#define _POSIX_C_SOURCE 200809L

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

#include "zpm.h"

#define DMARK fprintf(stderr, "mark %s %s:%d\n", __FILE__, __func__, __LINE__)

int zpm_parse_version(const char *pstr, struct zpm_version_info *info) {
	int cur = 0, ch;

	info->verstr = pstr;
	info->name = 0;
	info->namelen = 0;
	info->version = 0;
	info->verlen = 0;
	info->release = -1;
	info->rellen = 0;
	info->relstr = 0;

	if (!pstr) {
		return 0;
	}

	/* skip leading whitespace */
	while (isspace(pstr[cur])) {
		cur++;
	}

	/* get the name, if any */
	if (isalpha(pstr[cur])) {
		info->name = pstr + cur;
		for (ch = pstr[cur]; ch; ch = pstr[++cur]) {
			if (ch == '-') {
				if (isdigit(pstr[cur+1])) {
					break;
				}
			}
			if (!isgraph(ch)) {
				break;
			}
			info->namelen++;
		}
	}

	while (pstr[cur] == '-') {
		cur++;
	}

	/* should be pointing at a digit.  if not, we're done */
	if (isdigit(pstr[cur])) {
		info->version = pstr + cur;
		for (ch = pstr[cur]; ch; ch = pstr[++cur]) {
			if (ch == '-') {
				break;
			}
			if (!isgraph(ch)) {
				break;
			}
			info->verlen++;
		}
	}

	while (pstr[cur] == '-') {
		cur++;
	}

	if (isdigit(pstr[cur])) {
		info->relstr = pstr + cur;
		while (isdigit(pstr[cur++])) {
			info->rellen++;
		}
	}

	if (info->relstr) {
		info->release = atoi(info->relstr);
	}

	return info->namelen || info->verlen || info->rellen;
}

int zpm_parse_package(char *pstr, char *name, char *ver, int *rel) {
	if (name) *name = 0;
	if (ver) *ver = 0;
	if (rel) *rel = 0;
	int havename = 0;
	int havever = 0;
	int haverel = 0;

	/* string - ver - rel */
	/* rel is all digits */
	/* possible forms:
	 * ^(.+)-([0-9][^-]*)-([\d+])$
	 * ^(.+)-([0-9][^-]*)$
	 * ^(.+)$
	 * The main problem in parsing is that the package name itself
	 * can contain a '-', so you can't just split on '-'
	 * Also, the version can be just digits.
	 */

	/* everything up to the first '-' is in the name */
	while (*pstr) {
		if (*pstr == '\'' || !isgraph(*pstr)) {
			return 0;
		}
		if (*pstr == '-' && isdigit(*(pstr+1))) {
			break;
		}
		if (name) {
			*name++ = *pstr;
		}
		pstr++;
		havename = 1;
	}
	if (name) *name = 0;
	if (*pstr == '-') {
		pstr++;
	}
	while (*pstr && *pstr != '-') {
		if (*pstr == '\'' || !isgraph(*pstr)) {
			return 0;
		}
		if (ver) {
			*ver++ = *pstr;
		}
		pstr++;
		havever = 1;
	}
	if (ver) *ver = 0;
	if (*pstr == '-') {
		pstr++;
	}
	/* TODO use strtol */
	if (rel && *pstr) {
		haverel = 1;
		*rel = atoi(pstr);
	}

	return havename + havever + haverel;
}