/*
      This file is part of GNUnet
      Copyright (C) 2021 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 testing/testing_api_cmd_hello_world.c
 * @brief Command to start the netjail peers.
 * @author t3sserakt
 */
#include "platform.h"
#include "gnunet_testing_ng_lib.h"
#include "testing_cmds.h"

#define NETJAIL_EXEC_SCRIPT "./../testing/netjail_exec.sh"

struct HelperMessage;

struct HelperMessage
{

  struct HelperMessage *next;

  struct HelperMessage *prev;

  /**
   * Size of the original message.
   */
  uint16_t bytes_msg;

  /* Followed by @e bytes_msg of msg.*/
};



struct NetJailState
{

  unsigned int *rv;

  struct HelperMessage *hp_messages_head;

  struct HelperMessage *hp_messages_tail;

  /**
   * The process handle
   */
  struct GNUNET_HELPER_Handle **helper;

  unsigned int n_helper;

  char *binary_name;

  char *local_m;

  char *global_n;

  /**
   * The send handle for the helper
   */
  struct GNUNET_HELPER_SendHandle **shandle;

  unsigned int n_shandle;

  /**
   * The message corresponding to send handle
   */
  struct GNUNET_MessageHeader **msg;

  unsigned int n_msg;

  unsigned int number_of_testsystems_started;

  unsigned int number_of_peers_started;

  unsigned int number_of_local_test_finished;

  char *plugin_name;
};

struct TestingSystemCount
{
  unsigned int count;

  struct NetJailState *ns;
};

/**
*
*
* @param cls closure
* @param cmd current CMD being cleaned up.
*/
static void
netjail_exec_cleanup (void *cls,
                      const struct GNUNET_TESTING_Command *cmd)
{
  struct NetJailState *ns = cls;

  GNUNET_free (ns->binary_name);
}


/**
*
*
* @param cls closure.
* @param[out] ret result
* @param trait name of the trait.
* @param index index number of the object to offer.
* @return #GNUNET_OK on success.
*/
static int
netjail_exec_traits (void *cls,
                     const void **ret,
                     const char *trait,
                     unsigned int index)
{
  struct NetJailState *ns = cls;
  struct GNUNET_HELPER_Handle **helper = ns->helper;
  struct HelperMessage *hp_messages_head = ns->hp_messages_head;


  struct GNUNET_TESTING_Trait traits[] = {
    {
      .index = 0,
      .trait_name = "helper_handles",
      .ptr = (const void *) helper,
    },
    {
      .index = 1,
      .trait_name = "hp_msgs_head",
      .ptr = (const void *) hp_messages_head,
    },
    GNUNET_TESTING_trait_end ()
  };

  return GNUNET_TESTING_get_trait (traits,
                                   ret,
                                   trait,
                                   index);
}


/**
 * Offer handles to testing cmd helper from trait
 *
 * @param cmd command to extract the message from.
 * @param pt pointer to message.
 * @return #GNUNET_OK on success.
 */
int
GNUNET_TESTING_get_trait_helper_handles (const struct
                                         GNUNET_TESTING_Command *cmd,
                                         struct GNUNET_HELPER_Handle ***helper)
{
  return cmd->traits (cmd->cls,
                      (const void **) helper,
                      "helper_handles",
                      (unsigned int) 0);
}

/**
 * Offer messages received via testing cmd helper from trait
 *
 * @param cmd command to extract the message from.
 * @param pt pointer to message.
 * @return #GNUNET_OK on success.
 */
int
GNUNET_TESTING_get_trait_helper_messages (const struct
                                          GNUNET_TESTING_Command *cmd,
                                          struct HelperMessage ***
                                          hp_messages_head)
{
  return cmd->traits (cmd->cls,
                      (const void **) hp_messages_head,
                      "hp_msgs_head",
                      (unsigned int) 1);
}


/**
 * Continuation function from GNUNET_HELPER_send()
 *
 * @param cls closure
 * @param result GNUNET_OK on success,
 *               GNUNET_NO if helper process died
 *               GNUNET_SYSERR during GNUNET_HELPER_stop
 */
static void
clear_msg (void *cls, int result)
{
  struct TestingSystemCount *tbc = cls;
  struct NetJailState *ns = tbc->ns;

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "clear_msg tbc->count: %d\n",
              tbc->count);
  GNUNET_assert (NULL != ns->shandle[tbc->count - 1]);
  ns->shandle[tbc->count - 1] = NULL;
  GNUNET_free (ns->msg[tbc->count - 1]);
  ns->msg[tbc->count - 1] = NULL;
}


