class Async::HTTP::RelativeLocation

def call(request)
	# We don't want to follow redirects for HEAD requests:
	return super if request.head?
	
	if body = request.body
		# We need to cache the body as it might be submitted multiple times if we get a response status of 307 or 308:
		body = ::Protocol::HTTP::Body::Rewindable.new(body)
		request.body = body
	end
	
	hops = 0
	
	while hops <= @maximum_hops
		response = super(request)
		
		if response.redirection?
			hops += 1
			
			# Get the redirect location:
			unless location = response.headers['location']
				return response
			end
			
			response.finish
			
			uri = URI.parse(location)
			
			if uri.absolute?
				return response
			else
				request.path = Reference[request.path] + location
			end
			
			if request.method == GET or response.preserve_method?
				# We (might) need to rewind the body so that it can be submitted again:
				body&.rewind
			else
				# We are changing the method to GET:
				request.method = GET
				
				# Clear the request body:
				request.finish
				body = nil
				
				# Remove any headers which are not allowed in a GET request:
				PROHIBITED_GET_HEADERS.each do |header|
					request.headers.delete(header)
				end
			end
		else
			return response
		end
	end
	
	raise TooManyRedirects, "Redirected #{hops} times, exceeded maximum!"
end

def initialize(app, maximum_hops = 3)
	super(app)
	
	@maximum_hops = maximum_hops
end

def redirect_with_get?(request, response)
	# We only want to switch to GET if the request method is something other than get, e.g. POST.
	if request.method != GET
		# According to the RFC, we should only switch to GET if the response is a 301 or 302:
		return response.status == 301 || response.status == 302
	end
end