/*
     This file is part of GNUnet.
     Copyright (C) 2001, 2002, 2004-2007, 2009, 2016 GNUnet e.V.

     GNUnet is free software: you can redistribute it and/or modify it
     under the terms of the GNU Affero General Public License as published
     by the Free Software Foundation, either version 3 of the License,
     or (at your option) any later version.

     GNUnet 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
     Affero General Public License for more details.

     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.

     SPDX-License-Identifier: AGPL3.0-or-later
 */

/**
 * @file statistics/gnunet-statistics.c
 * @brief tool to obtain statistics
 * @author Christian Grothoff
 * @author Igor Wronsky
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_statistics_service.h"


/**
 * Final status code.
 */
static int ret;

/**
 * Set to subsystem that we're going to get stats for (or NULL for all).
 */
static char *subsystem;

/**
 * The path of the testbed data.
 */
static char *path_testbed;

/**
 * Set to the specific stat value that we are after (or NULL for all).
 */
static char *name;

/**
 * Make the value that is being set persistent.
 */
static int persistent;

/**
 * Watch value continuously
 */
static int watch;

/**
 * Quiet mode
 */
static int quiet;

/**
 * @brief Separator string for csv.
 */
static char *csv_separator_opt;

/**
 * @brief Separator string for csv.
 */
static const char *csv_separator;

/**
 * Remote host
 */
static char *remote_host;

/**
 * Remote host's port
 */
static unsigned long long remote_port;

/**
 * Value to set
 */
static unsigned long long set_val;

/**
 * Set operation
 */
static int set_value;

/**
 * @brief Representation of all (testbed) nodes.
 */
static struct Node
{
  /**
   * @brief Index of the node in this array.
   */
  unsigned index_node;

  /**
   * @brief Configuration handle for this node
   */
  struct GNUNET_CONFIGURATION_Handle *conf;

  /**
   * Handle for pending GET operation.
   */
  struct GNUNET_STATISTICS_GetHandle *gh;

  /**
   * @brief Statistics handle nodes.
   */
  struct GNUNET_STATISTICS_Handle *handle;
  /**
   * @brief Identifier for shutdown task for this node.
   */
  struct GNUNET_SCHEDULER_Task *shutdown_task;
} *nodes;

/**
 * @brief Number of configurations of all (testbed) nodes.
 */
static unsigned num_nodes;

/**
 * @brief Set of values for a combination of subsystem and name.
 */
struct ValueSet
{
  /**
   * @brief Subsystem of the valueset.
   */
  char *subsystem;

  /**
   * @brief Name of the valueset.
   */
  char *name;

  /**
   * @brief The values.
   */
  uint64_t *values;

  /**
   * @brief Persistence of the values.
   */
  int is_persistent;
};


/**
 * @brief Collection of all values (represented with #ValueSet).
 */
static struct GNUNET_CONTAINER_MultiHashMap *values;

/**
 * @brief Number of nodes that have their values ready.
 */
static int num_nodes_ready;

/**
 * @brief Number of nodes that have their values ready.
 */
static int num_nodes_ready_shutdown;


/**
 * @brief Create a new #ValueSet
 *
 * @param subsystem Subsystem of the valueset.
 * @param name Name of the valueset.
 * @param num_values Number of values in valueset - number of peers.
 * @param is_persistent Persistence status of values.
 * @return Newly allocated #ValueSet.
 */
static struct ValueSet *
new_value_set (const char *subsys,
               const char *new_name,
               unsigned num_values,
               int is_persistent)
{
  struct ValueSet *value_set;

  value_set = GNUNET_new (struct ValueSet);
  value_set->subsystem = GNUNET_strdup (subsys);
  value_set->name = GNUNET_strdup (new_name);
  value_set->values = GNUNET_new_array (num_values,
                                        uint64_t);
  value_set->is_persistent = persistent;
  return value_set;
}


