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#include "sshremoteprocessrunner.h"

#include "sshconnectionmanager.h"
#include "sshpseudoterminal.h"

#include <utils/qtcassert.h>


/*!
    \class Utils::SshRemoteProcessRunner

    \brief Convenience class for running a remote process over an SSH connection.
*/

namespace Utils {
namespace Internal {
namespace {
enum State { Inactive, Connecting, Connected, ProcessRunning };
} // anonymous namespace

class SshRemoteProcessRunnerPrivate
{
public:
    SshRemoteProcessRunnerPrivate() : m_state(Inactive) {}

    SshRemoteProcess::Ptr m_process;
    SshConnection::Ptr m_connection;
    bool m_runInTerminal;
    SshPseudoTerminal m_terminal;
    QByteArray m_command;
    Utils::SshError m_lastConnectionError;
    QString m_lastConnectionErrorString;
    State m_state;
};

} // namespace Internal

using namespace Internal;

SshRemoteProcessRunner::SshRemoteProcessRunner(QObject *parent)
    : QObject(parent), d(new SshRemoteProcessRunnerPrivate)
{
}

SshRemoteProcessRunner::~SshRemoteProcessRunner()
{
    disconnect();
    setState(Inactive);
    delete d;
}

void SshRemoteProcessRunner::run(const QByteArray &command,
    const SshConnectionParameters &sshParams)
{
    d->m_runInTerminal = false;
    runInternal(command, sshParams);
}

void SshRemoteProcessRunner::runInTerminal(const QByteArray &command,
    const SshPseudoTerminal &terminal, const SshConnectionParameters &sshParams)
{
    d->m_terminal = terminal;
    d->m_runInTerminal = true;
    runInternal(command, sshParams);
}

void SshRemoteProcessRunner::runInternal(const QByteArray &command,
    const SshConnectionParameters &sshParams)
{
    setState(Inactive);
    setState(Connecting);

    d->m_lastConnectionError = SshNoError;
    d->m_lastConnectionErrorString.clear();
    d->m_command = command;
    d->m_connection = SshConnectionManager::instance().acquireConnection(sshParams);
    connect(d->m_connection.data(), SIGNAL(error(Utils::SshError)),
        SLOT(handleConnectionError(Utils::SshError)));
    connect(d->m_connection.data(), SIGNAL(disconnected()), SLOT(handleDisconnected()));
    if (d->m_connection->state() == SshConnection::Connected) {
        handleConnected();
    } else {
        connect(d->m_connection.data(), SIGNAL(connected()), SLOT(handleConnected()));
        if (d->m_connection->state() == SshConnection::Unconnected)
            d->m_connection->connectToHost();
    }
}

void SshRemoteProcessRunner::handleConnected()
{
    QTC_ASSERT(d->m_state == Connecting, return);
    setState(Connected);

    d->m_process = d->m_connection->createRemoteProcess(d->m_command);
    connect(d->m_process.data(), SIGNAL(started()), SLOT(handleProcessStarted()));
    connect(d->m_process.data(), SIGNAL(closed(int)), SLOT(handleProcessFinished(int)));
    connect(d->m_process.data(), SIGNAL(readyReadStandardOutput()), SLOT(handleStdout()));
    connect(d->m_process.data(), SIGNAL(readyReadStandardError()), SLOT(handleStderr()));
    if (d->m_runInTerminal)
        d->m_process->requestTerminal(d->m_terminal);
    d->m_process->start();
}

void SshRemoteProcessRunner::handleConnectionError(Utils::SshError error)
{
    d->m_lastConnectionError = error;
    d->m_lastConnectionErrorString = d->m_connection->errorString();
    handleDisconnected();
    emit connectionError();
}

void SshRemoteProcessRunner::handleDisconnected()
{
    QTC_ASSERT(d->m_state == Connecting || d->m_state == Connected
        || d->m_state == ProcessRunning, return);
    setState(Inactive);
}

void SshRemoteProcessRunner::handleProcessStarted()
{
    QTC_ASSERT(d->m_state == Connected, return);

    setState(ProcessRunning);
    emit processStarted();
}

void SshRemoteProcessRunner::handleProcessFinished(int exitStatus)
{
    switch (exitStatus) {
    case SshRemoteProcess::FailedToStart:
        QTC_ASSERT(d->m_state == Connected, return);
        break;
    case SshRemoteProcess::KilledBySignal:
    case SshRemoteProcess::ExitedNormally:
        QTC_ASSERT(d->m_state == ProcessRunning, return);
        break;
    default:
        Q_ASSERT_X(false, Q_FUNC_INFO, "Impossible exit status.");
    }
    setState(Inactive);
    emit processClosed(exitStatus);
}

void SshRemoteProcessRunner::handleStdout()
{
    emit processOutputAvailable(d->m_process->readAllStandardOutput());
}

void SshRemoteProcessRunner::handleStderr()
{
    emit processErrorOutputAvailable(d->m_process->readAllStandardError());
}

void SshRemoteProcessRunner::setState(int newState)
{
    if (d->m_state == newState)
        return;

    d->m_state = static_cast<State>(newState);
    if (d->m_state == Inactive) {
        if (d->m_process)
            disconnect(d->m_process.data(), 0, this, 0);
        if (d->m_connection) {
            disconnect(d->m_connection.data(), 0, this, 0);
            SshConnectionManager::instance().releaseConnection(d->m_connection);
            d->m_connection.clear();
        }
    }
}

QByteArray SshRemoteProcessRunner::command() const { return d->m_command; }
SshError SshRemoteProcessRunner::lastConnectionError() const { return d->m_lastConnectionError; }
SshRemoteProcess::Ptr SshRemoteProcessRunner::process() const { return d->m_process; }
QString SshRemoteProcessRunner::lastConnectionErrorString() const {
    return d->m_lastConnectionErrorString;
}

} // namespace Utils