#include "imagepreviewwidget.h"
#include <QImageReader>
#include <QBuffer>
#include <QFileInfo>
#include <QDir>
#include <QScrollBar>
#include <QWheelEvent>
#include <QEvent>
#include "statusbarmanager.h"

ImagePreviewWidget::ImagePreviewWidget(QWidget *parent)
    : QWidget(parent)
    , mImageLabel(new QLabel(this))
    , mInfoLabel(new QLabel(this))
    , mScrollArea(new QScrollArea(this))
    , mDragging(false)
    , mZoomFactor(1.0)
{
    mImageLabel->setAlignment(Qt::AlignCenter);
    mImageLabel->setBackgroundRole(QPalette::Base);
    mImageLabel->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
    mImageLabel->setScaledContents(false);

    mScrollArea->setWidget(mImageLabel);
    mScrollArea->setWidgetResizable(false);  // Don't auto-resize, allow scrolling
    mScrollArea->setBackgroundRole(QPalette::Dark);
    mScrollArea->setAlignment(Qt::AlignCenter);
    mScrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    mScrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

    mInfoLabel->setAlignment(Qt::AlignCenter);
    mInfoLabel->setStyleSheet("QLabel { background-color: #333; color: #fff; padding: 4px; }");

    QVBoxLayout *layout = new QVBoxLayout(this);
    layout->setContentsMargins(0, 0, 0, 0);
    layout->setSpacing(0);
    layout->addWidget(mInfoLabel);
    layout->addWidget(mScrollArea, 1);
    setLayout(layout);

    // Enable mouse tracking for drag-to-pan
    setMouseTracking(true);
    mScrollArea->setMouseTracking(true);
    mScrollArea->viewport()->installEventFilter(this);
    mScrollArea->viewport()->setCursor(Qt::OpenHandCursor);
}

void ImagePreviewWidget::setFilename(const QString &filename)
{
    mFilename = filename;
}

QSize ImagePreviewWidget::imageSize() const
{
    return mImageSize;
}

bool ImagePreviewWidget::exportDebugImage(const QString &suffix)
{
    QPixmap pixmap = mImageLabel->pixmap();
    if (pixmap.isNull()) {
        return false;
    }

    QDir().mkdir("exports");

    QString filename = mFilename;
    if (filename.isEmpty()) {
        filename = "debug_image";
    }
    // Remove extension and add suffix
    int dotPos = filename.lastIndexOf('.');
    if (dotPos > 0) {
        filename = filename.left(dotPos);
    }
    if (!suffix.isEmpty()) {
        filename += "_" + suffix;
    }
    filename += "_DEBUG.png";

    QString path = "exports/" + filename;
    bool success = pixmap.save(path, "PNG");
    if (success) {
        StatusBarManager::instance().updateStatus(QString("Exported debug image: %1").arg(path), 2000);
    }
    return success;
}

bool ImagePreviewWidget::eventFilter(QObject *obj, QEvent *event)
{
    if (obj == mScrollArea->viewport()) {
        if (event->type() == QEvent::MouseButtonPress) {
            QMouseEvent *me = static_cast<QMouseEvent*>(event);
            if (me->button() == Qt::LeftButton) {
                mDragging = true;
                mLastDragPos = me->globalPosition().toPoint();
                mScrollArea->viewport()->setCursor(Qt::ClosedHandCursor);
                return true;
            }
        } else if (event->type() == QEvent::MouseMove) {
            if (mDragging) {
                QMouseEvent *me = static_cast<QMouseEvent*>(event);
                QPoint globalPos = me->globalPosition().toPoint();
                QPoint delta = globalPos - mLastDragPos;
                mLastDragPos = globalPos;

