[trends] Initial trends app

PROJECT.org

@@ -523,21 +523,19 @@ so we can probably use backtrace=True and diagnose=True to help us root cause
 bugs faster.
 
 ** TODO [#B] Add a /trends/ page that shows trends based on scrobble data :feature:trends:scrobbles:
+:PROPERTIES:
+:ID:       03e9fe30-2bc6-4062-bb24-e95b98daf05b
+:END:
 
 *** Description
 
 This project is a bit invovled. But we should add a top level URL `trends` that shows
 various trends as defined either in a static settings file, or dynamically via a database table.
 
-Examples of trends:
+Trends could be things like doing multiple things at the same time, like while driving, what
+did we listen to this week, or while running, what were listening to this week?
 
-- How often does the user:
-  + watch sports while doing a task?
-  + do a task while watching a video?
-  * how often do I do 
-  
-- trail_scrobble__average_heartrate per trail 
-- ...
+Or more complicated trends like, how time per page changes based on the book I was reading, or if I was doing something else (music or sport event) while reading.
 
 ** TODO [#B] Scrape ComicBookRoundUp ratings for comic book metadata :books:feature:comicbook:
 :PROPERTIES:
@@ -564,6 +562,7 @@ File: ~vrobbler/apps/podcasts/utils.py~ (line 13)
 :END:
 
 *** Description
+
 The zombie scrobble cleanup query lives in a utility function. Should be a
 custom model manager method (e.g. =Scrobble.objects.zombies()=).
 

vrobbler/apps/trends/admin.py

@@ -0,0 +1,10 @@
+from django.contrib import admin
+
+from trends.models import TrendResult
+
+
+@admin.register(TrendResult)
+class TrendResultAdmin(admin.ModelAdmin):
+    list_display = ("user", "trend_slug", "computed_at", "created")
+    list_filter = ("user", "trend_slug")
+    ordering = ("-computed_at",)

vrobbler/apps/trends/apps.py

@@ -0,0 +1,6 @@
+from django.apps import AppConfig
+
+
+class TrendsConfig(AppConfig):
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "trends"

vrobbler/apps/trends/management/commands/compute_trends.py

@@ -0,0 +1,40 @@
+from django.contrib.auth import get_user_model
+from django.core.management.base import BaseCommand
+
+from trends.tasks import compute_user_trends
+
+User = get_user_model()
+
+
+class Command(BaseCommand):
+    help = "Compute trends for all users (or a specific user)"
+
+    def add_arguments(self, parser):
+        parser.add_argument(
+            "--user-id",
+            type=int,
+            help="Compute trends for a specific user only",
+        )
+
+    def handle(self, *args, **options):
+        if options["user_id"]:
+            user = User.objects.filter(id=options["user_id"]).first()
+            if not user:
+                self.stderr.write(
+                    self.style.ERROR(f"User with id {options['user_id']} not found")
+                )
+                return
+            users = [user]
+            self.stdout.write(f"Computing trends for user: {user}")
+        else:
+            users = User.objects.filter(is_active=True)
+            self.stdout.write(f"Computing trends for {users.count()} users...")
+
+        for user in users:
+            try:
+                compute_user_trends(user.id)
+                self.stdout.write(self.style.SUCCESS(f"  OK {user}"))
+            except Exception as e:
+                self.stderr.write(self.style.ERROR(f"  FAILED {user}: {e}"))
+
+        self.stdout.write(self.style.SUCCESS("Done!"))

vrobbler/apps/trends/migrations/0001_initial.py

@@ -0,0 +1,57 @@
+# Generated by Django 4.2.29 on 2026-06-16 14:52
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+import django_extensions.db.fields
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="TrendResult",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                (
+                    "created",
+                    django_extensions.db.fields.CreationDateTimeField(
+                        auto_now_add=True, verbose_name="created"
+                    ),
+                ),
+                (
+                    "modified",
+                    django_extensions.db.fields.ModificationDateTimeField(
+                        auto_now=True, verbose_name="modified"
+                    ),
+                ),
+                ("trend_slug", models.CharField(db_index=True, max_length=100)),
+                ("computed_at", models.DateTimeField(auto_now_add=True)),
+                ("data", models.JSONField(default=dict)),
+                (
+                    "user",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        to=settings.AUTH_USER_MODEL,
+                    ),
+                ),
+            ],
+            options={
+                "unique_together": {("user", "trend_slug")},
+            },
+        ),
+    ]

