//================================================================================
// Name        : collectagent.cpp
// Author      : Axel Auweter
// Contact     : info@dcdb.it
// Copyright   : Leibniz Supercomputing Centre
// Description : Main code of the CollectAgent
//================================================================================

//================================================================================
// This file is part of DCDB (DataCenter DataBase)
// Copyright (C) 2011-2019 Leibniz Supercomputing Centre
//
// 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; either version 2
// of the License, or (at your option) any later version.
//
// 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 Street, Fifth Floor, Boston, MA  02110-1301, USA.
//================================================================================

/**
 * @defgroup ca Collect Agent
 *
 * @brief MQTT message broker in between pusher and storage backend.
 *
 * @details Collect Agent is a intermediary between one or multiple Pusher
 *          instances and one storage backend. It runs a reduced custom MQTT
 *          message server. Collect Agent receives data from Pusher
 *          via MQTT messages and stores them in the storage via libdcdb.
 */

/**
 * @file collectagent.cpp
 *
 * @brief Main function for the DCDB Collect Agent.
 *
 * @ingroup ca
 */

#include <cstdlib>
#include <signal.h>
#include <unistd.h>
#include <string>

#include <boost/date_time/posix_time/posix_time.hpp>

#include <dcdb/connection.h>
#include <dcdb/sensordatastore.h>
#include <dcdb/jobdatastore.h>
#include <dcdb/sensorconfig.h>
#include <dcdb/version.h>
#include <dcdb/sensor.h>
#include "version.h"

#include "CARestAPI.h"
#include "configuration.h"
#include "simplemqttserver.h"
#include "messaging.h"
#include "abrt.h"
#include "dcdbdaemon.h"
#include "sensorcache.h"
#include "analyticscontroller.h"
#include "../analytics/includes/QueryEngine.h"

#define __STDC_FORMAT_MACROS
#include <inttypes.h>

using namespace std;

int keepRunning;
bool statistics;
uint64_t msgCtr;
uint64_t pmsgCtr;
uint64_t readingCtr;
SensorCache mySensorCache;
AnalyticsController* analyticsController;
DCDB::Connection* dcdbConn;
DCDB::SensorDataStore *mySensorDataStore;
DCDB::JobDataStore *myJobDataStore;
DCDB::SensorConfig *mySensorConfig;
DCDB::SCError err;
QueryEngine& queryEngine = QueryEngine::getInstance();
logger_t lg;

bool jobQueryCallback(const uint32_t jobId, const uint64_t startTs, const uint64_t endTs, vector<qeJobData>& buffer, const bool rel, const bool range) {
    std::list<JobData> tempList;
    JobData   tempData;
    qeJobData tempQeData;
    JDError err;
    if(range) {
        // Getting a list of jobs in the given time range
        uint64_t now = getTimestamp();
        uint64_t startTsInt = rel ? now - startTs : startTs;
        uint64_t endTsInt = rel ? now - endTs : endTs;
        DCDB::TimeStamp start(startTsInt), end(endTsInt);
        err = myJobDataStore->getJobsInIntervalRunning(tempList, start, end);
        if(err != JD_OK) return false;
    } else {
        // Getting a single job by id
        err = myJobDataStore->getJobById(tempData, jobId);
        if(err != JD_OK) return false;
        tempList.push_back(tempData);
    }
    
    for(auto& jd : tempList) {
        tempQeData.jobId = jd.jobId;
        tempQeData.userId = jd.userId;
        tempQeData.startTime = jd.startTime.getRaw();
        tempQeData.endTime = jd.endTime.getRaw();
        tempQeData.nodes = jd.nodes;
        buffer.push_back(tempQeData);
    }
    return true;
}

