/**
  @file usb_moded-config.c
 
  Copyright (C) 2010 Nokia Corporation. All rights reserved.
  Copyright (C) 2012-2015 Jolla. All rights reserved.

  @author: Philippe De Swert <philippe.de-swert@nokia.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
*/

#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>

#include <sys/stat.h>
#include <sys/types.h>

#include <glib.h>
/*
#include <glib/gkeyfile.h>
#include <glib/gstdio.h>
*/
#include "usb_moded.h"
#include "usb_moded-config.h"
#include "usb_moded-config-private.h"
#include "usb_moded-log.h"
#include "usb_moded-modes.h"

static int get_conf_int(const gchar *entry, const gchar *key);
static char * get_conf_string(const gchar *entry, const gchar *key);
static char * get_kcmdline_string(const char *entry);

static int validate_ip(const char *ipadd)
{
  unsigned int b1, b2, b3, b4;
  unsigned char c;

  if (sscanf(ipadd, "%3u.%3u.%3u.%3u%c", &b1, &b2, &b3, &b4, &c) != 4)
        return(-1);

  if ((b1 | b2 | b3 | b4) > 255)
        return(-1);
  if (strspn(ipadd, "0123456789.") < strlen(ipadd))
        return(-1);
  /* all ok */
  return 0;
}

const char *find_mounts(void)
{
  
  const char *ret = NULL;

  ret = get_conf_string(FS_MOUNT_ENTRY, FS_MOUNT_KEY);
  if(ret == NULL)
  {
      ret = g_strdup(FS_MOUNT_DEFAULT);	  
      log_debug("Default mount = %s\n", ret);
  }
  return(ret);
}

int find_sync(void)
{

  return(get_conf_int(FS_SYNC_ENTRY, FS_SYNC_KEY));
}

const char * find_alt_mount(void)
{
  return(get_conf_string(ALT_MOUNT_ENTRY, ALT_MOUNT_KEY));
}

char * find_udev_path(void)
{
  return(get_conf_string(UDEV_PATH_ENTRY, UDEV_PATH_KEY));
}

char * find_udev_subsystem(void)
{
  return(get_conf_string(UDEV_PATH_ENTRY, UDEV_SUBSYSTEM_KEY));
}

char * check_trigger(void)
{
  return(get_conf_string(TRIGGER_ENTRY, TRIGGER_PATH_KEY));
}

char * get_trigger_subsystem(void)
{
  return(get_conf_string(TRIGGER_ENTRY, TRIGGER_UDEV_SUBSYSTEM));
}

char * get_trigger_mode(void)
{
  return(get_conf_string(TRIGGER_ENTRY, TRIGGER_MODE_KEY));
}

char * get_trigger_property(void)
{
  return(get_conf_string(TRIGGER_ENTRY, TRIGGER_PROPERTY_KEY));
}

char * get_trigger_value(void)
{
  return(get_conf_string(TRIGGER_ENTRY, TRIGGER_PROPERTY_VALUE_KEY));
}

static char * get_network_ip(void)
{
  char * ip = get_kcmdline_string(NETWORK_IP_KEY);
  if (ip != NULL)
    if(!validate_ip(ip))
	return(ip);

  return(get_conf_string(NETWORK_ENTRY, NETWORK_IP_KEY));
}

static char * get_network_interface(void)
{
  return(get_conf_string(NETWORK_ENTRY, NETWORK_INTERFACE_KEY));
}

static char * get_network_gateway(void)
{
  char * gw = get_kcmdline_string(NETWORK_GATEWAY_KEY);
  if (gw != NULL)
    return(gw);

  return(get_conf_string(NETWORK_ENTRY, NETWORK_GATEWAY_KEY));
}

static char * get_network_netmask(void)
{
  char * netmask = get_kcmdline_string(NETWORK_NETMASK_KEY);
  if (netmask != NULL)
    return(netmask);

  return(get_conf_string(NETWORK_ENTRY, NETWORK_NETMASK_KEY));
}

static char * get_network_nat_interface(void)
{
  return(get_conf_string(NETWORK_ENTRY, NETWORK_NAT_INTERFACE_KEY));
}

