module TheCity
  require 'cgi'
  require 'json'


  def self.admin_request(method, path, params = {}, body = '')
    headers = self._build_admin_headers(method, path, params, body)
    url = THE_CITY_ADMIN_PATH+path

    response =
    case method
    when :post
      Typhoeus::Request.post(url, {:headers => headers, :body => body})
    when :get
      Typhoeus::Request.get(url, {:headers => headers, :params => params})
    when :put
      Typhoeus::Request.put(url, {:headers => headers, :body => body})
    when :delete
      Typhoeus::Request.delete(url, {:headers => headers, :params => params})
    end    


    unless response.success?
      if response.code > 0
        raise TheCityExceptions::UnableToConnectToTheCity.new(response.body)
      else
        begin
          error_messages = JSON.parse(response.body)['error_message']
        rescue
          response_code_desc = response.headers.partition("\r\n")[0].sub(/^\S+/, '') rescue nil
          raise TheCityExceptions::UnknownErrorConnectingToTheCity.new("Unknown error when connecting to The City.#{response_code_desc}")
        else
          raise TheCityExceptions::TheCityResponseError.new(error_messages)
        end
      end
    end    
    
    response
  end


  def self._build_admin_headers(method, path, params, body)
    get_vars = method == :post ? '' : '?'
    if params
      get_vars += params.to_a.sort.collect { |kv_pair| "#{kv_pair[0]}=#{kv_pair[1].to_s}" }.join('&')
    end
    get_vars = '' if get_vars == '?'
    method_request = method.to_s.upcase
    url = THE_CITY_ADMIN_PATH + path + get_vars + body
    current_time = Time.now.to_i.to_s
    string_to_sign = current_time.to_s + method_request + url

    unencoded_hmac = OpenSSL::HMAC.digest('sha256', TheCity::AdminApi.api_key, string_to_sign)
    unescaped_hmac = Base64.encode64(unencoded_hmac).chomp
    hmac_signature = CGI.escape(unescaped_hmac)

    {'X-City-Sig' => hmac_signature,
     'X-City-User-Token' => TheCity::AdminApi.api_token,
     'X-City-Time' => current_time,
     'Accept' => 'application/vnd.thecity.admin.v1+json',
     'Content-Type' => 'application/json',
     'Content-Length' => body.length}
  end 

end