DEV: Create UserChatThreadMembership table and model (#21481)

This will enable us to begin work on user tracking
state for a thread so we can show thread-specific
unreads and mentions indicators. In this case are following
the core notification_level paradigm rather than the solution
UserChatChannelMembership went with, and eventually we
will want to refactor the other table to match this as well.

Co-authored-by: Joffrey JAFFEUX <j.jaffeux@gmail.com>

plugins/chat/app/models/chat/thread.rb

@@ -22,6 +22,7 @@ module Chat
              foreign_key: :thread_id,
              primary_key: :id,
              class_name: "Chat::Message"
+    has_many :user_chat_thread_memberships
 
     enum :status, { open: 0, read_only: 1, closed: 2, archived: 3 }, scopes: false
 

plugins/chat/app/models/chat/user_chat_thread_membership.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module Chat
+  class Chat::UserChatThreadMembership < ActiveRecord::Base
+    self.table_name = "user_chat_thread_memberships"
+
+    belongs_to :user
+    belongs_to :last_read_message, class_name: "Chat::Message", optional: true
+    belongs_to :thread, class_name: "Chat::Thread", foreign_key: :thread_id
+
+    enum :notification_level, NotificationLevels.chat_levels
+  end
+end
+
+# == Schema Information
+#
+# Table name: user_chat_thread_memberships
+#
+#  id                   :bigint           not null, primary key
+#  user_id              :bigint           not null
+#  thread_id            :bigint           not null
+#  last_read_message_id :bigint
+#  notification_level   :integer          default(2), not null
+#  created_at           :datetime         not null
+#  updated_at           :datetime         not null
+#

plugins/chat/db/migrate/20230510142249_add_user_chat_thread_memberships.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+class AddUserChatThreadMemberships < ActiveRecord::Migration[7.0]
+  def change
+    create_table :user_chat_thread_memberships do |t|
+      t.bigint :user_id, null: false
+      t.bigint :thread_id, null: false
+      t.bigint :last_read_message_id
+      t.integer :notification_level, default: 2, null: false # default to tracking
+      t.timestamps
+    end
+
+    add_index :user_chat_thread_memberships,
+              %i[user_id thread_id],
+              unique: true,
+              name: "user_chat_thread_unique_memberships"
+  end
+end

plugins/chat/lib/chat/notification_levels_extension.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module Chat
+  module NotificationLevelsExtension
+    extend ActiveSupport::Concern
+
+    class_methods do
+      def chat_levels
+        @chat_levels ||= Enum.new(muted: 0, normal: 1, tracking: 2, watching: 3)
+      end
+    end
+  end
+end

plugins/chat/lib/chat/user_extension.rb

@@ -8,6 +8,9 @@ module Chat
       has_many :user_chat_channel_memberships,
                class_name: "Chat::UserChatChannelMembership",
                dependent: :destroy
+      has_many :user_chat_thread_memberships,
+               class_name: "Chat::UserChatThreadMembership",
+               dependent: :destroy
       has_many :chat_message_reactions, class_name: "Chat::MessageReaction", dependent: :destroy
       has_many :chat_mentions, class_name: "Chat::Mention"
     end

plugins/chat/plugin.rb

@@ -63,6 +63,7 @@ after_initialize do
     User.prepend Chat::UserExtension
     Jobs::UserEmail.prepend Chat::UserEmailExtension
     Plugin::Instance.prepend Chat::PluginInstanceExtension
+    NotificationLevels.prepend Chat::NotificationLevelsExtension
   end
 
   if Oneboxer.respond_to?(:register_local_handler)

plugins/chat/spec/fabricators/chat_fabricator.rb

@@ -154,3 +154,5 @@ Fabricator(:chat_thread, class_name: "Chat::Thread") do
 
   after_create { |thread| thread.original_message.update!(thread_id: thread.id) }
 end
+
+Fabricator(:user_chat_thread_membership, class_name: "Chat::UserChatThreadMembership") { user }

plugins/chat/spec/models/chat/user_chat_thread_membership_spec.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+RSpec.describe Chat::UserChatThreadMembership do
+  it { is_expected.to belong_to(:user).class_name("User") }
+  it { is_expected.to belong_to(:last_read_message).class_name("Chat::Message") }
+  it { is_expected.to belong_to(:thread).class_name("Chat::Thread") }
+
+  it do
+    is_expected.to define_enum_for(:notification_level).with_values(
+      muted: 0,
+      normal: 1,
+      tracking: 2,
+      watching: 3,
+    )
+  end
+end