                QScrollBar *hBar = mScrollArea->horizontalScrollBar();
                QScrollBar *vBar = mScrollArea->verticalScrollBar();
                hBar->setValue(hBar->value() - delta.x());
                vBar->setValue(vBar->value() - delta.y());
                return true;
            }
        } else if (event->type() == QEvent::MouseButtonRelease) {
            QMouseEvent *me = static_cast<QMouseEvent*>(event);
            if (me->button() == Qt::LeftButton) {
                mDragging = false;
                mScrollArea->viewport()->setCursor(Qt::OpenHandCursor);
                return true;
            }
        } else if (event->type() == QEvent::Wheel) {
            QWheelEvent *we = static_cast<QWheelEvent*>(event);
            int delta = we->angleDelta().y();
            if (delta > 0) {
                mZoomFactor *= 1.15;
            } else if (delta < 0) {
                mZoomFactor /= 1.15;
            }
            mZoomFactor = qBound(0.1, mZoomFactor, 10.0);
            updateZoom();
            return true;
        }
    }
    return QWidget::eventFilter(obj, event);
}

void ImagePreviewWidget::wheelEvent(QWheelEvent *event)
{
    // Forward to viewport event filter
    int delta = event->angleDelta().y();
    if (delta > 0) {
        mZoomFactor *= 1.15;
    } else if (delta < 0) {
        mZoomFactor /= 1.15;
    }
    mZoomFactor = qBound(0.1, mZoomFactor, 10.0);
    updateZoom();
    event->accept();
}

void ImagePreviewWidget::updateZoom()
{
    if (mOriginalPixmap.isNull()) return;

    QSize newSize = mOriginalPixmap.size() * mZoomFactor;
    QPixmap scaled = mOriginalPixmap.scaled(newSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
    mImageLabel->setPixmap(scaled);
    mImageLabel->adjustSize();

    // Update info label with zoom level
    mInfoLabel->setText(QString("%1 - %2x%3 (%.0f%%)")
        .arg(mFilename)
        .arg(mImageSize.width())
        .arg(mImageSize.height())
        .arg(mZoomFactor * 100));
}

bool ImagePreviewWidget::loadFromData(const QByteArray &data, const QString &format)
{
    // Check for Xbox texture formats (XBTX2D, TX2D, etc.)
    if (data.size() >= 8) {
        QString magic = QString::fromLatin1(data.left(8));
        if (magic.startsWith("XBTX2D") || magic.startsWith("TX2D") || magic.startsWith("TX1D") || magic.startsWith("TX3D")) {
            // Try to decode Xbox 360 texture
            QImage image = loadXBTX2D(data);
            if (!image.isNull()) {
                mImageSize = image.size();
                mOriginalPixmap = QPixmap::fromImage(image);
                mZoomFactor = 1.0;
                mImageLabel->setPixmap(mOriginalPixmap);
                mImageLabel->adjustSize();
                mInfoLabel->setText(QString("%1 - %2x%3 (Xbox 360)").arg(mFilename).arg(image.width()).arg(image.height()));
                return true;
            }
            // Fallback to info display if decode fails
            mImageLabel->setText(QString("Xbox 360 Texture Format\n\nMagic: %1\nSize: %2 bytes\n\nCould not decode texture.")
                .arg(magic.left(6).trimmed())
                .arg(data.size()));
            mInfoLabel->setText(QString("%1 - Xbox 360 Texture (%2 bytes)").arg(mFilename).arg(data.size()));
            return true;
        }
    }

    // Check for DDS format (starts with "DDS ")
    if (data.size() >= 4 && data.left(4) == "DDS ") {
        mImageLabel->setText(QString("DDS Texture Format\n\nSize: %1 bytes\n\nDDS preview not yet implemented.")
            .arg(data.size()));
        mInfoLabel->setText(QString("%1 - DDS Texture (%2 bytes)").arg(mFilename).arg(data.size()));
        return true;
    }

    QImage image;

    // Try standard Qt loading first
    if (!format.isEmpty()) {
        image.loadFromData(data, format.toUtf8().constData());
    }

    if (image.isNull()) {
        image.loadFromData(data);
    }

    // If still null and looks like TGA, try manual loading
    if (image.isNull() && (format.toLower() == "tga" ||
        (data.size() > 18 && mFilename.toLower().endsWith(".tga")))) {
        image = loadTGA(data);
    }

    if (image.isNull()) {
        // Show hex dump of first bytes for debugging
        QString hexDump;
        for (int i = 0; i < qMin(16, data.size()); i++) {
            hexDump += QString("%1 ").arg((unsigned char)data[i], 2, 16, QChar('0'));
        }
        mImageLabel->setText(QString("Failed to load image\n\nFirst bytes: %1\nSize: %2 bytes")
            .arg(hexDump.trimmed())
            .arg(data.size()));
        mInfoLabel->setText(QString("%1 - Load failed").arg(mFilename));
        return false;
    }

    mImageSize = image.size();
    mOriginalPixmap = QPixmap::fromImage(image);
    mZoomFactor = 1.0;
    mImageLabel->setPixmap(mOriginalPixmap);
    mImageLabel->adjustSize();