/* create basic conffile with sensible defaults */
static void create_conf_file(void)
{
  GKeyFile *settingsfile;
  gchar *keyfile;
  int dir = 1;
  struct stat dir_stat;

  /* since this function can also be called when the dir exists we only create
     it if it is missing */
  if(stat(CONFIG_FILE_DIR, &dir_stat))
  {
	dir = mkdir(CONFIG_FILE_DIR, 0755);
	if(dir < 0)
	{
		log_warning("Could not create confdir, continuing without configuration!\n");
		/* no point in trying to generate the config file if the dir cannot be created */
		return;
	}
  }

  settingsfile = g_key_file_new();

  g_key_file_set_string(settingsfile, MODE_SETTING_ENTRY, MODE_SETTING_KEY, MODE_DEVELOPER );
  keyfile = g_key_file_to_data (settingsfile, NULL, NULL);
  if(g_file_set_contents(FS_MOUNT_CONFIG_FILE, keyfile, -1, NULL) == 0)
	log_debug("Conffile creation failed. Continuing without configuration!\n");
  free(keyfile);
  g_key_file_free(settingsfile);
}

static int get_conf_int(const gchar *entry, const gchar *key)
{
  GKeyFile *settingsfile;
  gboolean test = FALSE;
  gchar **keys, **origkeys;
  int ret = 0;

  settingsfile = g_key_file_new();
  test = g_key_file_load_from_file(settingsfile, FS_MOUNT_CONFIG_FILE, G_KEY_FILE_NONE, NULL);
  if(!test)
  {
      log_debug("no conffile, Creating\n");
      create_conf_file();
  }
  keys = g_key_file_get_keys (settingsfile, entry, NULL, NULL);
  if(keys == NULL)
        return ret;
  origkeys = keys;
  while (*keys != NULL)
  {
        if(!strcmp(*keys, key))
        {
                ret = g_key_file_get_integer(settingsfile, entry, *keys, NULL);
                log_debug("%s key value  = %d\n", key, ret);
        }
        keys++;
  }
  g_strfreev(origkeys);
  g_key_file_free(settingsfile);
  return(ret);

}

static char * get_conf_string(const gchar *entry, const gchar *key)
{
  GKeyFile *settingsfile;
  gboolean test = FALSE;
  gchar **keys, **origkeys, *tmp_char = NULL;
  settingsfile = g_key_file_new();
  test = g_key_file_load_from_file(settingsfile, FS_MOUNT_CONFIG_FILE, G_KEY_FILE_NONE, NULL);
  if(!test)
  {
      log_debug("No conffile. Creating\n");
      create_conf_file();
      /* should succeed now */
      g_key_file_load_from_file(settingsfile, FS_MOUNT_CONFIG_FILE, G_KEY_FILE_NONE, NULL);
  }
  keys = g_key_file_get_keys (settingsfile, entry, NULL, NULL);
  if(keys == NULL)
        goto end;
  origkeys = keys;
  while (*keys != NULL)
  {
        if(!strcmp(*keys, key))
        {
                tmp_char = g_key_file_get_string(settingsfile, entry, *keys, NULL);
                if(tmp_char)
                {
                        log_debug("key %s value  = %s\n", key, tmp_char);
                }
        }
        keys++;
  }
  g_strfreev(origkeys);
end:
  g_key_file_free(settingsfile);
  return(tmp_char);

}

static char * get_kcmdline_string(const char *entry)
{
  int fd;
  char cmdLine[1024];
  char *ret = NULL;
  int len;
  gint argc = 0;
  gchar **argv = NULL;
  gchar **arg_tokens = NULL, **network_tokens = NULL;
  GError *optErr = NULL;
  int i;

  if ((fd = open("/proc/cmdline", O_RDONLY)) < 0)
  {
    log_debug("could not read /proc/cmdline");
    return(ret);
  }

  len = read(fd, cmdLine, sizeof(cmdLine) - 1);
  close(fd);

  if (len <= 0)
  {
    log_debug("kernel command line was empty");
    return(ret);
  }

  cmdLine[len] = '\0';

