/*
   Copyright (c) 2008, 2018, Oracle and/or its affiliates. All rights reserved.

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

   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 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 <AtrtClient.hpp>
#include "atrt.hpp"

MYSQL* find_atrtdb_client(atrt_config& config) {
  atrt_cluster* cluster = 0;
  for (unsigned i = 0; i < config.m_clusters.size(); i++) {
    if (strcmp(config.m_clusters[i]->m_name.c_str(), ".atrt") == 0) {
      cluster = config.m_clusters[i];

      for (unsigned i = 0; i < cluster->m_processes.size(); i++) {
        if (cluster->m_processes[i]->m_type == atrt_process::AP_CLIENT) {
          atrt_process* atrt_client = cluster->m_processes[i];
          if (!atrt_client) return NULL; /* No atrt db */

          atrt_process* f_mysqld = atrt_client->m_mysqld;
          assert(f_mysqld);

          return &f_mysqld->m_mysql;
        }
      }
      break;
    }
  }
  return NULL;
}

static bool ack_command(AtrtClient& atrtdb, int command_id, const char* state) {
  BaseString sql;
  sql.assfmt("UPDATE command SET state = '%s' WHERE id = %d", state,
             command_id);
  return atrtdb.doQuery(sql);
}

BaseString set_env_var(const BaseString& existing, const BaseString& name,
                       const BaseString& value) {
  /* Split existing on space
   * (may have issues with env vars with spaces)
   * Split assignments on =
   * Where name == name, output new value
   */
  BaseString newEnv;
  Vector<BaseString> assignments;
  int assignmentCount = existing.split(assignments, BaseString(" "));

  for (int i = 0; i < assignmentCount; i++) {
    Vector<BaseString> terms;
    int termCount = assignments[i].split(terms, BaseString("="));

    if (termCount) {
      if (strcmp(name.c_str(), terms[0].c_str()) == 0) {
        /* Found element */
        newEnv.append(name);
        newEnv.append('=');
        newEnv.append(value);
      } else {
        newEnv.append(assignments[i]);
      }
    }
    newEnv.append(' ');
  }

  return newEnv;
}

static char* dirname(const char* path) {
  char* s = strdup(path);
  size_t len = strlen(s);
  for (size_t i = 1; i < len; i++) {
    if (s[len - i] == '/') {
      s[len - i] = 0;
      return s;
    }
  }
  free(s);
  return 0;
}

Vector<atrt_process> g_saved_procs;

static bool do_change_prefix(atrt_config& config, SqlResultSet& command) {
  const char* new_prefix = g_prefix1 ? g_prefix1 : g_prefix0;
  const char* process_args = command.column("process_args");
  atrt_process& proc = *config.m_processes[command.columnAsInt("process_id")];
  BaseString newEnv = set_env_var(
    proc.m_proc.m_env, BaseString("MYSQL_BASE_DIR"), BaseString(new_prefix));
  proc.m_proc.m_env.assign(newEnv);

  ssize_t pos = proc.m_proc.m_path.lastIndexOf('/') + 1;
  BaseString exename(proc.m_proc.m_path.substr(pos));
  char* exe = find_bin_path(new_prefix, exename.c_str());
  proc.m_proc.m_path = exe;
  if (exe) {
    free(exe);
  }
  if (process_args && strlen(process_args)) {
    /* Beware too long args */
    proc.m_proc.m_args.append(" ");
    proc.m_proc.m_args.append(process_args);
  }

  {
  /**
   * In 5.5...binaries aren't compiled with rpath
   * So we need an explicit LD_LIBRARY_PATH
   * So when upgrading..we need to change LD_LIBRARY_PATH
   * So I hate 5.5...
   */
#if defined(__MACH__)
    ssize_t p0 = proc.m_proc.m_env.indexOf(" DYLD_LIBRARY_PATH=");
#else
    ssize_t p0 = proc.m_proc.m_env.indexOf(" LD_LIBRARY_PATH=");
#endif
    ssize_t p1 = proc.m_proc.m_env.indexOf(' ', p0 + 1);

    BaseString part0 = proc.m_proc.m_env.substr(0, p0);
    BaseString part1 = proc.m_proc.m_env.substr(p1);

    proc.m_proc.m_env.assfmt("%s%s", part0.c_str(), part1.c_str());

    BaseString lib(g_libmysqlclient_so_path);
    ssize_t pos = lib.lastIndexOf('/') + 1;
    BaseString libname(lib.substr(pos));
    char* exe = find_bin_path(new_prefix, libname.c_str());
    char* dir = dirname(exe);
#if defined(__MACH__)
    proc.m_proc.m_env.appfmt(" DYLD_LIBRARY_PATH=%s", dir);
#else
    proc.m_proc.m_env.appfmt(" LD_LIBRARY_PATH=%s", dir);
#endif
    free(exe);
    free(dir);
  }
  return true;
}

static bool do_start_process(atrt_config& config, SqlResultSet& command,
                             AtrtClient& atrtdb) {
  uint process_id = command.columnAsInt("process_id");
  if (process_id > config.m_processes.size()) {
    g_logger.critical("Invalid process id %d", process_id);
    return false;
  }

  atrt_process& proc = *config.m_processes[process_id];

  if (proc.m_atrt_stopped != true) {
    g_logger.info("start process %s failed", proc.m_name.c_str());
    return false;
  }
  proc.m_atrt_stopped = false;
  g_logger.info("starting process - %s", proc.m_name.c_str());
  bool status = start_process(proc) == true;
  return status;
}

static bool do_stop_process(atrt_config& config, SqlResultSet& command,
                             AtrtClient& atrtdb) {
  uint process_id = command.columnAsInt("process_id");