/**
 * @brief Print the (collected) values.
 *
 * Implements #GNUNET_CONTAINER_HashMapIterator.
 *
 * @param cls Closure - unused
 * @param key #GNUNET_HashCode key of #GNUNET_CONTAINER_MultiHashMap iterator -
 *        unused
 * @param value Values represented as #ValueSet.
 * @return #GNUNET_YES - continue iteration.
 */
static int
printer (void *cls,
         const struct GNUNET_HashCode *key,
         void *value)
{
  struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
  const char *now_str;
  struct ValueSet *value_set = value;

  if (quiet == GNUNET_NO)
  {
    if (GNUNET_YES == watch)
    {
      now_str = GNUNET_STRINGS_absolute_time_to_string (now);
      fprintf (stdout,
               "%24s%s %s%s%12s%s %s%50s%s%s ",
               now_str,
               csv_separator,
               value_set->is_persistent ? "!" : " ",
               csv_separator,
               value_set->subsystem,
               csv_separator,
               (0 == strlen (csv_separator) ? "" : "\""),   /* quotes if csv */
               _ (value_set->name),
               (0 == strlen (csv_separator) ? "" : "\""),   /* quotes if csv */
               (0 == strlen (csv_separator) ? ":" : csv_separator));
    }
    else
    {
      fprintf (stdout,
               "%s%s%12s%s %s%50s%s%s ",
               value_set->is_persistent ? "!" : " ",
               csv_separator,
               value_set->subsystem,
               csv_separator,
               (0 == strlen (csv_separator) ? "" : "\""),   /* quotes if csv */
               _ (value_set->name),
               (0 == strlen (csv_separator) ? "" : "\""),   /* quotes if csv */
               (0 == strlen (csv_separator) ? ":" : csv_separator));
    }
  }
  for (unsigned i = 0; i < num_nodes; i++)
  {
    fprintf (stdout,
             "%16llu%s",
             (unsigned long long) value_set->values[i],
             csv_separator);
  }
  fprintf (stdout, "\n");
  GNUNET_free (value_set->subsystem);
  GNUNET_free (value_set->name);
  GNUNET_free (value_set->values);
  GNUNET_free (value_set);
  return GNUNET_YES;
}


/**
 * Callback function to process statistic values.
 *
 * @param cls closure
 * @param subsystem name of subsystem that created the statistic
 * @param name the name of the datum
 * @param value the current value
 * @param is_persistent #GNUNET_YES if the value is persistent, #GNUNET_NO if not
 * @return #GNUNET_OK to continue, #GNUNET_SYSERR to abort iteration
 */
static int
printer_watch (void *cls,
               const char *subsys,
               const char *print_name,
               uint64_t value,
               int is_persistent)
{
  struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
  const char *now_str;

  if (quiet == GNUNET_NO)
  {
    if (GNUNET_YES == watch)
    {
      now_str = GNUNET_STRINGS_absolute_time_to_string (now);
      fprintf (stdout,
               "%24s%s %s%s%12s%s %s%50s%s%s %16llu\n",
               now_str,
               csv_separator,
               is_persistent ? "!" : " ",
               csv_separator,
               subsys,
               csv_separator,
               (0 == strlen (csv_separator) ? "" : "\""),   /* quotes if csv */
               _ (print_name),
               (0 == strlen (csv_separator) ? "" : "\""),   /* quotes if csv */
               (0 == strlen (csv_separator) ? ":" : csv_separator),
               (unsigned long long) value);
    }
    else
    {
      fprintf (stdout,
               "%s%s%12s%s %s%50s%s%s %16llu\n",
               is_persistent ? "!" : " ",
               csv_separator,
               subsys,
               csv_separator,
               (0 == strlen (csv_separator) ? "" : "\""),   /* quotes if csv */
               _ (print_name),
               (0 == strlen (csv_separator) ? "" : "\""),   /* quotes if csv */
               (0 == strlen (csv_separator) ? ":" : csv_separator),
               (unsigned long long) value);
    }
  }
  else
    fprintf (stdout, "%llu\n", (unsigned long long) value);

