/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2009 Richard Hughes <richard@hughsie.com>
 *
 * Licensed under the GNU General Public License Version 2
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <sys/wait.h>
#include <glib/gi18n.h>
#include <gio/gio.h>
#include <gudev/gudev.h>

#include "up-backend.h"
#include "up-daemon.h"
#include "up-marshal.h"
#include "up-device.h"

#include "up-device-supply.h"
#include "up-device-csr.h"
#include "up-device-wup.h"
#include "up-device-hid.h"
#include "up-input.h"
#ifdef HAVE_IDEVICE
#include "up-device-idevice.h"
#endif /* HAVE_IDEVICE */

static void	up_backend_class_init	(UpBackendClass	*klass);
static void	up_backend_init	(UpBackend		*backend);
static void	up_backend_finalize	(GObject		*object);

#define UP_BACKEND_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), UP_TYPE_BACKEND, UpBackendPrivate))

struct UpBackendPrivate
{
	UpDaemon		*daemon;
	UpDeviceList		*device_list;
	GUdevClient		*gudev_client;
	UpDeviceList		*managed_devices;
};

enum {
	SIGNAL_DEVICE_ADDED,
	SIGNAL_DEVICE_REMOVED,
	SIGNAL_LAST
};

static guint signals [SIGNAL_LAST] = { 0 };

G_DEFINE_TYPE (UpBackend, up_backend, G_TYPE_OBJECT)

static gboolean up_backend_device_add (UpBackend *backend, GUdevDevice *native);
static void up_backend_device_remove (UpBackend *backend, GUdevDevice *native);

#define UP_BACKEND_SUSPEND_COMMAND		"/usr/sbin/pm-suspend"
#define UP_BACKEND_HIBERNATE_COMMAND		"/usr/sbin/pm-hibernate"
#define UP_BACKEND_POWERSAVE_TRUE_COMMAND	"/usr/sbin/pm-powersave true"
#define UP_BACKEND_POWERSAVE_FALSE_COMMAND	"/usr/sbin/pm-powersave false"

/**
 * up_backend_device_new:
 **/
static UpDevice *
up_backend_device_new (UpBackend *backend, GUdevDevice *native)
{
	const gchar *subsys;
	const gchar *native_path;
	UpDevice *device = NULL;
	UpInput *input;
	gboolean ret;

	subsys = g_udev_device_get_subsystem (native);
	if (g_strcmp0 (subsys, "power_supply") == 0) {

		/* are we a valid power supply */
		device = UP_DEVICE (up_device_supply_new ());
		ret = up_device_coldplug (device, backend->priv->daemon, G_OBJECT (native));
		if (ret)
			goto out;
		g_object_unref (device);

		/* no valid power supply object */
		device = NULL;

	} else if (g_strcmp0 (subsys, "tty") == 0) {

		/* try to detect a Watts Up? Pro monitor */
		device = UP_DEVICE (up_device_wup_new ());
		ret = up_device_coldplug (device, backend->priv->daemon, G_OBJECT (native));
		if (ret)
			goto out;
		g_object_unref (device);

		/* no valid TTY object */
		device = NULL;

	} else if (g_strcmp0 (subsys, "usb") == 0) {

#ifdef HAVE_IDEVICE
		/* see if this is an iDevice */
		device = UP_DEVICE (up_device_idevice_new ());
		ret = up_device_coldplug (device, backend->priv->daemon, G_OBJECT (native));
		if (ret)
			goto out;
		g_object_unref (device);
#endif /* HAVE_IDEVICE */

		/* see if this is a CSR mouse or keyboard */
		device = UP_DEVICE (up_device_csr_new ());
		ret = up_device_coldplug (device, backend->priv->daemon, G_OBJECT (native));
		if (ret)
			goto out;
		g_object_unref (device);

		/* try to detect a HID UPS */
		device = UP_DEVICE (up_device_hid_new ());
		ret = up_device_coldplug (device, backend->priv->daemon, G_OBJECT (native));
		if (ret)
			goto out;
		g_object_unref (device);