vrobbler/apps/trends/models.py

@@ -0,0 +1,18 @@
+from django.contrib.auth import get_user_model
+from django.db import models
+from django_extensions.db.models import TimeStampedModel
+
+User = get_user_model()
+
+
+class TrendResult(TimeStampedModel):
+    user = models.ForeignKey(User, on_delete=models.CASCADE)
+    trend_slug = models.CharField(max_length=100, db_index=True)
+    computed_at = models.DateTimeField(auto_now_add=True)
+    data = models.JSONField(default=dict)
+
+    class Meta:
+        unique_together = ["user", "trend_slug"]
+
+    def __str__(self):
+        return f"{self.user} - {self.trend_slug} ({self.computed_at})"

vrobbler/apps/trends/tasks.py

@@ -0,0 +1,39 @@
+import logging
+
+from celery import shared_task
+from django.contrib.auth import get_user_model
+from django.utils import timezone
+
+from trends.models import TrendResult
+from trends.trends import TREND_REGISTRY
+
+logger = logging.getLogger(__name__)
+User = get_user_model()
+
+
+@shared_task
+def compute_all_trends():
+    for user in User.objects.filter(is_active=True):
+        compute_user_trends.delay(user.id)
+
+
+@shared_task
+def compute_user_trends(user_id):
+    try:
+        user = User.objects.get(id=user_id)
+    except User.DoesNotExist:
+        logger.warning("User %s not found, skipping trends", user_id)
+        return
+
+    for slug, fn in TREND_REGISTRY.items():
+        try:
+            data = fn(user)
+            TrendResult.objects.update_or_create(
+                user=user,
+                trend_slug=slug,
+                defaults={"data": data, "computed_at": timezone.now()},
+            )
+        except Exception:
+            logger.exception(
+                "Failed to compute trend '%s' for user %s", slug, user_id
+            )

vrobbler/apps/trends/templates/trends/_concurrent_listening.html

@@ -0,0 +1,89 @@
+<div class="row">
+  {% if data.trails %}
+  <div class="col-md-6 mb-3">
+    <h4>🥾 While on Trails</h4>
+    {% for trail in data.trails %}
+    <div class="card mb-2">
+      <div class="card-body py-2">
+        <h6 class="card-title mb-1">
+          {% if trail.uuid %}
+          <a href="{% url 'trails:trail_detail' trail.uuid %}">{{ trail.name }}</a>
+          {% else %}
+          {{ trail.name }}
+          {% endif %}
+          <small class="text-muted">({{ trail.total_sessions }} sessions)</small>
+        </h6>
+        {% if trail.tracks %}
+        <table class="table table-sm table-borderless mb-0">
+          <thead>
+            <tr>
+              <th>Track</th>
+              <th>Artist</th>
+              <th class="text-end">Plays</th>
+            </tr>
+          </thead>
+          <tbody>
+            {% for t in trail.tracks %}
+            <tr>
+              <td>{% if t.track_uuid %}<a href="{% url 'music:track_detail' t.track_uuid %}">{{ t.track_name }}</a>{% else %}{{ t.track_name }}{% endif %}</td>
+              <td>{{ t.artist_name }}</td>
+              <td class="text-end">{{ t.count }}</td>
+            </tr>
+            {% endfor %}
+          </tbody>
+        </table>
+        {% endif %}
+      </div>
+    </div>
+    {% empty %}
+    <p class="text-muted">No concurrent listening data for trails.</p>
+    {% endfor %}
+  </div>
+  {% endif %}
+
+  {% if data.locations %}
+  <div class="col-md-6 mb-3">
+    <h4>📍 While at Locations</h4>
+    {% for loc in data.locations %}
+    <div class="card mb-2">
+      <div class="card-body py-2">
+        <h6 class="card-title mb-1">
+          {% if loc.uuid %}
+          <a href="{% url 'locations:geolocation_detail' loc.uuid %}">{{ loc.name }}</a>
+          {% else %}
+          {{ loc.name }}
+          {% endif %}
+          <small class="text-muted">({{ loc.total_sessions }} sessions)</small>
+        </h6>
+        {% if loc.tracks %}
+        <table class="table table-sm table-borderless mb-0">
+          <thead>
+            <tr>
+              <th>Track</th>
+              <th>Artist</th>
+              <th class="text-end">Plays</th>
+            </tr>
+          </thead>
+          <tbody>
+            {% for t in loc.tracks %}
+            <tr>
+              <td>{% if t.track_uuid %}<a href="{% url 'music:track_detail' t.track_uuid %}">{{ t.track_name }}</a>{% else %}{{ t.track_name }}{% endif %}</td>
+              <td>{{ t.artist_name }}</td>
+              <td class="text-end">{{ t.count }}</td>
+            </tr>
+            {% endfor %}
+          </tbody>
+        </table>
+        {% endif %}
+      </div>
+    </div>
+    {% empty %}
+    <p class="text-muted">No concurrent listening data for locations.</p>
+    {% endfor %}
+  </div>
+  {% endif %}
+</div>
+
+{% if not data.trails and not data.locations %}
+<p class="text-muted">No concurrent listening data found.</p>
+{% endif %}

