/*
 * SPDX-License-Identifier: Apache-2.0
 * Copyright (C) 2020 Raspberry Pi (Trading) Limited
 */

#include "imagewriter.h"
#include "drivelistitem.h"
#include "downloadextractthread.h"
#include "dependencies/drivelist/src/drivelist.hpp"
#include "driveformatthread.h"
#include <archive.h>
#include <archive_entry.h>
#include <QFileInfo>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include <QProcess>
#include <QFileDialog>
#include <QStandardPaths>
#include <QStorageInfo>
#include <QWindow>
#include <QDebug>

#ifdef Q_OS_WIN
#include <windows.h>
#include <winioctl.h>
#endif

ImageWriter::ImageWriter(QObject *parent)
    : QObject(parent), _repo(QUrl(QString(OSLIST_URL))), _dlnow(0), _verifynow(0),
      _engine(nullptr), _thread(nullptr), _verifyEnabled(false), _cachingEnabled(false)
{
    connect(&_polltimer, SIGNAL(timeout()), SLOT(pollProgress()));

#ifdef Q_OS_WIN
    QProcess *p = new QProcess(this);
    p->start("net stop ShellHWDetection");
#endif

    if (!_settings.isWritable() && !_settings.fileName().isEmpty())
    {
        /* Settings file is not writable, probably run by root previously */
        QString settingsFile = _settings.fileName();
        qDebug() << "Settings file" << settingsFile << "not writable. Recreating it";
        QFile f(_settings.fileName());
        QByteArray oldsettings;

        if (f.open(f.ReadOnly))
        {
            oldsettings = f.readAll();
            f.close();
        }
        f.remove();
        if (f.open(f.WriteOnly))
        {
            f.write(oldsettings);
            f.close();
            _settings.sync();
        }
        else
        {
            qDebug() << "Error deleting and recreating settings file. Please remove manually.";
        }
    }

    _settings.beginGroup("caching");
    _cachingEnabled = _settings.value("enabled", IMAGEWRITER_ENABLE_CACHE_DEFAULT).toBool();
    _cachedFileHash = _settings.value("lastDownloadSHA256").toByteArray();
    _cacheFileName = QStandardPaths::writableLocation(QStandardPaths::CacheLocation)+QDir::separator()+"lastdownload.cache";
    if (!_cachedFileHash.isEmpty())
    {
        QFileInfo f(_cacheFileName);
        if (!f.exists() || !f.isReadable() || !f.size())
        {
            _cachedFileHash.clear();
            _settings.remove("lastDownloadSHA256");
            _settings.sync();
        }
    }
    _settings.endGroup();
}

ImageWriter::~ImageWriter()
{
#ifdef Q_OS_WIN
    QProcess *p = new QProcess(this);
    p->startDetached("net start ShellHWDetection");
#endif
}

void ImageWriter::setEngine(QQmlApplicationEngine *engine)
{
    _engine = engine;
}

/* Set URL to download from */
void ImageWriter::setSrc(const QUrl &url, quint64 downloadLen, quint64 extrLen, QByteArray expectedHash, bool multifilesinzip)
{
    _src = url;
    _downloadLen = downloadLen;
    _extrLen = extrLen;
    _expectedHash = expectedHash;
    _multipleFilesInZip = multifilesinzip;

    if (!_downloadLen && url.isLocalFile())
    {
        QFileInfo fi(url.toLocalFile());
        _downloadLen = fi.size();
    }
}

/* Set device to write to */
void ImageWriter::setDst(const QString &device, quint64 deviceSize)
{
    _dst = device;
    _devLen = deviceSize;
}

/* Returns true if src and dst are set */
bool ImageWriter::readyToWrite()
{
    return !_src.isEmpty() && !_dst.isEmpty();
}

/* Start writing */
void ImageWriter::startWrite()
{
    if (!readyToWrite())
        return;

    if (_src.toString() == "internal://format")
    {
        DriveFormatThread *dft = new DriveFormatThread(_dst.toLatin1(), this);
        connect(dft, SIGNAL(success()), SLOT(onSuccess()));
        connect(dft, SIGNAL(error(QString)), SLOT(onError(QString)));
        dft->start();
        return;
    }

