Add Tle and LatestTle models

Signed-off-by: Alfredos-Panagiotis Damkalis <fredy@fredy.gr>

db/base/admin.py

@@ -9,7 +9,7 @@ from django.shortcuts import redirect
 from django.urls import reverse
 
 from db.base.models import Artifact, DemodData, ExportedFrameset, Mode, \
-    Operator, Satellite, Telemetry, Transmitter, TransmitterEntry, \
+    Operator, Satellite, Telemetry, Tle, Transmitter, TransmitterEntry, \
     TransmitterSuggestion
 from db.base.tasks import check_celery, decode_all_data
 
@@ -219,6 +219,17 @@ class TransmitterAdmin(admin.ModelAdmin):
     readonly_fields = ('uuid', 'satellite')
 
 
+@admin.register(Tle)
+class TleAdmin(admin.ModelAdmin):
+    """Define TLE view in django admin UI"""
+    list_display = ('satellite_name', 'tle0', 'tle1', 'updated', 'tle_source')
+    list_filter = ('tle_source', 'satellite__name')
+
+    def satellite_name(self, obj):  # pylint: disable=no-self-use
+        """Return the satellite name"""
+        return obj.satellite.name
+
+
 @admin.register(Telemetry)
 class TelemetryAdmin(admin.ModelAdmin):
     """Defines Telemetry view in django admin UI"""

db/base/migrations/0022_add_tle_model.py

@@ -0,0 +1,53 @@
+# Generated by Django 2.2.14 on 2020-08-03 02:04
+
+import django.core.validators
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('base', '0021_auto_20200808_1725'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Tle',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('tle0', models.CharField(blank=True, max_length=69, validators=[django.core.validators.MinLengthValidator(1), django.core.validators.MaxLengthValidator(69)])),
+                ('tle1', models.CharField(blank=True, max_length=69, validators=[django.core.validators.MinLengthValidator(69), django.core.validators.MaxLengthValidator(69)])),
+                ('tle2', models.CharField(blank=True, max_length=69, validators=[django.core.validators.MinLengthValidator(69), django.core.validators.MaxLengthValidator(69)])),
+                ('tle_source', models.CharField(blank=True, max_length=300)),
+                ('updated', models.DateTimeField(auto_now=True)),
+                ('satellite', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='tles', to='base.Satellite')),
+            ],
+            options={
+                'ordering': ['-updated'],
+            },
+        ),
+        migrations.CreateModel(
+            name='LatestTle',
+            fields=[
+            ],
+            options={
+                'proxy': True,
+                'indexes': [],
+                'constraints': [],
+            },
+            bases=('base.tle',),
+        ),
+        migrations.AddIndex(
+            model_name='tle',
+            index=models.Index(fields=['-updated'], name='base_tle_updated_8936f7_idx'),
+        ),
+        migrations.AddIndex(
+            model_name='tle',
+            index=models.Index(fields=['tle1', 'tle2', 'tle_source', 'satellite'], name='base_tle_tle1_30ea48_idx'),
+        ),
+        migrations.AddConstraint(
+            model_name='tle',
+            constraint=models.UniqueConstraint(fields=('tle1', 'tle2', 'tle_source', 'satellite'), name='unique_entry_from_source_for_satellite'),
+        ),
+    ]

db/base/models.py

@@ -9,8 +9,8 @@ from django.conf import settings
 from django.contrib.auth.models import User
 from django.core.cache import cache
 from django.core.exceptions import ValidationError
-from django.core.validators import MaxValueValidator, MinValueValidator, \
-    URLValidator
+from django.core.validators import MaxLengthValidator, MaxValueValidator, \
+    MinLengthValidator, MinValueValidator, URLValidator
 from django.db import models
 from django.db.models import OuterRef, Subquery
 from django.db.models.signals import post_save, pre_save
@@ -496,6 +496,73 @@ class Transmitter(TransmitterEntry):
         proxy = True
 
 
+class Tle(models.Model):
+    """Model for TLEs."""
+    tle0 = models.CharField(
+        max_length=69, blank=True, validators=[MinLengthValidator(1),
+                                               MaxLengthValidator(69)]
+    )
+    tle1 = models.CharField(
+        max_length=69, blank=True, validators=[MinLengthValidator(69),
+                                               MaxLengthValidator(69)]
+    )
+    tle2 = models.CharField(
+        max_length=69, blank=True, validators=[MinLengthValidator(69),
+                                               MaxLengthValidator(69)]
+    )
+    tle_source = models.CharField(max_length=300, blank=True)
+    updated = models.DateTimeField(auto_now=True, blank=True)
+    satellite = models.ForeignKey(
+        Satellite, related_name='tles', on_delete=models.CASCADE, null=True, blank=True
+    )
+
+    class Meta:
+        ordering = ['-updated']
+        constraints = [
+            models.UniqueConstraint(
+                fields=['tle1', 'tle2', 'tle_source', 'satellite'],
+                name='unique_entry_from_source_for_satellite'
+            ),
+        ]
+        indexes = [
+            models.Index(fields=['-updated']),
+            models.Index(fields=['tle1', 'tle2', 'tle_source', 'satellite'])
+        ]
+
+    def __str__(self):
+        return '{:d} - {:s}'.format(self.id, self.tle0)
+
+    @property
+    def str_array(self):
+        """Return TLE in string array format"""
+        # tle fields are unicode, pyephem and others expect python strings
+        return [str(self.tle0), str(self.tle1), str(self.tle2)]
+
+
+class LatestTleManager(models.Manager):  # pylint: disable=R0903
+    """Django Manager for latest Tle objects"""
+    def get_queryset(self):
+        """Returns query of latest Tle
+
+        :returns: the latest Tle for each Satellite
+        """
+        subquery = Tle.objects.filter(satellite=OuterRef('satellite')).order_by('-updated')
+        return super(LatestTleManager,
+                     self).get_queryset().filter(updated=Subquery(subquery.values('updated')[:1]))
+
+
+class LatestTle(Tle):
+    """LatestTle is the latest entry of a Satellite Tle objects
+    """
+    objects = LatestTleManager()
+
+    class Meta:
+        proxy = True
+
+    def __str__(self):
+        return '{:d} - {:s}'.format(self.id, self.tle0)
+
+
 class Telemetry(models.Model):
     """Model for satellite telemetry decoders."""
     satellite = models.ForeignKey(