#include "imagegallery.h"
#include <QMouseEvent>
#include <QFileInfo>
#include <QProcess>
#include <QDesktopServices>
#include <QUrl>
#include <QPainter>
#include <QApplication>

// ImageThumbnail implementation
ImageThumbnail::ImageThumbnail(const QString &filePath, QWidget *parent)
    : QLabel(parent)
    , m_filePath(filePath)
{
    setFixedSize(THUMBNAIL_WIDTH, THUMBNAIL_HEIGHT);
    setAlignment(Qt::AlignCenter);
    setFrameStyle(QFrame::Panel | QFrame::Sunken);
    setLineWidth(2);
    setScaledContents(false);
    setCursor(Qt::PointingHandCursor);
    setToolTip(filePath);
    
    // Enable text wrapping and text interaction
    setWordWrap(true);
    setTextInteractionFlags(Qt::TextSelectableByMouse);
    
    // Set a minimum size policy
    setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);
}

void ImageThumbnail::mousePressEvent(QMouseEvent *event)
{
    if (event->button() == Qt::LeftButton) {
        emit thumbnailClicked(m_filePath);
    }
    QLabel::mousePressEvent(event);
}

// ImageGallery implementation
ImageGallery::ImageGallery(QWidget *parent)
    : QWidget(parent)
    , m_dbManager(nullptr)
{
    // Create scroll area
    m_scrollArea = new QScrollArea(this);
    m_scrollArea->setWidgetResizable(true);
    m_scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAsNeeded);
    m_scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
    
    // Create container widget for the grid layout
    m_containerWidget = new QWidget(m_scrollArea);
    m_gridLayout = new QGridLayout(m_containerWidget);
    m_gridLayout->setSpacing(10);
    
    m_scrollArea->setWidget(m_containerWidget);
    
    // Create layout for the gallery widget
    QVBoxLayout *mainLayout = new QVBoxLayout(this);
    mainLayout->addWidget(m_scrollArea);
    setLayout(mainLayout);
}

ImageGallery::~ImageGallery()
{
    clearGallery();
}

void ImageGallery::setDatabaseManager(DatabaseManager *dbManager)
{
    m_dbManager = dbManager;
}

void ImageGallery::displayImages(const QList<DatabaseManager::ImageItem> &images)
{
    // Clear existing thumbnails
    clearGallery();
    
    const int numImages = images.size();
    int row = 0, col = 0;
    
    for (int i = 0; i < numImages; ++i) {
        const auto &item = images[i];
        
        // Check if file exists before creating thumbnail
        QFileInfo fileInfo(item.filePath);
        if (!fileInfo.exists() || !fileInfo.isReadable()) {
            qDebug() << "Image file does not exist or is not readable:" << item.filePath;
            continue;  // Skip this image
        }
        
        // Create and add thumbnail
        QPixmap thumbnail = createThumbnail(item.filePath, THUMBNAIL_WIDTH, THUMBNAIL_HEIGHT);
        ImageThumbnail *thumbnailLabel = new ImageThumbnail(item.filePath, this);
        thumbnailLabel->setPixmap(thumbnail);
        
        // Set tooltip to show file path and partial OCR text
        QString tooltipText = item.filePath;
        if (!item.ocrText.isEmpty()) {
            // Limit OCR text length in tooltip
            QString shortOcrText = item.ocrText;
            if (shortOcrText.length() > 100) {
                shortOcrText = shortOcrText.left(97) + "...";
            }
            tooltipText += "\n\nOCR Text:\n" + shortOcrText;
        }
        thumbnailLabel->setToolTip(tooltipText);
        
        // Connect the thumbnail click signal
        connect(thumbnailLabel, &ImageThumbnail::thumbnailClicked, 
                this, &ImageGallery::handleThumbnailClicked);
        
        // Add to grid
        m_gridLayout->addWidget(thumbnailLabel, row, col);
        m_thumbnails.append(thumbnailLabel);
        
        // Update row and column
        col++;
        if (col >= COLUMNS) {
            col = 0;
            row++;
        }
    }
    
    // Display a message when no images are found
    if (m_thumbnails.isEmpty()) {
        // Create a special ImageThumbnail for the "no images" message
        ImageThumbnail *noImagesLabel = new ImageThumbnail("", this);
        noImagesLabel->setText("No images found matching your search criteria");
        noImagesLabel->setAlignment(Qt::AlignCenter);
        m_gridLayout->addWidget(noImagesLabel, 0, 0, 1, COLUMNS);
        m_thumbnails.append(noImagesLabel);
    }
    
    // Add stretch to the bottom of the grid
    m_gridLayout->setRowStretch(row + 1, 1);
}

void ImageGallery::clearGallery()
{
    // Remove all thumbnails
    for (auto thumbnail : m_thumbnails) {
        m_gridLayout->removeWidget(thumbnail);
        disconnect(thumbnail, nullptr, this, nullptr);
        delete thumbnail;
    }
    
    m_thumbnails.clear();
}

void ImageGallery::handleSearchTextChanged(const QString &searchText)
{
    if (m_dbManager) {
        QList<DatabaseManager::ImageItem> images = m_dbManager->searchImages(searchText);
        displayImages(images);
    }
}

void ImageGallery::handleThumbnailClicked(const QString &filePath)
{
    // Show a wait cursor while attempting to open the file
    QApplication::setOverrideCursor(Qt::WaitCursor);
    
    // Check if file exists
    QFileInfo fileInfo(filePath);
    if (fileInfo.exists() && fileInfo.isFile()) {
        try {
            // Use QDesktopServices to open the file with the default application
            bool success = QDesktopServices::openUrl(QUrl::fromLocalFile(filePath));
            if (!success) {
                qDebug() << "Failed to open file with default application:" << filePath;
            }
        } catch (const std::exception &e) {
            qDebug() << "Exception occurred while opening file:" << e.what();
        }
    } else {
        qDebug() << "File does not exist:" << filePath;
    }
    
    // Restore cursor
    QApplication::restoreOverrideCursor();
}

QPixmap ImageGallery::createThumbnail(const QString &filePath, int width, int height)
{
    // Verify file exists before attempting to load
    QFileInfo fileInfo(filePath);
    if (!fileInfo.exists() || !fileInfo.isReadable()) {
        qDebug() << "Image file does not exist or is not readable:" << filePath;
        return createPlaceholderThumbnail(width, height, "File not found");
    }
    
    // Try to load the image
    QPixmap pixmap(filePath);
    
    // If loading failed, create a placeholder
    if (pixmap.isNull()) {
        qDebug() << "Failed to load image:" << filePath;
        return createPlaceholderThumbnail(width, height, "Failed to load");
    }
    
    // Scale pixmap while maintaining aspect ratio
    return pixmap.scaled(width, height, Qt::KeepAspectRatio, Qt::SmoothTransformation);
}

QPixmap ImageGallery::createPlaceholderThumbnail(int width, int height, const QString &message)
{
    // Create a placeholder image with text
    QPixmap placeholder(width, height);
    placeholder.fill(Qt::lightGray);
    
    // Draw some text on the placeholder
    QPainter painter(&placeholder);
    painter.setPen(Qt::darkGray);
    
    // Use a nice font
    QFont font = painter.font();
    font.setPointSize(12);
    font.setBold(true);
    painter.setFont(font);
    
    // Draw the text centered in the pixmap
    painter.drawText(placeholder.rect(), Qt::AlignCenter, message);
    
    // Add a border
    painter.setPen(QPen(Qt::darkGray, 2));
    painter.drawRect(1, 1, width-2, height-2);
    
    return placeholder;
}