POST',
-        headers: {
-            'X-CSRFToken': csrftoken
-        },
-        data: {
-            answer_id: answerId,
-            type: 'dislike'
-        },
-        success: function (response) {
-            $('#answer-rating-' + answerId)
-                .text(response.rating);
-            btn.remove();
-            $('.answer-like[data-id="' + answerId + '"]')
-                .remove();
-
-            $('#answer-rating-' + answerId)
-                .after('<span> voted </span>');
-        },
-
-        error: function (xhr) {
-
-            if (xhr.responseJSON) {
-                alert(xhr.responseJSON.error);
-            } else {
-                alert('Server error');
-            }
-        }
+    postReaction('/ajax/answer/react/', {answer_id: answerId, type: 'dislike'}, function (response) {
+        $('#answer-rating-' + answerId).text(response.rating);
+        btn.remove();
+        $('.answer-like[data-id="' + answerId + '"]').remove();
+        $('#answer-rating-' + answerId).after('<span> voted </span>');
     });
 });
 
-
 $(document).on('click', '.correct-answer-btn', function () {
     const btn = $(this);
-    $.ajax({
-        url: '/ajax/answer/correct/',
-        type: 'POST',
-        headers: {
-            'X-CSRFToken': csrftoken
-        },
-        data: {
-            question_id: btn.data('question'),
-            answer_id: btn.data('answer')
-        },
-        success: function (response) {
-            $('.correct-label').remove();
-            $('#answer-' + response.correct_answer_id)
-                .find('.answer-controls')
-                .html(`
-                    <span class="correct-label">
-                        ✔ Correct
-                    </span>
-                `);
-        },
-        error: function (xhr) {
-            if (xhr.responseJSON) {
-                alert(xhr.responseJSON.error);
-            } else {
-                alert('Server error');
-            }
-        }
+    postReaction('/ajax/answer/correct/', {
+        question_id: btn.data('question'),
+        answer_id: btn.data('answer')
+    }, function (response) {
+        $('.correct-label').remove();
+        $('#answer-' + response.correct_answer_id).find('.answer-controls').html(`
+            <span class="correct-label">
+                ✔ Correct
+            </span>
+        `);
     });
-});
+});
+
+(function () {
+    try {
+        if (window.ASK_QUESTION_ID) {
+            const host = location.hostname;
+            const protocol = location.protocol === 'https:' ? 'wss' : 'ws';
+            const centrifugoWs = protocol + '://' + host + ':8001/connection/websocket';
+
+            const centrifuge = new Centrifuge(centrifugoWs);
+            centrifuge.on('connect', function (ctx) {
+                console.log('centrifuge connected', ctx);
+            });
+
+            const channel = 'question_' + window.ASK_QUESTION_ID;
+            centrifuge.subscribe(channel, function (message) {
+                const data = message.data;
+                const answerHtml = `\n<article class="answer-card" id="answer-${data.id}">\n  <div>\n    <div class="avatar-box">avatar</div>\n    <div class="vote-box"><span id="answer-rating-${data.id}">0</span></div>\n  </div>\n  <div>\n    <p>${data.body}</p>\n    <div class="answer-controls"></div>\n  </div>\n</article>\n`;
+                const answers = document.querySelectorAll('.answer-card');
+                if (answers.length) {
+                    answers[answers.length - 1].insertAdjacentHTML('afterend', answerHtml);
+                } else {
+                    const questionArticle = document.querySelector('article.card');
+                    if (questionArticle) {
+                        questionArticle.insertAdjacentHTML('afterend', answerHtml);
+                    } else {
+                        location.reload();
+                    }
+                }
+            });
+            centrifuge.connect();
+        }
+    } catch (e) {
+        console.error('centrifuge init error', e);
+    }
+})();

questions/tasks.py

@@ -0,0 +1,94 @@
+from __future__ import annotations
+from celery import shared_task
+from django.core.cache import cache
+from django.conf import settings
+import requests
+from django.core.mail import send_mail
+from django.utils import timezone
+from datetime import timedelta
+from django.db.models import Count, Sum, Q
+from django.contrib.auth.models import User
+from .models import Tag, Question, Answer
+
+
+
+@shared_task
+def rebuild_popular_tags():
+    # compute top 10 tags by number of questions in last 3 months
+    three_months_ago = timezone.now() - timedelta(days=90)
+    popular_qs = Tag.objects.annotate(
+        q_count=Count('question', filter=Q(question__created_at__gte=three_months_ago))
+    ).order_by('-q_count')[:10]
+
+    popular = [
+        {'name': t.name, 'count': t.q_count}
+        for t in popular_qs
+    ]
+    # store in cache
+    cache.set('popular_tags', popular, timeout=60 * 60)
+    return popular
+
+
+@shared_task
+def rebuild_best_members():
+    # compute top 10 users by activity (questions created in last week + total answers)
+    week_ago = timezone.now() - timedelta(days=7)
+
+    # users with most questions in the last week (by count)
+    users_q = User.objects.annotate(
+        q_count=Count('question', filter=Q(question__created_at__gte=week_ago))
+    )
+
+    # users with most answers in the last week
+    users_a = User.objects.annotate(
+        a_count=Count('answer', filter=Q(answer__created_at__gte=week_ago))
+    )
+
+    # combine scores
+    scores = {}
+
+    for u in users_q:
+        scores[u.id] = scores.get(u.id, 0) + (u.q_count or 0)
+
+    for u in users_a:
+        scores[u.id] = scores.get(u.id, 0) + (u.a_count or 0)
+
+    # build list of users sorted by score
+    best_users = User.objects.filter(id__in=list(scores.keys()))
+    best = []
+    for u in best_users:
+        best.append({
+            'id': u.id,
+            'username': u.username,
+            'score': scores.get(u.id, 0)
+        })
+
+    best.sort(key=lambda x: x['score'], reverse=True)
+    best = best[:10]
+
+    cache.set('best_members', best, timeout=60 * 60)
+    return best
+
+
+@shared_task
+def publish_new_answer_centrifugo(question_id: int, payload: dict):
+    # Send message to centrifugo pushed via HTTP API
+    # Use Centrifugo HTTP API (v4) publish endpoint
+    api_url = settings.CENTRIFUGO_URL.rstrip('/') + '/api'
+    headers = {'Authorization': f'apikey {settings.CENTRIFUGO_API_KEY}'}
+    data = {
+        'method': 'publish',
+        'params': {
+            'channel': f'question_{question_id}',
+            'data': payload,
+        }
+    }
+    try:
+        requests.post(api_url, json=data, headers=headers, timeout=5)
+    except Exception:
+        pass
+
+
+@shared_task
+def send_new_answer_email(subject: str, message: str, recipient_list: list[str]):
+    send_mail(subject, message, settings.DEFAULT_FROM_EMAIL, recipient_list)

