package s19

import (
	"encoding/hex"
	"strconv"
)

func validateChecksum(line string, checksum byte) bool {
	sum := byte(0)
	for i := 2; i < len(line)-2; i += 2 {
		value, _ := strconv.ParseUint(line[i:i+2], 16, 8)
		sum += byte(value)
	}
	return ^sum == checksum
}

func computeChecksum(body string) byte {
	sum := byte(0)
	for i := 0; i < len(body); i += 2 {
		value, _ := hex.DecodeString(body[i : i+2])
		sum += value[0]
	}
	return ^sum
}