class Async::HTTP::Protocol::HTTP11

def call(request)
	request.version ||= self.version
	
	Async.logger.debug(self) {"#{request.method} #{request.path} #{request.headers.inspect}"}
	
	# We carefully interpret https://tools.ietf.org/html/rfc7230#section-6.3.1 to implement this correctly.
	begin
		write_request(request.authority, request.method, request.path, request.version, request.headers)
	rescue
		# If we fail to fully write the request and body, we can retry this request.
		raise RequestFailed.new
	end
	
	# Once we start writing the body, we can't recover if the request fails. That's because the body might be generated dynamically, streaming, etc.
	write_body(request.body)
	
	return Response.new(*read_response)
rescue
	# This will ensure that #reusable? returns false.
	@stream.close
	
	raise
end

def good?
	@stream.connected?
end

def initialize(stream)
	super(stream, CRLF)
	
	@persistent = true
	@count = 0
end

def multiplex
	1
end

def persistent?(headers)
	headers.delete(CONNECTION) != CLOSE
end

def read_body(headers)
	if headers.delete('transfer-encoding') == 'chunked'
		return Body::Chunked.new(self)
	elsif content_length = headers.delete('content-length')
		return Body::Fixed.new(@stream, Integer(content_length))
	end
end

def read_headers
	fields = []
	
	each_line do |line|
		if line =~ /^([a-zA-Z\-]+):\s*(.+?)\s*$/
			fields << [$1, $2]
		else
			break
		end
	end
	
	return Headers.new(fields)
end

def read_request
	method, path, version = read_line.split(/\s+/, 3)
	headers = read_headers
	body = read_body(headers)
	
	@count += 1
	
	return headers.delete(HOST), method, path, version, headers, body
end

def read_response
	version, status, reason = read_line.split(/\s+/, 3)
	headers = read_headers
	body = read_body(headers)
	
	@count += 1
	
	@persistent = persistent?(headers)
	
	return version, Integer(status), reason, headers, body
end

def receive_requests(task: Task.current)
	while @persistent
		request = Request.new(*read_request)
		
		unless persistent?(request.headers)
			@persistent = false
		end
		
		response = yield request
		
		response.version ||= request.version
		
		write_response(response.version, response.status, response.headers, response.body)
		
		request.finish
		
		# This ensures we yield at least once every iteration of the loop and allow other fibers to execute.
		task.yield
	end
end

def reusable?
	@persistent && !@stream.closed?
end

def version
	VERSION
end

def write_body(body, chunked = true)
	if body.nil? or body.empty?
		@stream.write("Content-Length: 0\r\n\r\n")
		body.read if body
	elsif chunked
		@stream.write("Transfer-Encoding: chunked\r\n\r\n")
		
		body.each do |chunk|
			next if chunk.size == 0
			
			@stream.write("#{chunk.bytesize.to_s(16).upcase}\r\n")
			@stream.write(chunk)
			@stream.write(CRLF)
			@stream.flush
		end
		
		@stream.write("0\r\n\r\n")
	else
		body = Body::Buffered.for(body)
		
		@stream.write("Content-Length: #{body.bytesize}\r\n\r\n")
		
		body.each do |chunk|
			@stream.write(chunk)
		end
	end
	
	@stream.flush
end

def write_headers(headers)
	headers.each do |name, value|
		@stream.write("#{name}: #{value}\r\n")
	end
	
	write_persistent_header
end

def write_persistent_header
	@stream.write("Connection: close\r\n") unless @persistent
end

def write_request(authority, method, path, version, headers)
	@stream.write("#{method} #{path} #{version}\r\n")
	@stream.write("Host: #{authority}\r\n")
	write_headers(headers)
	
	@stream.flush
end

def write_response(version, status, headers, body)
	@stream.write("#{version} #{status}\r\n")
	write_headers(headers)
	write_body(body)
	
	@stream.flush
end