  return GNUNET_OK;
}


/**
 * @brief Clean all data structures related to given node.
 *
 * Also clears global structures if we are the last node to clean.
 *
 * @param cls the index of the node
 */
static void
clean_node (void *cls)
{
  const unsigned index_node = *(unsigned *) cls;
  struct GNUNET_STATISTICS_Handle *h;
  struct GNUNET_STATISTICS_GetHandle *gh;

  if ((NULL != path_testbed) && /* were issued with -t <testbed-path> option */
      (NULL != nodes[index_node].conf))
  {
    GNUNET_CONFIGURATION_destroy (nodes[index_node].conf);
    nodes[index_node].conf = NULL;
  }

  h = nodes[index_node].handle;
  gh = nodes[index_node].gh;

  if (NULL != gh)
  {
    GNUNET_STATISTICS_get_cancel (gh);
    gh = NULL;
  }
  if (GNUNET_YES == watch)
  {
    GNUNET_assert (
      GNUNET_OK ==
      GNUNET_STATISTICS_watch_cancel (h,
                                      subsystem,
                                      name,
                                      &printer_watch,
                                      &nodes[index_node].index_node));
  }

  if (NULL != h)
  {
    GNUNET_STATISTICS_destroy (h, GNUNET_NO);
    h = NULL;
  }

  num_nodes_ready_shutdown++;
}


/**
 * @brief Print and shutdown
 *
 * @param cls unused
 */
static void
print_finish (void *cls)
{
  GNUNET_CONTAINER_multihashmap_iterate (values,
                                         &printer,
                                         NULL);
  GNUNET_CONTAINER_multihashmap_destroy (values);
  GNUNET_free (csv_separator_opt);
  GNUNET_SCHEDULER_shutdown ();
}


/**
 * @brief Called once all statistic values are available.
 *
 * Implements #GNUNET_STATISTICS_Callback
 *
 * @param cls Closure - The index of the node.
 * @param success Whether statistics were obtained successfully.
 */
static void
continuation_print (void *cls,
                    int success)
{
  const unsigned index_node = *(unsigned *) cls;

  nodes[index_node].gh = NULL;
  if (GNUNET_OK != success)
  {
    if (NULL == remote_host)
      fprintf (stderr,
               "%s",
               _ ("Failed to obtain statistics.\n"));
    else
      fprintf (stderr,
               _ ("Failed to obtain statistics from host `%s:%llu'\n"),
               remote_host,
               remote_port);
    ret = 1;
  }
  if (NULL != nodes[index_node].shutdown_task)
  {
    GNUNET_SCHEDULER_cancel (nodes[index_node].shutdown_task);
    nodes[index_node].shutdown_task = NULL;
  }
  GNUNET_SCHEDULER_add_now (&clean_node,
                            &nodes[index_node].index_node);
  num_nodes_ready++;
  if (num_nodes_ready == num_nodes)
  {
    GNUNET_SCHEDULER_add_now (&print_finish,
                              NULL);
  }
}


/**
 * Function called last by the statistics code.
 *
 * @param cls closure
 * @param success #GNUNET_OK if statistics were
 *        successfully obtained, #GNUNET_SYSERR if not.
 */
static void
cleanup (void *cls,
         int success)
{
  for (unsigned i = 0; i < num_nodes; i++)
  {
    nodes[i].gh = NULL;
  }
  if (GNUNET_OK != success)
  {
    if (NULL == remote_host)
      fprintf (stderr, "%s", _ ("Failed to obtain statistics.\n"));
    else
      fprintf (stderr,
               _ ("Failed to obtain statistics from host `%s:%llu'\n"),
               remote_host,
               remote_port);
    ret = 1;
  }
  GNUNET_SCHEDULER_shutdown ();
}