/**
 * Functions with this signature are called whenever a
 * complete message is received by the tokenizer.
 *
 * Do not call GNUNET_SERVER_mst_destroy in callback
 *
 * @param cls closure
 * @param client identification of the client
 * @param message the actual message
 *
 * @return #GNUNET_OK on success, #GNUNET_SYSERR to stop further processing
 */
static int
helper_mst (void *cls, const struct GNUNET_MessageHeader *message)
{
  struct TestingSystemCount *tbc = cls;
  struct NetJailState *ns = tbc->ns;
  struct HelperMessage *hp_msg;

  if (GNUNET_MESSAGE_TYPE_CMDS_HELPER_REPLY == ntohs (message->type))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "helper_mst tbc->count: %d\n",
                tbc->count);
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Received message from helper.\n");
    ns->number_of_testsystems_started++;
  }
  else if (GNUNET_MESSAGE_TYPE_CMDS_HELPER_PEER_STARTED == ntohs (
             message->type))
  {
    ns->number_of_peers_started++;
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "number_of_peers_started: %d\n",
                ns->number_of_peers_started);
  }
  else if (GNUNET_MESSAGE_TYPE_CMDS_HELPER_LOCAL_FINISHED == ntohs (
             message->type))
  {
    ns->number_of_local_test_finished++;
  }
  else
  {
    hp_msg = GNUNET_new (struct HelperMessage);
    hp_msg->bytes_msg = message->size;
    memcpy (&hp_msg[1], message, message->size);
    GNUNET_CONTAINER_DLL_insert (ns->hp_messages_head, ns->hp_messages_tail,
                                 hp_msg);
  }

  return GNUNET_OK;
}


static void
exp_cb (void *cls)
{
  struct NetJailState *ns = cls;
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Called exp_cb.\n");
  *ns->rv = 1;
}


static struct GNUNET_CMDS_HelperInit *
create_helper_init_msg_ (char *m_char,
                         char *n_char,
                         const char *plugin_name)
{
  struct GNUNET_CMDS_HelperInit *msg;
  uint16_t plugin_name_len;
  uint16_t msg_size;

  GNUNET_assert (NULL != plugin_name);
  plugin_name_len = strlen (plugin_name);
  msg_size = sizeof(struct GNUNET_CMDS_HelperInit) + plugin_name_len;
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "msg_size: %d \n",
              msg_size);
  msg = GNUNET_malloc (msg_size);
  msg->header.size = htons (msg_size);
  msg->header.type = htons (GNUNET_MESSAGE_TYPE_CMDS_HELPER_INIT);
  msg->plugin_name_size = htons (plugin_name_len);
  GNUNET_memcpy ((char *) &msg[1],
                 plugin_name,
                 plugin_name_len);
  return msg;
}


static void
start_helper (struct NetJailState *ns, struct
              GNUNET_CONFIGURATION_Handle *config,
              char *m_char,
              char *n_char)
{
  // struct GNUNET_CONFIGURATION_Handle *cfg;
  struct GNUNET_CMDS_HelperInit *msg;
  struct TestingSystemCount *tbc;
  char *const script_argv[] = {NETJAIL_EXEC_SCRIPT,
                               m_char,
                               n_char,
                               GNUNET_OS_get_libexec_binary_path (
                                 HELPER_CMDS_BINARY),
                               ns->global_n,
                               ns->local_m,
                               NULL};
  unsigned int m = atoi (m_char);
  unsigned int n = atoi (n_char);
  unsigned int helper_check = GNUNET_OS_check_helper_binary (
    NETJAIL_EXEC_SCRIPT,
    GNUNET_YES,
    NULL);

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "m: %d n: %d\n",
              m,
              n);

  tbc = GNUNET_new (struct TestingSystemCount);
  tbc->ns = ns;
  tbc->count = (n - 1) * atoi (ns->local_m) + m;


  if (GNUNET_NO == helper_check)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "No SUID for %s!\n",
                NETJAIL_EXEC_SCRIPT);
    *ns->rv = 1;
  }
  else if (GNUNET_NO == helper_check)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "%s not found!\n",
                NETJAIL_EXEC_SCRIPT);
    *ns->rv = 1;
  }

  GNUNET_array_append (ns->helper, ns->n_helper, GNUNET_HELPER_start (
                         GNUNET_YES,
                         NETJAIL_EXEC_SCRIPT,
                         script_argv,
                         &helper_mst,
                         &exp_cb,
                         tbc));

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "First using helper %d %d\n",
              tbc->count - 1,
              ns->n_helper);
  struct GNUNET_HELPER_Handle *helper = ns->helper[tbc->count - 1];

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "First using helper %d %d %p\n",
              tbc->count - 1,
              ns->n_helper,
              helper);

  msg = create_helper_init_msg_ (m_char,
                                 n_char,
                                 ns->plugin_name);
  GNUNET_array_append (ns->msg, ns->n_msg, &msg->header);