vrobbler/apps/trends/templates/trends/_concurrent_reading.html

@@ -0,0 +1,42 @@
+<div class="row">
+  {% if data.books %}
+  {% for book in data.books %}
+  <div class="col-md-6 mb-3">
+    <div class="card">
+      <div class="card-body py-2">
+        <h6 class="card-title mb-1">
+          {% if book.book_uuid %}
+          <a href="{% url 'books:book_detail' book.book_uuid %}">{{ book.book_title }}</a>
+          {% else %}
+          {{ book.book_title }}
+          {% endif %}
+          <small class="text-muted">({{ book.total_sessions }} listening sessions)</small>
+        </h6>
+        {% if book.tracks %}
+        <table class="table table-sm table-borderless mb-0">
+          <thead>
+            <tr>
+              <th>Track</th>
+              <th>Artist</th>
+              <th class="text-end">Plays</th>
+            </tr>
+          </thead>
+          <tbody>
+            {% for t in book.tracks %}
+            <tr>
+              <td>{% if t.track_uuid %}<a href="{% url 'music:track_detail' t.track_uuid %}">{{ t.track_name }}</a>{% else %}{{ t.track_name }}{% endif %}</td>
+              <td>{{ t.artist_name }}</td>
+              <td class="text-end">{{ t.count }}</td>
+            </tr>
+            {% endfor %}
+          </tbody>
+        </table>
+        {% endif %}
+      </div>
+    </div>
+  </div>
+  {% endfor %}
+  {% else %}
+  <p class="text-muted">No concurrent reading data found.</p>
+  {% endif %}
+</div>

vrobbler/apps/trends/templates/trends/_reading_pace.html

@@ -0,0 +1,52 @@
+<div class="row">
+  <div class="col-md-6 mb-3">
+    <div class="card">
+      <div class="card-body">
+        <h5 class="card-title">🎵 Reading with Music</h5>
+        {% if data.with_music %}
+        <table class="table table-sm mb-0">
+          <tr>
+            <th>Avg session duration</th>
+            <td>{{ data.with_music.avg_seconds }} seconds</td>
+          </tr>
+          <tr>
+            <th>Total reading time</th>
+            <td>{{ data.with_music.total_seconds }} seconds</td>
+          </tr>
+          <tr>
+            <th>Reading sessions</th>
+            <td>{{ data.with_music.sessions_count }}</td>
+          </tr>
+        </table>
+        {% else %}
+        <p class="text-muted mb-0">No data.</p>
+        {% endif %}
+      </div>
+    </div>
+  </div>
+  <div class="col-md-6 mb-3">
+    <div class="card">
+      <div class="card-body">
+        <h5 class="card-title">🔇 Reading without Music</h5>
+        {% if data.without_music %}
+        <table class="table table-sm mb-0">
+          <tr>
+            <th>Avg session duration</th>
+            <td>{{ data.without_music.avg_seconds }} seconds</td>
+          </tr>
+          <tr>
+            <th>Total reading time</th>
+            <td>{{ data.without_music.total_seconds }} seconds</td>
+          </tr>
+          <tr>
+            <th>Reading sessions</th>
+            <td>{{ data.without_music.sessions_count }}</td>
+          </tr>
+        </table>
+        {% else %}
+        <p class="text-muted mb-0">No data.</p>
+        {% endif %}
+      </div>
+    </div>
+  </div>
+</div>

