Firstboot, KVStore: merge old firstboot state fields

- use a migration to merge the old 'firstboot_state' and 'setup_state'
  fields into 'firstboot_completed' which is a more accurate name
- introduce kvstore.delete()

plinth/kvstore.py

@@ -40,3 +40,8 @@ def set(key, value):  # pylint: disable-msg=W0622
     """Store the value of a key"""
     store = KVStore(key=key, value=value)
     store.save()
+
+
+def delete(key):
+    """Delete a key"""
+    return KVStore.objects.get(key=key).delete()

plinth/migrations/0003_merge_firstboot_completed_fields.py

@@ -0,0 +1,82 @@
+#
+# This file is part of Plinth.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+"""
+Remove the deprecated KVStore entries 'setup_state' and 'firstboot_state',
+and only use the new entry 'firstboot_completed' instead.
+"""
+
+from __future__ import unicode_literals
+
+from django.db import migrations
+from plinth.models import KVStore
+
+
+def merge_firstboot_finished_fields(apps, schema_editor):
+    """
+    Merge 'setup_state' and 'firstboot_state' into 'firstboot_completed'.
+
+    'firstboot_completed' is the most accurate name for now, and by combining
+    the fields we do not have to deal with legacy states/fields anymore.
+    """
+    # Get and remove 'firstboot_state'
+    firstboot_state = 0
+    try:
+        _object = KVStore.objects.get(key='firstboot_state')
+    except KVStore.DoesNotExist:
+        pass
+    else:
+        firstboot_state = _object.value
+        _object.delete()
+
+    # Get and remove 'setup_state'
+    setup_state = 0
+    try:
+        _object = KVStore.objects.get(key='setup_state')
+    except KVStore.DoesNotExist:
+        pass
+    else:
+        setup_state = _object.value
+        _object.delete()
+
+    # Get current 'firstboot_completed'
+    firstboot_completed = False
+    try:
+        _object = KVStore.objects.get(key='firstboot_completed')
+    except KVStore.DoesNotExist:
+        pass
+    else:
+        firstboot_completed = _object.value
+
+    # Set new 'firstboot_completed' if needed
+    new_firstboot_completed = bool(firstboot_completed or setup_state or
+                                   firstboot_state)
+    if new_firstboot_completed and not firstboot_completed:
+        obj, created = KVStore.objects.get_or_create(key='firstboot_completed')
+        obj.value = 1
+        obj.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('plinth', '0002_modulestore'),
+    ]
+
+    operations = [
+        migrations.RunPython(merge_firstboot_finished_fields),
+    ]

plinth/modules/first_boot/__init__.py

@@ -115,10 +115,7 @@ def is_completed():
 
     global _is_completed
     if _is_completed is None:
-        # TODO
+        _is_completed = kvstore.get_default('firstboot_completed', 0)
-        # Rename setup_state to 'firstboot_completed',
-        # taking care of the existing kvstore variable name.
-        _is_completed = kvstore.get_default('setup_state', 0)
 
     return bool(_is_completed)
 
@@ -129,4 +126,4 @@ def set_completed():
 
     global _is_completed
     _is_completed = True
-    kvstore.set('setup_state', 1)
+    kvstore.set('firstboot_completed', 1)

plinth/modules/first_boot/middleware.py

@@ -25,7 +25,6 @@ from django.urls import reverse
 from django.conf import settings
 import logging
 
-from plinth import kvstore
 from plinth.modules import first_boot
 
 LOGGER = logging.getLogger(__name__)
@@ -49,14 +48,6 @@ class FirstBootMiddleware(object):
             return
 
         firstboot_completed = first_boot.is_completed()
-
-        # Migrate from old settings variable
-        if not firstboot_completed:
-            old_state = kvstore.get_default('firstboot_state', 0)
-            if old_state == 10:
-                firstboot_completed = True
-                first_boot.set_completed()
-
         user_requests_firstboot = first_boot.is_firstboot_url(request.path)
 
         # Redirect to first boot if requesting normal page and first

plinth/modules/first_boot/templatetags/firstboot_extras.py

@@ -22,7 +22,6 @@ Template tags for first boot module.
 from django import template
 
 from plinth.modules import first_boot
-from plinth import kvstore
 
 register = template.Library()