[RFC 2/2] Add migration for tagging changes

[vkabatov at redhat.com]

From: Veronika Kabatova <vkabatov at redhat.com>

Signed-off-by: Veronika Kabatova <vkabatov at redhat.com>
---
 patchwork/migrations/0024_rework_tagging.py | 137 ++++++++++++++++++++++++++++
 1 file changed, 137 insertions(+)
 create mode 100644 patchwork/migrations/0024_rework_tagging.py

diff --git a/patchwork/migrations/0024_rework_tagging.py b/patchwork/migrations/0024_rework_tagging.py
new file mode 100644
index 0000000..cea6cab
--- /dev/null
+++ b/patchwork/migrations/0024_rework_tagging.py
@@ -0,0 +1,137 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.contrib.contenttypes.models import ContentType
+from django.db import migrations, models
+import django.db.models.deletion
+
+import re
+
+
+# Django migrations don't allow us to call models' methods because the
+# migration will break if the methods change. Therefore we can't use the
+# overriden submission.save() and need to use an altered copy of all the
+# code needed.
+def extract_tags(content, tags):
+    found_tags = {}
+    for tag in tags:
+        regex = re.compile(tag.pattern + '\s(.*)',
+                           re.MULTILINE | re.IGNORECASE)
+        found_tags[tag.name] = regex.findall(content)
+
+    return found_tags
+
+
+def _set_tag_values(apps, tag_related_to, tag, value_list):
+    if not value_list:
+        # We don't need to delete tags since none exist yet and we can't
+        # delete comments etc. during the migration
+        return
+
+    RelatedTag = apps.get_model('patchwork', 'RelatedTag')
+    obj_type = ContentType.objects.get_for_model(tag_related_to)
+    relatedtag, _ = RelatedTag.objects.get_or_create(
+        content_type=obj_type,
+        object_id=tag_related_to.id,
+        tag=tag
+    )
+    TagValue = apps.get_model('patchwork', 'TagValue')
+    for new_value in set(value_list):
+        new, _ = TagValue.objects.get_or_create(value=new_value)
+        relatedtag.values.add(new)
+    relatedtag.save()
+
+
+def create_key_value_tags(apps, tags_related_to):
+    if hasattr(tag_related_to, 'project'):
+        tags = tags = self.project.tags
+    else:
+        tags = self.submission.project.tags
+
+    if tags_related_to.content:
+        related_to_tags = extract_tags(tags_related_to.content, tags)
+        for tag in tags:
+            _set_tag_values(apps,
+                            tags_related_to,
+                            tag,
+                            related_to_tags[tag.name])
+
+
+def call_all(apps, schema_editor):
+    Submission = apps.get_model('patchwork', 'Submission')
+    for submission in Submission.objects.all():
+        create_key_value_tags(apps, submission)
+    Comment = apps.get_model('patchwork', 'Comment')
+    for comment in Comment.objects.all():
+        create_key_value_tags(apps, comment)
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contenttypes', '0002_remove_content_type_name'),
+        ('patchwork', '0023_timezone_unify'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='RelatedTag',
+            fields=[
+                ('id', models.AutoField(auto_created=True,
+                                        primary_key=True,
+                                        serialize=False,
+                                        verbose_name='ID')),
+                ('object_id', models.PositiveIntegerField()),
+                ('content_type', models.ForeignKey(
+                    on_delete=django.db.models.deletion.CASCADE,
+                    to='contenttypes.ContentType'
+                )),
+                ('tag', models.ForeignKey(
+                    on_delete=django.db.models.deletion.CASCADE,
+                    to='patchwork.Tag'
+                )),
+            ],
+        ),
+        migrations.CreateModel(
+            name='TagValue',
+            fields=[
+                ('id', models.AutoField(auto_created=True,
+                                        primary_key=True,
+                                        serialize=False,
+                                        verbose_name='ID')),
+                ('value', models.CharField(max_length=255, unique=True)),
+            ],
+        ),
+        migrations.AlterUniqueTogether(
+            name='patchtag',
+            unique_together=set([]),
+        ),
+        migrations.RemoveField(
+            model_name='patchtag',
+            name='patch',
+        ),
+        migrations.RemoveField(
+            model_name='patchtag',
+            name='tag',
+        ),
+        migrations.RemoveField(
+            model_name='patch',
+            name='tags',
+        ),
+        migrations.DeleteModel(
+            name='PatchTag',
+        ),
+        migrations.AddField(
+            model_name='relatedtag',
+            name='values',
+            field=models.ManyToManyField(to='patchwork.TagValue'),
+        ),
+        migrations.AlterUniqueTogether(
+            name='relatedtag',
+            unique_together=set([('content_type',
+                                  'object_id',
+                                  'tag')]),
+        ),
+        # FIXME do we need to add related_to to submission and comment?
+        migrations.RunPython(call_all, atomic=False),
+    ]
-- 
2.13.6