vrobbler/apps/trends/templates/trends/_trending_up.html

@@ -0,0 +1,38 @@
+<div class="row">
+  <div class="col-12">
+    {% if data %}
+    <div class="table-responsive">
+      <table class="table table-striped table-sm">
+        <thead>
+          <tr>
+            <th>Media Type</th>
+            <th class="text-end">Recent (30 days)</th>
+            <th class="text-end">Previous (30 days)</th>
+            <th class="text-end">Change</th>
+          </tr>
+        </thead>
+        <tbody>
+          {% for mt, info in data.items %}
+          <tr>
+            <td>{{ mt }}</td>
+            <td class="text-end">{{ info.recent }}</td>
+            <td class="text-end">{{ info.previous }}</td>
+            <td class="text-end">
+              {% if info.change_pct > 0 %}
+              <span class="text-success">+{{ info.change_pct }}%</span>
+              {% elif info.change_pct < 0 %}
+              <span class="text-danger">{{ info.change_pct }}%</span>
+              {% else %}
+              <span class="text-muted">0%</span>
+              {% endif %}
+            </td>
+          </tr>
+          {% endfor %}
+        </tbody>
+      </table>
+    </div>
+    {% else %}
+    <p class="text-muted">No trending data found.</p>
+    {% endif %}
+  </div>
+</div>

vrobbler/apps/trends/templates/trends/trend_detail.html

@@ -0,0 +1,38 @@
+{% extends "base_list.html" %}
+
+{% block title %}{{ trend.title }}{% endblock %}
+
+{% block lists %}
+<div class="row mb-3">
+  <div class="col-12">
+    <a href="{% url 'trends:trends-home' %}" class="btn btn-sm btn-outline-secondary mb-2">&larr; All Trends</a>
+    <h2>{{ trend.icon }} {{ trend.title }}</h2>
+    <p class="text-muted">{{ trend.description }}</p>
+    {% if computed_at %}
+    <small class="text-muted">Last computed: {{ computed_at|date:"F j, Y H:i" }}</small>
+    {% endif %}
+  </div>
+</div>
+
+{% if trend_not_found %}
+<div class="alert alert-warning">Trend not found.</div>
+
+{% elif data is None %}
+<div class="alert alert-info">
+  No data computed yet. Trends are updated once daily, check back later.
+</div>
+
+{% elif trend.slug == "concurrent-listening" %}
+  {% include "trends/_concurrent_listening.html" %}
+
+{% elif trend.slug == "concurrent-reading" %}
+  {% include "trends/_concurrent_reading.html" %}
+
+{% elif trend.slug == "reading-pace-vs-activity" %}
+  {% include "trends/_reading_pace.html" %}
+
+{% elif trend.slug == "trending-up" %}
+  {% include "trends/_trending_up.html" %}
+
+{% endif %}
+{% endblock %}

vrobbler/apps/trends/templates/trends/trend_list.html

@@ -0,0 +1,39 @@
+{% extends "base_list.html" %}
+
+{% block title %}Trends{% endblock %}
+
+{% block lists %}
+<div class="row">
+  {% if not user.is_authenticated %}
+  <div class="col-12">
+    <div class="alert alert-info">Log in to see your trends.</div>
+  </div>
+  {% elif not trends %}
+  <div class="col-12">
+    <div class="alert alert-info">
+      No trends computed yet. Trends are computed once daily, check back later.
+    </div>
+  </div>
+  {% else %}
+  {% for trend in trends %}
+  <div class="col-md-6 mb-3">
+    <div class="card h-100">
+      <div class="card-body">
+        <h5 class="card-title">
+          <a href="{% url 'trends:trend-detail' trend.slug %}" class="stretched-link text-decoration-none">
+            {{ trend.icon }} {{ trend.title }}
+          </a>
+        </h5>
+        <p class="card-text text-muted">{{ trend.description }}</p>
+        {% if trend.computed_at %}
+        <small class="text-muted">Last computed: {{ trend.computed_at|date:"M j, Y H:i" }}</small>
+        {% else %}
+        <span class="badge bg-warning text-dark">Pending</span>
+        {% endif %}
+      </div>
+    </div>
+  </div>
+  {% endfor %}
+  {% endif %}
+</div>
+{% endblock %}