    QString info = QString("%1 - %2x%3 - %4 bytes")
        .arg(mFilename)
        .arg(image.width())
        .arg(image.height())
        .arg(data.size());
    mInfoLabel->setText(info);

    return true;
}

bool ImagePreviewWidget::loadFromFile(const QString &path)
{
    QFile file(path);
    if (!file.open(QIODevice::ReadOnly)) {
        return false;
    }

    mFilename = QFileInfo(path).fileName();
    QByteArray data = file.readAll();

    QString format;
    if (path.toLower().endsWith(".tga")) format = "TGA";
    else if (path.toLower().endsWith(".dds")) format = "DDS";
    else if (path.toLower().endsWith(".png")) format = "PNG";
    else if (path.toLower().endsWith(".jpg") || path.toLower().endsWith(".jpeg")) format = "JPG";
    else if (path.toLower().endsWith(".bmp")) format = "BMP";

    return loadFromData(data, format);
}

QImage ImagePreviewWidget::loadTGA(const QByteArray &data)
{
    // Simple TGA loader for uncompressed RGB/RGBA images
    if (data.size() < 18) return QImage();

    const uchar *d = reinterpret_cast<const uchar*>(data.constData());

    // TGA header
    uchar idLength = d[0];
    uchar colorMapType = d[1];
    uchar imageType = d[2];
    // Skip color map spec (5 bytes: 3-7)
    // Image spec starts at byte 8
    quint16 xOrigin = d[8] | (d[9] << 8);
    quint16 yOrigin = d[10] | (d[11] << 8);
    quint16 width = d[12] | (d[13] << 8);
    quint16 height = d[14] | (d[15] << 8);
    uchar bitsPerPixel = d[16];
    uchar descriptor = d[17];

    Q_UNUSED(xOrigin);
    Q_UNUSED(yOrigin);
    Q_UNUSED(colorMapType);

    // Only support uncompressed true-color (type 2) or grayscale (type 3)
    if (imageType != 2 && imageType != 3 && imageType != 10) {
        return QImage();
    }

    int bytesPerPixel = bitsPerPixel / 8;
    if (bytesPerPixel < 1 || bytesPerPixel > 4) {
        return QImage();
    }

    int dataOffset = 18 + idLength;
    int expectedSize = dataOffset + width * height * bytesPerPixel;

    // For RLE images, we can't easily predict size, so just check minimum
    if (imageType != 10 && data.size() < expectedSize) {
        return QImage();
    }

    QImage::Format format = (bytesPerPixel == 4) ? QImage::Format_ARGB32 : QImage::Format_RGB32;
    QImage image(width, height, format);
    if (image.isNull()) return QImage();

    const uchar *src = d + dataOffset;
    bool flipVertical = !(descriptor & 0x20); // Bit 5: origin is top-left if set

    if (imageType == 2 || imageType == 3) {
        // Uncompressed
        for (int y = 0; y < height; y++) {
            int destY = flipVertical ? (height - 1 - y) : y;
            QRgb *destLine = reinterpret_cast<QRgb*>(image.scanLine(destY));

            for (int x = 0; x < width; x++) {
                int idx = (y * width + x) * bytesPerPixel;
                if (dataOffset + idx + bytesPerPixel > data.size()) break;

                uchar b = src[idx];
                uchar g = (bytesPerPixel > 1) ? src[idx + 1] : b;
                uchar r = (bytesPerPixel > 2) ? src[idx + 2] : b;
                uchar a = (bytesPerPixel > 3) ? src[idx + 3] : 255;

                destLine[x] = qRgba(r, g, b, a);
            }
        }
    } else if (imageType == 10) {
        // RLE compressed
        int pixelCount = width * height;
        int currentPixel = 0;
        int srcIdx = 0;
        int maxSrcIdx = data.size() - dataOffset;

        while (currentPixel < pixelCount && srcIdx < maxSrcIdx) {
            uchar header = src[srcIdx++];
            int count = (header & 0x7F) + 1;

            if (header & 0x80) {
                // RLE packet
                if (srcIdx + bytesPerPixel > maxSrcIdx) break;

                uchar b = src[srcIdx];
                uchar g = (bytesPerPixel > 1) ? src[srcIdx + 1] : b;
                uchar r = (bytesPerPixel > 2) ? src[srcIdx + 2] : b;
                uchar a = (bytesPerPixel > 3) ? src[srcIdx + 3] : 255;
                srcIdx += bytesPerPixel;

