class Async::HTTP::Protocol::HTTP2::Stream

def add_header(key, value)
	if key == CONNECTION
		raise ::Protocol::HTTP2::HeaderError, "Connection header is not allowed!"
	elsif key.start_with? ':'
		raise ::Protocol::HTTP2::HeaderError, "Invalid pseudo-header #{key}!"
	elsif key =~ /[A-Z]/
		raise ::Protocol::HTTP2::HeaderError, "Invalid upper-case characters in header #{key}!"
	else
		@headers.add(key, value)
	end
end

def closed(error)
	super
	
	if @input
		@input.close(error)
		@input = nil
	end
	
	if @output
		@output.stop(error)
		@output = nil
	end
	
	return self
end

def finish_output(error = nil)
	trailers = @output&.trailers
	
	@output = nil
	
	if error
		send_reset_stream(::Protocol::HTTP2::Error::INTERNAL_ERROR)
	else
		# Write trailers?
		if trailers
			send_headers(nil, trailers, ::Protocol::HTTP2::END_STREAM)
		else
			send_data(nil, ::Protocol::HTTP2::END_STREAM)
		end
	end
end

def initialize(*)
	super
	
	@headers = nil
	@trailers = nil
	
	# Input buffer, reading request body, or response body (receive_data):
	@length = nil
	@input = nil
	
	# Output buffer, writing request body or response body (window_updated):
	@output = nil
end

def prepare_input(length)
	if @input.nil?
		@input = Input.new(self, length)
	else
		raise ArgumentError, "Input body already prepared!"
	end
end

def process_data(frame)
	data = frame.unpack
	
	if @input
		unless data.empty?
			@input.write(data)
		end
		
		if frame.end_stream?
			@input.close
			@input = nil
		end
	end
	
	return data
rescue ::Protocol::HTTP2::ProtocolError
	raise
rescue # Anything else...
	send_reset_stream(::Protocol::HTTP2::Error::INTERNAL_ERROR)
end

def process_headers(frame)
	if @headers.nil?
		@headers = ::Protocol::HTTP::Headers.new
		self.receive_initial_headers(super, frame.end_stream?)
		
		@trailers = @headers[TRAILERS]
	elsif @trailers and frame.end_stream?
		self.receive_trailing_headers(super, frame.end_stream?)
	else
		raise ::Protocol::HTTP2::HeaderError, "Unable to process headers!"
	end
	
	# TODO this might need to be in an ensure block:
	if @input and frame.end_stream?
		@input.close($!)
		@input = nil
	end
rescue ::Protocol::HTTP2::HeaderError => error
	Async.logger.error(self, error)
	
	send_reset_stream(error.code)
end

def receive_trailing_headers(headers, end_stream)
	headers.each do |key, value|
		if @trailers.include?(key)
			add_header(key, value)
		else
			raise ::Protocol::HTTP2::HeaderError, "Cannot add trailer #{key} as it was not specified as a trailer!"
		end
	end
end

def send_body(body, trailers = nil)
	@output = Output.new(self, body, trailers)
	
	@output.start
end

def update_local_window(frame)
	consume_local_window(frame)
	
	# This is done on demand in `Input#read`:
	# request_window_update
end

def wait_for_input
	return @input
end

def window_updated(size)
	super
	
	@output&.window_updated(size)
end