  /* we're looking for a piece of the kernel command line matching this:
    ip=192.168.3.100::192.168.3.1:255.255.255.0::usb0:on */
  if (!g_shell_parse_argv(cmdLine, &argc, &argv, &optErr)) 
  {
    g_error_free(optErr);
    return(ret);
  }

  /* find the ip token */
  for (i=0; i < argc; i++) 
  {
    arg_tokens = g_strsplit(argv[i], "=", 2);
    if (!g_ascii_strcasecmp(arg_tokens[0], "usb_moded_ip"))
    {
      network_tokens = g_strsplit(arg_tokens[1], ":", 7);
      /* check if it is for the usb or rndis interface */
      if(g_strrstr(network_tokens[5], "usb")|| (g_strrstr(network_tokens[5], "rndis")))
      {
	if(!strcmp(entry, NETWORK_IP_KEY))
	{
		ret = g_strdup(network_tokens[0]);
		log_debug("Command line ip = %s\n", ret);
	}
	if(!strcmp(entry, NETWORK_GATEWAY_KEY))
	{
		/* gateway might be empty, so we do not want to return an empty string */
		if(strlen(network_tokens[2]) > 2)
		{
		  ret = g_strdup(network_tokens[2]);
		  log_debug("Command line gateway = %s\n", ret);
		}
	}
	if(!strcmp(entry, NETWORK_NETMASK_KEY))
	{
		ret = g_strdup(network_tokens[3]);
		log_debug("Command line netmask = %s\n", ret);
	}
      } 
    }
    g_strfreev(arg_tokens);
  }
  g_strfreev(argv);
  g_strfreev(network_tokens);

  return(ret);
}

char * get_mode_setting(void)
{
  char * mode = get_kcmdline_string(MODE_SETTING_KEY);
  if (mode != NULL)
    return(mode);

  return(get_conf_string(MODE_SETTING_ENTRY, MODE_SETTING_KEY));
}
/*
 *  @param settingsfile: already opened settingsfile we want to read an entry from
 *  @param entry: entry we want to read
 *  @param key: key value of the entry we want to read
 *  @new_value: potentially new value we want to compare against
 *
 *  @return: 1 when the old value is the same as the new one, 0 otherwise
 */
int config_value_changed(GKeyFile *settingsfile, const char *entry, const char *key, const char *new_value)
{
  char *old = g_key_file_get_string(settingsfile, entry, key, NULL);
  if (old)
  {
	gboolean unchanged = (g_strcmp0(old, entry) == 0);
        g_free(old);
        if (unchanged)
        {
                return 1;
        }
  }
	
  return 0;
}

set_config_result_t set_config_setting(const char *entry, const char *key, const char *value)
{
  GKeyFile *settingsfile;
  gboolean test = FALSE;
  set_config_result_t ret = SET_CONFIG_ERROR;
  gchar *keyfile;

  settingsfile = g_key_file_new();
  test = g_key_file_load_from_file(settingsfile, FS_MOUNT_CONFIG_FILE, G_KEY_FILE_NONE, NULL);
  if(test)
  {
      if(config_value_changed(settingsfile, entry, key, value))
      {
              g_key_file_free(settingsfile);
              return SET_CONFIG_UNCHANGED;
      }
  }
  else
  {
      log_debug("No conffile. Creating.\n");
      create_conf_file();
  }

  g_key_file_set_string(settingsfile, entry, key, value);
  keyfile = g_key_file_to_data (settingsfile, NULL, NULL); 
  /* free the settingsfile before writing things out to be sure 
     the contents will be correctly written to file afterwards.
     Just a precaution. */
  g_key_file_free(settingsfile);
  if (g_file_set_contents(FS_MOUNT_CONFIG_FILE, keyfile, -1, NULL))
      ret = SET_CONFIG_UPDATED;
  g_free(keyfile);
  
  return (ret);
}

set_config_result_t set_mode_setting(const char *mode)
{
  return (set_config_setting(MODE_SETTING_ENTRY, MODE_SETTING_KEY, mode));
}

