/*
 * @project      The CERN Tape Archive (CTA)
 * @copyright    Copyright © 2021-2022 CERN
 * @license      This program is free software, distributed under the terms of the GNU General Public
 *               Licence version 3 (GPL Version 3), copied verbatim in the file "COPYING". You can
 *               redistribute it and/or modify it under the terms of the GPL Version 3, 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.
 *
 *               In applying this licence, CERN does not waive the privileges and immunities
 *               granted to it by virtue of its status as an Intergovernmental Organization or
 *               submit itself to any jurisdiction.
 */

#include "Agent.hpp"
#include "AgentRegister.hpp"
#include "RootEntry.hpp"
#include "GenericObject.hpp"
#include "common/exception/Errnum.hpp"
#include "ProtocolBuffersAlgorithms.hpp"
#include <string>
#include <sstream>
#include <ctime>
#include <cxxabi.h>
#include <google/protobuf/util/json_util.h>

cta::objectstore::Agent::Agent(GenericObject& go):
  ObjectOps<serializers::Agent, serializers::Agent_t>(go.objectStore()) {
  // Here we transplant the generic object into the new object
  go.transplantHeader(*this);
  // And interpret the header.
  getPayloadFromHeader();
}

cta::objectstore::Agent::Agent(const std::string & name, Backend & os):
  ObjectOps<serializers::Agent, serializers::Agent_t>(os, name), m_nextId(0) {}

void cta::objectstore::Agent::initialize() {
  ObjectOps<serializers::Agent, serializers::Agent_t>::initialize();
  m_payload.set_heartbeat(0);
  m_payload.set_timeout_us(240*1000*1000);
  m_payload.set_description("");
  m_payload.set_being_garbage_collected(false);
  m_payload.set_gc_needed(false);
  m_payloadInterpreted = true;
}

void cta::objectstore::Agent::insertAndRegisterSelf(log::LogContext & lc) {
  // We suppose initialize was already called, and that the agent name
  // is set.
  // We need to get hold of the agent register, which we suppose is available
  RootEntry re(m_objectStore);
  ScopedSharedLock reLock(re);
  re.fetch();
  AgentRegister ar(re.getAgentRegisterAddress(), m_objectStore);
  reLock.release();
  // Then we should first create a pointer to our agent
  ScopedExclusiveLock arLock(ar);
  ar.fetch();
  ar.addAgent(getAddressIfSet());
  ar.commit();
  // Set the agent register as owner and backup owner
  setBackupOwner(ar.getAddressIfSet());
  setOwner(ar.getAddressIfSet());
  // Create the agent
  insert();
  // And release the agent register's lock
  arLock.release();
}

void cta::objectstore::Agent::removeAndUnregisterSelf(log::LogContext & lc) {
  // Check that we own the proper lock
  checkPayloadWritable();
  // Check that we are not empty
  if (!isEmpty()) {
    // Log all owned objects by batches of 25.
    std::list<std::string> ownershipList = getOwnershipList();
    {
      auto ownedObj = ownershipList.begin();
      size_t currentCount=0;
      size_t startIndex=0;
      size_t endIndex=0;
      std::string currentObjs;
      while (ownedObj != ownershipList.end()) {
        if (currentObjs.size()) currentObjs+= " ";
        currentObjs += *(ownedObj++);
        endIndex++;
        if (++currentCount >= 25 || ownedObj == ownershipList.end()) {
          log::ScopedParamContainer params(lc);
          params.add("agentObject",getAddressIfSet())
                .add("objects", currentObjs)
                .add("startIndex", startIndex)
                .add("endIndex", endIndex - 1)
                .add("totalObjects", ownershipList.size());
          lc.log(log::ERR, "In Agent::deleteAndUnregisterSelf: agent still owns objects. Here is a part of the list.");
          startIndex = endIndex;
          currentCount = 0;
          currentObjs = "";
        }
      }
    }
    // Prepare exception to be thrown.
    std::stringstream exSs;
    exSs << "In Agent::removeAndUnregisterSelf: agent (agentObject=" << getAddressIfSet() << ") still owns objects. Here's the first few:";
    size_t count=0;
    for(auto i=ownershipList.begin(); i!=ownershipList.end(); i++) {
      exSs << " " << *i;
      if (++count > 3) {
        exSs << " [... trimmed at 3 of " << ownershipList.size() << "]";
        break;
      }
    }
    throw AgentStillOwnsObjects(exSs.str());
  }
  // First delete ourselves
  remove();
  log::ScopedParamContainer params(lc);
  params.add("agentObject", getAddressIfSet());
  lc.log(log::INFO, "In Agent::removeAndUnregisterSelf(): Removed agent object.");
  // Then we remove the dangling pointer about ourselves in the agent register.
  // We need to get hold of the agent register, which we suppose is available
  RootEntry re(m_objectStore);
  re.fetchNoLock();
  AgentRegister ar(re.getAgentRegisterAddress(), m_objectStore);
  // Then we should first create a pointer to our agent
  ScopedExclusiveLock arLock(ar);
  ar.fetch();
  ar.removeAgent(getAddressIfSet());
  ar.commit();
  arLock.release();
}

