class Dry::Monitor::Rack::Logger

def attach(rack_monitor)
  rack_monitor.on(:start) { |params| log_start_request(params[:env]) }
  rack_monitor.on(:stop) { |params| log_stop_request(**params) }
  rack_monitor.on(:error) { |event| log_exception(event[:exception]) }
end

def filter_backtrace(backtrace)
  # TODO: what do we want to do with this?
  backtrace.reject { |l| l.include?("gems") }
end

def filter_params(params)
  params.each do |k, v|
    if config.filtered_params.include?(k)
      params[k] = FILTERED
    elsif v.is_a?(Hash)
      filter_params(v)
    elsif v.is_a?(Array)
      v.map! { |m| m.is_a?(Hash) ? filter_params(m) : m }
    end
  end
  params
end

def info(*args)
  logger.info(*args)
end

def initialize(logger, config = self.class.config)
  @logger = logger
  @config = config
end

def log_exception(err)
  logger.error err.message
  logger.error filter_backtrace(err.backtrace).join("\n")
end

def log_request_params(request)
  with_http_params(request[QUERY_STRING]) do |params|
    logger.info QUERY_MSG + params.inspect
  end
end

def log_start_request(request)
  logger.info START_MSG % [
    request[REQUEST_METHOD],
    request[PATH_INFO],
    request[REMOTE_ADDR],
    Time.now
  ]
  log_request_params(request)
end

def log_stop_request(env:, status:, time:)
  logger.info STOP_MSG % [
    env[REQUEST_METHOD],
    env[PATH_INFO],
    env[REMOTE_ADDR],
    time,
    status
  ]
end

def with_http_params(params)
  params = ::Rack::Utils.parse_nested_query(params)
  yield(filter_params(params)) unless params.empty?
end