#include <errno.h>
#include <linux/limits.h>
#include <pthread.h>
#include <stdbool.h>
#include <stdio.h>
#include <systemd/sd-bus.h>

#include "npassd/common.h"
#include "npassd/session.h"
#include "util.h"

static int handle_close(__attribute__((unused)) sd_bus_message *msg, void *data,
			__attribute__((unused)) sd_bus_error *ret_error);

static const sd_bus_vtable session_vtable[] = {
	SD_BUS_VTABLE_START(0),
	SD_BUS_METHOD("Close", "", "", handle_close,
		      SD_BUS_VTABLE_UNPRIVILEGED),
	SD_BUS_VTABLE_END,
};

static int handle_close(__attribute__((unused)) sd_bus_message *msg, void *data,
			__attribute__((unused)) sd_bus_error *ret_error)
{
	int ret;

	ret = session_free((struct session *)data);
	if (ret < 0)
		print_err("Failed to free session: %s", strerror(-ret));

	return ret;
}

int session_slot_available(struct session *s, size_t n)
{
	static pthread_mutex_t lock;

	pthread_mutex_lock(&lock);
	for (size_t i = 0; i < n; i++) {
		if (s[i].isactive == false) {
			pthread_mutex_unlock(&lock);
			return i;
		}
	}

	pthread_mutex_unlock(&lock);
	return -ENOMEM;
}

int session_new(sd_bus *bus, struct session *session, unsigned session_no)
{
	int ret;

	snprintf(session->path, sizeof(session->path),
		 DBUS_OBJECT_PATH "/session/%d", session_no);
	ret = sd_bus_add_object_vtable(bus, &session->slot, session->path,
				       SESSION_IFACE, session_vtable, session);
	if (ret < 0)
		print_err("Failed to create session: %s", strerror(-ret));
	else
		session->isactive = true;

	return ret;
}

int session_free(struct session *s)
{
	if (!s->isactive)
		return -EINVAL;

	s->isactive = false;
	sd_bus_slot_unref(s->slot);

	return 0;
}

void session_init(struct session *s, size_t n)
{
	for (size_t i = 0; i < n; i++)
		s[i].isactive = false;
}