/******************************************************************************
 *   Copyright (C) 2011 Frank Osterfeld <frank.osterfeld@gmail.com>           *
 *                                                                            *
 * 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. For licensing and distribution        *
 * details, check the accompanying file 'COPYING'.                            *
 *****************************************************************************/
#include "keychain_p.h"
#include "keychain_dbus_p.h"

#include <QSettings>

using namespace QKeychain;

JobExecutor::JobExecutor()
    : QObject( 0 )
    , m_runningJob( 0 )
{
}

void JobExecutor::enqueue( Job* job ) {
    m_queue.append( job );
    startNextIfNoneRunning();
}

void JobExecutor::startNextIfNoneRunning() {
    if ( m_queue.isEmpty() || m_runningJob )
        return;
    QPointer<Job> next;
    while ( !next && !m_queue.isEmpty() ) {
        next = m_queue.first();
        m_queue.pop_front();
    }
    if ( next ) {
        connect( next, SIGNAL(finished(QKeychain::Job*)), this, SLOT(jobFinished(QKeychain::Job*)) );
        connect( next, SIGNAL(destroyed(QObject*)), this, SLOT(jobDestroyed(QObject*)) );
        m_runningJob = next;
        if ( ReadPasswordJob* rpj = qobject_cast<ReadPasswordJob*>( m_runningJob ) )
            rpj->d->scheduledStart();
        else if ( WritePasswordJob* wpj = qobject_cast<WritePasswordJob*>( m_runningJob) )
            wpj->d->scheduledStart();
    }
}

void JobExecutor::jobDestroyed( QObject* object ) {
    Q_UNUSED( object ) // for release mode
    Q_ASSERT( object == m_runningJob );
    m_runningJob->disconnect( this );
    m_runningJob = 0;
    startNextIfNoneRunning();
}

void JobExecutor::jobFinished( Job* job ) {
    Q_UNUSED( job ) // for release mode
    Q_ASSERT( job == m_runningJob );
    m_runningJob->disconnect( this );
    m_runningJob = 0;
    startNextIfNoneRunning();
}

JobExecutor* JobExecutor::s_instance = 0;

JobExecutor* JobExecutor::instance() {
    if ( !s_instance )
        s_instance = new JobExecutor;
    return s_instance;
}

void ReadPasswordJobPrivate::doStart() {
    JobExecutor::instance()->enqueue( q );
}

void ReadPasswordJobPrivate::scheduledStart() {
    iface = new org::kde::KWallet( QLatin1String("org.kde.kwalletd"), QLatin1String("/modules/kwalletd"), QDBusConnection::sessionBus(), this );
    const QDBusPendingReply<int> reply = iface->open( QLatin1String("kdewallet"), 0, q->service() );
    QDBusPendingCallWatcher* watcher = new QDBusPendingCallWatcher( reply, this );
    connect( watcher, SIGNAL(finished(QDBusPendingCallWatcher*)), this, SLOT(kwalletOpenFinished(QDBusPendingCallWatcher*)) );
}

void ReadPasswordJobPrivate::kwalletOpenFinished( QDBusPendingCallWatcher* watcher ) {
    watcher->deleteLater();
    const QDBusPendingReply<int> reply = *watcher;
    if ( reply.isError() ) {
        const QDBusError err = reply.error();
        if ( err.type() == QDBusError::ServiceUnknown ) //KWalletd not running
            q->emitFinishedWithError( NoBackendAvailable, tr("No keychain service available") );
        else
            q->emitFinishedWithError( OtherError, tr("Could not open wallet: %1; %2").arg( QDBusError::errorString( err.type() ), err.message() ) );
        return;
    }

    walletHandle = reply.value();

    if ( walletHandle < 0 ) {
        q->emitFinishedWithError( AccessDenied, tr("Access to keychain denied") );
        return;
    }

    const QDBusPendingReply<int> nextReply = iface->entryType( walletHandle, q->service(), key, q->service() );
    QDBusPendingCallWatcher* nextWatcher = new QDBusPendingCallWatcher( nextReply, this );
    connect( nextWatcher, SIGNAL(finished(QDBusPendingCallWatcher*)), this, SLOT(kwalletEntryTypeFinished(QDBusPendingCallWatcher*)) );
}