		/* no valid USB object */
		device = NULL;

	} else if (g_strcmp0 (subsys, "input") == 0) {

		/* check input device */
		input = up_input_new ();
		ret = up_input_coldplug (input, backend->priv->daemon, native);
		if (!ret) {
			g_object_unref (input);
			goto out;
		}

		/* we now have a lid */
		up_daemon_set_lid_is_present (backend->priv->daemon, TRUE);

		/* not a power device */
		up_device_list_insert (backend->priv->managed_devices, G_OBJECT (native), G_OBJECT (input));

		/* no valid input object */
		device = NULL;

	} else {
		native_path = g_udev_device_get_sysfs_path (native);
		g_warning ("native path %s (%s) ignoring", native_path, subsys);
	}
out:
	return device;
}

/**
 * up_backend_device_changed:
 **/
static void
up_backend_device_changed (UpBackend *backend, GUdevDevice *native)
{
	GObject *object;
	UpDevice *device;
	gboolean ret;

	/* first, check the device and add it if it doesn't exist */
	object = up_device_list_lookup (backend->priv->device_list, G_OBJECT (native));
	if (object == NULL) {
		g_warning ("treating change event as add on %s", g_udev_device_get_sysfs_path (native));
		up_backend_device_add (backend, native);
		goto out;
	}

	/* need to refresh device */
	device = UP_DEVICE (object);
	ret = up_device_refresh_internal (device);
	if (!ret) {
		g_debug ("no changes on %s", up_device_get_object_path (device));
		goto out;
	}
out:
	if (object != NULL)
		g_object_unref (object);
}

/**
 * up_backend_device_add:
 **/
static gboolean
up_backend_device_add (UpBackend *backend, GUdevDevice *native)
{
	GObject *object;
	UpDevice *device;
	gboolean ret = TRUE;

	/* does device exist in db? */
	object = up_device_list_lookup (backend->priv->device_list, G_OBJECT (native));
	if (object != NULL) {
		device = UP_DEVICE (object);
		/* we already have the device; treat as change event */
		g_warning ("treating add event as change event on %s", up_device_get_object_path (device));
		up_backend_device_changed (backend, native);
		goto out;
	}

	/* get the right sort of device */
	device = up_backend_device_new (backend, native);
	if (device == NULL) {
		ret = FALSE;
		goto out;
	}

	/* emit */
	g_signal_emit (backend, signals[SIGNAL_DEVICE_ADDED], 0, native, device);
out:
	if (object != NULL)
		g_object_unref (object);
	return ret;
}

/**
 * up_backend_device_remove:
 **/
static void
up_backend_device_remove (UpBackend *backend, GUdevDevice *native)
{
	GObject *object;
	UpDevice *device;

	/* does device exist in db? */
	object = up_device_list_lookup (backend->priv->device_list, G_OBJECT (native));
	if (object == NULL) {
		g_debug ("ignoring remove event on %s", g_udev_device_get_sysfs_path (native));
		goto out;
	}

	device = UP_DEVICE (object);
	/* emit */
	g_debug ("emitting device-removed: %s", g_udev_device_get_sysfs_path (native));
	g_signal_emit (backend, signals[SIGNAL_DEVICE_REMOVED], 0, native, device);

out:
	if (object != NULL)
		g_object_unref (object);
}

/**
 * up_backend_uevent_signal_handler_cb:
 **/
static void
up_backend_uevent_signal_handler_cb (GUdevClient *client, const gchar *action,
				      GUdevDevice *device, gpointer user_data)
{
	UpBackend *backend = UP_BACKEND (user_data);

	if (g_strcmp0 (action, "add") == 0) {
		g_debug ("SYSFS add %s", g_udev_device_get_sysfs_path (device));
		up_backend_device_add (backend, device);
	} else if (g_strcmp0 (action, "remove") == 0) {
		g_debug ("SYSFS remove %s", g_udev_device_get_sysfs_path (device));
		up_backend_device_remove (backend, device);
	} else if (g_strcmp0 (action, "change") == 0) {
		g_debug ("SYSFS change %s", g_udev_device_get_sysfs_path (device));
		up_backend_device_changed (backend, device);
	} else {
		g_warning ("unhandled action '%s' on %s", action, g_udev_device_get_sysfs_path (device));
	}
}