                QRgb color = qRgba(r, g, b, a);
                for (int i = 0; i < count && currentPixel < pixelCount; i++, currentPixel++) {
                    int x = currentPixel % width;
                    int y = currentPixel / width;
                    int destY = flipVertical ? (height - 1 - y) : y;
                    QRgb *destLine = reinterpret_cast<QRgb*>(image.scanLine(destY));
                    destLine[x] = color;
                }
            } else {
                // Raw packet
                for (int i = 0; i < count && currentPixel < pixelCount; i++, currentPixel++) {
                    if (srcIdx + bytesPerPixel > maxSrcIdx) break;

                    uchar b = src[srcIdx];
                    uchar g = (bytesPerPixel > 1) ? src[srcIdx + 1] : b;
                    uchar r = (bytesPerPixel > 2) ? src[srcIdx + 2] : b;
                    uchar a = (bytesPerPixel > 3) ? src[srcIdx + 3] : 255;
                    srcIdx += bytesPerPixel;

                    int x = currentPixel % width;
                    int y = currentPixel / width;
                    int destY = flipVertical ? (height - 1 - y) : y;
                    QRgb *destLine = reinterpret_cast<QRgb*>(image.scanLine(destY));
                    destLine[x] = qRgba(r, g, b, a);
                }
            }
        }
    }

    return image;
}

// DXT1 block decoder - read colors as big-endian (Xbox 360 native)
static void decodeDXT1BlockStatic(const uchar *src, QRgb *dest, int destPitch)
{
    // Read colors as big-endian (Xbox 360 native format)
    quint16 c0 = (src[0] << 8) | src[1];
    quint16 c1 = (src[2] << 8) | src[3];

    // Extract RGB565 components: bits 15-11=R, 10-5=G, 4-0=B
    // Xbox 360 stores as BGR565, so swap R and B
    int b0 = ((c0 >> 11) & 0x1F) * 255 / 31;
    int g0 = ((c0 >> 5) & 0x3F) * 255 / 63;
    int r0 = (c0 & 0x1F) * 255 / 31;

    int b1 = ((c1 >> 11) & 0x1F) * 255 / 31;
    int g1 = ((c1 >> 5) & 0x3F) * 255 / 63;
    int r1 = (c1 & 0x1F) * 255 / 31;

    // Build color table
    QRgb colors[4];
    colors[0] = qRgb(r0, g0, b0);
    colors[1] = qRgb(r1, g1, b1);

    if (c0 > c1) {
        colors[2] = qRgb((2 * r0 + r1) / 3, (2 * g0 + g1) / 3, (2 * b0 + b1) / 3);
        colors[3] = qRgb((r0 + 2 * r1) / 3, (g0 + 2 * g1) / 3, (b0 + 2 * b1) / 3);
    } else {
        colors[2] = qRgb((r0 + r1) / 2, (g0 + g1) / 2, (b0 + b1) / 2);
        colors[3] = qRgba(0, 0, 0, 0); // Transparent
    }

    // Read indices - standard order (no swap needed)
    for (int y = 0; y < 4; y++) {
        uchar rowByte = src[4 + y];
        for (int x = 0; x < 4; x++) {
            int idx = (rowByte >> (x * 2)) & 0x03;
            dest[y * destPitch + x] = colors[idx];
        }
    }
}

// DXT5 block decoder - read as big-endian (Xbox 360 native)
static void decodeDXT5BlockStatic(const uchar *src, QRgb *dest, int destPitch)
{
    // Alpha block (first 8 bytes) - standard order
    uchar alpha0 = src[0];
    uchar alpha1 = src[1];