/* Builds the string used for hidden modes, when hide set to one builds the
   new string of hidden modes when adding one, otherwise it will remove one */
static const char * make_hidden_modes_string(const char *hidden, int hide)
{
  GString *modelist_str;
  char *hidden_modes_list;
  gchar **hidden_mode_split;
  int i;


  hidden_modes_list = get_hidden_modes();
  if(hidden_modes_list)
  {
    hidden_mode_split = g_strsplit(hidden_modes_list, ",", 0);
  }
  else
  {
    /* no hidden modes yet. So just return the original string */
    return hidden;
  }

  modelist_str = g_string_new(NULL);

  for(i = 0; hidden_mode_split[i] != NULL; i++)
  {
     if(strlen(hidden_mode_split[i]) == 0)
       continue;
     if(!strcmp(hidden_mode_split[i], hidden))
     {
	/* if hiding a mode that is already hidden do nothing */
	if(hide)
		return(NULL);
        if(!hide)
        	continue;
     }
     if(strlen(modelist_str->str) != 0)
       modelist_str = g_string_append(modelist_str, ",");
     modelist_str = g_string_append(modelist_str, hidden_mode_split[i]);
  }
  if(hide)
  {
     if(strlen(modelist_str->str) != 0)
       modelist_str = g_string_append(modelist_str, ",");
     modelist_str = g_string_append(modelist_str, hidden);
  }
  
  g_strfreev(hidden_mode_split);
  return(g_string_free(modelist_str, FALSE));
}

set_config_result_t set_hide_mode_setting(const char *mode)
{
  set_config_result_t ret;

  ret = set_config_setting(MODE_SETTING_ENTRY, MODE_HIDE_KEY, make_hidden_modes_string(mode, 1));
  if(ret == SET_CONFIG_UPDATED) {
      send_hidden_modes_signal();
      send_supported_modes_signal();
  }
  return(ret);
}

set_config_result_t set_unhide_mode_setting(const char *mode)
{
  set_config_result_t ret;

  ret = set_config_setting(MODE_SETTING_ENTRY, MODE_HIDE_KEY, make_hidden_modes_string(mode, 0));
  if(ret == SET_CONFIG_UPDATED) {
      send_hidden_modes_signal();
      send_supported_modes_signal();
  }
  return(ret);
}

/*
 * @param config : the key to be set
 * @param setting : The value to be set
 */
set_config_result_t set_network_setting(const char *config, const char *setting)
{
  GKeyFile *settingsfile;
  gboolean test = FALSE;
  gchar *keyfile;

  if(!strcmp(config, NETWORK_IP_KEY) || !strcmp(config, NETWORK_GATEWAY_KEY))
	if(validate_ip(setting) != 0)
		return SET_CONFIG_ERROR;

  settingsfile = g_key_file_new();
  test = g_key_file_load_from_file(settingsfile, FS_MOUNT_CONFIG_FILE, G_KEY_FILE_NONE, NULL);

  if(!strcmp(config, NETWORK_IP_KEY) || !strcmp(config, NETWORK_INTERFACE_KEY) || !strcmp(config, NETWORK_GATEWAY_KEY))
  {
	set_config_result_t ret = SET_CONFIG_ERROR;
	if (test)
	{
		if(config_value_changed(settingsfile, NETWORK_ENTRY, config, setting))
		{
			g_key_file_free(settingsfile);
			return SET_CONFIG_UNCHANGED;
		}
	}
	else
	{
		log_debug("No conffile. Creating.\n");
		create_conf_file();
	}

