group unread count

app/controllers/api/v1/timelines/group_controller.rb

@@ -9,6 +9,8 @@ class Api::V1::Timelines::GroupController < Api::BaseController
   after_action :insert_pagination_headers, unless: -> { @statuses.empty? }
 
   def show
+    mark_as_unread
+
     render json: @statuses,
            each_serializer: REST::StatusSerializer,
            relationships: StatusRelationshipsPresenter.new(@statuses, current_user.account_id)
@@ -16,6 +18,10 @@ class Api::V1::Timelines::GroupController < Api::BaseController
 
   private
 
+  def mark_as_unread
+    GroupAccount.where(group: @group, account: current_account).update_all("unread_count = 0")
+  end
+
   def set_group
     @group = Group.find(params[:id])
   end

app/models/group_account.rb

@@ -9,6 +9,7 @@
 #  role              :string
 #  created_at        :datetime         not null
 #  updated_at        :datetime         not null
+#  unread_count      :integer          default(0)
 #
 
 class GroupAccount < ApplicationRecord

app/models/status.rb

@@ -256,6 +256,7 @@ class Status < ApplicationRecord
 
   after_create_commit :store_uri, if: :local?
   after_create_commit :update_statistics, if: :local?
+  after_create_commit :increase_group_unread_counts, if: Proc.new { |status| !status.group_id.nil? }
 
   around_create GabSocial::Snowflake::Callbacks
 
@@ -535,4 +536,8 @@ class Status < ApplicationRecord
       AccountConversation.remove_status(inbox_owner, self)
     end
   end
+
+  def increase_group_unread_counts
+    GroupAccount.where(group_id: group_id).where.not(account_id: account_id).update_all("unread_count = unread_count + 1")
+  end
 end

db/migrate/20190721214831_add_unread_count_to_group_accounts.rb

@@ -0,0 +1,5 @@
+class AddUnreadCountToGroupAccounts < ActiveRecord::Migration[5.2]
+  def change
+    add_column :group_accounts, :unread_count, :integer, default: 0
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2019_07_16_173227) do
+ActiveRecord::Schema.define(version: 2019_07_21_214831) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -327,6 +327,7 @@ ActiveRecord::Schema.define(version: 2019_07_16_173227) do
     t.string "role"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.integer "unread_count", default: 0
     t.index ["account_id", "group_id"], name: "index_group_accounts_on_account_id_and_group_id", unique: true
     t.index ["account_id"], name: "index_group_accounts_on_account_id"
     t.index ["group_id", "account_id"], name: "index_group_accounts_on_group_id_and_account_id"