User events management

pydis_site/apps/api/admin.py

@@ -19,7 +19,9 @@
     OffTopicChannelName,
     OffensiveMessage,
     Role,
-    User
+    ScheduledEvent,
+    User,
+    UserEvent
 )
 from .models.bot.nomination import NominationEntry
 
@@ -465,3 +467,49 @@ def has_add_permission(self, *args) -> bool:
     def has_change_permission(self, *args) -> bool:
         """Prevent editing from django admin."""
         return False
+
+
+class UserEventOrganizerFilter(admin.SimpleListFilter):
+    """List Filter for User Event list Admin page."""
+
+    title = "Organizer"
+    parameter_name = "organizer"
+
+    def lookups(self, request: HttpRequest, model: UserAdmin) -> Iterable[Tuple[str, str]]:
+        """Selectable values for viewer to filter by."""
+        user_events = UserEvent.objects.select_related("organizer")
+        organizers = {event.organizer for event in user_events}
+        return ((organizer.id, organizer.username) for organizer in organizers)
+
+    def queryset(self, request: HttpRequest, queryset: QuerySet) -> Optional[QuerySet]:
+        """Query to filter the list of User Events against."""
+        if not self.value():
+            return
+        return queryset.filter(organizer=self.value())
+
+
+@admin.register(UserEvent)
+class UserEventAdmin(admin.ModelAdmin):
+    """Admin formatting for UserEvents model."""
+
+    def organizer_username(self, user_event: UserEvent) -> str:
+        """Return organizer's username."""
+        return user_event.organizer.username
+
+    organizer_username.short_description = "Organizer"
+
+    list_display = ("name", "organizer_username")
+    list_filter = ("name", UserEventOrganizerFilter)
+
+
+@admin.register(ScheduledEvent)
+class ScheduledEventAdmin(admin.ModelAdmin):
+    """Admin formatting for ScheduledEvent model."""
+
+    def user_event_name(self, scheduled_event: ScheduledEvent) -> str:
+        """Return organizer's username."""
+        return scheduled_event.user_event.name
+
+    user_event_name.short_description = "User Event"
+
+    list_display = ("user_event_name", "start_time", "end_time")

pydis_site/apps/api/migrations/0068_scheduledevent_userevent.py

@@ -0,0 +1,36 @@
+# Generated by Django 3.0.9 on 2020-10-26 18:49
+
+import django.core.validators
+from django.db import migrations, models
+import django.db.models.deletion
+import pydis_site.apps.api.models.mixins
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0067_add_voice_ban_infraction_type'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='UserEvent',
+            fields=[
+                ('name', models.CharField(help_text='Name of the user event.', max_length=64, primary_key=True, serialize=False, verbose_name='Event Name')),
+                ('description', models.TextField()),
+                ('message_id', models.BigIntegerField(help_text='The message ID of the message sent in user events channel.', unique=True, validators=[django.core.validators.MinValueValidator(limit_value=0, message='message IDs cannot be negative.')])),
+                ('organizer', models.ForeignKey(help_text='The event organizer.', on_delete=django.db.models.deletion.CASCADE, to='api.User')),
+                ('subscriptions', models.ManyToManyField(blank=True, related_name='subscriptions', to='api.User')),
+            ],
+            bases=(pydis_site.apps.api.models.mixins.ModelReprMixin, models.Model),
+        ),
+        migrations.CreateModel(
+            name='ScheduledEvent',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('start_time', models.DateTimeField(unique=True)),
+                ('end_time', models.DateTimeField(unique=True)),
+                ('user_event', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, to='api.UserEvent')),
+            ],
+        ),
+    ]

