#define _POSIX_C_SOURCE 200809L

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

#include "zpm.h"

#include "sqlite3.h"

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;
}

/*
 * flags 0 = find installed
 * flags 1 = skip installed
 * flags 2 = skip not installed
 */

struct zpm_package *zpm_package_alloc(struct zpm *zpm) {
	struct zpm_package *pkg;

	pkg = malloc(sizeof *pkg);
	if (pkg) {
		pkg->zpm = zpm;
		pkg->release = 0;
	}
	return pkg;
}

void zpm_sqlite_error(struct zpm *zpm) {
	zpm->error = 1;
	if (zpm->errmsg) free(zpm->errmsg);
	zpm->errmsg = strdup((const char *)sqlite3_errmsg(zpm->db));
}

char *zpm_findpkg(struct zpm *zpm, char *pkgstr) {
	char *select = "select pkgid, package, version, release from packages_pkgid";
	char *group = "group by package having max( version||'-'||release collate vercmp) order by length(package), package, version||'-'||release collate vercmp limit 1";
#if 0
	char *sstr[] = {
		"status = 'installed'",
		"",
		"status != 'installed'"
	};
#endif

//	char *order = "order by package, version collate vercmp, cast(release as integer)";
	sqlite3_str *sql;
	sqlite3_stmt *stmt;
	char *query;
	char package[32];
	char version[32];
	int release;

	/* null pkgstr find "best" package
	 * best is shortest complete package if any are complete
	 * shortest incomplete if any are incomplete
	 * where more than one version is in those sets, best is
	 * latest as determined by vercmp
	 */

	/* given a package name, get the packages */
	/* no package name, get all */

	//		char where[1024] = "";

	zpm_parse_package(pkgstr, package, version, &release);

	/* install a collation function */
	zpm_addvercmp(zpm);

	/* TODO allow more args to nail down version and release */

	sql = sqlite3_str_new(zpm->db);
	sqlite3_str_appendall(sql, select);
	sqlite3_str_appendf(sql, " where package = %q", package);
	if (*version) {
		sqlite3_str_appendf(sql, " and version = %q", version);
	}
	if (release) {
		sqlite3_str_appendf(sql, " and release = %d", release);
	}
	sqlite3_str_appendf(sql, " %s", group);
	sqlite3_str_appendf(sql, " limit 1");

	if (sqlite3_str_errcode(sql)) {
		zpm->error = 1;
		sqlite3_free(sqlite3_str_finish(sql));
		return 0;
	}

	query = sqlite3_str_finish(sql);
	sqlite3_prepare_v2(zpm->db, query, strlen(query), &stmt, NULL);
	sqlite3_free(query);

	free(zpm->pkgid);
	zpm->pkgid = 0;

	switch (sqlite3_step(stmt)) {
		case SQLITE_ROW:
			zpm->pkgid = strdup((const char *)sqlite3_column_text(stmt, 0));
			break;
		case SQLITE_DONE:
			/* not found */
			break;
		default:
			zpm_sqlite_error(zpm);
			break;
	}
	sqlite3_finalize(stmt);

	return zpm->pkgid;
}