/**
 *   Copyright 2016 Pivotal Software, Inc.
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 **/

#include "query_execution/BlockLocator.hpp"

#include <cstdlib>
#include <string>
#include <utility>

#include "query_execution/QueryExecutionMessages.pb.h"
#include "query_execution/QueryExecutionTypedefs.hpp"
#include "query_execution/QueryExecutionUtil.hpp"
#include "storage/StorageBlockInfo.hpp"
#include "threading/ThreadUtil.hpp"

#include "glog/logging.h"

#include "tmb/id_typedefs.h"
#include "tmb/message_bus.h"
#include "tmb/tagged_message.h"

using std::free;
using std::malloc;
using std::move;

using tmb::TaggedMessage;
using tmb::client_id;

namespace quickstep {

void BlockLocator::run() {
  if (cpu_id_ >= 0) {
    ThreadUtil::BindToCPU(cpu_id_);
  }

  for (;;) {
    // Receive() is a blocking call, causing this thread to sleep until next
    // message is received.
    const tmb::AnnotatedMessage annotated_message = bus_->Receive(locator_client_id_, 0, true);
    const TaggedMessage &tagged_message = annotated_message.tagged_message;
    const client_id sender = annotated_message.sender;
    LOG(INFO) << "BlockLocator received the typed '" << tagged_message.message_type()
              << "' message from TMB Client " << sender;
    switch (tagged_message.message_type()) {
      case kBlockDomainRegistrationMessage: {
        serialization::BlockDomainRegistrationMessage proto;
        CHECK(proto.ParseFromArray(tagged_message.message(), tagged_message.message_bytes()));

        processBlockDomainRegistrationMessage(sender, proto.domain_network_address());
        break;
      }
      case kAddBlockLocationMessage: {
        serialization::BlockLocationMessage proto;
        CHECK(proto.ParseFromArray(tagged_message.message(), tagged_message.message_bytes()));

        const block_id block = proto.block_id();
        const block_id_domain domain = proto.block_domain();

        const auto result_block_locations = block_locations_[block].insert(domain);
        const auto result_domain_blocks = domain_blocks_[domain].insert(block);
        DCHECK_EQ(result_block_locations.second, result_domain_blocks.second);

        if (result_domain_blocks.second) {
          LOG(INFO) << "Block " << BlockIdUtil::ToString(block) << " loaded in Domain " << domain;
        } else {
          LOG(INFO) << "Block " << BlockIdUtil::ToString(block) << " existed in Domain " << domain;
        }
        break;
      }
      case kDeleteBlockLocationMessage: {
        serialization::BlockLocationMessage proto;
        CHECK(proto.ParseFromArray(tagged_message.message(), tagged_message.message_bytes()));

        const block_id block = proto.block_id();
        const block_id_domain domain = proto.block_domain();

        const auto cit = block_locations_[block].find(domain);
        if (cit != block_locations_[block].end()) {
          block_locations_[block].erase(domain);
          domain_blocks_[domain].erase(block);

          LOG(INFO) << "Block " << BlockIdUtil::ToString(block) << " evicted in Domain " << domain;
        } else {
          LOG(INFO) << "Block " << BlockIdUtil::ToString(block) << " not found in Domain " << domain;
        }
        break;
      }
      case kLocateBlockMessage: {
        serialization::BlockMessage proto;
        CHECK(proto.ParseFromArray(tagged_message.message(), tagged_message.message_bytes()));

        processLocateBlockMessage(sender, proto.block_id());
        break;
      }
      case kGetPeerDomainNetworkAddressesMessage: {
        serialization::BlockMessage proto;
        CHECK(proto.ParseFromArray(tagged_message.message(), tagged_message.message_bytes()));

        processGetPeerDomainNetworkAddressesMessage(sender, proto.block_id());
        break;
      }
      case kBlockDomainUnregistrationMessage: {
        serialization::BlockDomainMessage proto;
        CHECK(proto.ParseFromArray(tagged_message.message(), tagged_message.message_bytes()));

        const block_id_domain domain = proto.block_domain();

        domain_network_addresses_.erase(domain);

        for (const block_id block : domain_blocks_[domain]) {
          block_locations_[block].erase(domain);
        }
        domain_blocks_.erase(domain);