bool sensorQueryCallback(const string& name, const uint64_t startTs, const uint64_t endTs, std::vector<reading_t>& buffer, const bool rel) {
    std::string topic=name;
    // Getting the topic of the queried sensor from the Navigator
    // If not found, we try to use the input name as topic
    try {
        topic = queryEngine.getNavigator()->getNodeTopic(name);
    } catch(const std::domain_error& e) {}
    DCDB::SensorId sid;
    // Creating a SID to perform the query
    if(!sid.mqttTopicConvert(topic))
        return false;
    if(mySensorCache.getSensorMap().count(sid) > 0) {
        CacheEntry &entry = mySensorCache.getSensorMap()[sid];
        if (entry.getView(startTs, endTs, buffer, rel))
            return true;
    }
    // If we are here then the sensor was not found in the cache - we need to fetch data from Cassandra
    try {
        DCDB::PublicSensor publicSensor;
        publicSensor.name = name;
        publicSensor.pattern = topic;
        std::list <DCDB::SensorDataStoreReading> results;
        DCDB::Sensor sensor(dcdbConn, publicSensor);
        uint64_t now = getTimestamp();
        //Converting relative timestamps to absolute
        uint64_t startTsInt = rel ? now - startTs : startTs;
        uint64_t endTsInt = rel ? now - endTs : endTs;
        DCDB::TimeStamp start(startTsInt), end(endTsInt);
        sensor.query(results, start, end, DCDB::AGGREGATE_NONE, 3600000000000);
        if(results.empty())
            return false;
        reading_t reading;
        for (const auto &r : results) {
            reading.value = r.value;
            reading.timestamp = r.timeStamp.getRaw();
            buffer.push_back(reading);
        }
    }
    catch(const std::exception& e) {
        return false;
    }
    return true;
}

/* Normal termination (SIGINT, CTRL+C) */
void sigHandler(int sig)
{
  boost::log::sources::severity_logger<boost::log::trivial::severity_level> lg;
  if( sig == SIGINT )
      LOG(fatal) << "Received SIGINT";
  else if( sig == SIGTERM )
      LOG(fatal) << "Received SIGTERM";
  keepRunning = 0;
}

/* Crash */
void abrtHandler(int sig)
{
  abrt(EXIT_FAILURE, SIGNAL);
}

int mqttCallback(SimpleMQTTMessage *msg)
{
  /*
   * Increment the msgCtr/vmsgCtr for statistics.
   */
  msgCtr++;
  if (msg->isPublish())
    pmsgCtr++;

  uint64_t len;
  /*
   * Decode the message and put into the database.
   */
  if (msg->isPublish()) {
      const char *topic = msg->getTopic().c_str();
      // We check whether the topic includes the \DCDB_MAP\ keyword, indicating that the payload will contain the
      // sensor's name. In that case, we set the mappingMessage flag to true, and filter the keyword out of the prefix
      // We use strncmp as it is the most efficient way to do it
      if (strncmp(topic, DCDB_MAP, DCDB_MAP_LEN) == 0) {
          if ((len = msg->getPayloadLength()) == 0) {
              LOG(error) << "Empty topic-to-name mapping message received";
              return 1;
          }

          string sensorName((char *) msg->getPayload(), len);
          err = mySensorConfig->publishSensor(sensorName.c_str(), topic + DCDB_MAP_LEN);

          // PublishSensor does most of the error checking for us
          switch (err) {
              case DCDB::SC_INVALIDPATTERN:
                  LOG(error) << "Invalid sensor topic : " << msg->getTopic();
                  return 1;
              case DCDB::SC_INVALIDPUBLICNAME:
                  LOG(error) << "Invalid sensor public name: " << sensorName;
                  return 1;
              case DCDB::SC_INVALIDSESSION:
                  LOG(error) << "Cannot reach sensor data store.";
                  return 1;
              default:
                  break;
          }
      } else {
          mqttPayload buf, *payload;

          len = msg->getPayloadLength();
          //In the 64 bit message case, the collect agent provides a timestamp
          if (len == sizeof(uint64_t)) {
              payload = &buf;
              payload->value = *((int64_t *) msg->getPayload());
              payload->timestamp = Messaging::calculateTimestamp();
              len = sizeof(uint64_t) * 2;
          }
              //...otherwise it just retrieves it from the MQTT message payload.
          else if ((len % sizeof(mqttPayload) == 0) && (len > 0)) {
              payload = (mqttPayload *) msg->getPayload();
          }
              //...otherwise this message is malformed -> ignore...
          else {
              LOG(error) << "Message malformed";
              return 1;
          }