    QByteArray urlstr = _src.toString(_src.FullyEncoded).toLatin1();
    QString lowercaseurl = urlstr.toLower();
    bool compressed = lowercaseurl.endsWith(".zip") || lowercaseurl.endsWith(".xz") || lowercaseurl.endsWith(".bz2") || lowercaseurl.endsWith(".gz") || lowercaseurl.endsWith(".7z") || lowercaseurl.endsWith(".cache");
    if (!_extrLen && _src.isLocalFile())
    {
        if (!compressed)
            _extrLen = _downloadLen;
        else if (lowercaseurl.endsWith(".zip"))
            _parseCompressedFile();
    }

    if (_devLen && _extrLen > _devLen)
    {
        emit error(tr("Storage capacity is not large enough.\nNeeds to be at least %1 GB").arg(QString::number(_extrLen/1000000000.0, 'f', 1)));
        return;
    }

    if (_extrLen && !_multipleFilesInZip && _extrLen % 512 != 0)
    {
        emit error(tr("Input file is not a valid disk image.\nFile size %1 bytes is not a multiple of 512 bytes.").arg(_extrLen));
        return;
    }

    if (!_expectedHash.isEmpty() && _cachedFileHash == _expectedHash)
    {
        // Use cached file
        urlstr = QUrl::fromLocalFile(_cacheFileName).toString(_src.FullyEncoded).toLatin1();
    }

    if (compressed)
    {
        _thread = new DownloadExtractThread(urlstr, _dst.toLatin1(), _expectedHash, this);
    }
    else
    {
        _thread = new DownloadThread(urlstr, _dst.toLatin1(), _expectedHash, this);
    }

    _powersave.applyBlock(tr("Downloading and writing image"));

    connect(_thread, SIGNAL(success()), SLOT(onSuccess()));
    connect(_thread, SIGNAL(error(QString)), SLOT(onError(QString)));
    _thread->setVerifyEnabled(_verifyEnabled);

    if (!_expectedHash.isEmpty() && _cachedFileHash != _expectedHash && _cachingEnabled)
    {
        if (!_cachedFileHash.isEmpty())
        {
            if (_settings.isWritable() && QFile::remove(_cacheFileName))
            {
                _settings.remove("caching/lastDownloadSHA256");
                _settings.sync();
                _cachedFileHash.clear();
            }
            else
            {
                qDebug() << "Error removing old cache file. Disabling caching";
                _cachingEnabled = false;
            }
        }

        if (_cachingEnabled)
        {
            QStorageInfo si(QStandardPaths::writableLocation(QStandardPaths::CacheLocation));
            qint64 avail = si.bytesAvailable();
            qDebug() << "Available disk space for caching:" << avail/1024/1024/1024 << "GB";

            if (avail-_downloadLen < IMAGEWRITER_MINIMAL_SPACE_FOR_CACHING)
            {
                qDebug() << "Low disk space. Not caching files to disk.";
            }
            else
            {
                _thread->setCacheFile(_cacheFileName, _downloadLen);
                connect(_thread, SIGNAL(cacheFileUpdated(QByteArray)), SLOT(onCacheFileUpdated(QByteArray)));
            }
        }
    }

    if (_multipleFilesInZip)
    {
        static_cast<DownloadExtractThread *>(_thread)->enableMultipleFileExtraction();
        DriveFormatThread *dft = new DriveFormatThread(_dst.toLatin1(), this);
        connect(dft, SIGNAL(success()), _thread, SLOT(start()));
        connect(dft, SIGNAL(error(QString)), SLOT(onError(QString)));
        dft->start();
    }
    else
    {
        _thread->start();
    }

    _polltimer.start(PROGRESS_UPDATE_INTERVAL);
}

void ImageWriter::onCacheFileUpdated(QByteArray sha256)
{
    _settings.setValue("caching/lastDownloadSHA256", sha256);
    _settings.sync();
    _cachedFileHash = sha256;
    qDebug() << "Done writing cache file";
}

/* Cancel write */
void ImageWriter::cancelWrite()
{
    if (_thread)
    {
        connect(_thread, SIGNAL(finished()), SLOT(onCancelled()));
        _thread->cancelDownload();
    }

    if (!_thread || !_thread->isRunning())
    {
        emit cancelled();
    }
}

void ImageWriter::onCancelled()
{
    sender()->deleteLater();
    if (sender() == _thread)
    {
        _thread = nullptr;
    }
    emit cancelled();
}

/* Return true if url is in our local disk cache */
bool ImageWriter::isCached(const QUrl &, const QByteArray &sha256)
{
    return !sha256.isEmpty() && _cachedFileHash == sha256;
}

