#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>

#define ICHING_PATH "/usr/local/lib/ching.txt"

void cast(char *hexagram)
{
	int sum, c, i;

	sum = 0;
	while ((c = getchar()) != EOF) sum += c;
	srandom(sum + getuid() + getgid() + getpid() + time(0));
	for (i = 0; i < 6; i++) {
		sum = 2 + ((random() >> 15) & 1);
		sum += 2 + ((random() >> 15) & 1);
		sum += 2 + ((random() >> 15) & 1);
		hexagram[i] = '0' + sum;
	}
}

int changing(char *hexagram)
{
	int i;

	for (i = 0; i < 6; i++) if (hexagram[i] == '6' || hexagram[i] == '9') return 1;
	return 0;
}

void change(char *hexagram)
{
	int i;

	for (i = 0; i < 6; i++) {
		if (hexagram[i] == '6') hexagram[i] = '7';
		if (hexagram[i] == '9') hexagram[i] = '8';
	}
}

int number(char *hexagram)
{
	int i, h = 0;
	static char hnum[64] = {
		  2, 24,  7, 19, 15, 36, 46, 11,
		 16, 51, 40, 54, 62, 55, 32, 34,
		  8,  3, 29, 60, 39, 63, 48,  5,
		 45, 17, 47, 58, 31, 49, 28, 43,
		 23, 27,  4, 41, 52, 22, 18, 26,
		 35, 21, 64, 38, 56, 30, 50, 14,
		 20, 42, 59, 61, 53, 37, 57,  9,
		 12, 25,  6, 10, 33, 13, 44,  1
	};

	for (i = 0; i < 6; i++) if (hexagram[i] == '7' || hexagram[i] == '9') h += 1 << i;
	return hnum[h];
}

void print(char *hexagram)
{
	FILE *text;
	char line[80], top[8];
	int i = -3, echo = 0;

	if ((text = fopen(ICHING_PATH, "r")) == 0) {
		perror(ICHING_PATH);
		exit(1);
	}

	sprintf(top, "%d.  ", number(hexagram));
	fputs("\n", stdout);
	while (fgets(line, sizeof(line), text) != 0) {
		if (*line == '\f') *line = '\n';
		if (i == -3) {
			if (strstr(line, top) != 0 && strstr(line, " / ") != 0) echo = 1, i++;
		}
		else if (i == -2) {
			if (strstr(line, "The Lines") != 0)
				if (!changing(hexagram)) break;
				else i++;
		}
		else {
			if (*line == '\n') i++;
			if (i < 6) echo = (hexagram[i] == '6' || hexagram[i] == '9');
			else if (memcmp(hexagram, "666666", 6) && memcmp(hexagram, "999999", 6) || i > 6) break;
		}
		if (echo) fputs(line, stdout);
	}
	fclose(text);
}

int main(int argc, char *argv[])
{
	int i;
	char hexagram[6];

	if (argc == 1) {
		cast(hexagram);
		i = 6;
	}
	else for (i = 0; i < 6 && argv[1][i] >= '6' && argv[1][i] <= '9'; i++) hexagram[i] = argv[1][i];
	if (argc > 2 || i < 6) {
		fprintf(stderr, "usage: %s [hexagram]\n", argv[0]);
		exit(1);
	}
	print(hexagram);
	if (changing(hexagram)) {
		fputs("\n", stdout);
		change(hexagram);
		print(hexagram);
	}
	return 0;
}