class Protocol::HTTP::Body::Streamable::Body

def call(stream)
	if @block.nil?
		raise ConsumedError, "Streaming block has already been consumed!"
	end
	
	block = @block
	
	@input = @output = @block = nil
	
	# Ownership of the stream is passed into the block, in other words, the block is responsible for closing the stream.
	block.call(stream)
rescue => error
	# If, for some reason, the block raises an error, we assume it may not have closed the stream, so we close it here:
	stream.close
	raise
end

def close_input(error = nil)
	if input = @input
		@input = nil
		input.close(error)
	end
end

def close_output(error = nil)
	@output&.close(error)
end

def initialize(block, input = nil)
	@block = block
	@input = input
	@output = nil
end

def read
	# We are reading chunk by chunk, allocate an output stream and execute the block to generate the chunks:
	if @output.nil?
		if @block.nil?
			raise ConsumedError, "Streaming body has already been consumed!"
		end
		
		@output = Output.schedule(@input, @block)
		@block = nil
	end
	
	@output.read
end

def stream?
	true
end