	g_key_file_set_string(settingsfile, NETWORK_ENTRY, config, setting);
  	keyfile = g_key_file_to_data (settingsfile, NULL, NULL); 
  	/* free the settingsfile before writing things out to be sure 
     	the contents will be correctly written to file afterwards.
     	Just a precaution. */
  	g_key_file_free(settingsfile);
	if (g_file_set_contents(FS_MOUNT_CONFIG_FILE, keyfile, -1, NULL))
		ret = SET_CONFIG_UPDATED;
	free(keyfile);
	return ret;
  }
  else
  {
	g_key_file_free(settingsfile);
	return SET_CONFIG_ERROR;
  }
}

char * get_network_setting(const char *config)
{
  char * ret = 0;
  struct mode_list_elem *data;

  if(!strcmp(config, NETWORK_IP_KEY))
  {
	ret = get_network_ip();
	if(!ret)
		ret = strdup("192.168.2.15");
  }
  else if(!strcmp(config, NETWORK_INTERFACE_KEY))
  {

	/* check main configuration before using
	the information from the specific mode */
	ret = get_network_interface();

	if(ret)
		goto end;
	/* no interface override specified, let's use the one
	from the mode config */
	data = get_usb_mode_data();
	if(data)
	{
		if(data->network_interface)
		{
			ret = strdup(data->network_interface);
			goto end;
		}
	}
	ret = strdup("usb0");
  }
  else if(!strcmp(config, NETWORK_GATEWAY_KEY))
	return(get_network_gateway());
  else if(!strcmp(config, NETWORK_NETMASK_KEY))
  {
	ret = get_network_netmask();
	if(!ret)
		ret = strdup("255.255.255.0");
  }
  else if(!strcmp(config, NETWORK_NAT_INTERFACE_KEY))
	return(get_network_nat_interface());
  else
	/* no matching keys, return error */
	return(NULL);
end:
   return(ret);
}

int conf_file_merge(void)
{
  GDir *confdir;
  struct stat fileinfo, dir;
  char *mode = 0, *ip = 0, *gateway = 0, *udev = 0, *hide = 0;
  gchar *filename_full;
  const gchar *filename;
  GString *keyfile_string = NULL;
  GKeyFile *settingsfile;
  int ret = 0, test = 0, conffile_created = 0;

  confdir = g_dir_open(CONFIG_FILE_DIR, 0, NULL);
  if(!confdir)
  {
      log_debug("No configuration. Creating defaults.\n");
      create_conf_file();
      /* since there was no configuration at all there is no info to be merged */
      return (ret);
  }

  if (stat(FS_MOUNT_CONFIG_FILE, &fileinfo) == -1) 
  {
	/* conf file not created yet, make default and merge all */
      	create_conf_file();
	conffile_created = 1;
  }

  /* config file is created, so the dir must exists */
  if(stat(CONFIG_FILE_DIR, &dir))
  {
	log_warning("Directory still does not exists. FS might be ro/corrupted!\n");
	ret = 1;
	goto end;
  }