/**
 * @brief Iterate over statistics values and store them in #values.
 * They will be printed once all are available.
 *
 * @param cls Cosure - Node index.
 * @param subsystem Subsystem of the value.
 * @param name Name of the value.
 * @param value Value itself.
 * @param is_persistent Persistence.
 * @return #GNUNET_OK - continue.
 */
static int
collector (void *cls,
           const char *subsys,
           const char *coll_name,
           uint64_t value,
           int is_persistent)
{
  const unsigned index_node = *(unsigned *) cls;
  struct GNUNET_HashCode *key;
  struct GNUNET_HashCode hc;
  char *subsys_name;
  unsigned len_subsys_name;
  struct ValueSet *value_set;

  len_subsys_name = strlen (subsys) + 3 + strlen (coll_name) + 1;
  subsys_name = GNUNET_malloc (len_subsys_name);
  sprintf (subsys_name, "%s---%s", subsys, coll_name);
  key = &hc;
  GNUNET_CRYPTO_hash (subsys_name, len_subsys_name, key);
  GNUNET_free (subsys_name);
  if (GNUNET_YES == GNUNET_CONTAINER_multihashmap_contains (values, key))
  {
    value_set = GNUNET_CONTAINER_multihashmap_get (values, key);
  }
  else
  {
    value_set = new_value_set (subsys, coll_name, num_nodes, is_persistent);
  }
  value_set->values[index_node] = value;
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap_put (
                   values,
                   key,
                   value_set,
                   GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
  return GNUNET_OK;
}


/**
 * Main task that does the actual work.
 *
 * @param cls closure with our configuration
 */
static void
main_task (void *cls)
{
  unsigned index_node = *(unsigned *) cls;
  const struct GNUNET_CONFIGURATION_Handle *cfg = nodes[index_node].conf;

  if (set_value)
  {
    if (NULL == subsystem)
    {
      fprintf (stderr, "%s", _ ("Missing argument: subsystem \n"));
      ret = 1;
      return;
    }
    if (NULL == name)
    {
      fprintf (stderr, "%s", _ ("Missing argument: name\n"));
      ret = 1;
      return;
    }
    nodes[index_node].handle = GNUNET_STATISTICS_create (subsystem, cfg);
    if (NULL == nodes[index_node].handle)
    {
      ret = 1;
      return;
    }
    GNUNET_STATISTICS_set (nodes[index_node].handle,
                           name,
                           (uint64_t) set_val,
                           persistent);
    GNUNET_STATISTICS_destroy (nodes[index_node].handle, GNUNET_YES);
    nodes[index_node].handle = NULL;
    return;
  }
  if (NULL == (nodes[index_node].handle =
                 GNUNET_STATISTICS_create ("gnunet-statistics", cfg)))
  {
    ret = 1;
    return;
  }
  if (GNUNET_NO == watch)
  {
    if (NULL == (nodes[index_node].gh =
                   GNUNET_STATISTICS_get (nodes[index_node].handle,
                                          subsystem,
                                          name,
                                          &continuation_print,
                                          &collector,
                                          &nodes[index_node].index_node)))
      cleanup (nodes[index_node].handle, GNUNET_SYSERR);
  }
  else
  {
    if ((NULL == subsystem) || (NULL == name))
    {
      printf (_ ("No subsystem or name given\n"));
      GNUNET_STATISTICS_destroy (nodes[index_node].handle, GNUNET_NO);
      nodes[index_node].handle = NULL;
      ret = 1;
      return;
    }
    if (GNUNET_OK != GNUNET_STATISTICS_watch (nodes[index_node].handle,
                                              subsystem,
                                              name,
                                              &printer_watch,
                                              &nodes[index_node].index_node))
    {
      fprintf (stderr, _ ("Failed to initialize watch routine\n"));
      nodes[index_node].shutdown_task =
        GNUNET_SCHEDULER_add_now (&clean_node, &nodes[index_node].index_node);
      return;
    }
  }
  nodes[index_node].shutdown_task =
    GNUNET_SCHEDULER_add_shutdown (&clean_node, &nodes[index_node].index_node);
}


/**
 * @brief Iter over content of a node's directory to check for existence of a
 * config file.
 *
 * Implements #GNUNET_FileNameCallback
 *
 * @param cls pointer to indicate success
 * @param filename filename inside the directory of the potential node
 *
 * @return to continue iteration or not to
 */
static int
iter_check_config (void *cls,
                   const char *filename)
{
  if (0 == strncmp (GNUNET_STRINGS_get_short_name (filename), "config", 6))
  {
    /* Found the config - stop iteration successfully */
    GNUNET_array_grow (nodes, num_nodes, num_nodes + 1);
    nodes[num_nodes - 1].conf = GNUNET_CONFIGURATION_create (
      GNUNET_OS_project_data_gnunet ());
    nodes[num_nodes - 1].index_node = num_nodes - 1;
    if (GNUNET_OK !=
        GNUNET_CONFIGURATION_load (nodes[num_nodes - 1].conf, filename))
    {
      fprintf (stderr, "Failed loading config `%s'\n", filename);
      return GNUNET_SYSERR;
    }
    return GNUNET_NO;
  }
  else
  {
    /* Continue iteration */
    return GNUNET_OK;
  }
}


/**
 * @brief Iterates over filenames in testbed directory.
 *
 * Implements #GNUNET_FileNameCallback
 *
 * Checks if the file is a directory for a testbed node
 * and counts the nodes.
 *
 * @param cls counter of nodes
 * @param filename full path of the file in testbed
 * @return status whether to continue iteration
 */
static int
iter_testbed_path (void *cls,
                   const char *filename)
{
  unsigned index_node;

  GNUNET_assert (NULL != filename);
  if (1 == sscanf (GNUNET_STRINGS_get_short_name (filename),
                   "%u",
                   &index_node))
  {
    if (-1 == GNUNET_DISK_directory_scan (filename,
                                          iter_check_config,
                                          NULL))
    {
      /* This is probably no directory for a testbed node
       * Go on with iteration */
      return GNUNET_OK;
    }
    return GNUNET_OK;
  }
  return GNUNET_OK;
}


/**
 * @brief Count the number of nodes running in the testbed
 *
 * @param path_testbed path to the testbed data
 *
 * @return number of running nodes
 */
static int
discover_testbed_nodes (const char *path_testbed_discovered)
{
  int num_dir_entries;

  num_dir_entries =
    GNUNET_DISK_directory_scan (path_testbed_discovered,
                                &iter_testbed_path,
                                NULL);
  if (-1 == num_dir_entries)
  {
    fprintf (stderr,
             "Failure during scanning directory `%s'\n",
             path_testbed_discovered);
    return -1;
  }
  return 0;
}


/**
 * Main function that will be run by the scheduler.
 *
 * @param cls closure
 * @param args remaining command-line arguments
 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
 * @param cfg configuration
 */
static void
run (void *cls,
     char *const *args,
     const char *cfgfile,
     const struct GNUNET_CONFIGURATION_Handle *cfg)
{
  struct GNUNET_CONFIGURATION_Handle *c;

  c = (struct GNUNET_CONFIGURATION_Handle *) cfg;
  set_value = GNUNET_NO;
  if (NULL == csv_separator)
    csv_separator = "";
  if (NULL != args[0])
  {
    if (1 != sscanf (args[0], "%llu", &set_val))
    {
      fprintf (stderr, _ ("Invalid argument `%s'\n"), args[0]);
      ret = 1;
      return;
    }
    set_value = GNUNET_YES;
  }
  if (NULL != remote_host)
  {
    if (0 == remote_port)
    {
      if (GNUNET_SYSERR ==
          GNUNET_CONFIGURATION_get_value_number (cfg,
                                                 "statistics",
                                                 "PORT",
                                                 &remote_port))
      {
        fprintf (stderr,
                 _ ("A port is required to connect to host `%s'\n"),
                 remote_host);
        return;
      }
    }
    else if (65535 <= remote_port)
    {
      fprintf (stderr,
               _ (
                 "A port has to be between 1 and 65535 to connect to host `%s'\n"),
               remote_host);
      return;
    }

    /* Manipulate configuration */
    GNUNET_CONFIGURATION_set_value_string (c,
                                           "statistics",
                                           "UNIXPATH",
                                           "");
    GNUNET_CONFIGURATION_set_value_string (c,
                                           "statistics",
                                           "HOSTNAME",
                                           remote_host);
    GNUNET_CONFIGURATION_set_value_number (c,
                                           "statistics",
                                           "PORT",
                                           remote_port);
  }
  if (NULL == path_testbed)
  {
    values = GNUNET_CONTAINER_multihashmap_create (1, GNUNET_NO);
    GNUNET_array_grow (nodes, num_nodes, 1);
    nodes[0].index_node = 0;
    nodes[0].conf = c;
    GNUNET_SCHEDULER_add_now (&main_task, &nodes[0].index_node);
  }
  else
  {
    if (GNUNET_YES == watch)
    {
      printf (
        _ ("Not able to watch testbed nodes (yet - feel free to implement)\n"));
      ret = 1;
      return;
    }
    values = GNUNET_CONTAINER_multihashmap_create (4, GNUNET_NO);
    if (-1 == discover_testbed_nodes (path_testbed))
    {
      return;
    }
    /* For each config/node collect statistics */
    for (unsigned i = 0; i < num_nodes; i++)
    {
      GNUNET_SCHEDULER_add_now (&main_task, &nodes[i].index_node);
    }
  }
}


/**
 * The main function to obtain statistics in GNUnet.
 *
 * @param argc number of arguments from the command line
 * @param argv command line arguments
 * @return 0 ok, 1 on error
 */
int
main (int argc, char *const *argv)
{
  struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_option_string ('n',
                                 "name",
                                 "NAME",
                                 gettext_noop (
                                   "limit output to statistics for the given NAME"),
                                 &name),
    GNUNET_GETOPT_option_flag ('p',
                               "persistent",
                               gettext_noop (
                                 "make the value being set persistent"),
                               &persistent),
    GNUNET_GETOPT_option_string ('s',
                                 "subsystem",
                                 "SUBSYSTEM",
                                 gettext_noop (
                                   "limit output to the given SUBSYSTEM"),
                                 &subsystem),
    GNUNET_GETOPT_option_string ('S',
                                 "csv-separator",
                                 "CSV_SEPARATOR",
                                 gettext_noop ("use as csv separator"),
                                 &csv_separator_opt),
    GNUNET_GETOPT_option_filename ('t',
                                   "testbed",
                                   "TESTBED",
                                   gettext_noop (
                                     "path to the folder containing the testbed data"),
                                   &path_testbed),
    GNUNET_GETOPT_option_flag ('q',
                               "quiet",
                               gettext_noop (
                                 "just print the statistics value"),
                               &quiet),
    GNUNET_GETOPT_option_flag ('w',
                               "watch",
                               gettext_noop ("watch value continuously"),
                               &watch),
    GNUNET_GETOPT_option_string ('r',
                                 "remote",
                                 "REMOTE",
                                 gettext_noop ("connect to remote host"),
                                 &remote_host),
    GNUNET_GETOPT_option_ulong ('o',
                                "port",
                                "PORT",
                                gettext_noop ("port for remote host"),
                                &remote_port),
    GNUNET_GETOPT_OPTION_END
  };

  remote_port = 0;
  remote_host = NULL;

  ret = (GNUNET_OK ==
         GNUNET_PROGRAM_run (GNUNET_OS_project_data_gnunet (),
                             argc,
                             argv,
                             "gnunet-statistics [options [value]]",
                             gettext_noop (
                               "Print statistics about GNUnet operations."),
                             options,
                             &run,
                             NULL))
        ? ret
        : 1;
  GNUNET_array_grow (nodes,
                     num_nodes,
                     0);
  GNUNET_free (remote_host);
  return ret;
}


/* end of gnunet-statistics.c */
