#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include <dirent.h>

#include "stlfile.h"

#define ARRSIZE(x) (sizeof(x)/sizeof((x)[0]))
#define MIN(x,y)   ((x) > (y) ? (y) : (x))

struct command {
	const char *name;
	void (*func)(char *);
};

void* checkp(void *p);
const char* ask(const char *fmtstr, ...);
void* die(const char *fmtstr, ...);
char* aprintf(const char *fmtstr, ...);
void dump(const char *filepath);

void search_cmd(char *arg);
void submit_cmd(char *arg);
void list_cmd(char *arg);
void cat_cmd(char *arg);

struct command commands[] = {
	{ "submit", submit_cmd },
	{ "cat", cat_cmd },
	{ "help", list_cmd },
	{ "search", search_cmd }
};

struct parseinfo *lastrun = NULL;
const char *resultdir;

void*
checkp(void *p)
{
	if (!p) die("pointer assertion failed, OOM?\n");
	return p;
}

const char*
ask(const char *fmtstr, ...)
{
	static char linebuf[256];
	va_list ap;
	int fail;

	va_start(ap, fmtstr);
	vprintf(fmtstr, ap);
	va_end(ap);

	fail = !fgets(linebuf, sizeof(linebuf), stdin);

	if (!fail) linebuf[strlen(linebuf) - 1] = '\0';

	return fail ? "" : linebuf;
}

void*
die(const char *fmtstr, ...)
{
	va_list ap;

	va_start(ap, fmtstr);
	vfprintf(stderr, fmtstr, ap);
	va_end(ap);

	exit(EXIT_FAILURE);
}

char*
aprintf(const char *fmtstr, ...)
{
	va_list ap, cpy;
	size_t nb;
	char *str;

	va_copy(cpy, ap);

	va_start(cpy, fmtstr);
	nb = vsnprintf(NULL, 0, fmtstr, ap);
	va_end(cpy);

	if (nb <= 0) die("encountered invalid fmtstr!\n");

	str = checkp(malloc(nb));
	va_start(ap, fmtstr);
	nb = vsnprintf(str, nb, fmtstr, ap);
	va_end(ap);

	return str;
}

char*
strhash(const char *filename)
{
	static const char *hexalph = "0123456789ABCDEF";
	char *buf;
	int i, k;

	buf = checkp(malloc(33));
	for (i = 0; i < MIN(32, strlen(filename)); i++) {
		unsigned char v = 0;
		for (k = i; k < strlen(filename); k += 32)
			v ^= filename[k];
		buf[i*2+0] = hexalph[(v >> 0) & 0x0f];
		buf[i*2+1] = hexalph[(v >> 4) & 0x0f];
	}

	if (i == 0) {
		memset(buf, '0', 32);
	} else if (i < 32) {
		for (k = 0; k < 32; k++)
			buf[k] = buf[k % i];
	}

	buf[32] = '\0';

	return buf;
}

void
dump(const char *filename)
{
	char buf[256];
	FILE *f;
	int nb;

	if (!(f = fopen(filename, "r"))) return;

	while ((nb = fread(buf, 1, sizeof(buf), f)))
		printf("%.*s\n", nb, buf);

	fclose(f);
}

void
search_cmd(char *arg)
{
	char *end, *resultfile = NULL;
	char *hash;
	struct dirent *de;
	int i, which;
	DIR *d = NULL;

	if (!lastrun)
		hash = strhash(ask("What is the model name?\n"));
	else
		hash = checkp(strdup(lastrun->namehash));

	d = opendir("scans");
	if (!d) return;

	i = 0;
	while ((de = readdir(d))) {
		if (de->d_type != DT_DIR && !strncmp(hash, de->d_name, strlen(hash))) {
			printf("%i : %s\n", i, de->d_name);
			i++;
		}
	}

	if (i == 0) {
		fprintf(stderr, "Sorry, couldnt find any matching scan result!\n");
		goto cleanup;
	} else {
		which = strtoul(ask("Which of these results?\n"), &end, 10);
		if (which >= i || which < 0 || *end) {
			fprintf(stderr, "Invalid index!\n");
			goto cleanup;
		}
	}

	while ((de = readdir(d))) {
		if (de->d_type != DT_DIR && !strncmp(hash, de->d_name, strlen(hash))) {
			if (i == which) {
				resultfile = aprintf("scans/%s/info", strdup(de->d_name));
				break;
			}
			i++;
		}
	}

	if (resultfile)
		dump(resultfile);

cleanup:
	free(resultfile);
	closedir(d);
}

void
submit_cmd(char *arg)
{
	const char *bufp;
	char *end, *contents;
	size_t len;

	bufp = ask("How large is your file?\n");
	len = strtoul(bufp, &end, 10);
	if (len <= 0 || len >= 7000 || *end) {
		fprintf(stderr, "Invalid file length!\n");
		return;
	}

	printf("Ok! Im listening..\n");
	contents = checkp(malloc(len));
	fread(contents, 1, len, stdin);

	if (lastrun) free_parseinfo(lastrun);
	lastrun = parse_file(contents, len);

	dump(lastrun->infopath);

	free(contents);
}

void
cat_cmd(char *arg)
{
	if (arg && !strncmp(arg, "flag", 4))
		dump("msgs/cat_flag");
	else
		printf("meow\n");
}

void
list_cmd(char *arg)
{
	int i;

	printf("Available commands:\n");
	for (i = 0; i < ARRSIZE(commands); i++)
		printf("%s%s", i ? " " : "", commands[i].name);
	printf("\n");
}

int
main()
{
	char linebuf[256], *cp, *arg;
	int exit, i;

	setvbuf(stdin, NULL, _IONBF, 0);

	if (!(resultdir = getenv("RESULTDIR")))
		resultdir = "/data";

	dump("msgs/welcome");

	exit = 0;
	while (!exit) {
		memset(linebuf, ' ', sizeof(linebuf));

		printf("$ ");
		exit = !fgets(linebuf, sizeof(linebuf), stdin);
		if (exit || !*linebuf) break;

		if (*linebuf == '\n') continue;
		linebuf[strlen(linebuf) - 1] = '\0';

		cp = strchr(linebuf, ' ');
		arg = cp ? cp + 1 : NULL;
		if (cp) *cp = 0;

		for (i = 0; i < ARRSIZE(commands); i++) {
			if (!strcmp(commands[i].name, linebuf)) {
				commands[i].func(arg);
				break;
			}
		}

		if (i == ARRSIZE(commands) && strlen(linebuf) != 0)
			fprintf(stderr, "No such command!\n");
	}

	printf("see you later!\n");
}