/**
  @file usb_moded-appsync.c

  Copyright (C) 2010 Nokia Corporation. All rights reserved.
  Copyright (C) 2013-2016 Jolla Ltd.

  @author: Philippe De Swert <philippe.de-swert@nokia.com>
  @author: Philippe De Swert <philippe.deswert@jollamobile.com>
  @author: Simo Piiroinen <simo.piiroinen@jollamobile.com>

  This program is free software; you can redistribute it and/or
  modify it under the terms of the Lesser GNU General Public License
  version 2 as published by the Free Software Foundation.

  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 Lesser GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  02110-1301 USA
*/

#define _GNU_SOURCE

#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/time.h>

#include <glib.h>
#include <glib/gstdio.h>

#include "usb_moded-appsync.h"
#include "usb_moded-appsync-dbus.h"
#include "usb_moded-appsync-dbus-private.h"
#include "usb_moded-modesetting.h"
#include "usb_moded-log.h"
#include "usb_moded-systemd.h"

static struct list_elem *read_file(const gchar *filename, int diag);
static void enumerate_usb(void);
static gboolean enumerate_usb_cb(gpointer data);
static void start_enumerate_usb_timer(void);
static void cancel_enumerate_usb_timer(void);

static GList *sync_list = NULL;

static guint enumerate_usb_id = 0;
static struct timeval sync_tv;
#ifdef APP_SYNC_DBUS
static  int no_dbus = 0;
#else
static  int no_dbus = 0;
#endif /* APP_SYNC_DBUS */


static void free_elem(struct list_elem *elem)
{
  g_free(elem->name);
  g_free(elem->launch);
  g_free(elem->mode);
  free(elem);
}

static void free_elem_cb(gpointer elem, gpointer user_data)
{
  (void)user_data;
  free_elem(elem);
}

void free_appsync_list(void)
{
  if( sync_list != 0 )
  {
    /*g_list_free_full(sync_list, free_elem); */
    g_list_foreach (sync_list, free_elem_cb, NULL);
    g_list_free (sync_list);
    sync_list = 0;
    log_debug("Appsync list freed\n");
  }
}

static gint list_sort_func(gconstpointer a, gconstpointer b)
{ 
  return strcasecmp( (char*)a, (char*)b ); 
}

void readlist(int diag)
{
  GDir *confdir = 0;

  const gchar *dirname;
  struct list_elem *list_item;

  free_appsync_list();

  if(diag)
  {
    if( !(confdir = g_dir_open(CONF_DIR_DIAG_PATH, 0, NULL)) )
	goto cleanup;
  }
  else
  {
    if( !(confdir = g_dir_open(CONF_DIR_PATH, 0, NULL)) )
	goto cleanup;
  }

  while( (dirname = g_dir_read_name(confdir)) )
  {
    log_debug("Read file %s\n", dirname);
    if( (list_item = read_file(dirname, diag)) )
      sync_list = g_list_append(sync_list, list_item);
  }

cleanup:
  if( confdir ) g_dir_close(confdir);

  /* sort list alphabetically so services for a mode
     can be run in a certain order */
  sync_list=g_list_sort(sync_list, list_sort_func);

  /* set up session bus connection if app sync in use
   * so we do not need to make the time consuming connect
   * operation at enumeration time ... */

  if( sync_list )
  {
    log_debug("Sync list valid\n");
#ifdef APP_SYN_DBUS
    usb_moded_app_sync_init_connection();
#endif
  }
}

static struct list_elem *read_file(const gchar *filename, int diag)
{
  gchar *full_filename = NULL;
  GKeyFile *settingsfile = NULL;
  struct list_elem *list_item = NULL;

  if(diag)
  {
    if( !(full_filename = g_strconcat(CONF_DIR_DIAG_PATH, "/", filename, NULL)) )
	goto cleanup;
  }
  else
  {
    if( !(full_filename = g_strconcat(CONF_DIR_PATH, "/", filename, NULL)) )
	goto cleanup;
  }

  if( !(settingsfile = g_key_file_new()) )
    goto cleanup;

  if( !g_key_file_load_from_file(settingsfile, full_filename, G_KEY_FILE_NONE, NULL) )
    goto cleanup;

  if( !(list_item = calloc(1, sizeof *list_item)) )
    goto cleanup;

