class Github
  cattr_accessor :CLIENT_ID, :CLIENT_SECRET

  # these need to be overridden in config/initializers/production.rb
  @@CLIENT_ID = nil
  @@CLIENT_SECRET = nil

  def self.enabled?
    self.CLIENT_ID.present?
  end

  def self.oauth_consumer
    OAuth::Consumer.new(self.CLIENT_ID, self.CLIENT_SECRET,
      { :site => "https://api.github.com" })
  end

  def self.token_and_user_from_code(code)
    s = Sponge.new
    res = s.fetch("https://github.com/login/oauth/access_token", :post,
      { :client_id => self.CLIENT_ID, :client_secret => self.CLIENT_SECRET,
      :code => code })
    ps = CGI.parse(res)
    tok = ps["access_token"].first

    if tok.present?
      res = s.fetch("https://api.github.com/user?access_token=#{tok}")
      js = JSON.parse(res)
      if js && js["login"].present?
        return [ tok, js["login"] ]
      end
    end

    return [ nil, nil ]
  end

  def self.oauth_auth_url(state)
    "https://github.com/login/oauth/authorize?client_id=#{self.CLIENT_ID}&" <<
      "state=#{state}"
  end
end