#include "avatarcrop.h"
#include "avatarcache.h"
#include <QDialog>
#include <QDialogButtonBox>
#include <QFileInfo>
#include <QImageReader>
#include <QImageIOHandler>
#include <QLabel>
#include <QMouseEvent>
#include <QPainter>
#include <QPainterPath>
#include <QPointer>
#include <QPushButton>
#include <QRunnable>
#include <QThreadPool>
#include <QVBoxLayout>
#include <QWheelEvent>
extern "C" {
#include "debug_config.h"
}

namespace {
class CropView : public QWidget {
public:
    QImage image;
    QSize originalSize;
    explicit CropView(QWidget* parent) : QWidget(parent) { setMinimumSize(320, 320); setCursor(Qt::OpenHandCursor); }
    QRectF frame() const { const double side = qMin(width(), height()) * 0.8; return {(width()-side)/2, (height()-side)/2, side, side}; }
    double scale() const { return qMax(frame().width()/originalSize.width(), frame().height()/originalSize.height()) * zoom; }
    void clamp() {
        if (image.isNull()) return;
        const double s = scale(), mx = (originalSize.width()*s-frame().width())/2, my = (originalSize.height()*s-frame().height())/2;
        offset = {qBound(-mx, offset.x(), mx), qBound(-my, offset.y(), my)};
    }
    QRectF selection() const {
        const double s = scale();
        const QPointF top = QPointF(width()/2.0,height()/2.0) + offset - QPointF(originalSize.width()*s/2, originalSize.height()*s/2);
        const QRectF f = frame();
        return {(f.x()-top.x())/s/originalSize.width(), (f.y()-top.y())/s/originalSize.height(),
            f.width()/s/originalSize.width(), f.height()/s/originalSize.height()};
    }
protected:
    void paintEvent(QPaintEvent*) override {
        QPainter p(this); p.fillRect(rect(), QColor(20,20,22)); if (image.isNull()) return;
        clamp(); const double s = scale(); const QSizeF size(originalSize.width()*s, originalSize.height()*s);
        p.setRenderHint(QPainter::SmoothPixmapTransform);
        p.setRenderHint(QPainter::Antialiasing);
        p.drawImage(QRectF(QPointF(width()/2.0,height()/2.0)+offset-QPointF(size.width()/2,size.height()/2), size), image);
        QPainterPath mask; mask.addRect(rect()); mask.addEllipse(frame()); p.fillPath(mask, QColor(0,0,0,150));
        p.setPen(QPen(Qt::white, 2)); p.drawEllipse(frame());
    }
    void wheelEvent(QWheelEvent* e) override {
        if (image.isNull()) return;
        const double previous = zoom; zoom = qBound(1.0, zoom * (e->angleDelta().y()>0 ? 1.15 : 1/1.15), 16.0);
        offset *= zoom/previous; clamp(); update(); e->accept();
    }
    void mousePressEvent(QMouseEvent* e) override { if (e->button()==Qt::LeftButton) { last=e->pos(); dragging=true; } }
    void mouseMoveEvent(QMouseEvent* e) override { if (dragging) { offset+=e->pos()-last; last=e->pos(); clamp(); update(); } }
    void mouseReleaseEvent(QMouseEvent*) override { dragging=false; }
private:
    double zoom = 1; QPointF offset; QPoint last; bool dragging = false;
};
}

bool selectAvatarCrop(const QString& source, QRectF& crop, QWidget* parent) {
    QDialog dialog(parent); dialog.setWindowTitle(QCoreApplication::translate("ChatGui", "Crop avatar")); dialog.resize(620,650);
    auto* layout = new QVBoxLayout(&dialog); auto* view = new CropView(&dialog); layout->addWidget(view, 1);
    view->setObjectName("avatarCropView");
    auto* status = new QLabel(QCoreApplication::translate("ChatGui", "Drag photo and use the wheel to fit the circle"), &dialog);
    layout->addWidget(status); auto* buttons = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel, &dialog);
    buttons->button(QDialogButtonBox::Ok)->setText(QCoreApplication::translate("ChatGui", "Upload avatar"));
    buttons->button(QDialogButtonBox::Ok)->setObjectName("avatarCropUpload");
    buttons->button(QDialogButtonBox::Ok)->setEnabled(false); layout->addWidget(buttons);
    QObject::connect(buttons, &QDialogButtonBox::accepted, &dialog, &QDialog::accept);
    QObject::connect(buttons, &QDialogButtonBox::rejected, &dialog, &QDialog::reject);
    QThreadPool pool; pool.setMaxThreadCount(1);
    pool.start(QRunnable::create([source, &dialog, view, status, buttons] {
        QImageReader reader(source); reader.setAutoTransform(true); const QSize size = reader.size(); QImage image;
        QSize orientedSize=size;
        if (reader.transformation() & QImageIOHandler::TransformationRotate90) orientedSize.transpose();
        if (QFileInfo(source).size() <= AvatarCache::OriginalMaxBytes && size.isValid() &&
            qint64(size.width())*size.height() <= 16*1024*1024 &&
            (reader.format()=="jpeg" || reader.format()=="png" || reader.format()=="webp")) {
            reader.setScaledSize(size.scaled(1600,1600,Qt::KeepAspectRatio)); image = reader.read();
        }
        QMetaObject::invokeMethod(&dialog, [view, image, orientedSize, status, buttons] {
            if (image.isNull()) {
                DEBUG_WARN(DEBUG_CATEGORY_MEDIA, "avatar: editor cannot decode selected source");
                status->setText(QCoreApplication::translate("ChatGui", "Cannot load avatar image")); return;
            }
            view->image=image; view->originalSize=orientedSize; view->update(); buttons->button(QDialogButtonBox::Ok)->setEnabled(true);
            DEBUG_DEBUG(DEBUG_CATEGORY_MEDIA, "avatar: editor loaded original=%dx%d preview=%dx%d mask=circle",
                orientedSize.width(), orientedSize.height(), image.width(), image.height());
        }, Qt::QueuedConnection);
    }));
    const int result=dialog.exec(); pool.waitForDone();
    if (result!=QDialog::Accepted) { DEBUG_DEBUG(DEBUG_CATEGORY_MEDIA, "avatar: crop cancelled"); return false; }
    crop=view->selection(); DEBUG_INFO(DEBUG_CATEGORY_MEDIA, "avatar: crop selected x=%.5f y=%.5f w=%.5f h=%.5f",
        crop.x(), crop.y(), crop.width(), crop.height()); return true;
}