/**
 * up_backend_coldplug:
 * @backend: The %UpBackend class instance
 * @daemon: The %UpDaemon controlling instance
 *
 * Finds all the devices already plugged in, and emits device-add signals for
 * each of them.
 *
 * Return value: %TRUE for success
 **/
gboolean
up_backend_coldplug (UpBackend *backend, UpDaemon *daemon)
{
	GUdevDevice *native;
	GList *devices;
	GList *l;
	guint i;
	const gchar *subsystems[] = {"power_supply", "usb", "tty", "input", NULL};

	backend->priv->daemon = g_object_ref (daemon);
	backend->priv->device_list = up_daemon_get_device_list (daemon);
	backend->priv->gudev_client = g_udev_client_new (subsystems);
	g_signal_connect (backend->priv->gudev_client, "uevent",
			  G_CALLBACK (up_backend_uevent_signal_handler_cb), backend);

	/* add all subsystems */
	for (i=0; subsystems[i] != NULL; i++) {
		g_debug ("registering subsystem : %s", subsystems[i]);
		devices = g_udev_client_query_by_subsystem (backend->priv->gudev_client, subsystems[i]);
		for (l = devices; l != NULL; l = l->next) {
			native = l->data;
			up_backend_device_add (backend, native);
		}
		g_list_foreach (devices, (GFunc) g_object_unref, NULL);
		g_list_free (devices);
	}

	return TRUE;
}

/**
 * up_backend_supports_sleep_state:
 *
 * use pm-is-supported to test for supported sleep states
 **/
static gboolean
up_backend_supports_sleep_state (const gchar *state)
{
	gboolean ret = FALSE;
	gchar *command;
	GError *error = NULL;
	gint exit_status;

	/* run script from pm-utils */
	command = g_strdup_printf ("/usr/bin/pm-is-supported --%s", state);
	g_debug ("excuting command: %s", command);
	ret = g_spawn_command_line_sync (command, NULL, NULL, &exit_status, &error);
	if (!ret) {
		g_warning ("failed to run script: %s", error->message);
		g_error_free (error);
		goto out;
	}
	if (WIFEXITED(exit_status) && (WEXITSTATUS(exit_status) == EXIT_SUCCESS))
		ret = TRUE;
out:
	g_free (command);
	return ret;
}

/**
 * up_backend_kernel_can_suspend:
 **/
gboolean
up_backend_kernel_can_suspend (UpBackend *backend)
{
	return up_backend_supports_sleep_state ("suspend");
}

/**
 * up_backend_kernel_can_hibernate:
 **/
gboolean
up_backend_kernel_can_hibernate (UpBackend *backend)
{
	return up_backend_supports_sleep_state ("hibernate");
}

/**
 * up_backend_has_encrypted_swap:
 *
 * user@local:~$ cat /proc/swaps
 * Filename                                Type            Size    Used    Priority
 * /dev/mapper/cryptswap1                  partition       4803392 35872   -1
 *
 * user@local:~$ cat /etc/crypttab
 * # <target name> <source device>         <key file>      <options>
 * cryptswap1 /dev/sda5 /dev/urandom swap,cipher=aes-cbc-essiv:sha256
 *
 * Loop over the swap partitions in /proc/swaps, looking for matches in /etc/crypttab
 **/
gboolean
up_backend_has_encrypted_swap (UpBackend *backend)
{
	gchar *contents_swaps = NULL;
	gchar *contents_crypttab = NULL;
	gchar **lines_swaps = NULL;
	gchar **lines_crypttab = NULL;
	GError *error = NULL;
	gboolean ret;
	gboolean encrypted_swap = FALSE;
	const gchar *filename_swaps = "/proc/swaps";
	const gchar *filename_crypttab = "/etc/crypttab";
	GPtrArray *devices = NULL;
	gchar *device;
	guint i, j;

