require "cbor"
require "option_parser"

class Context
	class_property debug = false
end

OptionParser.parse do |parser|
	parser.banner = "usage: string-keys-to-int < file.cbor"

	parser.on "-d", "--debug",
		"Debug: print keys to convert, input and output data." do
		Context.debug = true
	end

	parser.on "-h", "--help", "Displays this help and exits." do
		puts parser
		exit 0
	end
end

def are_hash_keys_all_int?(data)
	case d = data
	when Hash
		keys = d.keys
		if keys.all? {|v| v.is_a?(String) }
		  keys.all?  {|v| v.as(String).to_i64 rescue false }
		else
		  false
		end
	else
		false
	end
end

def change(data)
	# 1. change keys
	if are_hash_keys_all_int? data 
		if Context.debug
			puts "keys to convert: #{data.as(Hash).keys}"
		end

		# Do something
		case d = data
		when Hash
			keys = d.keys
			keys.each do |k|
				d[k.as(String).to_i32] = d[k]
				d.delete k
			end
		end
	end

	# 2. dig
	case d = data
	when Hash
		keys = d.keys
		keys.each do |k|
			change d[k]
		end
	end
rescue e
	STDERR.puts "something went wrong: #{e}"
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 Context.debug
			puts "input data:"
			pp data
		end

		change data

		if Context.debug
			puts "output data:"
			pp data
		else
			STDOUT.write data.to_cbor
			STDOUT.flush
		end
	end
	buffer = Bytes.new 1_000_000 # 1 MB
end