    // Build alpha table
    uchar alphas[8];
    alphas[0] = alpha0;
    alphas[1] = alpha1;

    if (alpha0 > alpha1) {
        alphas[2] = (6 * alpha0 + 1 * alpha1) / 7;
        alphas[3] = (5 * alpha0 + 2 * alpha1) / 7;
        alphas[4] = (4 * alpha0 + 3 * alpha1) / 7;
        alphas[5] = (3 * alpha0 + 4 * alpha1) / 7;
        alphas[6] = (2 * alpha0 + 5 * alpha1) / 7;
        alphas[7] = (1 * alpha0 + 6 * alpha1) / 7;
    } else {
        alphas[2] = (4 * alpha0 + 1 * alpha1) / 5;
        alphas[3] = (3 * alpha0 + 2 * alpha1) / 5;
        alphas[4] = (2 * alpha0 + 3 * alpha1) / 5;
        alphas[5] = (1 * alpha0 + 4 * alpha1) / 5;
        alphas[6] = 0;
        alphas[7] = 255;
    }

    // Alpha indices (6 bytes, 48 bits = 16 pixels * 3 bits each) - standard order
    quint64 alphaIndices = src[2] | ((quint64)src[3] << 8) | ((quint64)src[4] << 16) |
                           ((quint64)src[5] << 24) | ((quint64)src[6] << 32) | ((quint64)src[7] << 40);

    // Color block (bytes 8-15, same as DXT1) - big-endian
    const uchar *colorSrc = src + 8;
    quint16 c0 = (colorSrc[0] << 8) | colorSrc[1];  // Big-endian (Xbox 360)
    quint16 c1 = (colorSrc[2] << 8) | colorSrc[3];  // Big-endian (Xbox 360)

    // BGR565: bits 15-11=B, 10-5=G, 4-0=R (Xbox 360 swapped)
    int b0 = ((c0 >> 11) & 0x1F) * 255 / 31;
    int g0 = ((c0 >> 5) & 0x3F) * 255 / 63;
    int r0 = (c0 & 0x1F) * 255 / 31;

    int b1 = ((c1 >> 11) & 0x1F) * 255 / 31;
    int g1 = ((c1 >> 5) & 0x3F) * 255 / 63;
    int r1 = (c1 & 0x1F) * 255 / 31;

    QRgb colors[4];
    colors[0] = qRgb(r0, g0, b0);
    colors[1] = qRgb(r1, g1, b1);
    colors[2] = qRgb((2 * r0 + r1) / 3, (2 * g0 + g1) / 3, (2 * b0 + b1) / 3);
    colors[3] = qRgb((r0 + 2 * r1) / 3, (g0 + 2 * g1) / 3, (b0 + 2 * b1) / 3);

    // Decode 4x4 block - standard order
    for (int y = 0; y < 4; y++) {
        uchar colorRowByte = colorSrc[4 + y];
        for (int x = 0; x < 4; x++) {
            int pixelIdx = y * 4 + x;
            int alphaIdx = (alphaIndices >> (pixelIdx * 3)) & 0x07;
            int colorIdx = (colorRowByte >> (x * 2)) & 0x03;

            QRgb color = colors[colorIdx];
            dest[y * destPitch + x] = qRgba(qRed(color), qGreen(color), qBlue(color), alphas[alphaIdx]);
        }
    }
}

// Swap endianness in 16-bit chunks (required for Xbox 360)
static void swapEndian16(uchar *data, int size)
{
    for (int i = 0; i < size - 1; i += 2) {
        uchar tmp = data[i];
        data[i] = data[i + 1];
        data[i + 1] = tmp;
    }
}

// Xbox 360 XGAddress2DTiledX - convert tiled offset to linear X
// From Noesis inc_xbox360_untile.py (credits: Banz99's Nier-Texture-Manager, GTA XTD editor)
static unsigned int xgAddress2DTiledX(unsigned int offset, unsigned int width, unsigned int texelPitch)
{
    unsigned int alignedWidth = (width + 31) & ~31;
    unsigned int logBpp = (texelPitch >> 2) + ((texelPitch >> 1) >> (texelPitch >> 2));
    unsigned int offsetB = offset << logBpp;
    unsigned int offsetT = ((offsetB & ~4095) >> 3) + ((offsetB & 1792) >> 2) + (offsetB & 63);
    unsigned int offsetM = offsetT >> (7 + logBpp);
    unsigned int macroX = ((offsetM % (alignedWidth >> 5)) << 2);
    unsigned int tile = ((((offsetT >> (5 + logBpp)) & 2) + (offsetB >> 6)) & 3);
    unsigned int macro = (macroX + tile) << 3;
    unsigned int micro = ((((offsetT >> 1) & ~15) + (offsetT & 15)) & ((texelPitch << 3) - 1)) >> logBpp;
    return macro + micro;
}

