class Protocol::HTTP2::Settings

def difference(other)
	changes = []
	
	if @header_table_size != other.header_table_size
		changes << [HEADER_TABLE_SIZE, @header_table_size]
	end
	
	if @enable_push != other.enable_push
		changes << [ENABLE_PUSH, @enable_push]
	end
	
	if @maximum_concurrent_streams != other.maximum_concurrent_streams
		changes << [MAXIMUM_CONCURRENT_STREAMS, @maximum_concurrent_streams]
	end
	
	if @initial_window_size != other.initial_window_size
		changes << [INITIAL_WINDOW_SIZE, @initial_window_size]
	end
	
	if @maximum_frame_size != other.maximum_frame_size
		changes << [MAXIMUM_FRAME_SIZE, @maximum_frame_size]
	end
	
	if @maximum_header_list_size != other.maximum_header_list_size
		changes << [MAXIMUM_HEADER_LIST_SIZE, @maximum_header_list_size]
	end
	
	if @enable_connect_protocol != other.enable_connect_protocol
		changes << [ENABLE_CONNECT_PROTOCOL, @enable_connect_protocol]
	end
	
	return changes
end

def enable_connect_protocol= value
	if value == 0 or value == 1
		@enable_connect_protocol = value
	else
		raise ProtocolError, "Invalid value for enable_connect_protocol: #{value}"
	end
end

def enable_connect_protocol?
	@enable_connect_protocol == 1
end

def enable_push= value
	if value == 0 or value == 1
		@enable_push = value
	else
		raise ProtocolError, "Invalid value for enable_push: #{value}"
	end
end

def enable_push?
	@enable_push == 1
end

def initial_window_size= value
	if value <= MAXIMUM_ALLOWED_WINDOW_SIZE
		@initial_window_size = value
	else
		raise ProtocolError, "Invalid value for initial_window_size: #{value} > #{MAXIMUM_ALLOWED_WINDOW_SIZE}"
	end
end

def initialize
	# These limits are taken from the RFC:
	# https://tools.ietf.org/html/rfc7540#section-6.5.2
	@header_table_size = 4096
	@enable_push = 1
	@maximum_concurrent_streams = 0xFFFFFFFF
	@initial_window_size = 0xFFFF # 2**16 - 1
	@maximum_frame_size = 0x4000 # 2**14
	@maximum_header_list_size = 0xFFFFFFFF
	@enable_connect_protocol = 0
end

def maximum_frame_size= value
	if value > MAXIMUM_ALLOWED_FRAME_SIZE
		raise ProtocolError, "Invalid value for maximum_frame_size: #{value} > #{MAXIMUM_ALLOWED_FRAME_SIZE}"
	elsif value < MINIMUM_ALLOWED_FRAME_SIZE
		raise ProtocolError, "Invalid value for maximum_frame_size: #{value} < #{MINIMUM_ALLOWED_FRAME_SIZE}"
	else
		@maximum_frame_size = value
	end
end

def update(changes)
	changes.each do |key, value|
		if name = ASSIGN[key]
			self.send(name, value)
		end
	end
end