  list_item->name = g_key_file_get_string(settingsfile, APP_INFO_ENTRY, APP_INFO_NAME_KEY, NULL);
  log_debug("Appname = %s\n", list_item->name);
  list_item->launch = g_key_file_get_string(settingsfile, APP_INFO_ENTRY, APP_INFO_LAUNCH_KEY, NULL);
  log_debug("Launch = %s\n", list_item->launch);
  list_item->mode = g_key_file_get_string(settingsfile, APP_INFO_ENTRY, APP_INFO_MODE_KEY, NULL);
  log_debug("Launch mode = %s\n", list_item->mode);
  list_item->systemd = g_key_file_get_integer(settingsfile, APP_INFO_ENTRY, APP_INFO_SYSTEMD_KEY, NULL);
  log_debug("Systemd control = %d\n", list_item->systemd);
  list_item->post = g_key_file_get_integer(settingsfile, APP_INFO_ENTRY, APP_INFO_POST, NULL);
  list_item->state = APP_STATE_DONTCARE;

cleanup:

  if(settingsfile) 
	g_key_file_free(settingsfile);
  g_free(full_filename);

  /* if a minimum set of required elements is not filled in we discard the list_item */
  if( list_item && !(list_item->name && list_item->mode) )
  {
    log_debug("Element invalid, discarding\n");
    free_elem(list_item); 
    list_item = 0;
  }

  return list_item;
}

/* @return 0 on succes, 1 if there is a failure */
int activate_sync(const char *mode)
{
  GList *iter;
  int count = 0;

  log_debug("activate sync");

  /* Get start of activation timestamp */
  gettimeofday(&sync_tv, 0);

  if( sync_list == 0 )
  {
    log_debug("No sync list! Enumerating\n");
    enumerate_usb();
    return 0;
  }

  /* Count apps that need to be activated for this mode and
   * mark them as currently inactive */
  for( iter = sync_list; iter; iter = g_list_next(iter) )
  {
    struct list_elem *data = iter->data;

    if(!strcmp(data->mode, mode))
    {
      ++count;
      data->state = APP_STATE_INACTIVE;
    }
    else
    {
      data->state = APP_STATE_DONTCARE;
    }
  }

  /* If there is nothing to activate, enumerate immediately */
  if(count <= 0)
  {
      log_debug("Nothing to launch.\n");
      enumerate_usb();
      return(0);
   }

#ifdef APP_SYNC_DBUS
  /* check dbus initialisation, skip dbus activated services if this fails */
  if(!usb_moded_app_sync_init())
  {
      log_debug("dbus setup failed => skipping dbus launched apps \n");
      no_dbus = 1;
   }
#endif /* APP_SYNC_DBUS */

  /* start timer */
  start_enumerate_usb_timer();

  /* go through list and launch apps */
  for( iter = sync_list; iter; iter = g_list_next(iter) )
  {
    struct list_elem *data = iter->data;
    if(!strcmp(mode, data->mode))
    {
      /* do not launch items marked as post, will be launched after usb is up */
      if(data->post)
      {
	continue;
      }
      log_debug("launching pre-enum-app %s\n", data->name);
      if(data->systemd)
      {
        if(!systemd_control_service(data->name, SYSTEMD_START))
		goto error;
	mark_active(data->name, 0);
      }
      else if(data->launch)
      {
		/* skipping if dbus session bus is not available,
		   or not compiled in */
		if(no_dbus)
			mark_active(data->name, 0);
#ifdef APP_SYNC_DBUS
		else
			if(!usb_moded_dbus_app_launch(data->launch))
				mark_active(data->name, 0);
			else
				goto error;
#endif /* APP_SYNC_DBUS */
      }
    }
  }

  return(0);

error:
  log_warning("Error launching a service!\n");
  return(1);
}

int activate_sync_post(const char *mode)
{
  GList *iter;

  log_debug("activate post sync");

  if( sync_list == 0 )
  {
    log_debug("No sync list! skipping post sync\n");
    return 0;
  }

#ifdef APP_SYNC_DBUS
  /* check dbus initialisation, skip dbus activated services if this fails */
  if(!usb_moded_app_sync_init())
  {
      log_debug("dbus setup failed => skipping dbus launched apps \n");
      no_dbus = 1;
   }
#endif /* APP_SYNC_DBUS */

