/*-
 * Licensed under the SPDX BSD-2-Clause identifier.
 * Use is subject to license terms, as specified in the LICENSE file.
 */

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

#include "xbps_api_impl.h"

struct thread_data {
	pthread_t thread;
	xbps_array_t array;
	xbps_dictionary_t dict;
	struct xbps_handle *xhp;
	unsigned int start;
	unsigned int arraycount;
	unsigned int *reserved;
	pthread_mutex_t *reserved_lock;
	unsigned int slicecount;
	int (*fn)(struct xbps_handle *, xbps_object_t, const char *, void *, bool *);
	void *fn_arg;
};

/**
 * @file lib/plist.c
 * @brief PropertyList generic routines
 * @defgroup plist PropertyList generic functions
 *
 * These functions manipulate plist files and objects shared by almost
 * all library functions.
 */
static void *
array_foreach_thread(void *arg)
{
	xbps_object_t obj, pkgd;
	struct thread_data *thd = arg;
	const char *key;
	int rv;
	bool loop_done = false;
	unsigned i = thd->start;
	unsigned int end = i + thd->slicecount;

	while(i < thd->arraycount) {
		/* process pkgs from start until end */
		for (; i < end && i < thd->arraycount; i++) {
			obj = xbps_array_get(thd->array, i);
			if (xbps_object_type(thd->dict) == XBPS_TYPE_DICTIONARY) {
				pkgd = xbps_dictionary_get_keysym(thd->dict, obj);
				key = xbps_dictionary_keysym_cstring_nocopy(obj);
				/* ignore internal objs */
				if (strncmp(key, "_XBPS_", 6) == 0)
					continue;
			} else {
				pkgd = obj;
				key = NULL;
			}
			rv = (*thd->fn)(thd->xhp, pkgd, key, thd->fn_arg, &loop_done);
			if (rv != 0 || loop_done)
				return NULL;
		}
		/* Reserve more elements to compute */
		pthread_mutex_lock(thd->reserved_lock);
		i = *thd->reserved;
		end = i + thd->slicecount;
		*thd->reserved = end;
		pthread_mutex_unlock(thd->reserved_lock);
	}
	return NULL;
}

int
xbps_array_foreach_cb_multi(struct xbps_handle *xhp,
	xbps_array_t array,
	xbps_dictionary_t dict,
	int (*fn)(struct xbps_handle *, xbps_object_t, const char *, void *, bool *),
	void *arg)
{
	struct thread_data *thd;
	unsigned int arraycount, slicecount;
	int rv = 0, error = 0, i, maxthreads;
	unsigned int reserved;
	pthread_mutex_t reserved_lock = PTHREAD_MUTEX_INITIALIZER;

	assert(fn != NULL);

	if (xbps_object_type(array) != XBPS_TYPE_ARRAY)
		return 0;

	arraycount = xbps_array_count(array);
	if (arraycount == 0)
		return 0;

	maxthreads = (int)sysconf(_SC_NPROCESSORS_ONLN);
	if (maxthreads <= 1 || arraycount <= 1) /* use single threaded routine */
		return xbps_array_foreach_cb(xhp, array, dict, fn, arg);

	thd = calloc(maxthreads, sizeof(*thd));
	assert(thd);

	// maxthread is boundchecked to be > 1
	if((unsigned int)maxthreads >= arraycount) {
		maxthreads = arraycount;
		slicecount = 1;
	} else {
		slicecount = arraycount / maxthreads;
		if (slicecount > 32) {
			slicecount = 32;
		}
	}

	reserved = slicecount * maxthreads;

	for (i = 0; i < maxthreads; i++) {
		thd[i].array = array;
		thd[i].dict = dict;
		thd[i].xhp = xhp;
		thd[i].fn = fn;
		thd[i].fn_arg = arg;
		thd[i].start = i * slicecount;
		thd[i].reserved = &reserved;
		thd[i].reserved_lock = &reserved_lock;
		thd[i].slicecount = slicecount;
		thd[i].arraycount = arraycount;

		if ((rv = pthread_create(&thd[i].thread, NULL, array_foreach_thread, &thd[i])) != 0) {
			error = rv;
			break;
		}