          /*
           * Check if we can decode the message topic
           * into a valid SensorId. If successful, store
           * the record in the database.
           */
          DCDB::SensorId sid;
          if (sid.mqttTopicConvert(msg->getTopic())) {
#if 0
              cout << "Topic decode successful:" << endl
                  << "  Raw:            " << hex << setw(16) << setfill('0') << sid.getRaw()[0] << hex << setw(16) << setfill('0') << sid.getRaw()[1] << endl
                  << "  DeviceLocation: " << hex << setw(16) << setfill('0') << sid.getDeviceLocation() << endl
                  << "  device_id:      " << hex << setw(8) << setfill('0') << sid.getDeviceSensorId().device_id << endl
                  << "  sensor_number:  " << hex << setw(4) << setfill('0') << sid.getDeviceSensorId().sensor_number << endl << dec;

              cout << "Payload ("  << len/sizeof(mqttPayload) << " messages):"<< endl;
              for (uint64_t i=0; i<len/sizeof(mqttPayload); i++) {
                cout << "  " << i << ": ts=" << payload[i].timestamp << " val=" << payload[i].value << endl;
              }
              cout << endl;
#endif
	      std::list<DCDB::SensorDataStoreReading> readings;
          for (uint64_t i = 0; i < len / sizeof(mqttPayload); i++) {
              DCDB::SensorDataStoreReading r(sid, payload[i].timestamp, payload[i].value);
              readings.push_back(r);
              mySensorCache.storeSensor(sid, payload[i].timestamp, payload[i].value);
          }
          mySensorCache.getSensorMap()[sid].updateBatchSize(uint64_t(len / sizeof(mqttPayload)));
	      mySensorDataStore->insertBatch(readings);
	      readingCtr+= readings.size();

              //mySensorCache.dump();
          }
#if 1
          else {
              cout << "Wrong topic format: " << msg->getTopic() << "\n";
              return 1;
          }
#endif
      }
  }
  return 0;
}




/*
 * Print usage information
 */
void usage() {
  Configuration config("", "collectagent.conf");
  /*
             1         2         3         4         5         6         7         8
   012345678901234567890123456789012345678901234567890123456789012345678901234567890
   */
  cout << "Usage:" << endl;
  cout << "  collectagent [-d] [-s] [-x] [-a] [-m<host>] [-c<host>] [-u<username>] [-p<password>] [-t<ttl>] [-v<verbosity>] <path/to/configfiles/>" << endl;
  cout << "  collectagent -h" << endl;
  cout << endl;
  
  cout << "Options:" << endl;
  cout << "  -m<host>      MQTT listen address     [default: " << config.mqttListenHost << ":" << config.mqttListenPort << "]" << endl;
  cout << "  -c<host>      Cassandra host          [default: " << config.cassandraSettings.host << ":" << config.cassandraSettings.port << "]" << endl;
  cout << "  -u<username>  Cassandra username      [default: none]" << endl;
  cout << "  -p<password>  Cassandra password      [default: none]" << endl;
  cout << "  -t<ttl>       Cassandra insert TTL    [default: " << config.cassandraSettings.ttl << "]" << endl;
  cout << "  -v<level>     Set verbosity of output [default: " << config.logLevelCmd << "]" << endl
       << "                Can be a number between 5 (all) and 0 (fatal)." << endl;
  cout << endl;
  cout << "  -d            Daemonize" << endl;
  cout << "  -s            Print message stats" <<endl;
  cout << "  -x            Parse and print the config but do not actually start collectagent" << endl;
  cout << "  -a			   Enable sensor auto-publish" << endl;
  cout << "  -h            This help page" << endl;
  cout << endl;
}

int main(int argc, char* const argv[]) {
    cout << "CollectAgent " << VERSION << " (libdcdb " << DCDB::Version::getVersion() << ")" << endl << endl;

  try{

      // Checking if path to config is supplied
      if (argc <= 1) {
          cout << "Please specify a path to the config-directory" << endl << endl;
          usage();
          exit(EXIT_FAILURE);
      }

      // Defining options
      const char* opts = "m:r:c:C:u:p:t:v:dDsaxh";