	/* get swaps data */
	ret = g_file_get_contents (filename_swaps, &contents_swaps, NULL, &error);
	if (!ret) {
		g_warning ("failed to open %s: %s", filename_swaps, error->message);
		g_error_free (error);
		goto out;
	}

	/* get crypttab data */
	ret = g_file_get_contents (filename_crypttab, &contents_crypttab, NULL, &error);
	if (!ret) {
		g_warning ("failed to open %s: %s", filename_crypttab, error->message);
		g_error_free (error);
		goto out;
	}

	/* split both into lines */
	lines_swaps = g_strsplit (contents_swaps, "\n", -1);
	lines_crypttab = g_strsplit (contents_crypttab, "\n", -1);

	/* get valid swap devices */
	devices = g_ptr_array_new_with_free_func (g_free);
	for (i=0; lines_swaps[i] != NULL; i++) {

		/* is a device? */
		if (lines_swaps[i][0] != '/')
			continue;

		/* only look at first parameter */
		g_strdelimit (lines_swaps[i], "\t ", '\0');

		/* add base device to list */
		device = g_path_get_basename (lines_swaps[i]);
		g_debug ("adding swap device: %s", device);
		g_ptr_array_add (devices, device);
	}

	/* no swap devices? */
	if (devices->len == 0) {
		g_debug ("no swap devices");
		goto out;
	}

	/* find matches in crypttab */
	for (i=0; lines_crypttab[i] != NULL; i++) {

		/* ignore invalid lines */
		if (lines_crypttab[i][0] == '#' ||
		    lines_crypttab[i][0] == '\n' ||
		    lines_crypttab[i][0] == '\t' ||
		    lines_crypttab[i][0] == '\0')
			continue;

		/* only look at first parameter */
		g_strdelimit (lines_crypttab[i], "\t ", '\0');

		/* is a swap device? */
		for (j=0; j<devices->len; j++) {
			device = g_ptr_array_index (devices, j);
			if (g_strcmp0 (device, lines_crypttab[i]) == 0) {
				g_debug ("swap device %s is encrypted (so cannot hibernate)", device);
				encrypted_swap = TRUE;
				goto out;
			}
			g_debug ("swap device %s is not encrypted (allows hibernate)", device);
		}
	}

out:
	if (devices != NULL)
		g_ptr_array_unref (devices);
	g_free (contents_swaps);
	g_free (contents_crypttab);
	g_strfreev (lines_swaps);
	g_strfreev (lines_crypttab);
	return encrypted_swap;
}

/**
 * up_backend_get_used_swap:
 *
 * Return value: a percentage value how much of the available swap memory would
 * be taken by currently active memory
 **/
gfloat
up_backend_get_used_swap (UpBackend *backend)
{
	gchar *contents = NULL;
	gchar **lines = NULL;
	GError *error = NULL;
	gchar **tokens;
	gboolean ret;
	guint active = 0;
	guint swap_free = 0;
	guint swap_total = 0;
	guint len;
	guint i;
	gfloat percentage = 0.0f;
	const gchar *filename = "/proc/meminfo";

	/* get memory data */
	ret = g_file_get_contents (filename, &contents, NULL, &error);
	if (!ret) {
		g_warning ("failed to open %s: %s", filename, error->message);
		g_error_free (error);
		goto out;
	}