  /* st_mtime is changed by file modifications, st_mtime of a directory is changed by the creation or deletion of files in that directory.
  So if the st_mtime of the config file is equal to the directory time we can be sure the config is untouched and we do not need 
  to re-merge the config.
  */
  if(fileinfo.st_mtime == dir.st_mtime)
  {
	/* if a conffile was created, the st_mtime would have been updated so this check will miss information that might be there already,
	   like after a config file removal for example. So we run a merge anyway if we needed to create the conf file */
	if(!conffile_created)
		goto end;
  }
  log_debug("Merging/creating configuration.\n");
  keyfile_string = g_string_new(NULL);
  /* check each ini file and get contents */
  while((filename = g_dir_read_name(confdir)) != NULL)
  {
	if(!strstr(filename, ".ini"))
	{
		/* skip this file as it might be a dir or not an ini file */
		continue;
	}
	filename_full = g_strconcat(CONFIG_FILE_DIR, "/", filename, NULL);
	log_debug("filename = %s\n", filename_full);
	if(!strcmp(filename_full, FS_MOUNT_CONFIG_FILE))
	{
		/* store mode info to add it later as we want to keep it */
		mode = get_mode_setting();
		/* store udev path (especially important for the upgrade path */
		udev = find_udev_path();
		/* store network info */
		ip = get_conf_string(NETWORK_ENTRY, NETWORK_IP_KEY);
		gateway = get_conf_string(NETWORK_ENTRY, NETWORK_GATEWAY_KEY);
		/* store hidden modes */
		hide = get_hidden_modes();
		continue;
	}
	/* load contents of file, if it fails skip to next one */
	settingsfile = g_key_file_new();
 	test = g_key_file_load_from_file(settingsfile, filename_full, G_KEY_FILE_KEEP_COMMENTS, NULL);
	if(!test)
	{
		log_debug("%d failed loading config file %s\n", test, filename_full);
		goto next;
	}
        log_debug("file data = %s\n", g_key_file_to_data(settingsfile, NULL, NULL));
	keyfile_string = g_string_append(keyfile_string, g_key_file_to_data(settingsfile, NULL, NULL));
	log_debug("keyfile_string = %s\n", keyfile_string->str);
  	g_key_file_free(settingsfile);

next:	
	g_free(filename_full);
  }

  if(keyfile_string)
  {
	/* write out merged config file */
  	/* g_file_set_contents returns 1 on succes, this function returns 0 */
  	ret = !g_file_set_contents(FS_MOUNT_CONFIG_FILE, keyfile_string->str, -1, NULL);
	g_string_free(keyfile_string, TRUE);
	if(mode)
	{
		set_mode_setting(mode);
	}
	if(udev)
	{
		set_config_setting(UDEV_PATH_ENTRY, UDEV_PATH_KEY, udev);
	}
	/* check if no network data came from an ini file */
	if( get_conf_string(NETWORK_ENTRY, NETWORK_IP_KEY))
		goto cleanup;
	if(ip) 
		set_network_setting(NETWORK_IP_KEY, ip);
	if(gateway)
		set_network_setting(NETWORK_GATEWAY_KEY, gateway);
	/* re-add hidden modes info */
	if(hide)
		set_hide_mode_setting(hide);
  }
  else
	ret = 1;
cleanup:
  if(mode)
	free(mode);
  if(udev)
	free(udev);
  if(ip)
	free(ip);
  if(gateway)
	free(gateway);
	
end:
  g_dir_close(confdir);
  return(ret);
}

char * get_android_manufacturer(void)
{
  return(get_conf_string(ANDROID_ENTRY, ANDROID_MANUFACTURER_KEY));
}

char * get_android_vendor_id(void)
{
  return(get_conf_string(ANDROID_ENTRY, ANDROID_VENDOR_ID_KEY));
}

char * get_android_product(void)
{
  return(get_conf_string(ANDROID_ENTRY, ANDROID_PRODUCT_KEY));
}

char * get_android_product_id(void)
{
  return(get_conf_string(ANDROID_ENTRY, ANDROID_PRODUCT_ID_KEY));
}

char * get_hidden_modes(void)
{
  return(get_conf_string(MODE_SETTING_ENTRY, MODE_HIDE_KEY));
}

int check_android_section(void)
{
  GKeyFile *settingsfile;
  gboolean test = FALSE;
  gchar **keys;
  int ret = 1;

  settingsfile = g_key_file_new();
  test = g_key_file_load_from_file(settingsfile, FS_MOUNT_CONFIG_FILE, G_KEY_FILE_NONE, NULL);
  if(!test)
  {
	ret = 0;
	goto cleanup;
  }
  keys = g_key_file_get_keys (settingsfile, ANDROID_ENTRY, NULL, NULL);
  if(keys == NULL)
  {  
        ret =  0;
	goto cleanup;
  }

  g_strfreev(keys);
cleanup:
  g_key_file_free(settingsfile);
  return(ret);
}

int is_roaming_not_allowed(void)
{
  return(get_conf_int(NETWORK_ENTRY, NO_ROAMING_KEY));
}