mastodon/app/models/account.rb

class Account < ActiveRecord::Base
  # Local users
  has_one :user, inverse_of: :account

  # Timelines
  has_many :stream_entries, inverse_of: :account
  has_many :statuses, inverse_of: :account

  # Follow relations
  has_many :active_relationships,  class_name: 'Follow', foreign_key: 'account_id',        dependent: :destroy
  has_many :passive_relationships, class_name: 'Follow', foreign_key: 'target_account_id', dependent: :destroy

  has_many :following, through: :active_relationships,  source: :target_account
  has_many :followers, through: :passive_relationships, source: :account

  def follow!(other_account)
    self.active_relationships.create!(target_account: other_account)
  end

  def unfollow!(other_account)
    self.active_relationships.find_by(target_account: other_account).destroy
  end

  def following?(other_account)
    following.include?(other_account)
  end

  def local?
    self.domain.nil?
  end

  def keypair
    self.private_key.nil? ? OpenSSL::PKey::RSA.new(self.public_key) : OpenSSL::PKey::RSA.new(self.private_key)
  end

  def subscription(webhook_url)
    @subscription ||= OStatus2::Subscription.new(self.remote_url, secret: self.secret, token: self.verify_token, webhook: webhook_url, hub: self.hub_url)
  end
end