add access tokens

app/models/access_token.rb

@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: access_tokens
+#
+#  id         :bigint           not null, primary key
+#  sha256     :text             not null
+#  token      :text             not null
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#  user_id    :bigint           not null
+#
+# Indexes
+#
+#  index_access_tokens_on_sha256   (sha256) UNIQUE
+#  index_access_tokens_on_user_id  (user_id)
+#
+# Foreign Keys
+#
+#  fk_rails_...  (user_id => users.id)
+#
+class AccessToken < ApplicationRecord
+  TOKEN_LENGTH = 22
+
+  belongs_to :user
+
+  before_validation :set_sha256, on: :create
+
+  attribute :token, :string, default: -> { SecureRandom.base58(TOKEN_LENGTH) }
+
+  encrypts :token
+
+  private
+
+  def set_sha256
+    self.sha256 = Digest::SHA256.hexdigest(token)
+  end
+end