// Xbox 360 XGAddress2DTiledY - convert tiled offset to linear Y
static unsigned int xgAddress2DTiledY(unsigned int offset, unsigned int width, unsigned int texelPitch)
{
    unsigned int alignedWidth = (width + 31) & ~31;
    unsigned int logBpp = (texelPitch >> 2) + ((texelPitch >> 1) >> (texelPitch >> 2));
    unsigned int offsetB = offset << logBpp;
    unsigned int offsetT = ((offsetB & ~4095) >> 3) + ((offsetB & 1792) >> 2) + (offsetB & 63);
    unsigned int offsetM = offsetT >> (7 + logBpp);
    unsigned int macroY = ((offsetM / (alignedWidth >> 5)) << 2);
    unsigned int tile = ((offsetT >> (6 + logBpp)) & 1) + (((offsetB & 2048) >> 10));
    unsigned int macro = (macroY + tile) << 3;
    unsigned int micro = ((((offsetT & (((texelPitch << 6) - 1) & ~31)) + ((offsetT & 15) << 1)) >> (3 + logBpp)) & ~1);
    return macro + micro + ((offsetT & 16) >> 4);
}

// Xbox 360 texture untiling - iterate tiled source, write to linear dest
// Based on official Xbox 360 SDK XGAddress2DTiledX/Y functions
static void untileXbox360(const uchar *src, uchar *dest, int width, int height, int blockSize)
{
    // For DXT, work in blocks (4x4 pixels per block)
    unsigned int blocksWide = (width + 3) / 4;
    unsigned int blocksHigh = (height + 3) / 4;

    // Calculate aligned dimensions for iteration (SDK aligns internally, but we need to iterate aligned space)
    unsigned int alignedBlocksWide = (blocksWide + 31) & ~31;
    unsigned int alignedBlocksHigh = (blocksHigh + 31) & ~31;
    unsigned int totalAlignedBlocks = alignedBlocksWide * alignedBlocksHigh;

    // texelPitch is the block size (8 for DXT1, 16 for DXT5)
    unsigned int texelPitch = blockSize;

    // Iterate through aligned source blocks
    for (unsigned int blockOffset = 0; blockOffset < totalAlignedBlocks; blockOffset++) {
        // Pass the ACTUAL width in blocks - XGAddress functions align internally!
        // This is the key fix: SDK expects real width, not pre-aligned
        unsigned int x = xgAddress2DTiledX(blockOffset, blocksWide, texelPitch);
        unsigned int y = xgAddress2DTiledY(blockOffset, blocksWide, texelPitch);

        // Skip blocks outside actual texture bounds
        if (x >= blocksWide || y >= blocksHigh) {
            continue;
        }

        // Source is sequential tiled (aligned), dest is linear (actual size)
        unsigned int srcOffset = blockOffset * texelPitch;
        unsigned int destOffset = (y * blocksWide + x) * texelPitch;

        memcpy(dest + destOffset, src + srcOffset, texelPitch);
    }
}

// Helper to decode DXT data into an image
static QImage decodeDXTToImage(const uchar *srcData, int width, int height, int blockSize, bool isDXT5, int textureDataSize)
{
    int blocksWide = (width + 3) / 4;
    int blocksHigh = (height + 3) / 4;

    QImage image(width, height, QImage::Format_ARGB32);
    if (image.isNull()) return QImage();
    image.fill(Qt::black);

    for (int by = 0; by < blocksHigh; by++) {
        for (int bx = 0; bx < blocksWide; bx++) {
            int blockIdx = by * blocksWide + bx;
            int blockOffset = blockIdx * blockSize;

            if (blockOffset + blockSize > textureDataSize) break;

            const uchar *blockData = srcData + blockOffset;

            // Decode into temporary 4x4 block
            QRgb block[16];

            if (isDXT5) {
                decodeDXT5BlockStatic(blockData, block, 4);
            } else {
                decodeDXT1BlockStatic(blockData, block, 4);
            }