bool cta::objectstore::Agent::isEmpty() {
  checkPayloadReadable();
  if (m_payload.ownedobjects_size())
    return false;
  return true;
}

bool cta::objectstore::Agent::isBeingGarbageCollected() {
  checkPayloadReadable();
  return m_payload.being_garbage_collected();
}

void cta::objectstore::Agent::setBeingGarbageCollected() {
  checkPayloadWritable();
  m_payload.set_being_garbage_collected(true);
}

void cta::objectstore::Agent::setNeedsGarbageCollection() {
  checkPayloadWritable();
  m_payload.set_gc_needed(true);
}

bool cta::objectstore::Agent::needsGarbageCollection() {
  checkPayloadReadable();
  if (!m_payload.has_gc_needed()) return false;
  return m_payload.gc_needed();
}

void cta::objectstore::Agent::garbageCollect(const std::string& presumedOwner, AgentReference & agentReference, log::LogContext & lc,
    cta::catalogue::Catalogue & catalogue) {
  checkPayloadWritable();
  // We are here limited to checking the presumed owner and mark the agent as
  // untracked in the agent register in case of match, else we do nothing
  if (m_header.owner() == presumedOwner) {
    // We need to get hold of the agent register, which we suppose is available
    RootEntry re(m_objectStore);
    ScopedSharedLock reLock(re);
    re.fetch();
    AgentRegister ar(re.getAgentRegisterAddress(), m_objectStore);
    reLock.release();
    // Then we should first create a pointer to our agent
    ScopedExclusiveLock arLock(ar);
    ar.fetch();
    ar.untrackAgent(getAddressIfSet());
    ar.commit();
    arLock.release();
    // We now mark ourselves as owned by the agent register
    setOwner(ar.getAddressIfSet());
    commit();
  }
}



/*void cta::objectstore::Agent::create() {
  if (!m_setupDone)
    throw SetupNotDone("In Agent::create(): setup() not yet done");
  RootEntry re(m_objectStore);
  AgentRegister ar(re.allocateOrGetAgentRegister(*this), m_objectStore);
  ar.addIntendedElement(selfName(), *this);
  serializers::Agent as;
  as.set_heartbeat(0);
  writeChild(selfName(), as);
  ar.upgradeIntendedElementToActual(selfName(), *this);
  m_creationDone = true;
}*/

void cta::objectstore::Agent::addToOwnership(const std::string& name) {
  checkPayloadWritable();
  std::string * owned = m_payload.mutable_ownedobjects()->Add();
  *owned = name;
}

void cta::objectstore::Agent::removeFromOwnership(std::string name) {
  checkPayloadWritable();
  serializers::removeString(m_payload.mutable_ownedobjects(), name);
}

std::list<std::string>
  cta::objectstore::Agent::getOwnershipList() {
  checkPayloadReadable();
  std::list<std::string> ret;
  for (int i=0; i<m_payload.ownedobjects_size(); i++) {
    ret.push_back(m_payload.ownedobjects(i));
  }
  return ret;
}

std::set<std::string> cta::objectstore::Agent::getOwnershipSet() {
  checkPayloadReadable();
  std::set<std::string> ret;
  for (const auto &oo: m_payload.ownedobjects())
    ret.insert(oo);
  return ret;
}

void cta::objectstore::Agent::resetOwnership(const std::set<std::string>& ownershipSet) {
  checkPayloadWritable();
  m_payload.mutable_ownedobjects()->Clear();
  for (const auto &oo: ownershipSet)
    *m_payload.mutable_ownedobjects()->Add() = oo;
}

size_t cta::objectstore::Agent::getOwnershipListSize() {
  checkPayloadReadable();
  return m_payload.ownedobjects_size();
}


void cta::objectstore::Agent::bumpHeartbeat() {
  checkPayloadWritable();
  auto heartbeat=m_payload.heartbeat()+1;
  m_payload.set_heartbeat(heartbeat);
}

uint64_t cta::objectstore::Agent::getHeartbeatCount() {
  checkPayloadReadable();
  return m_payload.heartbeat();
}

double cta::objectstore::Agent::getTimeout() {
  checkPayloadReadable();
  return 0.000001 * m_payload.timeout_us();
}

void cta::objectstore::Agent::setTimeout_us(uint64_t timeout) {
  checkPayloadWritable();
  m_payload.set_timeout_us(timeout);
}

std::string cta::objectstore::Agent::dump() {
  checkPayloadReadable();
  google::protobuf::util::JsonPrintOptions options;
  options.add_whitespace = true;
  options.always_print_primitive_fields = true;
  std::string headerDump;
  google::protobuf::util::MessageToJsonString(m_payload, &headerDump, options);
  return headerDump;
}