void ReadPasswordJobPrivate::kwalletEntryTypeFinished( QDBusPendingCallWatcher* watcher ) {
    watcher->deleteLater();
    if ( watcher->isError() ) {
        const QDBusError err = watcher->error();
        q->emitFinishedWithError( OtherError, tr("Could not determine data type: %1; %2").arg( QDBusError::errorString( err.type() ), err.message() ) );
        return;
    }

    const QDBusPendingReply<int> reply = *watcher;

    dataType = reply.value() == 1/*Password*/ ? Text : Binary;

    const QDBusPendingCall nextReply = dataType == Text
        ? QDBusPendingCall( iface->readPassword( walletHandle, q->service(), key, q->service() ) )
        : QDBusPendingCall( iface->readEntry( walletHandle, q->service(), key, q->service() ) );
    QDBusPendingCallWatcher* nextWatcher = new QDBusPendingCallWatcher( nextReply, this );
    connect( nextWatcher, SIGNAL(finished(QDBusPendingCallWatcher*)), this, SLOT(kwalletReadFinished(QDBusPendingCallWatcher*)) );
}

void ReadPasswordJobPrivate::kwalletReadFinished( QDBusPendingCallWatcher* watcher ) {
    watcher->deleteLater();
    if ( watcher->isError() ) {
        const QDBusError err = watcher->error();
        q->emitFinishedWithError( OtherError, tr("Could not read password: %1; %2").arg( QDBusError::errorString( err.type() ), err.message() ) );
        return;
    }

    if ( dataType == Binary ) {
        QDBusPendingReply<QByteArray> reply = *watcher;
        data = reply.value();
    } else {
        QDBusPendingReply<QString> reply = *watcher;
        data = reply.value().toUtf8();
    }
    q->emitFinished();
}

void WritePasswordJobPrivate::doStart() {
    JobExecutor::instance()->enqueue( q );
}

void WritePasswordJobPrivate::scheduledStart() {
    iface = new org::kde::KWallet( QLatin1String("org.kde.kwalletd"), QLatin1String("/modules/kwalletd"), QDBusConnection::sessionBus(), this );
    const QDBusPendingReply<int> reply = iface->open( QLatin1String("kdewallet"), 0, q->service() );
    QDBusPendingCallWatcher* watcher = new QDBusPendingCallWatcher( reply, this );
    connect( watcher, SIGNAL(finished(QDBusPendingCallWatcher*)), this, SLOT(kwalletOpenFinished(QDBusPendingCallWatcher*)) );
}

void WritePasswordJobPrivate::kwalletOpenFinished( QDBusPendingCallWatcher* watcher ) {
    watcher->deleteLater();
    QDBusPendingReply<int> reply = *watcher;
    if ( reply.isError() ) {
        const QDBusError err = reply.error();
        q->emitFinishedWithError( OtherError, tr("Could not open wallet: %1; %2").arg( QDBusError::errorString( err.type() ), err.message() ) );
        return;
    }

    const int handle = reply.value();

    if ( handle < 0 ) {
        q->emitFinishedWithError( AccessDenied, tr("Access to keychain denied") );
        return;
    }

    QDBusPendingReply<int> nextReply;

    if ( !textData.isEmpty() )
        nextReply = iface->writePassword( handle, q->service(), key, textData, q->service() );
    else if ( !binaryData.isEmpty() )
        nextReply = iface->writeEntry( handle, q->service(), key, binaryData, q->service() );
    else
        nextReply = iface->removeEntry( handle, q->service(), key, q->service() );

    QDBusPendingCallWatcher* nextWatcher = new QDBusPendingCallWatcher( nextReply, this );
    connect( nextWatcher, SIGNAL(finished(QDBusPendingCallWatcher*)), this, SLOT(kwalletWriteFinished(QDBusPendingCallWatcher*)) );
}

void WritePasswordJobPrivate::kwalletWriteFinished( QDBusPendingCallWatcher* watcher ) {
    watcher->deleteLater();
    QDBusPendingReply<int> reply = *watcher;
    if ( reply.isError() ) {
        const QDBusError err = reply.error();
        q->emitFinishedWithError( OtherError, tr("Could not open wallet: %1; %2").arg( QDBusError::errorString( err.type() ), err.message() ) );
        return;
    }

    q->emitFinished();
}