/*-
 * Copyright (c) 2014-2019 Juan Romero Pardines.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include "xbps_api_impl.h"

struct item;

struct depn {
	struct depn *dnext;
	struct item *item;
};

struct item {
	struct item *hnext;
	struct item *bnext;
	struct depn *dbase;
	char *pkgn;
	const char *pkgver;
	xbps_array_t rdeps;
};

#define ITHSIZE	1024
#define ITHMASK	(ITHSIZE - 1)

static struct item *ItemHash[ITHSIZE];
static xbps_array_t result;

static int
itemhash(const char *pkgn)
{
	int hv = 0xA1B5F342;
	int i;

	assert(pkgn);

	for (i = 0; pkgn[i]; ++i)
		hv = (hv << 5) ^ (hv >> 23) ^ pkgn[i];

	return hv & ITHMASK;
}

static struct item *
lookupItem(const char *pkgn)
{
	struct item *item;

	assert(pkgn);

	for (item = ItemHash[itemhash(pkgn)]; item; item = item->hnext) {
		if (strcmp(pkgn, item->pkgn) == 0)
			return item;
	}
	return NULL;
}

static struct item *
addItem(xbps_array_t rdeps, const char *pkgn)
{
	struct item **itemp;
	struct item *item = calloc(sizeof(*item), 1);

	assert(pkgn);
	assert(item);

	itemp = &ItemHash[itemhash(pkgn)];
	item->hnext = *itemp;
	item->pkgn = strdup(pkgn);
	assert(item->pkgn);
	item->rdeps = xbps_array_copy(rdeps);
	*itemp = item;

	return item;
}

static void
addDepn(struct item *item, struct item *xitem)
{
	struct depn *depn = calloc(sizeof(*depn), 1);

	assert(item);
	assert(xitem);

	depn->item = item;
	depn->dnext = xitem->dbase;
	xitem->dbase = depn;
}

/*
 * Recursively calculate all dependencies.
 */
static struct item *
ordered_depends(struct xbps_handle *xhp, xbps_dictionary_t pkgd, bool rpool)
{
	xbps_array_t rdeps, provides;
	xbps_string_t str;
	struct item *item, *xitem;
	const char *pkgver;
	char *pkgn;

	assert(xhp);
	assert(pkgd);

	rdeps = xbps_dictionary_get(pkgd, "run_depends");
	provides = xbps_dictionary_get(pkgd, "provides");
	xbps_dictionary_get_cstring_nocopy(pkgd, "pkgver", &pkgver);

	pkgn = xbps_pkg_name(pkgver);
	assert(pkgn);
	item = addItem(rdeps, pkgn);
	item->pkgver = pkgver;
	assert(item);
	free(pkgn);

	for (unsigned int i = 0; i < xbps_array_count(rdeps); i++) {
		xbps_dictionary_t curpkgd;
		const char *curdep;
		char *curdepname;

		xbps_array_get_cstring_nocopy(rdeps, i, &curdep);
		if (rpool) {
			if ((curpkgd = xbps_rpool_get_pkg(xhp, curdep)) == NULL)
				curpkgd = xbps_rpool_get_virtualpkg(xhp, curdep);
		} else {
			if ((curpkgd = xbps_pkgdb_get_pkg(xhp, curdep)) == NULL)
				curpkgd = xbps_pkgdb_get_virtualpkg(xhp, curdep);
		}
		assert(curpkgd);
		if ((curdepname = xbps_pkgpattern_name(curdep)) == NULL)
			curdepname = xbps_pkg_name(curdep);

		assert(curdepname);

		if (provides && xbps_match_pkgname_in_array(provides, curdepname)) {
			xbps_dbg_printf(xhp, "%s: ignoring dependency %s "
			    "already in provides\n", pkgver, curdep);
			free(curdepname);
			continue;
		}
		xitem = lookupItem(curdepname);
		if (xitem == NULL)
			xitem = ordered_depends(xhp, curpkgd, rpool);

		assert(xitem);
		addDepn(item, xitem);
		free(curdepname);
	}
	/* all deps were processed, add item to head */
	str = xbps_string_create_cstring(item->pkgver);
	assert(str);
	xbps_array_add_first(result, str);
	xbps_object_release(str);

	return item;
}

xbps_array_t HIDDEN
xbps_get_pkg_fulldeptree(struct xbps_handle *xhp, const char *pkg, bool rpool)
{
	xbps_dictionary_t pkgd;

	result = xbps_array_create();
	assert(result);

	if (rpool) {
		if (((pkgd = xbps_rpool_get_pkg(xhp, pkg)) == NULL) &&
		    ((pkgd = xbps_rpool_get_virtualpkg(xhp, pkg)) == NULL))
			return NULL;
	} else {
		if (((pkgd = xbps_pkgdb_get_pkg(xhp, pkg)) == NULL) &&
		    ((pkgd = xbps_pkgdb_get_virtualpkg(xhp, pkg)) == NULL))
			return NULL;
	}
	(void)ordered_depends(xhp, pkgd, rpool);

	return result;
}