  /* go through list and launch apps */
  for( iter = sync_list; iter; iter = g_list_next(iter) )
  {
    struct list_elem *data = iter->data;
    if(!strcmp(mode, data->mode))
    {
      /* launch only items marked as post, others are already running */
      if(!data->post)
	continue;
      log_debug("launching post-enum-app %s\n", data->name);
      if(data->systemd)
      {
        if(!systemd_control_service(data->name, SYSTEMD_START))
		goto error;
	mark_active(data->name, 1);
      }
      else if(data->launch)
      {
		/* skipping if dbus session bus is not available,
		   or not compiled in */
		if(no_dbus)
			continue;
#ifdef APP_SYNC_DBUS
		else
			if(usb_moded_dbus_app_launch(data->launch) != 0)
				goto error;
#endif /* APP_SYNC_DBUS */
      }
    }
  }

  return(0);

error:
  log_warning("Error launching a service!\n");
  return(1);
}

int mark_active(const gchar *name, int post)
{
  int ret = -1; // assume name not found
  int missing = 0;

  GList *iter;

  log_debug("%s-enum-app %s is started\n", post ? "post" : "pre", name);

  for( iter = sync_list; iter; iter = g_list_next(iter) )
  {
    struct list_elem *data = iter->data;

    if(!strcmp(data->name, name))
    {
      /* TODO: do we need to worry about duplicate names in the list? */
      ret = (data->state != APP_STATE_ACTIVE);
      data->state = APP_STATE_ACTIVE;

      /* updated + missing -> not going to enumerate */
      if( missing ) break;
    }
    else if( data->state == APP_STATE_INACTIVE && data->post == post )
    {
      missing = 1;

      /* updated + missing -> not going to enumerate */
      if( ret != -1 ) break;
    }
  }
  if( !post && !missing )
  {
    log_debug("All pre-enum-apps active. Let's enumerate\n");
    enumerate_usb();
  }
  
  /* -1=not found, 0=already active, 1=activated now */
  return ret; 
}

static gboolean enumerate_usb_cb(gpointer data)
{
  (void)data;
  enumerate_usb_id = 0;
  log_debug("handling enumeration timeout");
  enumerate_usb();
  /* return false to stop the timer from repeating */
  return FALSE;
}

static void start_enumerate_usb_timer(void)
{
  log_debug("scheduling enumeration timeout");
  if( enumerate_usb_id )
    g_source_remove(enumerate_usb_id), enumerate_usb_id = 0;
  enumerate_usb_id = g_timeout_add_seconds(2, enumerate_usb_cb, NULL);
}

static void cancel_enumerate_usb_timer(void)
{
  if( enumerate_usb_id )
  {
    log_debug("canceling enumeration timeout");
    g_source_remove(enumerate_usb_id), enumerate_usb_id = 0;
  }
}

static void enumerate_usb(void)
{
  struct timeval tv;

  /* Stop the timer in case of explicit enumeration call */
  cancel_enumerate_usb_timer();

  /* Debug: how long it took from sync start to get here */
  gettimeofday(&tv, 0);
  timersub(&tv, &sync_tv, &tv);
  log_debug("sync to enum: %.3f seconds", tv.tv_sec + tv.tv_usec * 1e-6);

#ifdef APP_SYNC_DBUS
  /* remove dbus service */
  usb_moded_appsync_cleanup();
#endif /* APP_SYNC_DBUS */
}

static void appsync_stop_apps(int post)
{
  GList *iter = 0;

  for( iter = sync_list; iter; iter = g_list_next(iter) )
  {
    struct list_elem *data = iter->data;

    if(data->systemd && data->state == APP_STATE_ACTIVE && data->post == post)
    {
      log_debug("stopping %s-enum-app %s", post ? "post" : "pre", data->name);
        if(!systemd_control_service(data->name, SYSTEMD_STOP))
		log_debug("Failed to stop %s\n", data->name);
      data->state = APP_STATE_DONTCARE;
    }
  }
}

int appsync_stop(gboolean force)
{
  /* If force arg is used, stop all applications that
   * could have been started by usb-moded */
  if(force)
  {
    GList *iter;
    log_debug("assuming all applications are active");

    for( iter = sync_list; iter; iter = g_list_next(iter) )
    {
      struct list_elem *data = iter->data;
      data->state = APP_STATE_ACTIVE;
    }
  }

  /* Stop post-apps 1st */
  appsync_stop_apps(1);

  /* Then pre-apps */
  appsync_stop_apps(0);

  /* Do not leave active timers behind */
  cancel_enumerate_usb_timer();
  return(0);
}