/* Utility function to return filename part from URL */
QString ImageWriter::fileNameFromUrl(const QUrl &url)
{
    //return QFileInfo(url.toLocalFile()).fileName();
    return url.fileName();
}

QString ImageWriter::srcFileName()
{
    return _src.isEmpty() ? "" : _src.fileName();
}

/* Function to return OS list URL */
QUrl ImageWriter::constantOsListUrl() const
{
    return _repo;
}

/* Function to return version */
QString ImageWriter::constantVersion() const
{
    return IMAGER_VERSION_STR;
}

void ImageWriter::setCustomOsListUrl(const QUrl &url)
{
    _repo = url;
}

/* Refresh the list of available drives */
void ImageWriter::refreshDriveList()
{
    _drivelist.refreshDriveList();
}

DriveListModel *ImageWriter::getDriveList()
{
    return &_drivelist;
}

void ImageWriter::pollProgress()
{
    if (!_thread)
        return;

    quint64 newDlNow, dlTotal;
    if (_extrLen)
    {
        newDlNow = _thread->bytesWritten();
        dlTotal = _extrLen;
    }
    else
    {
        newDlNow = _thread->dlNow();
        dlTotal = _thread->dlTotal();
    }

    if (newDlNow != _dlnow)
    {
        _dlnow = newDlNow;
        emit downloadProgress(newDlNow, dlTotal);
    }

    quint64 newVerifyNow = _thread->verifyNow();

    if (newVerifyNow != _verifynow)
    {
        _verifynow = newVerifyNow;
        quint64 verifyTotal = _thread->verifyTotal();
        emit verifyProgress(newVerifyNow, verifyTotal);
    }
}

void ImageWriter::setVerifyEnabled(bool verify)
{
    _verifyEnabled = verify;
    if (_thread)
        _thread->setVerifyEnabled(verify);
}

/* Relay events from download thread to QML */
void ImageWriter::onSuccess()
{
    _polltimer.stop();
    pollProgress();
    _powersave.removeBlock();
    emit success();
}

void ImageWriter::onError(QString msg)
{
    _polltimer.stop();
    pollProgress();
    _powersave.removeBlock();
    emit error(msg);
}

void ImageWriter::onFinalizing()
{
    _polltimer.stop();
    emit finalizing();
}

void ImageWriter::openFileDialog()
{
    QFileDialog *fd = new QFileDialog(nullptr, tr("Select image"),
                                      QStandardPaths::writableLocation(QStandardPaths::DownloadLocation),
                                      "Image files (*.img *.zip *.gz *.xz);;All files (*.*)");
    connect(fd, SIGNAL(fileSelected(QString)), SLOT(onFileSelected(QString)));

    if (_engine)
    {
        fd->createWinId();
        QWindow *handle = fd->windowHandle();
        QWindow *qmlwindow = qobject_cast<QWindow *>(_engine->rootObjects().value(0));
        if (qmlwindow)
        {
            handle->setTransientParent(qmlwindow);
        }
    }

    fd->show();
}

void ImageWriter::onFileSelected(QString filename)
{
    QFileInfo fi(filename);

    if (fi.isFile())
    {
        emit fileSelected(QUrl::fromLocalFile(filename));
    }
    else
    {
        qDebug() << "Item selected is not a regular file";
    }

    sender()->deleteLater();
}

void ImageWriter::_parseCompressedFile()
{
    struct archive *a = archive_read_new();
    struct archive_entry *entry;
    QByteArray fn = _src.toLocalFile().toLatin1();
    int numFiles = 0;
    _extrLen = 0;

    archive_read_support_filter_all(a);
    archive_read_support_format_all(a);

    if (archive_read_open_filename(a, fn.data(), 10240) == ARCHIVE_OK)
    {
        while ( (archive_read_next_header(a, &entry)) == ARCHIVE_OK)
        {
            if (archive_entry_size(entry) > 0)
            {
              _extrLen += archive_entry_size(entry);
              numFiles++;
            }
        }
    }

    if (numFiles > 1)
        _multipleFilesInZip = true;

    qDebug() << "Parsed .zip file containing" << numFiles << "files, uncompressed size:" << _extrLen;
}

void MountUtilsLog(std::string msg) {
    qDebug() << "mountutils:" << msg.c_str();
}