class Doorkeeper::OAuth::AuthorizationCodeRequest

def access_token
  @access_token ||= Doorkeeper::AccessToken.matching_token_for client, grant.resource_owner_id, grant.scopes
end

def authorize
  validate
  @response = if valid?
    grant.revoke
    find_or_create_access_token
    TokenResponse.new access_token
  else
    ErrorResponse.from_request self
  end
end

def create_access_token
  @access_token = Doorkeeper::AccessToken.create!({
    :application_id    => grant.application_id,
    :resource_owner_id => grant.resource_owner_id,
    :scopes            => grant.scopes_string,
    :expires_in        => server.access_token_expires_in,
    :use_refresh_token => server.refresh_token_enabled?
  })
end

def find_or_create_access_token
  if access_token
    access_token.expired? ? revoke_and_create_access_token : access_token
  else
    create_access_token
  end
end

def initialize(server, grant, client, parameters = {})
  @server = server
  @client = client
  @grant  = grant
  @redirect_uri = parameters[:redirect_uri]
end

def revoke_and_create_access_token
  access_token.revoke
  create_access_token
end

def valid?
  self.error.nil?
end

def validate_attributes
  redirect_uri.present?
end

def validate_client
  !!client
end

def validate_grant
  return false unless grant && grant.application_id == client.id
  grant.accessible?
end

def validate_redirect_uri
  grant.redirect_uri == redirect_uri
end