#include "rsmcore/sessionworker.hh"
#include "radixbug/bug.hh"

#include <cassert>
#include <sstream>

#include <QByteArray>
#include <QString>

namespace rsm
{
class SessionWorkerImpl
{
 private:
  // privatize copy of this object to prevent their use.
  // would be nice to use c++14 '= delete' but c'est la vie.
  SessionWorkerImpl(const SessionWorkerImpl& orig) { void(sizeof(orig)); }
  void operator=(const SessionWorkerImpl& orig) { void(sizeof(orig)); }

 public:
  Session* session = nullptr;
  QByteArray output_buffer;
  SessionWorkerImpl() { session = new Session(); }
  ~SessionWorkerImpl()
  {
    if (session != nullptr)
    {
      delete session;
    }
  }
};  // class SessionWorkerImpl

void SessionWorker::processPrompts()
{
  QString instruction = p->session->keyboardInteractiveInstruction();
  QString name        = p->session->keyboardInteractiveName();
  // build list of prompts
  QStringList prompts = p->session->keyboardInteractivePrompts();
  emit interactiveAuthenticationRequested(instruction, name, prompts);
}

SessionWorker::SessionWorker(QObject* parent)
    : QObject(parent)
{
  p = new SessionWorkerImpl();
}

SessionWorker::SessionWorker(QString host, QObject* parent)
    : QObject(parent)
{
  p = new SessionWorkerImpl();
  setHost(host);
}

SessionWorker::~SessionWorker()
{
  if (p != nullptr) delete p;
}

QByteArray SessionWorker::readExecOutput() { return p->output_buffer; }

Session* SessionWorker::session() { return p->session; }

void SessionWorker::setHost(QString host) { p->session->setHost(host); }
void SessionWorker::setLogVerbosity(SessionVerbosity level)
{
  p->session->setLogVerbosity(level);
}
void SessionWorker::setPort(int port) { p->session->setPort(port); }
void SessionWorker::setUser(QString name) { p->session->setUser(name); }

void SessionWorker::setProxyCommand(QString command)
{
  p->session->setProxyCommand(command);
}
void SessionWorker::connect()
{
  radix_tagged_line("connect()");
  if (p->session->isConnected()) p->session->disconnect();
  bool rc = p->session->connect();
  if (!rc)
  {
    // get error message
    QString host    = p->session->host();
    QString error   = p->session->getError();
    QString message = "Error connecting to ";
    message.append(host).append(": ").append(error);
    emit connectionFailed(message);
    return;
  }
  emit connectionSuccessful();
}
void SessionWorker::disconnect()
{
  radix_tagged_line("disconnect()");
  if (p->session->isConnected())
  {
    radix_tagged_line("Disconnecting session.");
    p->session->disconnect();
    emit disconnectSuccessful();
  }
}

void SessionWorker::verifyKnownHost()
{
  SessionHostState state = p->session->verifyKnownHost();
  QString qhexa;

  switch (state)
  {
    case SessionHostState::OK:
      /* OK */

      break;
    case SessionHostState::CHANGED:

      qhexa = p->session->getHexa();
      radix_tagged_line("SSH_KNOWN_HOSTS_CHANGED: " << qhexa.toStdString());
      emit hostPublicKeyChanged(qhexa);
      break;
    case SessionHostState::OTHER:
      radix_tagged_line("SSH_KNOWN_HOSTS_OTHER");
      emit hostPublicKeyUnavailable();
      break;
    case SessionHostState::NOT_FOUND:
      /* FALL THROUGH to SSH_SERVER_NOT_KNOWN behavior */
      radix_tagged_line("SSH_KNOWN_HOSTS_NOT_FOUND");

    case SessionHostState::UNKNOWN:
      qhexa = p->session->getHexa();
      radix_tagged_line("SSH_KNOWN_HOSTS_UNKNOWN: " << qhexa.toStdString());
      emit hostUnknown(qhexa);
      break;
    case SessionHostState::ERROR_STATE:
      QString message = p->session->getError();
      radix_tagged_line("SSH_KNOWN_HOSTS_ERROR: " << message.toStdString());
      emit knownHostError(message);
      break;
  }
  emit verifyKnownHostSuccessful();
}

void SessionWorker::acceptHostPublicKeyUpdate()
{
  radix_tagged_line("authenticateHostPublicKeyUpdate()");
  bool rc = p->session->updateKnownHosts();

  if (!rc)
  {
    emit updateKnownHostsFailed();
  }
}

void SessionWorker::authenticate()
{
  radix_tagged_line("Authenticate.");

