require "cbor"

if ARGV.size >= 1 && ARGV[0] == "-h"
	puts "usage: cq < file.cbor"
	puts "usage: cq [attribute] < file"
	exit 0
end

def dig(data, attribute : String)
	case data
	when Hash
		if v = data[attribute]?
			return v
		end
	else
		STDERR.puts "attribute not found: #{attribute}"
		return nil
	end
end

buffer = Bytes.new 1_000_000 # 1 MB

until STDIN.read(buffer) == 0
	decoder = CBOR::Decoder.new(buffer)
	while data = decoder.read_value
		break if data == 0

		if ARGV.size == 0
			pp data
			next
		end

		ARGV.each do |attribute|
			current_data = data.clone
			attribute.split(/[.]/).each do |attr|
				current_data = dig current_data, attr
			end
			pp current_data
		end
	end
	buffer = Bytes.new 1_000_000 # 1 MB
end