  // Get the process
  if (process_id > config.m_processes.size()) {
    g_logger.critical("Invalid process id %d", process_id);
    return false;
  }

  atrt_process& proc = *config.m_processes[process_id];
  proc.m_atrt_stopped = true;

  const char* new_prefix = g_prefix1 ? g_prefix1 : g_prefix0;
  const char* old_prefix = g_prefix0;
  const char* start = strstr(proc.m_proc.m_path.c_str(), old_prefix);
  if (!start) {
    /* Process path does not contain old prefix.
     * Perhaps it contains the new prefix - e.g. is already
     * upgraded?
     */
    if (strstr(proc.m_proc.m_path.c_str(), new_prefix)) {
      /* Process is already upgraded, *assume* that this
       * is ok
       * Alternatives could be - error, or downgrade.
       */
      g_logger.info("Process already upgraded");
      return true;
    }

    g_logger.critical("Could not find '%s' in '%s'", old_prefix,
                      proc.m_proc.m_path.c_str());
    return false;
  }

  g_logger.info("stopping process - %s", proc.m_name.c_str());
  if (!stop_process(proc)) {
    return false;
  }

  g_logger.info("waiting for process to stop...");
  if (!wait_for_process_to_stop(config, proc)) {
    g_logger.critical("Failed to stop process");
    return false;
  }

  // Save current proc state
  if (proc.m_save.m_saved == false) {
    proc.m_save.m_proc = proc.m_proc;
    proc.m_save.m_saved = true;
  }
  return true;
}

static bool do_change_version(atrt_config& config, SqlResultSet& command,
                              AtrtClient& atrtdb) {
  if (!do_stop_process(config, command, atrtdb)) {
    return false;
  }

  if (!do_change_prefix(config, command)) {
    return false;
  }

  if (!do_start_process(config, command, atrtdb)) {
    return false;
  }

  return true;
}

static bool do_reset_proc(atrt_config& config, SqlResultSet& command,
                          AtrtClient& atrtdb) {
  uint process_id = command.columnAsInt("process_id");
  g_logger.info("Reset process: %d", process_id);

  // Get the process
  if (process_id > config.m_processes.size()) {
    g_logger.critical("Invalid process id %d", process_id);
    return false;
  }
  atrt_process& proc = *config.m_processes[process_id];

  g_logger.info("stopping process...");
  if (!stop_process(proc)) return false;

  if (!wait_for_process_to_stop(config, proc)) return false;

  if (proc.m_save.m_saved) {
    ndbout << "before: " << proc << endl;

    proc.m_proc = proc.m_save.m_proc;
    proc.m_save.m_saved = false;

    ndbout << "after: " << proc << endl;

  } else {
    ndbout << "process has not changed" << endl;
  }

  return true;
}

bool do_command(atrt_config& config) {
#ifdef _WIN32
  return true;
#endif

  MYSQL* mysql = find_atrtdb_client(config);
  if (!mysql) return true;

  AtrtClient atrtdb(mysql);
  SqlResultSet command;
  if (!atrtdb.doQuery("SELECT * FROM command "
                      "WHERE state = 'new' ORDER BY id LIMIT 1",
                      command)) {
    g_logger.critical("query failed");
    return false;
  }

  if (command.numRows() == 0) return true;

  uint id = command.columnAsInt("id");
  uint cmd = command.columnAsInt("cmd");
  g_logger.info("Got command, id: %d, cmd: %d", id, cmd);
  // command.print();

  // Set state of command to running
  if (!ack_command(atrtdb, id, "running")) return false;

  switch (cmd) {
    case AtrtClient::ATCT_CHANGE_VERSION:
      if (!do_change_version(config, command, atrtdb)) return false;
      break;

    case AtrtClient::ATCT_RESET_PROC:
      if (!do_reset_proc(config, command, atrtdb)) return false;
      break;

    case AtrtClient::ATCT_START_PROCESS:
      if (!do_start_process(config, command, atrtdb)) return false;
      break;

    case AtrtClient::ATCT_STOP_PROCESS:
      if (!do_stop_process(config, command, atrtdb)) return false;
      break;

    case AtrtClient::ATCT_SWITCH_CONFIG:
      if (!do_change_prefix(config, command)) return false;
      break;

    default:
      command.print();
      g_logger.error("got unknown command: %d", cmd);
      return false;
  }

  // Set state of command to done
  if (!ack_command(atrtdb, id, "done")) return false;

  g_logger.info("done!");

  return true;
}

template class Vector<atrt_process>;
