[Feature] Introduce nest_level attribute to posts and API to help apps visualize nesting in threads

4 files changed, 44 insertions, 1 deletions

diff --git a/app/models/status.rb b/app/models/status.rb
index 731bb6eee..bee7d1e67 100644
--- a/app/models/status.rb
+++ b/app/models/status.rb
@@ -26,6 +26,7 @@
 #  content_type           :string
 #  deleted_at             :datetime
 #  edited                 :integer          default(0), not null
+#  nest_level             :integer          default(0), not null
 #
 
 class Status < ApplicationRecord
@@ -272,6 +273,7 @@ class Status < ApplicationRecord
   around_create Mastodon::Snowflake::Callbacks
 
   before_create :set_locality
+  before_create :set_nest_level
 
   before_validation :prepare_contents, if: :local?
   before_validation :set_reblog
@@ -546,6 +548,16 @@ class Status < ApplicationRecord
     self.local = account.local?
   end
 
+  def set_nest_level
+    return if attribute_changed?(:nest_level)
+
+    if reply?
+      self.nest_level = [thread&.account_id == account_id ? thread&.nest_level.to_i : thread&.nest_level.to_i + 1, 127].min
+    else
+      self.nest_level = 0
+    end
+  end
+
   def update_statistics
     return unless distributable?
 
diff --git a/app/serializers/rest/status_serializer.rb b/app/serializers/rest/status_serializer.rb
index 26748f683..6baa20ca9 100644
--- a/app/serializers/rest/status_serializer.rb
+++ b/app/serializers/rest/status_serializer.rb
@@ -4,7 +4,7 @@ class REST::StatusSerializer < ActiveModel::Serializer
   attributes :id, :created_at, :in_reply_to_id, :in_reply_to_account_id,
              :sensitive, :spoiler_text, :visibility, :language,
              :uri, :url, :replies_count, :reblogs_count,
-             :favourites_count
+             :favourites_count, :nest_level
 
   # Monsterfork additions
   attributes :updated_at, :edited
diff --git a/db/migrate/20200717014609_add_nest_level_to_statuses.rb b/db/migrate/20200717014609_add_nest_level_to_statuses.rb
new file mode 100644
index 000000000..0b2196ad6
--- /dev/null
+++ b/db/migrate/20200717014609_add_nest_level_to_statuses.rb
@@ -0,0 +1,7 @@
+class AddNestLevelToStatuses < ActiveRecord::Migration[5.2]
+  def change
+    safety_assured do
+      add_column :statuses, :nest_level, :integer, limit: 1, null: false, default: 0
+    end
+  end
+end
diff --git a/db/migrate/20200717015413_backfill_status_nest_level.rb b/db/migrate/20200717015413_backfill_status_nest_level.rb
new file mode 100644
index 000000000..1f37ef847
--- /dev/null
+++ b/db/migrate/20200717015413_backfill_status_nest_level.rb
@@ -0,0 +1,24 @@
+class BackfillStatusNestLevel < ActiveRecord::Migration[5.2]
+  disable_ddl_transaction!
+
+  def up
+    Rails.logger.info("Populating nest levels for orphaned replies...")
+    Status.select(:id, :account_id).where(reply: true, in_reply_to_id: nil).reorder(nil).in_batches.update_all(nest_level: 1)
+
+    count = 1.0
+    total = Conversation.count
+
+    Conversation.reorder('conversations.id DESC').find_each do |conversation|
+      Rails.logger.info("(#{(count/total*100).to_i}%) Populating nest levels for threads...")
+      conversation.statuses.where(reply: true).reorder('statuses.id ASC').find_each do |status|
+        level = [status.thread&.account_id == status.account_id ? status.thread&.nest_level.to_i : status.thread&.nest_level.to_i + 1, 127].min
+        status.update(nest_level: level) if level != status.nest_level
+      end
+      count += 1
+    end
+  end
+
+  def down
+    true
+  end
+end