class Protocol::Rack::Adapter::Rack2

def self.make_response(env, response)
	# These interfaces should be largely compatible:
	headers = response.headers.to_h
	
	if protocol = response.protocol
		headers['rack.protocol'] = protocol
		# headers['upgrade'] = protocol
	end
	
	if body = response.body and body.stream?
		if env[RACK_IS_HIJACK]
			headers[RACK_HIJACK] = body
			body = []
		end
	end
	
	headers.transform_values! do |value|
		value.is_a?(Array) ? value.join("\n") : value
	end
	
	[response.status, headers, body]
end

def self.wrap(app)
	Rewindable.new(self.new(app))
end

def call(request)
	env = self.make_environment(request)
	
	status, headers, body = @app.call(env)
	
	headers, meta = self.wrap_headers(headers)
	
	# Rack 2 spec does not allow only partial hijacking.
	# if hijack_body = meta[RACK_HIJACK]
	# 	body = hijack_body
	# end
	
	return Response.wrap(env, status, headers, meta, body, request)
rescue => exception
	Console.logger.error(self) {exception}
	
	body&.close if body.respond_to?(:close)
	
	return failure_response(exception)
end

def make_environment(request)
	request_path, query_string = request.path.split('?', 2)
	server_name, server_port = (request.authority || '').split(':', 2)
	
	env = {
		RACK_VERSION => [2, 0],
		RACK_MULTITHREAD => false,
		RACK_MULTIPROCESS => true,
		RACK_RUN_ONCE => false,
		
		PROTOCOL_HTTP_REQUEST => request,
		
		RACK_INPUT => Input.new(request.body),
		RACK_ERRORS => $stderr,
		RACK_LOGGER => self.logger,
		# The request protocol, either from the upgrade header or the HTTP/2 pseudo header of the same name.
		RACK_PROTOCOL => request.protocol,
		
		# The HTTP request method, such as “GET” or “POST”. This cannot ever be an empty string, and so is always required.
		CGI::REQUEST_METHOD => request.method,
		
		# The initial portion of the request URL's “path” that corresponds to the application object, so that the application knows its virtual “location”. This may be an empty string, if the application corresponds to the “root” of the server.
		CGI::SCRIPT_NAME => '',
		
		# The remainder of the request URL's “path”, designating the virtual “location” of the request's target within the application. This may be an empty string, if the request URL targets the application root and does not have a trailing slash. This value may be percent-encoded when originating from a URL.
		CGI::PATH_INFO => request_path,
		CGI::REQUEST_PATH => request_path,
		CGI::REQUEST_URI => request.path,
		# The portion of the request URL that follows the ?, if any. May be empty, but is always required!
		CGI::QUERY_STRING => query_string || '',
		
		# The server protocol (e.g. HTTP/1.1):
		CGI::SERVER_PROTOCOL => request.version,
		
		# The request scheme:
		RACK_URL_SCHEME => request.scheme,
		
		# I'm not sure what sane defaults should be here:
		CGI::SERVER_NAME => server_name,
		CGI::SERVER_PORT => server_port,
	}
	
	self.unwrap_request(request, env)
	
	return env
end

def wrap_headers(fields)
	headers = ::Protocol::HTTP::Headers.new
	meta = {}
	
	fields.each do |key, value|
		key = key.downcase
		
		if key.start_with?('rack.')
			meta[key] = value
		else
			value.split("\n").each do |value|
				headers[key] = value
			end
		end
	end
	
	return headers, meta
end