      // Same mechanism as in DCDBPusher - checking if help string is requested before loading config
      char ret;
      while ((ret = getopt(argc, argv, opts)) != -1) {
          switch (ret)
          {
              case 'h':
                  usage();
                  exit(EXIT_FAILURE);
                  break;
              default:
                  //do nothing (other options are read later on)
                  break;
          }
      }

      initLogging();
      auto cmdSink = setupCmdLogger();

      Configuration config(argv[argc - 1], "collectagent.conf");
      if( !config.readConfig() ) {
          LOG(fatal) << "Failed to read global configuration!";
          exit(EXIT_FAILURE);
      }

      // References to shorten access to config parameters
      Configuration& settings = config;
      cassandra_t& cassandraSettings = config.cassandraSettings;
      pluginSettings_t& pluginSettings = config.pluginSettings;
      serverSettings_t& restAPISettings = config.restAPISettings;
      analyticsSettings_t& analyticsSettings = config.analyticsSettings;
      
      optind = 1;
      while ((ret=getopt(argc, argv, opts))!=-1) {
          switch(ret) {
              case 'a':
                  pluginSettings.autoPublish = true;
                  break;
              case 'm':
                  settings.mqttListenHost = parseNetworkHost(optarg);
                  settings.mqttListenPort = parseNetworkPort(optarg);
                  if(settings.mqttListenPort=="") settings.mqttListenPort = string(LISTENPORT);
                  break;
              case 'c':
                  cassandraSettings.host = parseNetworkHost(optarg);
                  cassandraSettings.port = parseNetworkPort(optarg);
                  if(cassandraSettings.port=="") cassandraSettings.port = string(CASSANDRAPORT);
                  break;
              case 'u':
                  cassandraSettings.username = optarg;
                  break;
              case 'p': {
                  cassandraSettings.password = optarg;
                  // What does this do? Mask the password?
                  size_t pwdLen = strlen(optarg);
                  memset(optarg, 'x', (pwdLen >= 3) ? 3 : pwdLen);
                  if (pwdLen > 3) {
                      memset(optarg+3, 0, pwdLen-3);
                  }
                  break;
              }
              case 't':
                  cassandraSettings.ttl = stoul(optarg);
                  break;
              case 'v':
                  settings.logLevelCmd = stoi(optarg);
                  break;
              case 'd':
              case 'D':
                  settings.daemonize = 1;
                  break;
              case 's':
                  settings.statistics = 1;
                  break;
              case 'x':
                  settings.validateConfig = true;
                  break;
              case 'h':
              default:
                  usage();
                  exit(EXIT_FAILURE);
          }
      }

      //set up logger to file
      if (settings.logLevelFile >= 0) {
	  auto fileSink = setupFileLogger(pluginSettings.tempdir, std::string("collectagent"));
	  fileSink->set_filter(boost::log::trivial::severity >= translateLogLevel(settings.logLevelFile));
      }
      
      //severity level may be overwritten (per option or config-file) --> set it according to globalSettings
      if (settings.logLevelCmd >= 0) {
	  cmdSink->set_filter(boost::log::trivial::severity >= translateLogLevel(settings.logLevelCmd));
      }

      /*
       * Catch SIGINT and SIGTERM signals to allow for proper server shutdowns.
       */
      signal(SIGINT, sigHandler);
      signal(SIGTERM, sigHandler);

      /*
       * Catch critical signals to allow for backtraces
       */
      signal(SIGABRT, abrtHandler);
      signal(SIGSEGV, abrtHandler);

      // Daemonizing the collectagent
      if(settings.daemonize)
          dcdbdaemon();
      
      // Setting the size of the sensor cache
      // Conversion from milliseconds to nanoseconds
      mySensorCache.setMaxHistory(uint64_t(pluginSettings.cacheInterval) * 1000000);

