module Slack::Web::Faraday::Connection

def connection
  @connection ||=
    begin
      options = {
        headers: { 'Accept' => 'application/json; charset=utf-8' }
      }
      options[:headers]['User-Agent'] = user_agent if user_agent
      options[:proxy] = proxy if proxy
      options[:ssl] = { ca_path: ca_path, ca_file: ca_file } if ca_path || ca_file
      request_options = {}
      request_options[:timeout] = timeout if timeout
      request_options[:open_timeout] = open_timeout if open_timeout
      options[:request] = request_options if request_options.any?
      ::Faraday::Connection.new(endpoint, options) do |connection|
        connection.request :multipart
        connection.request :url_encoded
        connection.use ::Slack::Web::Faraday::Response::RaiseError
        connection.response :mashify, mash_class: Slack::Messages::Message
        connection.response :json, content_type: /\b*$/
        connection.use ::Slack::Web::Faraday::Response::WrapError
        connection.response :logger, logger if logger
        connection.adapter adapter
      end
    end
end