	}
	/* wait for all threads that were created successfully */
	for (int c = 0; c < i; c++) {
		if ((rv = pthread_join(thd[c].thread, NULL)) != 0)
			error = rv;
	}

	free(thd);
	pthread_mutex_destroy(&reserved_lock);

	return error ? error : rv;
}

int
xbps_array_foreach_cb(struct xbps_handle *xhp,
	xbps_array_t array,
	xbps_dictionary_t dict,
	int (*fn)(struct xbps_handle *, xbps_object_t, const char *, void *, bool *),
	void *arg)
{
	xbps_dictionary_t pkgd;
	xbps_object_t obj;
	const char *key;
	int rv = 0;
	bool loop_done = false;

	for (unsigned int i = 0; i < xbps_array_count(array); i++) {
		obj = xbps_array_get(array, i);
		if (xbps_object_type(dict) == XBPS_TYPE_DICTIONARY) {
			pkgd = xbps_dictionary_get_keysym(dict, obj);
			key = xbps_dictionary_keysym_cstring_nocopy(obj);
			/* ignore internal objs */
			if (strncmp(key, "_XBPS_", 6) == 0)
				continue;
		} else {
			pkgd = obj;
			key = NULL;
		}
		rv = (*fn)(xhp, pkgd, key, arg, &loop_done);
		if (rv != 0 || loop_done)
			break;
	}
	return rv;
}

xbps_object_iterator_t
xbps_array_iter_from_dict(xbps_dictionary_t dict, const char *key)
{
	xbps_array_t array;

	assert(xbps_object_type(dict) == XBPS_TYPE_DICTIONARY);
	assert(key != NULL);

	array = xbps_dictionary_get(dict, key);
	if (xbps_object_type(array) != XBPS_TYPE_ARRAY) {
		errno = EINVAL;
		return NULL;
	}

	return xbps_array_iterator(array);
}

static int
array_replace_dict(xbps_array_t array,
		   xbps_dictionary_t dict,
		   const char *str,
		   bool bypattern)
{
	xbps_object_t obj;
	const char *pkgver, *pkgname;

	assert(xbps_object_type(array) == XBPS_TYPE_ARRAY);
	assert(xbps_object_type(dict) == XBPS_TYPE_DICTIONARY);
	assert(str != NULL);

	for (unsigned int i = 0; i < xbps_array_count(array); i++) {
		obj = xbps_array_get(array, i);
		if (obj == NULL) {
			continue;
		}
		if (!xbps_dictionary_get_cstring_nocopy(obj, "pkgver", &pkgver)) {
			continue;
		}
		if (bypattern) {
			/* pkgpattern match */
			if (xbps_pkgpattern_match(pkgver, str)) {
				if (!xbps_array_set(array, i, dict)) {
					return EINVAL;
				}
				return 0;
			}
		} else {
			/* pkgname match */
			xbps_dictionary_get_cstring_nocopy(obj, "pkgname", &pkgname);
			if (strcmp(pkgname, str) == 0) {
				if (!xbps_array_set(array, i, dict)) {
					return EINVAL;
				}
				return 0;
			}
		}
	}
	/* no match */
	return ENOENT;
}

int HIDDEN
xbps_array_replace_dict_by_name(xbps_array_t array,
				xbps_dictionary_t dict,
				const char *pkgver)
{
	return array_replace_dict(array, dict, pkgver, false);
}

int HIDDEN
xbps_array_replace_dict_by_pattern(xbps_array_t array,
				   xbps_dictionary_t dict,
				   const char *pattern)
{
	return array_replace_dict(array, dict, pattern, true);
}