      //Allocate and initialize connection to Cassandra.
      dcdbConn = new DCDB::Connection(cassandraSettings.host, atoi(cassandraSettings.port.c_str()), 
                                      cassandraSettings.username, cassandraSettings.password);
      dcdbConn->setNumThreadsIo(cassandraSettings.numThreadsIo);
      dcdbConn->setQueueSizeIo(cassandraSettings.queueSizeIo);
      uint32_t params[1] = {cassandraSettings.coreConnPerHost};
      dcdbConn->setBackendParams(params);
      
      if (!dcdbConn->connect()) {
          LOG(fatal) << "Cannot connect to Cassandra!";
          exit(EXIT_FAILURE);
      }

      /*
       * Legacy behavior: Initialize the DCDB schema in Cassandra.
       */
      dcdbConn->initSchema();
      
      /*
       * Allocate the SensorDataStore.
       */
      mySensorDataStore = new DCDB::SensorDataStore(dcdbConn);
      mySensorConfig = new DCDB::SensorConfig(dcdbConn);
      myJobDataStore = new DCDB::JobDataStore(dcdbConn);

      /*
       * Set TTL for data store inserts if TTL > 0.
       */
      if (cassandraSettings.ttl > 0)
        mySensorDataStore->setTTL(cassandraSettings.ttl);
      mySensorDataStore->setDebugLog(cassandraSettings.debugLog);

      analyticsController = new AnalyticsController(mySensorConfig, mySensorDataStore);
      analyticsController->setCache(&mySensorCache);
      queryEngine.setFilter(analyticsSettings.filter);
      queryEngine.setJobFilter(analyticsSettings.jobFilter);
      queryEngine.setSensorHierarchy(analyticsSettings.hierarchy);
      queryEngine.setQueryCallback(sensorQueryCallback);
      queryEngine.setJobQueryCallback(jobQueryCallback);
      if(!analyticsController->initialize(settings, argv[argc - 1]))
          return EXIT_FAILURE;
      
      LOG_LEVEL vLogLevel = settings.validateConfig ? LOG_LEVEL::info : LOG_LEVEL::debug;
      LOG_VAR(vLogLevel) << "-----  Configuration  -----";

      //print global settings in either case
      LOG(info) << "Global Settings:";
      LOG(info) << "    MQTT-listenAddress: " << settings.mqttListenHost << ":" << settings.mqttListenPort;
      LOG(info) << "    CacheInterval:      " << int(pluginSettings.cacheInterval/1000) << " [s]";
      LOG(info) << "    CleaningInterval:   " << settings.cleaningInterval << " [s]";
      LOG(info) << "    MessageThreads:     " << settings.messageThreads;
      LOG(info) << "    MessageSlots:       " << settings.messageSlots;
      LOG(info) << "    Daemonize:          " << (settings.daemonize ? "Enabled" : "Disabled");
      LOG(info) << "    Statistics:         " << (settings.statistics ? "Enabled" : "Disabled");
      LOG(info) << "    MQTT-prefix:        " << pluginSettings.mqttPrefix;
      LOG(info) << "    Auto-publish:       " << (pluginSettings.autoPublish ? "Enabled" : "Disabled");
      LOG(info) << "    Write-Dir:          " << pluginSettings.tempdir;
      LOG(info) << (settings.validateConfig ? "    Only validating config files." : "    ValidateConfig:     Disabled");

      LOG(info) << "Analytics Settings:";
      LOG(info) << "    Hierarchy:          " << (analyticsSettings.hierarchy!="" ? analyticsSettings.hierarchy : "none");
      LOG(info) << "    Filter:             " << (analyticsSettings.filter!="" ? analyticsSettings.filter : "none");
      
      LOG(info) << "Cassandra Driver Settings:";
      LOG(info) << "    Address:            " << cassandraSettings.host << ":" << cassandraSettings.port;
      LOG(info) << "    TTL:                " << cassandraSettings.ttl;
      LOG(info) << "    NumThreadsIO:       " << cassandraSettings.numThreadsIo;
      LOG(info) << "    QueueSizeIO:        " << cassandraSettings.queueSizeIo;
      LOG(info) << "    CoreConnPerHost:    " << cassandraSettings.coreConnPerHost;
      LOG(info) << "    DebugLog:           " << (cassandraSettings.debugLog ? "Enabled" : "Disabled");
#ifdef SimpleMQTTVerbose
      LOG(info) << "    Username:           " << cassandraSettings.username;
	  LOG(info) << "    Password:           " << cassandraSettings.password;
#else
      LOG(info) << "    Username and password not printed.";
#endif

