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// Session Server
#include "session/session_server.h"

#include "base/base.h"
#include "base/scheduler.h"
#include "ipc/ipc.h"
#include "ipc/named_event.h"
#include "session/commands.pb.h"
#include "session/session_handler.h"
#include "session/session_usage_observer.h"
#include "usage_stats/usage_stats.h"


namespace {
const int kNumConnections = 10;
const int kTimeOut = 5000;  // 5000msec
const char kSessionName[] = "session";
const char kEventName[] = "session";
}

namespace mozc {

SessionServer::SessionServer()
    : IPCServer(kSessionName, kNumConnections, kTimeOut),
      handler_(new SessionHandler()),
      usage_observer_(new session::SessionUsageObserver()) {
  using usage_stats::UsageStats;
  // start session watch dog timer
  handler_->StartWatchDog();
  handler_->AddObserver(usage_observer_.get());

  // start usage stats timer
  // send usage stats within 5 min later
  // attempt to send every 5 min -- 2 hours.
  Scheduler::AddJob(Scheduler::JobSetting(
      "UsageStatsTimer",
      UsageStats::kDefaultScheduleInterval,
      UsageStats::kDefaultScheduleMaxInterval,
      UsageStats::kDefaultSchedulerDelay,
      UsageStats::kDefaultSchedulerRandomDelay,
      &UsageStats::Send,
      NULL));


  // Send a notification event to the UI.
  NamedEventNotifier notifier(kEventName);
  if (!notifier.Notify()) {
    LOG(WARNING) << "NamedEvent " << kEventName << " is not found";
  }
}

SessionServer::~SessionServer() {}

bool SessionServer::Connected() const {
  return (handler_.get() != NULL &&
          handler_->IsAvailable() &&
          IPCServer::Connected());
}

bool SessionServer::Process(const char *request,
                            size_t request_size,
                            char *response,
                            size_t *response_size) {
  if (handler_.get() == NULL) {
    LOG(WARNING) << "handler is not available";
    return false;   // shutdown the server if handler doesn't exist
  }

  commands::Command command;   // can define as a private member?
  if (!command.mutable_input()->ParseFromArray(request, request_size)) {
    LOG(WARNING) << "Invalid request";
    *response_size = 0;
    return true;
  }

  if (!handler_->EvalCommand(&command)) {
    LOG(WARNING) << "EvalCommand() returned false. Exiting the loop.";
    *response_size = 0;
    return false;
  }

  string output;
  if (!command.output().SerializeToString(&output)) {
    LOG(WARNING) << "SerializeToString() failed";
    *response_size = 0;
    return true;
  }

  // TODO(taku) automatically increase the buffer.
  // Needs to fix IPCServer as well
  if (*response_size < output.size()) {
    LOG(WARNING) << "response size < output.size";
    *response_size = 0;
    return true;
  }

  ::memcpy(response, output.data(), output.size());
  *response_size = output.size();

  // debug message
  VLOG(2) << command.DebugString();

  return true;
}
}  // namespace mozc