module Puma::Request

def normalize_env(env, client)
  if host = env[HTTP_HOST]
    # host can be a hostname, ipv4 or bracketed ipv6. Followed by an optional port.
    if colon = host.rindex("]:") # IPV6 with port
      env[SERVER_NAME] = host[0, colon+1]
      env[SERVER_PORT] = host[colon+2, host.bytesize]
    elsif !host.start_with?("[") && colon = host.index(":") # not hostname or IPV4 with port
      env[SERVER_NAME] = host[0, colon]
      env[SERVER_PORT] = host[colon+1, host.bytesize]
    else
      env[SERVER_NAME] = host
      env[SERVER_PORT] = default_server_port(env)
    end
  else
    env[SERVER_NAME] = LOCALHOST
    env[SERVER_PORT] = default_server_port(env)
  end
  unless env[REQUEST_PATH]
    # it might be a dumbass full host request header
    uri = begin
      URI.parse(env[REQUEST_URI])
    rescue URI::InvalidURIError
      raise Puma::HttpParserError
    end
    env[REQUEST_PATH] = uri.path
    # A nil env value will cause a LintError (and fatal errors elsewhere),
    # so only set the env value if there actually is a value.
    env[QUERY_STRING] = uri.query if uri.query
  end
  env[PATH_INFO] = env[REQUEST_PATH].to_s # #to_s in case it's nil
  # From https://www.ietf.org/rfc/rfc3875 :
  # "Script authors should be aware that the REMOTE_ADDR and
  # REMOTE_HOST meta-variables (see sections 4.1.8 and 4.1.9)
  # may not identify the ultimate source of the request.
  # They identify the client for the immediate request to the
  # server; that client may be a proxy, gateway, or other
  # intermediary acting on behalf of the actual source client."
  #
  unless env.key?(REMOTE_ADDR)
    begin
      addr = client.peerip
    rescue Errno::ENOTCONN
      # Client disconnects can result in an inability to get the
      # peeraddr from the socket; default to unspec.
      if client.peer_family == Socket::AF_INET6
        addr = UNSPECIFIED_IPV6
      else
        addr = UNSPECIFIED_IPV4
      end
    end
    # Set unix socket addrs to localhost
    if addr.empty?
      if client.peer_family == Socket::AF_INET6
        addr = LOCALHOST_IPV6
      else
        addr = LOCALHOST_IPV4
      end
    end
    env[REMOTE_ADDR] = addr
  end
  # The legacy HTTP_VERSION header can be sent as a client header.
  # Rack v4 may remove using HTTP_VERSION.  If so, remove this line.
  env[HTTP_VERSION] = env[SERVER_PROTOCOL]
end