            // Copy block to image
            int px = bx * 4;
            int py = by * 4;
            for (int y = 0; y < 4 && py + y < height; y++) {
                QRgb *destLine = reinterpret_cast<QRgb*>(image.scanLine(py + y));
                for (int x = 0; x < 4 && px + x < width; x++) {
                    destLine[px + x] = block[y * 4 + x];
                }
            }
        }
    }

    return image;
}

QImage ImagePreviewWidget::loadXBTX2D(const QByteArray &data)
{
    if (data.size() < 0x60) return QImage();

    const uchar *d = reinterpret_cast<const uchar*>(data.constData());

    // XBTX2D header (big-endian) - actual format from hex analysis:
    // 0x00-0x07: Magic "XBTX2D  " (8 bytes)
    // 0x08-0x0B: Version (4 bytes, BE)
    // 0x0C-0x0F: Width (4 bytes, BE)
    // 0x10-0x13: Height (4 bytes, BE)
    // 0x14-0x17: Hash/ID
    // 0x18-0x1B: Mip count (4 bytes, BE)
    // 0x1C-0x1F: Size field 1
    // 0x20-0x23: Size field 2 (base mip size for DXT1)
    // 0x24-0x27: Format (3=DXT1?)
    // 0x58: Data start

    quint32 width = (d[0x0C] << 24) | (d[0x0D] << 16) | (d[0x0E] << 8) | d[0x0F];
    quint32 height = (d[0x10] << 24) | (d[0x11] << 16) | (d[0x12] << 8) | d[0x13];
    quint32 baseMipSize = (d[0x20] << 24) | (d[0x21] << 16) | (d[0x22] << 8) | d[0x23];

    // Sanity checks
    if (width == 0 || height == 0 || width > 8192 || height > 8192) {
        return QImage();
    }

    // Determine format from base mip size
    // DXT1: 8 bytes per 4x4 block = width*height/2
    // DXT5: 16 bytes per 4x4 block = width*height
    int blockSize;
    int dataOffset = 0x58;  // Fixed header size
    bool isDXT5;

    quint32 expectedDXT1Size = (width * height) / 2;
    quint32 expectedDXT5Size = width * height;

    if (baseMipSize == expectedDXT5Size) {
        // DXT5 (or similar 16-byte block format)
        blockSize = 16;
        isDXT5 = true;
        StatusBarManager::instance().updateStatus(
            QString("XBTX2D: %1 - DXT5 %2x%3").arg(mFilename).arg(width).arg(height), 3000);
    } else {
        // DXT1 (or similar 8-byte block format)
        blockSize = 8;
        isDXT5 = false;
        StatusBarManager::instance().updateStatus(
            QString("XBTX2D: %1 - DXT1 %2x%3").arg(mFilename).arg(width).arg(height), 3000);
    }

    int blocksWide = (width + 3) / 4;
    int blocksHigh = (height + 3) / 4;
    int totalBlocks = blocksWide * blocksHigh;
    int textureDataSize = totalBlocks * blockSize;

    if (data.size() < dataOffset) return QImage();

    int availableData = data.size() - dataOffset;
    if (availableData < textureDataSize) {
        textureDataSize = availableData;
    }

    const uchar *srcData = d + dataOffset;

    // Xbox 360 DXT textures require:
    // 1. Untiling (GPU memory layout to linear)
    // 2. DXT decode with big-endian color reading

    // Try both untiled and linear to compare
    QByteArray untiled(textureDataSize, 0);
    untileXbox360(srcData, reinterpret_cast<uchar*>(untiled.data()), width, height, blockSize);

    // Decode both versions
    QImage untiledResult = decodeDXTToImage(reinterpret_cast<const uchar*>(untiled.constData()),
                                            width, height, blockSize, isDXT5, textureDataSize);
    QImage linearResult = decodeDXTToImage(srcData, width, height, blockSize, isDXT5, textureDataSize);

    // Export both for comparison
    QDir().mkdir("exports");
    QString debugName = mFilename.isEmpty() ? "xbtx2d_debug" : mFilename;
    int dot = debugName.lastIndexOf('.');
    if (dot > 0) debugName = debugName.left(dot);
    if (!untiledResult.isNull()) {
        untiledResult.save("exports/" + debugName + "_UNTILED.png", "PNG");
    }
    if (!linearResult.isNull()) {
        linearResult.save("exports/" + debugName + "_LINEAR.png", "PNG");
    }

    // Return the untiled version
    return untiledResult;
}