vrobbler/apps/trends/trends/__init__.py

@@ -0,0 +1,25 @@
+from trends.trends.concurrent import compute_concurrent_listening, compute_concurrent_reading
+from trends.trends.reading import compute_reading_pace_vs_activity
+from trends.trends.trending import compute_trending_up
+
+TREND_REGISTRY = {}
+
+def register(slug):
+    def decorator(fn):
+        TREND_REGISTRY[slug] = fn
+        return fn
+    return decorator
+
+
+compute_concurrent_listening = register("concurrent-listening")(
+    compute_concurrent_listening
+)
+compute_concurrent_reading = register("concurrent-reading")(
+    compute_concurrent_reading
+)
+compute_reading_pace_vs_activity = register("reading-pace-vs-activity")(
+    compute_reading_pace_vs_activity
+)
+compute_trending_up = register("trending-up")(
+    compute_trending_up
+)

vrobbler/apps/trends/trends/concurrent.py

@@ -0,0 +1,222 @@
+import datetime
+from collections import defaultdict
+
+from scrobbles.models import Scrobble
+
+
+def _range_for(scrobble):
+    start = scrobble.timestamp
+    end = scrobble.stop_timestamp
+    if end is None:
+        try:
+            end = start + datetime.timedelta(hours=12)
+        except AttributeError:
+            end = start
+    return start, end
+
+
+def _find_concurrent(anchor_scrobbles, paired_scrobbles):
+    """Find paired scrobbles that overlap in time with anchor scrobbles.
+
+    Returns a dict mapping each anchor scrobble PK to a list of
+    paired scrobble PKs that overlap with it.
+    """
+    anchor_ranges = {
+        s.pk: _range_for(s) for s in anchor_scrobbles
+    }
+    paired_ranges = {
+        s.pk: _range_for(s) for s in paired_scrobbles
+    }
+
+    anchor_to_paired = defaultdict(list)
+
+    for a_pk, (a_start, a_end) in anchor_ranges.items():
+        for p_pk, (p_start, p_end) in paired_ranges.items():
+            if a_start <= p_end and p_start <= a_end:
+                anchor_to_paired[a_pk].append(p_pk)
+
+    return anchor_to_paired
+
+
+def _get_media_name(scrobble):
+    """Return the name of the media object associated with a scrobble."""
+    for attr in [
+        "trail", "geo_location", "book", "track",
+    ]:
+        obj = getattr(scrobble, attr, None)
+        if obj is not None:
+            return str(obj)
+    return "Unknown"
+
+
+def compute_concurrent_listening(user):
+    """Find what music was listened to while on trails or at locations.
+
+    Returns a dict with two keys: 'trails' and 'locations', each containing
+    a list of entries with the trail/location name and the tracks listened to.
+    """
+    media_types_to_exclude_from_anchor = ("Track", "Book", "Video", "PodcastEpisode",
+                                          "VideoGame", "BoardGame", "Puzzle", "Food",
+                                          "Beer", "Task", "WebPage", "LifeEvent",
+                                          "Mood", "BrickSet", "Channel", "BirdingLocation",
+                                          "Paper", "SportEvent")
+
+    anchor_scrobbles = list(
+        Scrobble.objects.filter(
+            user=user,
+            timestamp__isnull=False,
+            played_to_completion=True,
+        )
+        .exclude(media_type__in=media_types_to_exclude_from_anchor)
+        .select_related("trail", "geo_location")
+        .order_by("-timestamp")
+    )
+
+    paired_scrobbles = list(
+        Scrobble.objects.filter(
+            user=user,
+            media_type="Track",
+            timestamp__isnull=False,
+            stop_timestamp__isnull=False,
+            played_to_completion=True,
+        )
+        .select_related("track")
+        .order_by("-timestamp")
+    )
+
+    if not anchor_scrobbles or not paired_scrobbles:
+        return {"trails": [], "locations": []}
+
+    anchor_to_paired = _find_concurrent(anchor_scrobbles, paired_scrobbles)
+
+    paired_by_pk = {s.pk: s for s in paired_scrobbles}
+
+    trails = []
+    locations = []
+
+    for anchor in anchor_scrobbles:
+        paired_pks = anchor_to_paired.get(anchor.pk, [])
+        if not paired_pks:
+            continue
+
+        tracks_by_name = defaultdict(int)