  // get acceptable methods
  int method = p->session->authenticationMethodList();

  // Try to authenticate with public key first
  if (method & SessionAuthMethodPUBLICKEY)
  {
    SessionAuthState state = p->session->authenticateWithPublicKey();
    if (state == SessionAuthState::ERROR_STATE)
    {
      QString message = p->session->getError();
      emit authenticationError(message);
      return;
    }
    else if (state == SessionAuthState::SUCCESS)
    {
      radix_tagged_line("SSH_AUTH_METHOD_PUBLICKEY succeeded.");
      emit authenticationSucceeded();
      return;
    }
    radix_tagged_line("SSH_AUTH_METHOD_PUBLICKEY didn't work.");
  }  // public key authentication

  // Try to authenticate with keyboard interactive";
  if (method & SessionAuthMethodINTERACTIVE)
  {
    SessionAuthState state = p->session->authenticateInteractively();
    while (state == SessionAuthState::INFO)
    {
      processPrompts();
      return;
    }
  }

  // Try to authenticate with password
  if (method & SessionAuthMethodPASSWORD)
  {
    radix_tagged_line("SSH_AUTH_METHOD_PASSWORD required.");
    emit passwordRequested();
    return;
  }
  if (method & SessionAuthMethodUNKNOWN)
  {
    radix_tagged_line("SSH_AUTH_METHOD_UNKNOWN.");
    emit authenticationError(p->session->getError());
  }
}

void SessionWorker::authenticateWithPassword(QString pswd)
{
  radix_tagged_line("Authenticate with password.");
  SessionAuthState state = p->session->authenticateWithPassword(pswd);
  if (state == SessionAuthState::ERROR_STATE ||
      state == SessionAuthState::DENIED)
  {
    QString message = p->session->getError();
    emit authenticationError(message);
  }
  else if (state == SessionAuthState::SUCCESS)
  {
    radix_tagged_line("SSH_AUTH_METHOD_PASSWORD succeeded.");
    emit authenticationSucceeded();
    QString banner = p->session->loginIssueBanner();
    if (!banner.isEmpty())
    {
      emit loginBannerIssued(banner);
    }
  }
}

void SessionWorker::authenticatePrompts(QStringList responses)
{
  radix_tagged_line("authenticatePrompts()");
  SessionAuthState state = p->session->authenticatePrompts(responses);
  if (state == SessionAuthState::DENIED)
  {
    emit authenticationError("Authentication denied.");
    p->session->disconnect();
    return;
  }
  if (state == SessionAuthState::INFO)
  {
    processPrompts();
    return;
  }
  if (state == SessionAuthState::SUCCESS)
  {
    emit authenticationSucceeded();
    return;
  }
}

void SessionWorker::requestExec(QString command)
{
  radix_tagged_line("requestExec(" << command.toStdString() << ")");
  Channel* channel = p->session->newChannel();
  // clear any previous buffer
  p->output_buffer.clear();
  bool rc = channel->open();
  if (!rc)
  {
    radix_tagged_line("Failed to open channel");
    emit execFailed("Failed to open a channel on the session.");
    delete channel;
    return;
  }

  rc = channel->exec(command);
  if (!rc)
  {
    radix_tagged_line("Failed to request exec.");
    emit execFailed("Failed to execute remote command.");
    channel->close();
    delete channel;
    return;
  }

  // TODO: should we use timeout or non-blocking version of this call?
  // read stdout
  QString bytes = channel->readExecOut();
  while (!bytes.isEmpty())
  {
    p->output_buffer.append(bytes);
    bytes = channel->readExecOut();
  }

  // read stderr
  bytes = channel->readExecErr();
  while (!bytes.isEmpty())
  {
    p->output_buffer.append(bytes);
    bytes = channel->readExecErr();
  }
  emit execOutputReady();
  radix_tagged_line("nbytes=" << p->output_buffer.size());
  radix_tagged_line("Finished reading response\n" << p->output_buffer.data());
  channel->close();
  delete channel;
  radix_tagged_line("'" << command.toStdString() << "' finished.");
  emit execFinished();
}

}  // namespace rsm