questions/templates/core/layout/base.html

@@ -7,12 +7,14 @@
     <meta name="description" content="VkDesk Q&A">
     <link rel="stylesheet" href="{% static 'core/css/style.css' %}">
     <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
+    <script src="https://unpkg.com/centrifuge@2.2.1/centrifuge.min.js"></script>
 </head>
 <body>
     <header class="site-header">
         <a href="/" class="logo not-underlined">VkDesk</a>
         <form class="search">
-            <input type="text" placeholder="Search">
+            <input id="search-input" type="text" placeholder="Search">
+            <div id="search-suggestions" class="search-suggestions"></div>
             <a class="button button--ask" href="ask">ASK IT</a>
         </form>
         <div class="user-block">
@@ -49,11 +51,19 @@
             <div class="sidebar-section">
                 <h2>Trending Tags</h2>
                 <div class="tag-cloud">
-                    {% for tag in tags %}
-                    <a href="/?tag={{ tag }}" class="not-underlined">{{tag}}</a>
+                    {% for tag in popular_tags %}
+                    <a href="/?tag={{ tag.name }}" class="not-underlined">{{ tag.name }}</a>
                     {% endfor %}
                 </div>
             </div>
+            <div class="sidebar-section">
+                <h2>Best Members</h2>
+                <ul class="best-members">
+                    {% for member in best_members %}
+                    <li>{{ member.username }} ({{ member.score }})</li>
+                    {% endfor %}
+                </ul>
+            </div>
         </aside>
     </div>
     <footer class="footer">2026</footer>

questions/templates/core/question.html

@@ -187,4 +187,9 @@
 
 </form>
 
-{% endblock %}
+{% endblock %}
+
+<script>
+    window.ASK_QUESTION_ID = {{ question.id }};
+    window.ANSWERS_COUNT = {{ answers|length }};
+</script>

questions/urls.py

@@ -12,6 +12,7 @@ urlpatterns = [
     path('question', views.question, name='question'),
     path('signup', views.signup, name='signup'),
     path('hot', views.hot, name='hot'),
+    path('search', views.search, name='search'),
     path('logout', views.logout, name='logout'),
     path('ajax/question/react/', views.question_react),
     path('ajax/answer/react/', views.answer_react),

questions/views.py

@@ -6,6 +6,7 @@ from django.utils.http import url_has_allowed_host_and_scheme
 from django.contrib.auth.decorators import login_required
 from django.http import JsonResponse
 from django.views.decorators.http import require_POST
+from django.contrib.postgres.search import SearchQuery, SearchRank, SearchVector
 
 from .models import (
     Question,
@@ -22,6 +23,7 @@ from .forms import (
     AskForm,
     AnswerForm
 )
+from . import tasks as tasks_module
 
 
 def index(request):
@@ -104,6 +106,30 @@ def hot(request):
     })
 
 
+def search(request):
+    query_text = request.GET.get('q', '').strip()
+
+    if not query_text:
+        return JsonResponse({'results': []})
+
+    vector = SearchVector('title', 'body')
+    query = SearchQuery(query_text)
+    questions = Question.objects.annotate(
+        rank=SearchRank(vector, query)
+    ).filter(rank__gte=0.1).order_by('-rank')[:10]
+
+    results = [
+        {
+            'id': q.id,
+            'title': q.title,
+            'url': f'/question?question_id={q.id}'
+        }
+        for q in questions
+    ]
+
+    return JsonResponse({'results': results})
+
+
 def question(request):
 
     question_id = request.GET.get('question_id')
@@ -130,6 +156,36 @@ def question(request):
                 question=question
             )
 
+            # trigger async notifications and cache updates
+            try:
+                payload = {
+                    'id': answer.id,
+                    'body': answer.body,
+                    'user': answer.user.username
+                }
+                tasks_module.publish_new_answer_centrifugo.delay(question.id, payload)
+            except Exception:
+                pass
+
+            try:
+                # send email to question author
+                recipient = []
+                if hasattr(question.user, 'profile'):
+                    recipient = [question.user.profile.email]
+                subject = f'New answer to your question: {question.title}'
+                message = f'User {answer.user.username} answered your question.\n\n{answer.body}'
+                if recipient and recipient[0]:
+                    tasks_module.send_new_answer_email.delay(subject, message, recipient)
+            except Exception:
+                pass
+
+            # optionally trigger cache rebuilds
+            try:
+                tasks_module.rebuild_popular_tags.delay()
+                tasks_module.rebuild_best_members.delay()
+            except Exception:
+                pass
+
             return redirect(
                 f'/question?question_id={question.id}#answer-{answer.id}'
             )