+        track_details = {}
+        for p_pk in paired_pks:
+            ps = paired_by_pk[p_pk]
+            track = ps.track
+            if track is None:
+                continue
+            name = str(track)
+            tracks_by_name[name] += 1
+            if name not in track_details:
+                track_details[name] = {
+                    "track_name": name,
+                    "track_uuid": str(track.uuid) if track.uuid else "",
+                    "artist_name": str(track.artist) if track.artist else "",
+                }
+
+        anchor_name = _get_media_name(anchor)
+        entry = {
+            "name": anchor_name,
+            "uuid": "",
+            "total_sessions": len(paired_pks),
+            "tracks": sorted(
+                [
+                    {**track_details[name], "count": count}
+                    for name, count in tracks_by_name.items()
+                ],
+                key=lambda x: x["count"],
+                reverse=True,
+            )[:20],
+        }
+
+        if anchor.media_type == "Trail":
+            entry["uuid"] = str(anchor.trail.uuid) if anchor.trail and anchor.trail.uuid else ""
+            trails.append(entry)
+        else:
+            entry["uuid"] = str(anchor.geo_location.uuid) if anchor.geo_location and anchor.geo_location.uuid else ""
+            locations.append(entry)
+
+    return {
+        "trails": sorted(trails, key=lambda x: x["total_sessions"], reverse=True)[:20],
+        "locations": sorted(locations, key=lambda x: x["total_sessions"], reverse=True)[:20],
+    }
+
+
+def compute_concurrent_reading(user):
+    """Find what music was listened to while reading books.
+
+    Returns a dict with key 'books' containing a list of entries with the
+    book title and the tracks listened to while reading.
+    """
+    anchor_scrobbles = list(
+        Scrobble.objects.filter(
+            user=user,
+            media_type="Book",
+            timestamp__isnull=False,
+            stop_timestamp__isnull=False,
+            played_to_completion=True,
+        )
+        .select_related("book")
+        .order_by("-timestamp")
+    )
+
+    paired_scrobbles = list(
+        Scrobble.objects.filter(
+            user=user,
+            media_type="Track",
+            timestamp__isnull=False,
+            stop_timestamp__isnull=False,
+            played_to_completion=True,
+        )
+        .select_related("track")
+        .order_by("-timestamp")
+    )
+
+    if not anchor_scrobbles or not paired_scrobbles:
+        return {"books": []}
+
+    anchor_to_paired = _find_concurrent(anchor_scrobbles, paired_scrobbles)
+    paired_by_pk = {s.pk: s for s in paired_scrobbles}
+
+    books = []
+
+    for anchor in anchor_scrobbles:
+        paired_pks = anchor_to_paired.get(anchor.pk, [])
+        if not paired_pks:
+            continue
+
+        tracks_by_name = defaultdict(int)
+        track_details = {}
+        for p_pk in paired_pks:
+            ps = paired_by_pk[p_pk]
+            track = ps.track
+            if track is None:
+                continue
+            name = str(track)
+            tracks_by_name[name] += 1
+            if name not in track_details:
+                track_details[name] = {
+                    "track_name": name,
+                    "track_uuid": str(track.uuid) if track.uuid else "",
+                    "artist_name": str(track.artist) if track.artist else "",
+                }
+
+        book = anchor.book
+        books.append({
+            "book_title": str(book) if book else "Unknown",
+            "book_uuid": str(book.uuid) if book and book.uuid else "",
+            "total_sessions": len(paired_pks),
+            "tracks": sorted(
+                [
+                    {**track_details[name], "count": count}
+                    for name, count in tracks_by_name.items()
+                ],
+                key=lambda x: x["count"],
+                reverse=True,
+            )[:20],
+        })
+
+    return {
+        "books": sorted(books, key=lambda x: x["total_sessions"], reverse=True)[:20],
+    }

