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,
    ).body
    ps = CGI.parse(res)
    tok = ps["access_token"].first

    if tok.present?
      headers = { "Authorization" => "token #{tok}" }
      res = s.fetch("https://api.github.com/user", :get, nil, nil, headers).body
      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