	/* process each line */
	lines = g_strsplit (contents, "\n", -1);
	for (i=1; lines[i] != NULL; i++) {
		tokens = g_strsplit_set (lines[i], ": ", -1);
		len = g_strv_length (tokens);
		if (len > 3) {
			if (g_strcmp0 (tokens[0], "SwapFree") == 0)
				swap_free = atoi (tokens[len-2]);
			if (g_strcmp0 (tokens[0], "SwapTotal") == 0)
				swap_total = atoi (tokens[len-2]);
			else if (g_strcmp0 (tokens[0], "Active(anon)") == 0)
				active = atoi (tokens[len-2]);
		}
		g_strfreev (tokens);
	}

	/* first check if we even have swap, if not consider all swap space used */
	if (swap_total == 0) {
		g_debug ("no swap space found");
		percentage = 100.0f;
		goto out;
	}

	/* work out how close to the line we are */
	if (swap_free > 0 && active > 0)
		percentage = (active * 100) / swap_free;
	g_debug ("total swap available %i kb, active memory %i kb (%.1f%%)", swap_free, active, percentage);
out:
	g_free (contents);
	g_strfreev (lines);
	return percentage;
}

/**
 * up_backend_get_suspend_command:
 **/
const gchar *
up_backend_get_suspend_command (UpBackend *backend)
{
	return UP_BACKEND_SUSPEND_COMMAND;
}

/**
 * up_backend_get_hibernate_command:
 **/
const gchar *
up_backend_get_hibernate_command (UpBackend *backend)
{
	return UP_BACKEND_HIBERNATE_COMMAND;
}

/**
 * up_backend_get_powersave_command:
 **/
const gchar *
up_backend_get_powersave_command (UpBackend *backend, gboolean powersave)
{
	if (powersave)
		return UP_BACKEND_POWERSAVE_TRUE_COMMAND;
	return UP_BACKEND_POWERSAVE_FALSE_COMMAND;
}

/**
 * up_backend_class_init:
 * @klass: The UpBackendClass
 **/
static void
up_backend_class_init (UpBackendClass *klass)
{
	GObjectClass *object_class = G_OBJECT_CLASS (klass);
	object_class->finalize = up_backend_finalize;

	signals [SIGNAL_DEVICE_ADDED] =
		g_signal_new ("device-added",
			      G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (UpBackendClass, device_added),
			      NULL, NULL, up_marshal_VOID__POINTER_POINTER,
			      G_TYPE_NONE, 2, G_TYPE_POINTER, G_TYPE_POINTER);
	signals [SIGNAL_DEVICE_REMOVED] =
		g_signal_new ("device-removed",
			      G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (UpBackendClass, device_removed),
			      NULL, NULL, up_marshal_VOID__POINTER_POINTER,
			      G_TYPE_NONE, 2, G_TYPE_POINTER, G_TYPE_POINTER);

	g_type_class_add_private (klass, sizeof (UpBackendPrivate));
}

/**
 * up_backend_init:
 **/
static void
up_backend_init (UpBackend *backend)
{
	backend->priv = UP_BACKEND_GET_PRIVATE (backend);
	backend->priv->daemon = NULL;
	backend->priv->device_list = NULL;
	backend->priv->managed_devices = up_device_list_new ();
}

/**
 * up_backend_finalize:
 **/
static void
up_backend_finalize (GObject *object)
{
	UpBackend *backend;

	g_return_if_fail (UP_IS_BACKEND (object));

	backend = UP_BACKEND (object);

	if (backend->priv->daemon != NULL)
		g_object_unref (backend->priv->daemon);
	if (backend->priv->device_list != NULL)
		g_object_unref (backend->priv->device_list);
	if (backend->priv->gudev_client != NULL)
		g_object_unref (backend->priv->gudev_client);

	g_object_unref (backend->priv->managed_devices);

	G_OBJECT_CLASS (up_backend_parent_class)->finalize (object);
}

/**
 * up_backend_new:
 *
 * Return value: a new %UpBackend object.
 **/
UpBackend *
up_backend_new (void)
{
	UpBackend *backend;
	backend = g_object_new (UP_TYPE_BACKEND, NULL);
	return UP_BACKEND (backend);
}