vrobbler/apps/trends/trends/reading.py

@@ -0,0 +1,86 @@
+import datetime
+from collections import defaultdict
+
+from scrobbles.models import Scrobble
+
+
+def compute_reading_pace_vs_activity(user):
+    """Compare reading pace (seconds per session) when music is playing vs. not.
+
+    For each Book scrobble with a playback_position_seconds value, checks
+    whether there is an overlapping Track scrobble and groups the data.
+    Returns average session duration for both groups.
+    """
+    book_scrobbles = list(
+        Scrobble.objects.filter(
+            user=user,
+            media_type="Book",
+            timestamp__isnull=False,
+            playback_position_seconds__isnull=False,
+            played_to_completion=True,
+        )
+        .select_related("book")
+        .order_by("-timestamp")
+    )
+
+    if not book_scrobbles:
+        return {"with_music": None, "without_music": None}
+
+    track_scrobbles = list(
+        Scrobble.objects.filter(
+            user=user,
+            media_type="Track",
+            timestamp__isnull=False,
+            played_to_completion=True,
+        )
+        .order_by("-timestamp")
+    )
+
+    track_ranges = []
+    for ts in track_scrobbles:
+        p_start = ts.timestamp
+        p_end = ts.stop_timestamp
+        if p_end is None:
+            try:
+                p_end = p_start + datetime.timedelta(hours=12)
+            except AttributeError:
+                p_end = p_start
+        track_ranges.append((p_start, p_end))
+
+    with_music_durations = []
+    without_music_durations = []
+
+    for bs in book_scrobbles:
+        b_start = bs.timestamp
+        b_end = bs.stop_timestamp
+        if b_end is None:
+            try:
+                b_end = b_start + datetime.timedelta(hours=12)
+            except AttributeError:
+                b_end = b_start
+
+        has_overlap = False
+        for p_start, p_end in track_ranges:
+            if b_start <= p_end and p_start <= b_end:
+                has_overlap = True
+                break
+
+        duration = bs.playback_position_seconds
+        if has_overlap:
+            with_music_durations.append(duration)
+        else:
+            without_music_durations.append(duration)
+
+    def _stats(durations):
+        if not durations:
+            return None
+        return {
+            "avg_seconds": int(sum(durations) / len(durations)),
+            "sessions_count": len(durations),
+            "total_seconds": sum(durations),
+        }
+
+    return {
+        "with_music": _stats(with_music_durations),
+        "without_music": _stats(without_music_durations),
+    }

vrobbler/apps/trends/trends/trending.py

@@ -0,0 +1,64 @@
+from collections import defaultdict
+
+from django.db.models import Count
+from django.utils import timezone
+
+from scrobbles.models import Scrobble
+
+
+def compute_trending_up(user, days=30):
+    """Compare scrobble counts per media type between two periods.
+
+    Compares the most recent N days against the N days before that,
+    returning the count for each period and the percentage change.
+
+    Returns a dict keyed by media_type with count and change info.
+    """
+    now = timezone.now()
+    recent_start = now - timezone.timedelta(days=days)
+    previous_start = recent_start - timezone.timedelta(days=days)
+
+    recent_counts = defaultdict(int)
+    for row in (
+        Scrobble.objects.filter(
+            user=user,
+            timestamp__gte=recent_start,
+            timestamp__lte=now,
+            played_to_completion=True,
+        )
+        .values("media_type")
+        .annotate(count=Count("id"))
+    ):
+        recent_counts[row["media_type"]] = row["count"]
+
+    previous_counts = defaultdict(int)
+    for row in (
+        Scrobble.objects.filter(
+            user=user,
+            timestamp__gte=previous_start,
+            timestamp__lt=recent_start,
+            played_to_completion=True,
+        )
+        .values("media_type")
+        .annotate(count=Count("id"))
+    ):
+        previous_counts[row["media_type"]] = row["count"]
+
+    all_types = set(list(recent_counts.keys()) + list(previous_counts.keys()))
+    changes = {}
+    for mt in sorted(all_types):
+        rc = recent_counts.get(mt, 0)
+        pc = previous_counts.get(mt, 0)
+        if pc > 0:
+            change_pct = round(((rc - pc) / pc) * 100, 1)
+        elif rc > 0:
+            change_pct = 100.0
+        else:
+            change_pct = 0.0
+        changes[mt] = {
+            "recent": rc,
+            "previous": pc,
+            "change_pct": change_pct,
+        }
+
+    return changes

vrobbler/apps/trends/urls.py

@@ -0,0 +1,10 @@
+from django.urls import path
+
+from trends.views import TrendDetailView, TrendListView
+
+app_name = "trends"
+
+urlpatterns = [
+    path("trends/", TrendListView.as_view(), name="trends-home"),
+    path("trends/<slug:trend_slug>/", TrendDetailView.as_view(), name="trend-detail"),
+]

