Chore: Enable Users to create multiple accounts (#440)

Addresses: #402
- migrations to split roles and other attributes from users table
- make changes in code to accommodate this change

Co-authored-by: Sojan Jose <sojan@pepalo.com>
Co-authored-by: Pranav Raj Sreepuram <pranavrajs@gmail.com>

db/migrate/20200121190901_create_account_users.rb

@@ -0,0 +1,42 @@
+class CreateAccountUsers < ActiveRecord::Migration[6.0]
+  def change
+    create_table :account_users do |t|
+      t.references :account, foreign_key: true, index: true
+      t.references :user, foreign_key: true, index: true
+      t.integer :role, default: 0
+      t.bigint :inviter_id
+      t.timestamps
+    end
+
+    migrate_to_account_users
+
+    remove_column :users, :account_id, :bigint
+    remove_column :users, :role, :integer
+    remove_column :users, :inviter_id, :bigint
+  end
+
+  def migrate_to_account_users
+    ::User.find_in_batches.each do |users|
+      users.each do |user|
+        account_user = ::AccountUser.find_by(account_id: user.account_id, user_id: user.id, role: user.role)
+
+        notification_setting = ::NotificationSetting.find_by(account_id: user.account_id, user_id: user.id)
+        selected_email_flags = notification_setting.selected_email_flags
+        notification_setting.destroy!
+
+        next if account_user.present?
+
+        ::AccountUser.create!(
+          account_id: user.account_id,
+          user_id: user.id,
+          role: user[:role], # since we are overriding role method, lets fetch value from attribute
+          inviter_id: user.inviter_id
+        )
+
+        updated_notification_setting = ::NotificationSetting.find_by(account_id: user.account_id, user_id: user.id)
+        updated_notification_setting.selected_email_flags = selected_email_flags
+        updated_notification_setting.save!
+      end
+    end
+  end
+end

db/migrate/20200121220431_add_uniqueness_constraint_to_account_users.rb

@@ -0,0 +1,5 @@
+class AddUniquenessConstraintToAccountUsers < ActiveRecord::Migration[6.0]
+  def change
+    add_index :account_users, [:account_id, :user_id], unique: true, name: 'uniq_user_id_per_account_id'
+  end
+end

db/schema.rb

@@ -14,6 +14,18 @@ ActiveRecord::Schema.define(version: 20_200_226_194_012) do
   # These are extensions that must be enabled in order to support this database
   enable_extension 'plpgsql'
 
+  create_table 'account_users', force: :cascade do |t|
+    t.bigint 'account_id'
+    t.bigint 'user_id'
+    t.integer 'role', default: 0
+    t.bigint 'inviter_id'
+    t.datetime 'created_at', precision: 6, null: false
+    t.datetime 'updated_at', precision: 6, null: false
+    t.index %w[account_id user_id], name: 'uniq_user_id_per_account_id', unique: true
+    t.index ['account_id'], name: 'index_account_users_on_account_id'
+    t.index ['user_id'], name: 'index_account_users_on_user_id'
+  end
+
   create_table 'accounts', id: :serial, force: :cascade do |t|
     t.string 'name', null: false
     t.datetime 'created_at', null: false
@@ -230,11 +242,9 @@ ActiveRecord::Schema.define(version: 20_200_226_194_012) do
     t.index %w[taggable_id taggable_type context], name: 'index_taggings_on_taggable_id_and_taggable_type_and_context'
     t.index %w[taggable_id taggable_type tagger_id context], name: 'taggings_idy'
     t.index ['taggable_id'], name: 'index_taggings_on_taggable_id'
-    t.index %w[taggable_type taggable_id], name: 'index_taggings_on_taggable_type_and_taggable_id'
     t.index ['taggable_type'], name: 'index_taggings_on_taggable_type'
     t.index %w[tagger_id tagger_type], name: 'index_taggings_on_tagger_id_and_tagger_type'
     t.index ['tagger_id'], name: 'index_taggings_on_tagger_id'
-    t.index %w[tagger_type tagger_id], name: 'index_taggings_on_tagger_type_and_tagger_id'
   end
 
   create_table 'tags', id: :serial, force: :cascade do |t|
@@ -271,14 +281,10 @@ ActiveRecord::Schema.define(version: 20_200_226_194_012) do
     t.string 'nickname'
     t.string 'email'
     t.json 'tokens'
-    t.integer 'account_id', null: false
     t.datetime 'created_at', null: false
     t.datetime 'updated_at', null: false
     t.string 'pubsub_token'
-    t.integer 'role', default: 0
-    t.bigint 'inviter_id'
     t.index ['email'], name: 'index_users_on_email'
-    t.index ['inviter_id'], name: 'index_users_on_inviter_id'
     t.index ['pubsub_token'], name: 'index_users_on_pubsub_token', unique: true
     t.index ['reset_password_token'], name: 'index_users_on_reset_password_token', unique: true
     t.index %w[uid provider], name: 'index_users_on_uid_and_provider', unique: true
@@ -293,10 +299,11 @@ ActiveRecord::Schema.define(version: 20_200_226_194_012) do
     t.integer 'webhook_type', default: 0
   end
 
+  add_foreign_key 'account_users', 'accounts'
+  add_foreign_key 'account_users', 'users'
   add_foreign_key 'active_storage_attachments', 'active_storage_blobs', column: 'blob_id'
   add_foreign_key 'contact_inboxes', 'contacts'
   add_foreign_key 'contact_inboxes', 'inboxes'
   add_foreign_key 'conversations', 'contact_inboxes'
   add_foreign_key 'messages', 'contacts'
-  add_foreign_key 'users', 'users', column: 'inviter_id', on_delete: :nullify
 end

db/seeds.rb

@@ -1,9 +1,15 @@
 account = Account.create!(name: 'Acme Inc')
 
-user = User.new(name: 'John', email: 'john@acme.inc', password: '123456', account: account, role: :administrator)
+user = User.new(name: 'John', email: 'john@acme.inc', password: '123456')
 user.skip_confirmation!
 user.save!
 
+AccountUser.create!(
+  account_id: account.id,
+  user_id: user.id,
+  role: :administrator
+)
+
 web_widget = Channel::WebWidget.create!(account: account, website_name: 'Acme', website_url: 'https://acme.inc')
 
 inbox = Inbox.create!(channel: web_widget, account: account, name: 'Acme Support')