/*
  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License
  as published by the Free Software Foundation; either version
  2 of the License, or (at your option) any later version.
*/

#include <QDesktopWidget>
#include <QApplication>
#include <QGraphicsScene>
#include <QGraphicsPixmapItem>
#include <QImage>
#include <QWheelEvent>
#include <QContextMenuEvent>
#include <QMenu>
#include <QTimer>
#include <QPainter>
#include <QStyleOptionGraphicsItem>

#include "pictureviewer2.h"
#include "pictureswidget.h"

PictureViewer2::PictureViewer2(QWidget *parent) : QGraphicsView(parent), mCur(0), mCurPos(0), mDefaultFile(":/picgone.png"), mFnItem(0) {
    //behave like QDialog, but don't be one...
    setWindowFlags(QFlags<Qt::WindowType>(0x1|0x2|0x1000|0x2000|0x10000|0x8000000));

    //initial file list
    PicData initialData;
    for(int i = 0; i < PicFilesModel::NumFields; ++i){
        initialData << QVariant();
    }
    initialData[PicFilesModel::FullPath] = mDefaultFile;
    mFiles << initialData;

    //picture show
    mSlideTimer = new QTimer(this);
    connect(mSlideTimer, SIGNAL(timeout()), this, SLOT(next()));

    //setup gui
    mScene = new QGraphicsScene(this);
    setScene(mScene);
    QDesktopWidget *dw = QApplication::desktop();
    QSize screenSize = dw->availableGeometry().size();
    mMinimunSize = QSize(screenSize.width() - 100, screenSize.height() - 100);
    setMinimumSize(mMinimunSize);
    move(50, 50);
    setVisible(false);
    mScene->setSceneRect(QRectF(0, 0, width() - 10, height() - 10));
    showFile(mFiles.at(mCurPos));
}

void PictureViewer2::addFiles(const PicDataList &files, bool clear){
    if(clear){
        mFiles.clear();
        mFiles = files;
        mCurPos = 0;
        return;
    }
    foreach(const PicData &f, files){
        if(!mFiles.contains(f)){
            mFiles.append(f);
        }
    }
}

void PictureViewer2::setFile(const PicData &file){
    addFiles(PicDataList() << file, true);
    showFile(mFiles.at(mCurPos));
}

QSize PictureViewer2::sizeHint() const{
    return mMinimunSize;
}

void PictureViewer2::next(){
    if(mCurPos + 1 >= mFiles.size()){
        mCurPos = 0;
    }else{
        ++mCurPos;
    }
    showFile(mFiles.at(mCurPos));
}

void PictureViewer2::previous(){
    if(mCurPos - 1 < 0){
        mCurPos = mFiles.size() - 1;
    }else{
        --mCurPos;
    }
    showFile(mFiles.at(mCurPos));
}

void PictureViewer2::slide(){
    if(mSlideTimer->isActive()){
        mSlideTimer->stop();
    }else{
        mSlideTimer->start(5000);
    }
}

void PictureViewer2::wheelEvent(QWheelEvent *event){
    int steps = event->delta() / 8 / 15;
    if(steps < 0){
        next();
    }else{
        previous();
    }
}

void PictureViewer2::contextMenuEvent(QContextMenuEvent *e){
    QMenu ctxMenu;
    foreach(QAction *a, actions()){
        ctxMenu.addAction(a);
    }
    ctxMenu.exec(e->globalPos());
}

void PictureViewer2::showFile(const PicData &file){
    QPixmap pixmap(file.at(PicFilesModel::FullPath).toString());
    if(pixmap.isNull()){
        return;
    }
    setCurPalette(pixmap);
    if((pixmap.height() > height()) || (pixmap.width() > width())){
        pixmap = pixmap.scaled(QSize(width() - 3, height() - 10), Qt::KeepAspectRatio, Qt::SmoothTransformation);
    }
    if(mCur){
        mScene->removeItem(mCur);
        delete mCur;
        mCur = 0;
    }
    mCur = new QGraphicsPixmapItem(pixmap);
    float cX = (width() / 2) - (pixmap.width() / 2);
    float cY = height() / 2 - pixmap.height() / 2;
    mScene->addItem(mCur);
    mCur->setPos(cX, cY);
    setWindowTitle(constructWindowTitle());
    constructFilenameItem(mFiles.at(mCurPos).at(PicFilesModel::FileName).toString());
}

void PictureViewer2::constructFilenameItem(const QString &filename){
    if(mFnItem){
        mScene->removeItem(mFnItem);
        delete mFnItem;
    }
    mFnItem = new PictureViewer2FilenameItem(filename);
    QSizeF itemSize = mFnItem->boundingRect().size();
    int thisWidth = size().width();
    int xPos = (thisWidth / 2) - (itemSize.width() / 2);
    mFnItem->setPos(xPos, 0);
    mScene->addItem(mFnItem);
}

void PictureViewer2::setCurPalette(const QPixmap &pic){
    QPoint val1 = QPoint(qrand() % pic.width(), qrand() % pic.height());
    QPoint val2 = QPoint(qrand() % pic.width(), qrand() % pic.height());
    QImage img = pic.toImage();
    QColor c1(img.pixel(val1));
    QColor c2(img.pixel(val2));
    QLinearGradient g(QPoint(0,0), QPoint(rect().bottomRight()));
    g.setColorAt(0, c1);
    g.setColorAt(1, c2);
    setBackgroundBrush(QBrush(g));
}

QString PictureViewer2::constructWindowTitle() const {
    QString retval = QString(tr("PicViewer 2 - [%1]")).arg(mFiles.at(mCurPos).at(PicFilesModel::FileName).toString());
    return retval;
}

PictureViewer2FilenameItem::PictureViewer2FilenameItem(const QString &fileName, QGraphicsItem *parent) : QGraphicsItem(parent), mFilename(fileName) {
    setZValue(1);
}

QRectF PictureViewer2FilenameItem::boundingRect() const {
    QSize size = qApp->fontMetrics().size(Qt::TextSingleLine, mFilename);
    size += QSize(2, 2);
    QRectF retval;
    retval.setWidth(size.width());
    retval.setHeight(size.height());
    return retval;
}

void PictureViewer2FilenameItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget){
    Q_UNUSED(option);
    Q_UNUSED(widget);
    painter->save();
    painter->setRenderHint(QPainter::Antialiasing, false);
    painter->setRenderHint(QPainter::TextAntialiasing, true);
    QColor bgColor = QColor(237, 12, 102);
    bgColor.setAlpha(70);
    QColor fgColor = QColor(209, 207, 232);
    QBrush brush(bgColor);
    painter->setPen(QColor(Qt::yellow));
    painter->setBrush(brush);
    painter->drawRect(boundingRect());
    painter->setPen(QPen(fgColor));
    QPoint start(1, qApp->fontMetrics().ascent() + 1);
    painter->drawText(start, mFilename);
    painter->restore();
}