      if (restAPISettings.enabled) {
	  
	  LOG(info) << "RestAPI Settings:";
	  LOG(info) << "    REST Server: " << restAPISettings.host << ":" << restAPISettings.port;
	  LOG(info) << "    Certificate: " << restAPISettings.certificate;
	  LOG(info) << "    Private key file: " << restAPISettings.privateKey;
	  LOG(info) << "    DH params from: " << restAPISettings.dhFile;
      }
      LOG_VAR(vLogLevel) << "-----  Analytics Configuration  -----";
      for(auto& p : analyticsController->getManager()->getPlugins()) {
          LOG_VAR(vLogLevel) << "Operator Plugin \"" << p.id << "\"";
          p.configurator->printConfig(vLogLevel);
      }
      LOG_VAR(vLogLevel) << "-----  End Configuration  -----";

      if (settings.validateConfig)
          return EXIT_SUCCESS;
      else
          analyticsController->start();

      /*
       * Start the MQTT Message Server.
       */
      SimpleMQTTServer ms(settings.mqttListenHost, settings.mqttListenPort, settings.messageThreads, settings.messageSlots);
      
      ms.setMessageCallback(mqttCallback);
      ms.start();

      LOG(info) << "MQTT Server running...";
      
      /*
       * Start the HTTP Server for the REST API
       */
      CARestAPI* httpsServer = nullptr;
      if (restAPISettings.enabled) {
	  httpsServer = new CARestAPI(restAPISettings, &mySensorCache, analyticsController);
	  config.readRestAPIUsers(httpsServer);
	  httpsServer->start();
	  LOG(info) <<  "HTTP Server running...";
      }

      /*
       * Run (hopefully) forever...
       */
      keepRunning = 1;
      timeval start, end;
      double elapsed;
      msgCtr = 0;
      pmsgCtr = 0;
      readingCtr = 0;

      gettimeofday(&start, NULL);
      uint64_t lastCleanup = start.tv_sec;

      LOG(info) << "Collect Agent running...";
      while(keepRunning) {
          gettimeofday(&start, NULL);
          if(start.tv_sec - lastCleanup > settings.cleaningInterval) {
              uint64_t purged = mySensorCache.clean(settings.cleaningInterval * 1000000000);
              lastCleanup = start.tv_sec;
              if(purged > 0)
                  LOG(info) << "Cache: purged " << purged << " obsolete entries";
          }

          sleep(60);
          /* not really thread safe but will do the job */
          gettimeofday(&end, NULL);
          elapsed = (end.tv_sec - start.tv_sec) * 1000.0;
          elapsed += (end.tv_usec - start.tv_usec) / 1000.0;
          float publish = msgCtr?(pmsgCtr*100.0)/msgCtr:0;
          if (settings.statistics && keepRunning) {
              LOG(info) << "Performance: " << (readingCtr/elapsed)*1000.0 << " inserts/s, " << (msgCtr/elapsed)*1000.0 << " messages/s (" << publish << "% PUBLISH)";
              LOG(info) << "Analytics Performance: " << (analyticsController->getReadingCtr()/elapsed)*1000.0 << " inserts/s ";
          }
          msgCtr = 0;
          pmsgCtr = 0;
	  readingCtr = 0;
      }

      LOG(info) << "Stopping...";
      analyticsController->stop();
      ms.stop();
      LOG(info) << "MQTT Server stopped...";
      if (restAPISettings.enabled) {
	  httpsServer->stop();
	  delete httpsServer;
	  LOG(info) << "HTTP Server stopped...";
      }
      delete mySensorDataStore;
      delete myJobDataStore;
      delete mySensorConfig;
      dcdbConn->disconnect();
      delete dcdbConn;
      LOG(info) << "Collect Agent closed. Bye bye...";
  }
  catch (const exception& e) {
      LOG(fatal) << "Exception: " << e.what();
      abrt(EXIT_FAILURE, INTERR);
  }

  return EXIT_SUCCESS;
}