#include "mainwindow.h"

#include "bottombuttongroup.h"
#include "graphicsview.h"
#include "graphicsscene.h"

#include <QMouseEvent>
#include <QMovie>
#include <QDebug>
#include <QGraphicsTextItem>
#include <QApplication>
#include <QStyle>
#include <QScreen>
#include <QGraphicsOpacityEffect>

#ifdef _WIN32
#include <windows.h>
#endif // _WIN32

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent)
{
    this->setWindowFlags(Qt::Window | Qt::FramelessWindowHint | Qt::WindowStaysOnTopHint);
    this->setAttribute(Qt::WA_TranslucentBackground, true);
    this->setMinimumSize(710, 530);
    this->setWindowIcon(QIcon(":/icons/app-icon.svg"));

    m_fadeOutAnimation = new QPropertyAnimation(this, "windowOpacity");
    m_fadeOutAnimation->setDuration(300);
    m_fadeOutAnimation->setStartValue(1);
    m_fadeOutAnimation->setEndValue(0);
    m_floatUpAnimation = new QPropertyAnimation(this, "geometry");
    m_floatUpAnimation->setDuration(300);
    m_floatUpAnimation->setEasingCurve(QEasingCurve::OutCirc);
    m_exitAnimationGroup = new QParallelAnimationGroup;
    m_exitAnimationGroup->addAnimation(m_fadeOutAnimation);
    m_exitAnimationGroup->addAnimation(m_floatUpAnimation);
    connect(m_exitAnimationGroup, &QParallelAnimationGroup::finished,
            this, &QMainWindow::close);

    GraphicsScene * scene = new GraphicsScene(this);

    m_graphicsView = new GraphicsView(this);
    m_graphicsView->setScene(scene);
    this->setCentralWidget(m_graphicsView);

    m_closeButton = new QPushButton(m_graphicsView);
    m_closeButton->setFlat(true);
    m_closeButton->setFixedSize(50, 50);
    m_closeButton->setStyleSheet("QPushButton {"
                                 "background: transparent;"
                                 "}"
                                 "QPushButton:hover {"
                                 "background: red;"
                                 "}");

    connect(m_closeButton, &QAbstractButton::clicked,
            this, &MainWindow::closeWindow);

    m_bottomButtonGroup = new BottomButtonGroup(this);

    connect(m_bottomButtonGroup, &BottomButtonGroup::resetToOriginalBtnClicked,
            this, [ = ](){ m_graphicsView->resetScale(); });
    connect(m_bottomButtonGroup, &BottomButtonGroup::zoomInBtnClicked,
            this, [ = ](){ m_graphicsView->zoomView(1.25); });
    connect(m_bottomButtonGroup, &BottomButtonGroup::zoomOutBtnClicked,
            this, [ = ](){ m_graphicsView->zoomView(0.75); });
    connect(m_bottomButtonGroup, &BottomButtonGroup::toggleCheckerboardBtnClicked,
            this, [ = ](){ m_graphicsView->toggleCheckerboard(); });
    connect(m_bottomButtonGroup, &BottomButtonGroup::rotateRightBtnClicked,
            this, [ = ](){
        m_graphicsView->resetScale();
        m_graphicsView->rotateView(90);
        m_graphicsView->checkAndDoFitInView();
    });

    m_opacityEffect = new QGraphicsOpacityEffect(m_bottomButtonGroup);
    m_bottomButtonGroup->setGraphicsEffect(m_opacityEffect);
    m_btnGrpAnimation = new QPropertyAnimation(m_opacityEffect, "opacity");
    m_btnGrpAnimation->setDuration(300);

    m_opacityEffect->setOpacity(0);

    centerWindow();
}

MainWindow::~MainWindow()
{

}

void MainWindow::showUrls(const QList<QUrl> &urls)
{
    m_graphicsView->showFromUrlList(urls);
}

void MainWindow::adjustWindowSizeBySceneRect()
{
    if (m_graphicsView->scaleFactor() < 1) {
        // if it scaled down by the resize policy:
        QSize screenSize = qApp->screenAt(QCursor::pos())->availableSize();
        QSize sceneSize = m_graphicsView->sceneRect().toRect().size();
        QSize sceneSizeWithMargins = sceneSize + QSize(20, 20);
        if (screenSize.expandedTo(sceneSize) == screenSize) {
            // we can show the picture by increase the window size.
            if (screenSize.expandedTo(sceneSizeWithMargins) == screenSize) {
                this->resize(sceneSizeWithMargins);
            } else {
                this->resize(screenSize);
            }
            centerWindow();
        } else {
            // toggle maximum
            showMaximized();
        }
    }
}

void MainWindow::showEvent(QShowEvent *event)
{
    updateWidgetsPosition();

    return QMainWindow::showEvent(event);
}

void MainWindow::enterEvent(QEvent *event)
{
    m_btnGrpAnimation->stop();
    m_btnGrpAnimation->setStartValue(m_opacityEffect->opacity());
    m_btnGrpAnimation->setEndValue(1);
    m_btnGrpAnimation->start();

    return QMainWindow::enterEvent(event);
}

void MainWindow::leaveEvent(QEvent *event)
{
    m_btnGrpAnimation->stop();
    m_btnGrpAnimation->setStartValue(m_opacityEffect->opacity());
    m_btnGrpAnimation->setEndValue(0);
    m_btnGrpAnimation->start();

