#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct Elems Elems;
struct Elems {
	char **e;
	int num;
};

typedef struct Indexs Indexs;
struct Indexs {
	Elems **n;
	int num;
};


void *
xcalloc(size_t nmemb, size_t size)
{
	void *p;

	if (!(p = calloc(nmemb, size))) {
		perror("calloc");
		exit(1);
	}

	return p;
}

void *
xmalloc(size_t size)
{
	void *p;

	if (!(p = malloc(size))) {
		perror("malloc");
		exit(1);
	}

	return p;
}

void *
xrealloc(void *ptr, size_t size)
{
	if (!(ptr = realloc(ptr, size))) {
		perror("realloc");
		exit(1);
	}

	return ptr;
}

char *
xstrdup(const char *str)
{
	char *ret;

	if (!(ret = strdup(str))) {
		perror("strdup");
		exit(1);
	}

	return ret;
}

void
freeelem(Elems *e)
{
	if (e != NULL) {
		if (e->e != NULL) {
			for (;e->num > 0; e->num--)
				if (e->e[e->num - 1] != NULL)
					free(e->e[e->num - 1]);
			free(e->e);
		}
		free(e);
	}
	return;
}

void
freeindex(Indexs *i)
{
	if (i != NULL) {
		if (i->n != NULL) {
			for (;i->num > 0; i->num--)
				freeelem(i->n[i->num - 1]);
			free(i->n);
		}
		free(i);
	}

	return;
}

void
addelem(Elems *e, char *s)
{
	e->num++;
	e->e = xrealloc(e->e, sizeof(char *) * e->num);
	e->e[e->num - 1] = xstrdup(s);

	return;
}

Elems *
getadv(char *str)
{
	char *b, *e, *o, *bo;
	Elems *ret;

	ret = xcalloc(1, sizeof(Elems));

	if (strchr(str, '\t')) {
		addelem(ret, "i");
		addelem(ret, "Happy helping ☃ here: You tried to "
			"output a spurious tab character. This will "
			"break gopher. Please review your scripts. "
			"Have a nice day!");
		addelem(ret, "Err");
		addelem(ret, "server");
		addelem(ret, "port");

		return ret;
	}

	if (str[0] == '[') {
		o = xstrdup(str);
		b = o + 1;
		bo = b;
		while ((e = strchr(bo, '|')) != NULL) {
			if (e != bo && e[-1] == '\\') {
				memmove(&e[-1], e, strlen(e));
				bo = e;
				continue;
			}
			*e = '\0';
			e++;
			addelem(ret, b);
			b = e;
			bo = b;
		}

		e = strchr(b, ']');
		if (e != NULL) {
			*e = '\0';
			addelem(ret, b);
		}
		free(o);

		if (ret->e != NULL && ret->e[0] != NULL && ret->e[0][0] == '\0') {
			freeelem(ret);
			ret = xcalloc(1, sizeof(Elems));

			addelem(ret, "i");
			addelem(ret, "Happy helping ☃ here: You did not "
				"specify an item type on this line. Please "
				"review your scripts. "
				"Have a nice day!");
			addelem(ret, "Err");
			addelem(ret, "server");
			addelem(ret, "port");

			return ret;
		}

		if (ret->e != NULL && ret->num == 5)
			return ret;

		/* Invalid entry: Give back the whole line. */
		freeelem(ret);
		ret = xcalloc(1, sizeof(Elems));
	}

	b = str;
	if (*str == 't')
		b++;
	addelem(ret, "i");
	addelem(ret, b);
	addelem(ret, "Err");
	addelem(ret, "server");
	addelem(ret, "port");

	return ret;
}

void
addindexs(Indexs *idx, Elems *el)
{
	idx->num++;
	idx->n = xrealloc(idx->n, sizeof(Elems) * idx->num);
	idx->n[idx->num - 1] = el;

	return;
}

Indexs *
scanfile(char *fname)
{
	char *ln = NULL;
	size_t linesiz = 0;
	ssize_t n;
	FILE *fp;
	Indexs *ret;
	Elems *el;

	if (!(fp = fopen(fname, "r")))
		return NULL;

	ret = xcalloc(1, sizeof(Indexs));

	while ((n = getline(&ln, &linesiz, fp)) > 0) {
		if (ln[n - 1] == '\n')
			ln[--n] = '\0';
		el = getadv(ln);
		if(el == NULL)
			continue;

		addindexs(ret, el);
	}
	if (ferror(fp))
		perror("getline");
	free(ln);
	fclose(fp);

	if (ret->n == NULL) {
		free(ret);
		return NULL;
	}

	return ret;
}

int
printelem(int fd, Elems *el, char *file, char *base, char *addr, char *port)
{
	char *path, *p, buf[PATH_MAX+1];
	int len;

	if (!strcmp(el->e[3], "server")) {
		free(el->e[3]);
		el->e[3] = xstrdup(addr);
	}
	if (!strcmp(el->e[4], "port")) {
		free(el->e[4]);
		el->e[4] = xstrdup(port);
	}

	/*
	 * Ignore if the path is from base, if it might be some h type with
	 * some URL and ignore various types that have different semantics but
	 * to point to some file or directory.
	 */
	if ((el->e[2][0] != '\0'
	    && el->e[2][0] != '/'
	    && el->e[0][0] != 'i'
	    && el->e[0][0] != '2'
	    && el->e[0][0] != '3'
	    && el->e[0][0] != '8'
	    && el->e[0][0] != 'w'
	    && el->e[0][0] != 'T') &&
	    !(el->e[0][0] == 'h' && !strncmp(el->e[2], "URL:", 4))) {
		path = file + strlen(base);
		if ((p = strrchr(path, '/')))
			len = p - path;
		else
			len = strlen(path);
		snprintf(buf, sizeof(buf), "%s%.*s/%s", base, len, path, el->e[2]);

		if ((path = realpath(buf, NULL)) &&
				!strncmp(base, path, strlen(base))) {
			p = path + strlen(base);
			free(el->e[2]);
			el->e[2] = xstrdup(p[0]? p : "/");
		}
		free(path);
	}

	if (dprintf(fd, "%.1s%s\t%s\t%s\t%s\r\n", el->e[0], el->e[1], el->e[2],
			el->e[3], el->e[4]) < 0) {
		perror("printelem: dprintf");
		return -1;
	}
	return 0;
}