pydis_site/apps/api/migrations/0069_auto_20201104_1833.py

@@ -0,0 +1,34 @@
+# Generated by Django 3.0.9 on 2020-11-04 18:33
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0068_scheduledevent_userevent'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='scheduledevent',
+            name='end_time',
+            field=models.DateTimeField(help_text='The end time of the scheduled user event.', unique=True),
+        ),
+        migrations.AlterField(
+            model_name='scheduledevent',
+            name='start_time',
+            field=models.DateTimeField(help_text='The start time of the scheduled user event.', unique=True),
+        ),
+        migrations.AlterField(
+            model_name='scheduledevent',
+            name='user_event',
+            field=models.OneToOneField(help_text='The user event which is scheduled.', on_delete=django.db.models.deletion.CASCADE, to='api.UserEvent'),
+        ),
+        migrations.AlterField(
+            model_name='userevent',
+            name='subscriptions',
+            field=models.ManyToManyField(blank=True, help_text="List of discord user id's how those who have subscribed to this event.", related_name='subscriptions', to='api.User'),
+        ),
+    ]

pydis_site/apps/api/migrations/0070_remove_userevent_subscriptions.py

@@ -0,0 +1,17 @@
+# Generated by Django 3.0.9 on 2020-11-06 17:55
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0069_auto_20201104_1833'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='userevent',
+            name='subscriptions',
+        ),
+    ]

pydis_site/apps/api/migrations/0072_merge_20210820_0724.py

@@ -0,0 +1,14 @@
+# Generated by Django 3.0.14 on 2021-08-20 07:24
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0071_increase_message_content_4000'),
+        ('api', '0070_remove_userevent_subscriptions'),
+    ]
+
+    operations = [
+    ]

pydis_site/apps/api/models/__init__.py

@@ -13,5 +13,7 @@
     OffTopicChannelName,
     Reminder,
     Role,
-    User
+    ScheduledEvent,
+    User,
+    UserEvent
 )

pydis_site/apps/api/models/bot/__init__.py

@@ -11,4 +11,6 @@
 from .offensive_message import OffensiveMessage
 from .reminder import Reminder
 from .role import Role
+from .scheduled_event import ScheduledEvent
 from .user import User
+from .user_event import UserEvent

pydis_site/apps/api/models/bot/scheduled_event.py

@@ -0,0 +1,78 @@
+from collections import namedtuple
+
+from django.core.exceptions import ValidationError
+from django.db import models
+
+from .user_event import UserEvent
+
+DATETIME_RANGE = namedtuple("datetime_range", ("start", "end"))
+
+
+class ScheduledEvent(models.Model):
+    """A scheduled user event."""
+
+    user_event = models.OneToOneField(
+        UserEvent,
+        on_delete=models.CASCADE,
+        help_text="The user event which is scheduled."
+    )
+    start_time = models.DateTimeField(
+        unique=True,
+        help_text="The start time of the scheduled user event."
+    )
+    end_time = models.DateTimeField(
+        unique=True,
+        help_text="The end time of the scheduled user event."
+    )
+
+    def clean(self) -> None:
+        """
+        Check for event time overlap and if an organizer has already scheduled an event.
+
+        Note: not overriding the save() method as the save() method is not called when creating
+        model instances via the admin interface.
+        """
+        # Check if organizer has already scheduled an event
+        scheduled_events_by_organizer = ScheduledEvent.objects.filter(
+            user_event__organizer=self.user_event.organizer
+        )
+        if scheduled_events_by_organizer:
+            raise ValidationError(
+                {
+                    "user_event": [
+                        f"Organizer {self.user_event.organizer} has already "
+                        f"scheduled an event!"
+                    ]
+                }
+            )
+
+        # Check for event duration
+        # Event should be at least 30min or at most 5 hours
+        duration = (self.end_time - self.start_time).total_seconds()
+        if duration < 30*60 or duration > 5*60*60:
+            raise ValidationError(
+                {
+                    "end_time": ["Event should be at least 30min or at most 5 hours."]
+                }
+            )
+
+        # Check for time overlap
+        new_dt_range = DATETIME_RANGE(self.start_time, self.end_time)
+
+        scheduled_events = ScheduledEvent.objects.select_related("user_event").all()
+
+        for event in scheduled_events:
+            event_dt_range = DATETIME_RANGE(event.start_time, event.end_time)
+            late_start = max(new_dt_range.start, event_dt_range.start)
+            early_end = min(new_dt_range.end, event_dt_range.end)
+
+            # 30min should be the minimum time gap between 2 events
+            if (late_start - early_end).total_seconds() < 30*60:
+                raise ValidationError(
+                    {
+                        "start_time": [
+                            f"Event schedule overlaps with already "
+                            f"scheduled event {event.user_event.name}."
+                        ]
+                    }
+                )

