Resolve "Filter discussion (tab) by comments or activity in issues and merge requests"

3 files changed, 69 insertions, 0 deletions

diff --git a/app/models/note.rb b/app/models/note.rb
index 95e1d3afa00..e1bd943e8e4 100644
--- a/app/models/note.rb
+++ b/app/models/note.rb
@@ -110,6 +110,15 @@ class Note < ActiveRecord::Base
              :system_note_metadata, :note_diff_file)
   end
 
+  scope :with_notes_filter, -> (notes_filter) do
+    case notes_filter
+    when UserPreference::NOTES_FILTERS[:only_comments]
+      user
+    else
+      all
+    end
+  end
+
   scope :diff_notes, -> { where(type: %w(LegacyDiffNote DiffNote)) }
   scope :new_diff_notes, -> { where(type: 'DiffNote') }
   scope :non_diff_notes, -> { where(type: ['Note', 'DiscussionNote', nil]) }
diff --git a/app/models/user.rb b/app/models/user.rb
index 34efb22b359..ca7fc3b058f 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -152,6 +152,7 @@ class User < ActiveRecord::Base
   belongs_to :accepted_term, class_name: 'ApplicationSetting::Term'
 
   has_one :status, class_name: 'UserStatus'
+  has_one :user_preference
 
   #
   # Validations
@@ -224,6 +225,8 @@ class User < ActiveRecord::Base
   enum project_view: [:readme, :activity, :files]
 
   delegate :path, to: :namespace, allow_nil: true, prefix: true
+  delegate :notes_filter_for, to: :user_preference
+  delegate :set_notes_filter, to: :user_preference
 
   state_machine :state, initial: :active do
     event :block do
@@ -1367,6 +1370,11 @@ class User < ActiveRecord::Base
     !consented_usage_stats? && 7.days.ago > self.created_at && !has_current_license? && User.single_user?
   end
 
+  # Avoid migrations only building user preference object when needed.
+  def user_preference
+    super.presence || build_user_preference
+  end
+
   def todos_limited_to(ids)
     todos.where(id: ids)
   end
diff --git a/app/models/user_preference.rb b/app/models/user_preference.rb
new file mode 100644
index 00000000000..6cd91abc261
--- /dev/null
+++ b/app/models/user_preference.rb
@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+class UserPreference < ActiveRecord::Base
+  # We could use enums, but Rails 4 doesn't support multiple
+  # enum options with same name for multiple fields, also it creates
+  # extra methods that aren't really needed here.
+  NOTES_FILTERS = { all_notes: 0, only_comments: 1 }.freeze
+
+  belongs_to :user
+
+  validates :issue_notes_filter, :merge_request_notes_filter, inclusion: { in: NOTES_FILTERS.values }, presence: true
+
+  class << self
+    def notes_filters
+      {
+        s_('Notes|Show all activity') => NOTES_FILTERS[:all_notes],
+        s_('Notes|Show comments only') => NOTES_FILTERS[:only_comments]
+      }
+    end
+  end
+
+  def set_notes_filter(filter_id, issuable)
+    # No need to update the column if the value is already set.
+    if filter_id && NOTES_FILTERS.values.include?(filter_id)
+      field = notes_filter_field_for(issuable)
+      self[field] = filter_id
+
+      save if attribute_changed?(field)
+    end
+
+    notes_filter_for(issuable)
+  end
+
+  # Returns the current discussion filter for a given issuable
+  # or issuable type.
+  def notes_filter_for(resource)
+    self[notes_filter_field_for(resource)]
+  end
+
+  private
+
+  def notes_filter_field_for(resource)
+    field_key =
+      if resource.is_a?(Issuable)
+        resource.model_name.param_key
+      else
+        resource
+      end
+
+    "#{field_key}_notes_filter"
+  end
+end