    return QMainWindow::leaveEvent(event);
}

void MainWindow::mousePressEvent(QMouseEvent *event)
{
    if (event->buttons() & Qt::LeftButton) {
        m_clickedOnWindow = true;
        m_oldMousePos = event->pos();
        qDebug() << m_oldMousePos << m_graphicsView->transform().m11()
                 << m_graphicsView->transform().m22() << m_graphicsView->matrix().m12();
        event->accept();
    }

    return QMainWindow::mousePressEvent(event);
}

void MainWindow::mouseMoveEvent(QMouseEvent *event)
{
    if (event->buttons() & Qt::LeftButton && m_clickedOnWindow) {
        move(event->globalPos() - m_oldMousePos);
        event->accept();
    }

    return QMainWindow::mouseMoveEvent(event);
}

void MainWindow::mouseReleaseEvent(QMouseEvent *event)
{
    m_clickedOnWindow = false;

    return QMainWindow::mouseReleaseEvent(event);
}

void MainWindow::mouseDoubleClickEvent(QMouseEvent *event)
{
    closeWindow();

    return QMainWindow::mouseDoubleClickEvent(event);
}

void MainWindow::resizeEvent(QResizeEvent *event)
{
    updateWidgetsPosition();

    return QMainWindow::resizeEvent(event);
}

bool MainWindow::nativeEvent(const QByteArray &eventType, void *message, long *result)
{
#ifdef _WIN32
    // https://stackoverflow.com/questions/6649936/c-compiling-on-windows-and-linux-ifdef-switch
    // Too lazy to do this now.. just stackoverflow it and did a copy and paste..
    Q_UNUSED(eventType);
    MSG* msg = static_cast<MSG*>(message);

    if (msg->message == WM_NCHITTEST) {
        if (isMaximized()) {
            return false;
        }

        *result = 0;
        const LONG borderWidth = 8;
        RECT winrect;
        GetWindowRect(reinterpret_cast<HWND>(winId()), &winrect);

        // must be short to correctly work with multiple monitors (negative coordinates)
        short x = msg->lParam & 0x0000FFFF;
        short y = (msg->lParam & 0xFFFF0000) >> 16;

        bool resizeWidth = minimumWidth() != maximumWidth();
        bool resizeHeight = minimumHeight() != maximumHeight();
        if (resizeWidth) {
            //left border
            if (x >= winrect.left && x < winrect.left + borderWidth) {
                *result = HTLEFT;
            }
            //right border
            if (x < winrect.right && x >= winrect.right - borderWidth) {
                *result = HTRIGHT;
            }
        }
        if (resizeHeight) {
            //bottom border
            if (y < winrect.bottom && y >= winrect.bottom - borderWidth) {
                *result = HTBOTTOM;
            }
            //top border
            if (y >= winrect.top && y < winrect.top + borderWidth) {
                *result = HTTOP;
            }
        }
        if (resizeWidth && resizeHeight) {
            //bottom left corner
            if (x >= winrect.left && x < winrect.left + borderWidth &&
                    y < winrect.bottom && y >= winrect.bottom - borderWidth)
            {
                *result = HTBOTTOMLEFT;
            }
            //bottom right corner
            if (x < winrect.right && x >= winrect.right - borderWidth &&
                    y < winrect.bottom && y >= winrect.bottom - borderWidth)
            {
                *result = HTBOTTOMRIGHT;
            }
            //top left corner
            if (x >= winrect.left && x < winrect.left + borderWidth &&
                    y >= winrect.top && y < winrect.top + borderWidth)
            {
                *result = HTTOPLEFT;
            }
            //top right corner
            if (x < winrect.right && x >= winrect.right - borderWidth &&
                    y >= winrect.top && y < winrect.top + borderWidth)
            {
                *result = HTTOPRIGHT;
            }
        }

        if (*result != 0)
            return true;

        QWidget *action = QApplication::widgetAt(QCursor::pos());
        if (action == this) {
            *result = HTCAPTION;
            return true;
        }
    }

    return false;
#else
    return QMainWindow::nativeEvent(eventType, message, result);
#endif // _WIN32
}

void MainWindow::centerWindow()
{
    this->setGeometry(
        QStyle::alignedRect(
            Qt::LeftToRight,
            Qt::AlignCenter,
            this->size(),
            qApp->screenAt(QCursor::pos())->geometry()
        )
    );
}

void MainWindow::closeWindow()
{
    QRect windowRect(this->geometry());
    m_floatUpAnimation->setStartValue(windowRect);
    m_floatUpAnimation->setEndValue(windowRect.adjusted(0, -80, 0, 0));
    m_floatUpAnimation->setStartValue(QRect(this->geometry().x(), this->geometry().y(), this->geometry().width(), this->geometry().height()));
    m_floatUpAnimation->setEndValue(QRect(this->geometry().x(), this->geometry().y()-80, this->geometry().width(), this->geometry().height()));
    m_exitAnimationGroup->start();
}

void MainWindow::updateWidgetsPosition()
{
    m_closeButton->move(width() - m_closeButton->width(), 0);
    m_bottomButtonGroup->move((width() - m_bottomButtonGroup->width()) / 2,
                              height() - m_bottomButtonGroup->height());
}