pydis_site/apps/api/models/bot/user_event.py

@@ -0,0 +1,35 @@
+from django.core.validators import MinValueValidator
+from django.db import models
+
+from pydis_site.apps.api.models.bot.user import User
+from pydis_site.apps.api.models.mixins import ModelReprMixin
+
+
+class UserEvent(ModelReprMixin, models.Model):
+    """A user event in the server."""
+
+    name = models.CharField(
+        max_length=64,
+        verbose_name="Event Name",
+        primary_key=True,
+        help_text="Name of the user event."
+    )
+    organizer = models.ForeignKey(
+        User,
+        on_delete=models.CASCADE,
+        help_text="The event organizer."
+    )
+    description = models.TextField()
+    message_id = models.BigIntegerField(
+        unique=True,
+        validators=(
+            MinValueValidator(
+                limit_value=0,
+                message="message IDs cannot be negative."
+            ),
+        ),
+        help_text=(
+            "The ID of the message "
+            "listing the event."
+        )
+    )

pydis_site/apps/api/serializers.py

@@ -1,4 +1,5 @@
 """Converters from Django models to data interchange formats and back."""
+from django.core.exceptions import ValidationError as DjangoValidationError
 from django.db.models.query import QuerySet
 from django.db.utils import IntegrityError
 from rest_framework.exceptions import NotFound
@@ -25,7 +26,9 @@
     OffensiveMessage,
     Reminder,
     Role,
-    User
+    ScheduledEvent,
+    User,
+    UserEvent
 )
 
 
@@ -379,3 +382,62 @@ class Meta:
 
         model = OffensiveMessage
         fields = ('id', 'channel_id', 'delete_date')
+
+
+class UserEventSerializer(ModelSerializer):
+    """A class providing (de-)serialization of `UserEvent` instances."""
+
+    class Meta:
+        """Metadata defined for the Django REST Framework."""
+
+        model = UserEvent
+        fields = ("name", "organizer", "description", "message_id")
+
+
+class ScheduledEventSerializer(ModelSerializer):
+    """A class providing (de-)serialization of `UserEvent` instances."""
+
+    user_event = UserEventSerializer(read_only=True)
+    user_event_name = PrimaryKeyRelatedField(
+        queryset=UserEvent.objects.select_related("organizer"),
+        source="user_event", write_only=True
+    )
+
+    class Meta:
+        """Metadata defined for the Django REST Framework."""
+
+        model = ScheduledEvent
+        fields = ("id", "user_event_name", "user_event", "start_time", "end_time")
+
+    def validate(self, attrs: dict) -> dict:
+        """
+        Catch model validation errors and send 400 response.
+
+        This is being done because the DRF uses model_instance.save()
+        method and the clean() method is not called in save()
+        hence, manually calling clean() and checking for validation errors.
+
+        reference of the above:
+        https://docs.djangoproject.com/en/3.1/ref/models/instances/#django.db.models.Model.full_clean
+        https://docs.djangoproject.com/en/3.1/ref/models/instances/#django.db.models.Model.clean
+        Note:
+        `
+        Note that full_clean() will not be called automatically when you call your model’s
+        save() method. You’ll need to call it manually when you want to run
+        one-step model validation for your own manually created models.
+        `
+
+        `
+        Note, however, that like Model.full_clean(), a model’s clean()
+        method is not invoked when you call your model’s save() method.
+        `
+         - from django docs (follow the above links).
+
+        Note: only works for POST requests.
+        """
+        scheduled_event = ScheduledEvent(**attrs)
+        try:
+            scheduled_event.clean()
+        except DjangoValidationError as e:
+            raise ValidationError(e.message_dict)
+        return attrs