  GNUNET_array_append (ns->shandle, ns->n_shandle, GNUNET_HELPER_send (
                         helper,
                         &msg->header,
                         GNUNET_NO,
                         &clear_msg,
                         tbc));

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Message %d send!\n",
              tbc->count);

  if (NULL == ns->shandle[tbc->count - 1])
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Send handle is NULL!\n");
    GNUNET_free (msg);
    *ns->rv = 1;
  }
}


/**
* Run the "hello world" CMD.
*
* @param cls closure.
* @param cmd CMD being run.
* @param is interpreter state.
*/
static void
netjail_exec_run (void *cls,
                  const struct GNUNET_TESTING_Command *cmd,
                  struct GNUNET_TESTING_Interpreter *is)
{
  char str_m[12];
  char str_n[12];
  struct NetJailState *ns = cls;
  struct GNUNET_CONFIGURATION_Handle *config =
    GNUNET_CONFIGURATION_create ();

  for (int i = 1; i <= atoi (ns->global_n); i++) {
    for (int j = 1; j <= atoi (ns->local_m); j++)
    {
      sprintf (str_n, "%d", i);
      sprintf (str_m, "%d", j);
      start_helper (ns, config,
                    str_m,
                    str_n);
    }
  }
}


static int
netjail_start_finish (void *cls,
                      GNUNET_SCHEDULER_TaskCallback cont,
                      void *cont_cls)
{
  unsigned int ret = GNUNET_NO;
  struct NetJailState *ns = cls;
  unsigned int total_number = atoi (ns->local_m) * atoi (ns->global_n);
  struct GNUNET_CMDS_ALL_PEERS_STARTED *reply;
  size_t msg_length;
  struct GNUNET_HELPER_Handle *helper;
  struct TestingSystemCount *tbc;

  if (ns->number_of_local_test_finished == total_number)
  {
    ret = GNUNET_YES;
    cont (cont_cls);
  }

  if (ns->number_of_testsystems_started == total_number)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "All helpers started!\n");
    ns->number_of_testsystems_started = 0;
  }

  if (ns->number_of_peers_started == total_number)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "All peers started!\n");

    for (int i = 1; i <= atoi (ns->global_n); i++) {
      for (int j = 1; j <= atoi (ns->local_m); j++)
      {
        tbc = GNUNET_new (struct TestingSystemCount);
        tbc->ns = ns;
        // TODO This needs to be more generic. As we send more messages back and forth, we can not grow the arrays again and again, because this is to error prone.
        tbc->count = (i - 1) * atoi (ns->local_m) + j + total_number;
        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                    "Second using helper %d %d %d\n",
                    tbc->count - 1 - total_number,
                    i,
                    j);
        helper = ns->helper[tbc->count - 1 - total_number];
        msg_length = sizeof(struct GNUNET_CMDS_ALL_PEERS_STARTED);
        reply = GNUNET_new (struct GNUNET_CMDS_ALL_PEERS_STARTED);
        reply->header.type = htons (
          GNUNET_MESSAGE_TYPE_CMDS_HELPER_ALL_PEERS_STARTED);
        reply->header.size = htons ((uint16_t) msg_length);

        GNUNET_array_append (ns->msg, ns->n_msg, &reply->header);

        struct GNUNET_HELPER_SendHandle *sh = GNUNET_HELPER_send (
          helper,
          &reply->header,
          GNUNET_NO,
          &clear_msg,
          tbc);

        GNUNET_array_append (ns->shandle, ns->n_shandle, sh);

        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                    "All peers started message %d send!\n",
                    tbc->count);
      }
    }
    ns->number_of_peers_started = 0;
  }
  return ret;
}


/**
 * Create command.
 *
 * @param label name for command.
 * @param binaryname to exec.
 * @return command.
 */
struct GNUNET_TESTING_Command
GNUNET_TESTING_cmd_netjail_start_testing_system (const char *label,
                                                 char *local_m,
                                                 char *global_n,
                                                 char *plugin_name,
                                                 unsigned int *rv)
{
  struct NetJailState *ns;

  ns = GNUNET_new (struct NetJailState);
  ns->local_m = local_m;
  ns->global_n = global_n;
  ns->plugin_name = plugin_name;
  ns->rv = rv;

  struct GNUNET_TESTING_Command cmd = {
    .cls = ns,
    .label = label,
    .run = &netjail_exec_run,
    .finish = &netjail_start_finish,
    .cleanup = &netjail_exec_cleanup,
    .traits = &netjail_exec_traits
  };

  return cmd;
}