vrobbler/apps/trends/views.py

@@ -0,0 +1,89 @@
+from django.contrib.auth.mixins import LoginRequiredMixin
+from django.views.generic import TemplateView
+
+from trends.models import TrendResult
+from trends.trends import TREND_REGISTRY
+
+TREND_METADATA = {
+    "concurrent-listening": {
+        "title": "Concurrent Listening",
+        "description": "What music were you listening to while on trails or at locations?",
+        "icon": "🎧",
+    },
+    "concurrent-reading": {
+        "title": "Concurrent Reading",
+        "description": "What music did you listen to while reading books?",
+        "icon": "📖",
+    },
+    "reading-pace-vs-activity": {
+        "title": "Reading Pace vs Music",
+        "description": "Compare how long you read per session with and without concurrent music.",
+        "icon": "📊",
+    },
+    "trending-up": {
+        "title": "Trending Media Types",
+        "description": "Which media types have you been consuming more or less of recently?",
+        "icon": "📈",
+    },
+}
+
+
+class TrendListView(LoginRequiredMixin, TemplateView):
+    template_name = "trends/trend_list.html"
+
+    def get_context_data(self, **kwargs):
+        ctx = super().get_context_data(**kwargs)
+        results = {
+            r.trend_slug: r
+            for r in TrendResult.objects.filter(
+                user=self.request.user
+            )
+        }
+        trends = []
+        for slug in TREND_REGISTRY:
+            meta = TREND_METADATA.get(slug, {})
+            result = results.get(slug)
+            trends.append({
+                "slug": slug,
+                "title": meta.get("title", slug),
+                "description": meta.get("description", ""),
+                "icon": meta.get("icon", ""),
+                "computed_at": result.computed_at if result else None,
+                "has_data": result is not None,
+            })
+        ctx["trends"] = trends
+        return ctx
+
+
+class TrendDetailView(LoginRequiredMixin, TemplateView):
+    template_name = "trends/trend_detail.html"
+
+    def get_context_data(self, **kwargs):
+        ctx = super().get_context_data(**kwargs)
+        slug = kwargs["trend_slug"]
+
+        if slug not in TREND_REGISTRY:
+            ctx["trend_not_found"] = True
+            return ctx
+
+        meta = TREND_METADATA.get(slug, {})
+        ctx["trend"] = {
+            "slug": slug,
+            "title": meta.get("title", slug),
+            "description": meta.get("description", ""),
+            "icon": meta.get("icon", ""),
+        }
+
+        result = TrendResult.objects.filter(
+            user=self.request.user,
+            trend_slug=slug,
+        ).first()
+
+        if result:
+            ctx["computed_at"] = result.computed_at
+            ctx["data"] = result.data
+        else:
+            ctx["computed_at"] = None
+            ctx["data"] = None
+
+        return ctx

vrobbler/settings.py

@@ -134,6 +134,10 @@ CELERY_BEAT_SCHEDULE = {
         "task": "scrobbles.tasks.rebuild_yearly_charts",
         "schedule": crontab(hour=0, minute=30, day_of_month=1, month_of_year=1),
     },
+    "compute-daily-trends": {
+        "task": "trends.tasks.compute_all_trends",
+        "schedule": crontab(hour=0, minute=10),
+    },
     # ── Crontab replacements ─────────────────────────────────────────────
     "database-backup": {
         "task": "scrobbles.tasks.backup_database",
@@ -192,6 +196,7 @@ INSTALLED_APPS = [
     "scrobbles",
     "people",
     "charts",
+    "trends",
     "videos",
     "music",
     "podcasts",

vrobbler/urls.py

@@ -105,6 +105,7 @@ from vrobbler.apps.webpages.api.views import DomainViewSet, WebPageViewSet
 
 from vrobbler.apps.people import urls as people_urls
 from vrobbler.apps.charts import urls as charts_urls
+from vrobbler.apps.trends import urls as trends_urls
 
 # from vrobbler.apps.modern_ui import urls as modern_ui_urls
 
@@ -182,6 +183,7 @@ urlpatterns = [
     path("", include(profiles_urls, namespace="profiles")),
     path("", include(people_urls, namespace="people")),
     path("", include(charts_urls, namespace="charts")),
+    path("", include(trends_urls, namespace="trends")),
     path("", scrobbles_views.RecentScrobbleList.as_view(), name="vrobbler-home"),
 ]
 if settings.DEBUG: