/*
      This file is part of GNUnet
      Copyright (C) 2008--2014 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 testbed/generate-underlay-topology.c
 * @brief Program to generate a database file containing given underlay topology
 * @author Sree Harsha Totakura <sreeharsha@totakura.in>
 */

#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_testbed_service.h"
#include "testbed_api_topology.h"
#include "sqlite3.h"

#define LOG(type, ...) GNUNET_log (type, __VA_ARGS__)


#define LOG_ERROR(...) LOG (GNUNET_ERROR_TYPE_ERROR, __VA_ARGS__)

/**
 * Log an error message at log-level 'level' that indicates
 * a failure of the command 'cmd' on file 'filename'
 * with the message given by strerror(errno).
 */
#define LOG_SQLITE(db, msg, level, cmd)                           \
  do                                                              \
  {                                                               \
    GNUNET_log_from (level,                                       \
                     "sqlite",                                    \
                     _ ("`%s' failed at %s:%d with error: %s\n"), \
                     cmd,                                         \
                     __FILE__,                                    \
                     __LINE__,                                    \
                     sqlite3_errmsg (db));                        \
    if (msg != NULL)                                              \
      GNUNET_asprintf (msg,                                       \
                       _ ("`%s' failed at %s:%u with error: %s"), \
                       cmd,                                       \
                       __FILE__,                                  \
                       __LINE__,                                  \
                       sqlite3_errmsg (db));                      \
  } while (0)


/**
 * Handle to the sqlite3 database
 */
static struct sqlite3 *db;

/**
 * Prepared statement for inserting link values into db
 */
struct sqlite3_stmt *stmt_insert;

/**
 * The topology to generate
 */
enum GNUNET_TESTBED_TopologyOption topology;

/**
 * The number of peers to include in the topology
 */
static unsigned int num_peers;

/**
 * program result
 */
static int exit_result;


/**
 * Functions of this type are called to process underlay link
 *
 * @param cls closure
 * @param A offset of first peer
 * @param B offset of second peer
 * @param bandwidth the bandwidth of the link in bytes per second
 * @param latency the latency of link in milliseconds
 * @param loss the percentage of messages dropped on the link
 * @return GNUNET_OK to continue processing; GNUNET_SYSERR to abort
 */
static int
link_processor (void *cls,
                unsigned int A,
                unsigned int B,
                unsigned int bandwidth,
                unsigned int latency,
                unsigned int loss)
{
  if ((SQLITE_OK != sqlite3_bind_int (stmt_insert, 1, A)) ||
      (SQLITE_OK != sqlite3_bind_int (stmt_insert, 2, B)) ||
      (SQLITE_OK != sqlite3_bind_int (stmt_insert, 3, bandwidth)) ||
      (SQLITE_OK != sqlite3_bind_int (stmt_insert, 4, latency)) ||
      (SQLITE_OK != sqlite3_bind_int (stmt_insert, 5, loss)))
  {
    LOG_SQLITE (db, NULL, GNUNET_ERROR_TYPE_ERROR, "sqlite3_bind_int");
    return GNUNET_SYSERR;
  }
  if (SQLITE_DONE != sqlite3_step (stmt_insert))
  {
    LOG_SQLITE (db, NULL, GNUNET_ERROR_TYPE_ERROR, "sqlite3_step");
    return GNUNET_SYSERR;
  }
  fprintf (stdout, "%u -> %u\n", A, B);
  GNUNET_break (SQLITE_OK == sqlite3_reset (stmt_insert));
  // GNUNET_break (SQLITE_OK == sqlite3_clear_bindings (stmt_insert));
  if ((SQLITE_OK != sqlite3_bind_int (stmt_insert, 1, B)) ||
      (SQLITE_OK != sqlite3_bind_int (stmt_insert, 2, A)))
  {
    LOG_SQLITE (db, NULL, GNUNET_ERROR_TYPE_ERROR, "sqlite3_bind_int");
    return GNUNET_SYSERR;
  }
  if (SQLITE_DONE != sqlite3_step (stmt_insert))
  {
    LOG_SQLITE (db, NULL, GNUNET_ERROR_TYPE_ERROR, "sqlite3_step");
    return GNUNET_SYSERR;
  }
  fprintf (stdout, "%u -> %u\n", B, A);
  GNUNET_break (SQLITE_OK == sqlite3_reset (stmt_insert));
  return GNUNET_OK;
}


/**
 * Open the database file, creating a new database if not existing and setup the
 * whitelist table
 *
 * @param dbfile the database filename
 * @return GNUNET_OK upon success; GNUNET_SYSERR upon failure (error message has
 * to be printed)
 */
static int
setup_db (const char *dbfile)
{
  const char *query_create = "CREATE TABLE whitelist ("
                             "id INTEGER,"
                             "oid INTEGER,"
                             "bandwidth INTEGER DEFAULT NULL,"
                             "latency INTEGER DEFAULT NULL,"
                             "loss INTEGER DEFAULT NULL,"
                             " UNIQUE ("
                             "  id,"
                             "  oid"
                             " ) ON CONFLICT IGNORE"
                             ");";
  const char *query_insert = "INSERT INTO whitelist("
                             " id,"
                             " oid,"
                             " bandwidth,"
                             " latency,"
                             " loss"
                             ") VALUES ("
                             " ?1,"
                             " ?2,"
                             " ?3,"
                             " ?4,"
                             " ?5);";
  int ret;

  ret = GNUNET_SYSERR;
  if (SQLITE_OK != sqlite3_open (dbfile, &db))
  {
    LOG_SQLITE (db, NULL, GNUNET_ERROR_TYPE_ERROR, "sqlite3_open");
    goto err_ret;
  }
  if (0 != sqlite3_exec (db, query_create, NULL, NULL, NULL))
  {
    LOG_SQLITE (db, NULL, GNUNET_ERROR_TYPE_ERROR, "sqlite3_exec");
    fprintf (stderr,
             "Error: %d.  Perhaps the database `%s' already exits.\n",
             sqlite3_errcode (db),
             dbfile);
    goto err_ret;
  }
  GNUNET_break (0 ==
                sqlite3_exec (db, "PRAGMA synchronous = 0;", NULL, NULL, NULL));
  if (SQLITE_OK !=
      sqlite3_prepare_v2 (db, query_insert, -1, &stmt_insert, NULL))
  {
    LOG_SQLITE (db, NULL, GNUNET_ERROR_TYPE_ERROR, "sqlite3_prepare_v2");
    goto err_ret;
  }
  ret = GNUNET_OK;

err_ret:
  return ret;
}


/**
 * Main run function.
 *
 * @param cls NULL
 * @param args arguments passed to GNUNET_PROGRAM_run
 * @param cfgfile the path to configuration file
 * @param cfg the configuration file handle
 */
static void
run (void *cls,
     char *const *args,
     const char *cfgfile,
     const struct GNUNET_CONFIGURATION_Handle *config)
{
  const char *dbfile;
  const char *topology_string;
  unsigned int arg_uint1;
  unsigned int arg_uint2;
  const char *arg_str1;
  const char *value;
  unsigned int argc;

  argc = 0;
  arg_uint1 = 0; /* make compilers happy */
  arg_uint2 = 0; /* make compilers happy */
  if (NULL == args)
  {
    LOG_ERROR (_ ("Need at least 2 arguments\n"));
    return;
  }
  if (NULL == (dbfile = args[argc++]))
  {
    LOG_ERROR (_ ("Database filename missing\n"));
    return;
  }
  if (GNUNET_OK != setup_db (dbfile))
    return;
  if (NULL == (topology_string = args[argc++]))
  {
    LOG_ERROR (_ ("Topology string missing\n"));
    return;
  }
  if (GNUNET_YES != GNUNET_TESTBED_topology_get_ (&topology, topology_string))
  {
    LOG_ERROR (_ ("Invalid topology: %s\n"), topology_string);
    return;
  }
  arg_str1 = NULL;
  /* parse for first TOPOOPT.  This can either be arg_uint1 or arg_str1 */
  switch (topology)
  {
  case GNUNET_TESTBED_TOPOLOGY_ERDOS_RENYI:
  case GNUNET_TESTBED_TOPOLOGY_SMALL_WORLD_RING:
  case GNUNET_TESTBED_TOPOLOGY_SMALL_WORLD:
  case GNUNET_TESTBED_TOPOLOGY_SCALE_FREE:
    if (NULL == (value = args[argc++]))
    {
      LOG_ERROR (_ ("An argument is missing for given topology `%s'\n"),
                 topology_string);
      return;
    }
    if (-1 == sscanf (value, "%u", &arg_uint1))
    {
      LOG_ERROR (_ ("Invalid argument `%s' given as topology argument\n"),
                 value);
      return;
    }
    break;

  case GNUNET_TESTBED_TOPOLOGY_FROM_FILE:
    if (NULL == (arg_str1 = args[argc++]))
    {
      LOG_ERROR (_ ("Filename argument missing for topology `%s'\n"),
                 topology_string);
      return;
    }
    break;

  default:
    break;
  }
  /* parse for second TOPOOPT.  Only required for SCALE_FREE topology */
  switch (topology)
  {
  case GNUNET_TESTBED_TOPOLOGY_SCALE_FREE:
    if (NULL == (value = args[argc++]))
    {
      LOG_ERROR (_ ("Second argument for topology `%s' is missing\n"),
                 topology_string);
      return;
    }
    if (-1 == sscanf (value, "%u", &arg_uint2))
    {
      LOG_ERROR (_ ("Invalid argument `%s'; expecting unsigned int\n"), value);
      return;
    }
    break;

  default:
    break;
  }
  /* contruct topologies */
  switch (topology)
  {
  case GNUNET_TESTBED_TOPOLOGY_LINE:
  case GNUNET_TESTBED_TOPOLOGY_RING:
  case GNUNET_TESTBED_TOPOLOGY_STAR:
  case GNUNET_TESTBED_TOPOLOGY_CLIQUE:
  case GNUNET_TESTBED_TOPOLOGY_2D_TORUS:
    GNUNET_TESTBED_underlay_construct_ (num_peers,
                                        link_processor,
                                        NULL,
                                        topology);
    break;

  case GNUNET_TESTBED_TOPOLOGY_ERDOS_RENYI:
  case GNUNET_TESTBED_TOPOLOGY_SMALL_WORLD_RING:
  case GNUNET_TESTBED_TOPOLOGY_SMALL_WORLD:
    GNUNET_TESTBED_underlay_construct_ (num_peers,
                                        link_processor,
                                        NULL,
                                        topology,
                                        arg_uint1);
    break;

  case GNUNET_TESTBED_TOPOLOGY_FROM_FILE:
    GNUNET_TESTBED_underlay_construct_ (num_peers,
                                        link_processor,
                                        NULL,
                                        topology,
                                        arg_str1);
    break;

  case GNUNET_TESTBED_TOPOLOGY_SCALE_FREE:
    GNUNET_TESTBED_underlay_construct_ (num_peers,
                                        link_processor,
                                        NULL,
                                        topology,
                                        arg_uint1,
                                        arg_uint2);
    break;

  default:
    GNUNET_assert (0);
  }
}


/**
 * Main
 */
int
main (int argc, char *const argv[])
{
  struct GNUNET_GETOPT_CommandLineOption option[] = {
    GNUNET_GETOPT_option_uint ('p',
                               "num-peers",
                               "COUNT",
                               gettext_noop ("create COUNT number of peers"),
                               &num_peers),
    GNUNET_GETOPT_OPTION_END
  };

  int ret;

  exit_result = GNUNET_SYSERR;
  ret = GNUNET_PROGRAM_run (
    argc,
    argv,
    "gnunet-underlay-topology",
    _ (
      "Generates SQLite3 database representing a given underlay topology.\n"
      "Usage: gnunet-underlay-topology [OPTIONS] db-filename TOPO [TOPOOPTS]\n"
      "The following options are available for TOPO followed by TOPOOPTS if applicable:\n"
      "\t LINE\n"
      "\t RING\n"
      "\t RANDOM <num_rnd_links>\n"
      "\t SMALL_WORLD <num_rnd_links>\n"
      "\t SMALL_WORLD_RING <num_rnd_links>\n"
      "\t CLIQUE\n"
      "\t 2D_TORUS\n"
      "\t SCALE_FREE <cap> <m>\n"
      "\t FROM_FILE <filename>\n"
      "TOPOOPTS:\n"
      "\t num_rnd_links: The number of random links\n"
      "\t cap: the maximum number of links a node can have\n"
      "\t m: the number of links a node should have while joining the network\n"
      "\t filename: the path of the file which contains topology information\n"
      "NOTE: the format of the above file is descibed here: https://www.gnunet.org/content/topology-file-format\n"),
    option,
    &run,
    NULL);
  if (NULL != stmt_insert)
    sqlite3_finalize (stmt_insert);
  if (NULL != db)
    GNUNET_break (SQLITE_OK == sqlite3_close (db));
  if ((GNUNET_OK != ret) || (GNUNET_OK != exit_result))
    return 1;
  return 0;
}