        LOG(INFO) << "Unregistered Domain " << domain;
        break;
      }
      case kPoisonMessage: {
        return;
      }
    }
  }
}

void BlockLocator::processBlockDomainRegistrationMessage(const client_id receiver,
                                                         const std::string &network_address) {
  DCHECK_LT(block_domain_, kMaxDomain);

  domain_network_addresses_.emplace(++block_domain_, network_address);
  domain_blocks_[block_domain_];

  serialization::BlockDomainMessage proto;
  proto.set_block_domain(block_domain_);

  const int proto_length = proto.ByteSize();
  char *proto_bytes = static_cast<char*>(malloc(proto_length));
  CHECK(proto.SerializeToArray(proto_bytes, proto_length));

  TaggedMessage message(static_cast<const void*>(proto_bytes),
                                 proto_length,
                                 kBlockDomainRegistrationResponseMessage);
  free(proto_bytes);

  LOG(INFO) << "BlockLocator (id '" << locator_client_id_
            << "') sent BlockDomainRegistrationResponseMessage (typed '"
            << kBlockDomainRegistrationResponseMessage
            << "') to Worker (id '" << receiver << "')";
  CHECK(tmb::MessageBus::SendStatus::kOK ==
      QueryExecutionUtil::SendTMBMessage(bus_,
                                         locator_client_id_,
                                         receiver,
                                         move(message)));
}

void BlockLocator::processLocateBlockMessage(const client_id receiver,
                                             const block_id block) {
  serialization::LocateBlockResponseMessage proto;

  for (const block_id_domain domain : block_locations_[block]) {
    proto.add_block_domains(domain);
  }

  const int proto_length = proto.ByteSize();
  char *proto_bytes = static_cast<char*>(malloc(proto_length));
  CHECK(proto.SerializeToArray(proto_bytes, proto_length));

  TaggedMessage message(static_cast<const void*>(proto_bytes),
                                 proto_length,
                                 kLocateBlockResponseMessage);
  free(proto_bytes);

  LOG(INFO) << "BlockLocator (id '" << locator_client_id_
            << "') sent LocateBlockResponseMessage (typed '" << kLocateBlockResponseMessage
            << "') to StorageManager (id '" << receiver << "')";
  CHECK(tmb::MessageBus::SendStatus::kOK ==
      QueryExecutionUtil::SendTMBMessage(bus_,
                                         locator_client_id_,
                                         receiver,
                                         move(message)));
}

void BlockLocator::processGetPeerDomainNetworkAddressesMessage(const client_id receiver,
                                                               const block_id block) {
  serialization::GetPeerDomainNetworkAddressesResponseMessage proto;

  for (const block_id_domain domain : block_locations_[block]) {
    proto.add_domain_network_addresses(domain_network_addresses_[domain]);
  }

  const int proto_length = proto.ByteSize();
  char *proto_bytes = static_cast<char*>(malloc(proto_length));
  CHECK(proto.SerializeToArray(proto_bytes, proto_length));

  TaggedMessage message(static_cast<const void*>(proto_bytes),
                                 proto_length,
                                 kGetPeerDomainNetworkAddressesResponseMessage);
  free(proto_bytes);

  LOG(INFO) << "BlockLocator (id '" << locator_client_id_
            << "') sent GetPeerDomainNetworkAddressesResponseMessage (typed '"
            << kGetPeerDomainNetworkAddressesResponseMessage
            << "') to StorageManager (id '" << receiver << "')";
  CHECK(tmb::MessageBus::SendStatus::kOK ==
      QueryExecutionUtil::SendTMBMessage(bus_,
                                         locator_client_id_,
                                         receiver,
                                         move(message)));
}

}  // namespace quickstep