#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <QFileDialog>
#include <QLineEdit>
#include <QMessageBox>
#include <QScroller>
#include <QPdfDocument>
#include <QtMath>
#include "sequentialpagewidget.h"

const qreal zoomMultiplier = qSqrt(2.0);

Q_LOGGING_CATEGORY(lcExample, "qt.examples.pdfviewer")

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
    , m_pageWidget(new SequentialPageWidget(this))
    , m_zoomEdit(new QLineEdit(this))
    , m_pageEdit(new QLineEdit(this))
{
    ui->setupUi(this);
    ui->scrollArea->setWidget(m_pageWidget);
    m_zoomEdit->setMaximumWidth(50);
    m_zoomEdit->setAlignment(Qt::AlignHCenter);
    ui->mainToolBar->insertWidget(ui->actionZoom_In, m_zoomEdit);
    m_pageEdit->setMaximumWidth(50);
    m_pageEdit->setAlignment(Qt::AlignHCenter);
    ui->mainToolBar->insertWidget(ui->actionGo, m_pageEdit);
    connect(m_pageWidget, SIGNAL(showingPageRange(int,int)),
            this, SLOT(showingPageRange(int,int)), Qt::QueuedConnection);
    connect(m_pageWidget, SIGNAL(zoomChanged(qreal)),
            this, SLOT(zoomChanged(qreal)));
    connect(m_zoomEdit, SIGNAL(returnPressed()), this, SLOT(zoomEdited()));
    connect(m_pageEdit, SIGNAL(returnPressed()), this, SLOT(on_actionGo_triggered()));

    QScroller::grabGesture(ui->scrollArea);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::open(const QUrl &docLocation)
{
    m_pageWidget->openDocument(docLocation);
    qCDebug(lcExample) << docLocation;
    ui->scrollArea->ensureVisible(0, 0, 0, 0);
}

void MainWindow::showingPageRange(int start, int end)
{
    ui->statusBar->clearMessage();
    if (start == end)
        ui->statusBar->showMessage(tr("showing page %1").arg(start));
    else
        ui->statusBar->showMessage(tr("showing pages %1 to %2").arg(start).arg(end));
    m_pageEdit->setText(QString::number(end));
}

void MainWindow::zoomChanged(qreal factor)
{
    m_zoomEdit->setText(tr("%1%").arg(factor * 100., 0, 'f', 0));
}

void MainWindow::zoomEdited()
{
    bool ok = false;
    qreal factor = m_zoomEdit->text().remove(QChar('%')).toDouble(&ok);
    if (ok)
        m_pageWidget->setZoom(factor / 100.);
}

void MainWindow::on_actionOpen_triggered()
{
    QUrl toOpen = QFileDialog::getOpenFileUrl(this, tr("Choose a PDF"), QUrl(), "Portable Documents (*.pdf)");
    if (toOpen.isValid())
        open(toOpen);
}

void MainWindow::on_actionQuit_triggered()
{
    QApplication::quit();
}

void MainWindow::on_actionAbout_triggered()
{
    QMessageBox::about(this, tr("About PdfViewer"),
        tr("An example using QPdfDocument"));
}

void MainWindow::on_actionAbout_Qt_triggered()
{
    QMessageBox::aboutQt(this);
}

void MainWindow::on_actionZoom_In_triggered()
{
    m_pageWidget->setZoom(m_pageWidget->zoom() * zoomMultiplier);
}

void MainWindow::on_actionZoom_Out_triggered()
{
    m_pageWidget->setZoom(m_pageWidget->zoom() / zoomMultiplier);
}

void MainWindow::on_actionGo_triggered()
{
    bool ok = false;
    int page = m_pageEdit->text().toInt(&ok);
    if (!ok) return;
    ui->scrollArea->ensureVisible(0, m_pageWidget->yForPage(page));
}

void MainWindow::on_actionPrevious_Page_triggered()
{
    ui->scrollArea->ensureVisible(0, m_pageWidget->yForPage(m_pageWidget->topPageShowing() - 1));
}

void MainWindow::on_actionNext_Page_triggered()
{
    ui->scrollArea->ensureVisible(0, m_pageWidget->yForPage(m_pageWidget->bottomPageShowing() + 1));
}