#include "wtf8.h"

/*
 * Check if first two bits of the character are "10", meaning it's a UTF-8
 * continuation character
 */
int is_utf8_cont(unsigned char c) {
	return (c & 0xC0) == 0x80;
}

/*
 * Print each octet of a string of characters as lowercase hex followed by a
 * trailing space, ending with a newline
 */
void print_octets(char *s) {
	unsigned char c;

	/*
	 * Iterate through the string, printing each octet, ending with a newline
	 */
	while ((c = *s++))
		printf("%c%02x", (is_utf8_cont(c) ? '-' : ' '), c);
	putchar('\n');

	return;
}

/*
 * Print each of the UTF-8 characters to align with the output of
 * print_octets(), with each character in line with the end of the octet that
 * terminates it, ending with a newline
 */
void print_characters(char *s) {

	/*
	 * We need a short counter to find how long each character is
	 */
	int c;

	/*
	 * Iterate through the string
	 */
	while (*s) {

		/*
		 * Print blanks and increment a counter until we find how long this
		 * character is
		 */
		for (c = 1; is_utf8_cont(s[c]); c++)
			printf("   ");

		/*
		 * Print two spaces, and then the full character
		 */
		printf("  ");
		while (c--)
			putchar(*s++);
	}

	/*
	 * End with a newline
	 */
	putchar('\n');
	return;
}

/*
 * Main function
 */
int main(int argc, char **argv) {

	/*
	 * Check we have one and only one argument
	 */
	if (argc != 2)
		exit(EXIT_FAILURE);

	/*
	 * Print the sole argument first as hex octets, then as characters, spaced
	 * accordingly
	 */
	print_octets(argv[1]);
	print_characters(argv[1]);

	/*
	 * Done!
	 */
	exit(EXIT_SUCCESS);
}