/**
 * Copyright (C) 2004 Scott Wheeler <wheeler@kde.org>
 * Copyright (C) 2009 Michael Pyne <mpyne@kde.org>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "nowplaying.h"

#include <KIO/StoredTransferJob>
#include <KJobWidgets>
#include <KLocalizedString>
#include <kiconloader.h>

#include <QApplication>
#include <QDrag>
#include <QDragEnterEvent>
#include <QDropEvent>
#include <QFontDatabase>
#include <QFontMetrics>
#include <QImage>
#include <QLabel>
#include <QLayout>
#include <QList>
#include <QMouseEvent>
#include <QPoint>
#include <QTimer>
#include <QUrl>
#include <QVBoxLayout>

#include "playlistcollection.h"
#include "playlistitem.h"
#include "coverinfo.h"
#include "juktag.h"
#include "collectionlist.h"
#include "juk_debug.h"

////////////////////////////////////////////////////////////////////////////////
// NowPlaying
////////////////////////////////////////////////////////////////////////////////

NowPlaying::NowPlaying(QWidget *parent, PlaylistCollection *collection) :
    QWidget(parent),
    m_observer(this, collection),
    // Also watch the collection
    m_collectionListObserver(this, CollectionList::instance()),
    m_collection(collection)
{
    setObjectName(QLatin1String("NowPlaying"));

    QHBoxLayout *layout = new QHBoxLayout(this);
    setLayout(layout);

    layout->setContentsMargins(0, 0, 0, 0);
    layout->setSpacing(3);

    // With HiDPI the text might actually be bigger... try to account for
    // that.
    const QFont defaultLargeFont(QFontDatabase::systemFont(QFontDatabase::TitleFont));
    const QFontMetrics fm(defaultLargeFont, this);

    const int coverIconHeight = qMax(64, fm.lineSpacing() * 2);
    setFixedHeight(coverIconHeight + 4);

    layout->addWidget(new CoverItem(this), 0);
    layout->addWidget(new TrackItem(this), 2);

    hide();
}

void NowPlaying::addItem(NowPlayingItem *item)
{
    m_items.append(item);
}

PlaylistCollection *NowPlaying::collection() const
{
    return m_collection;
}

void NowPlaying::slotUpdate(const FileHandle &file)
{
    m_file = file;
    if(file.isNull()) {
        hide();
        emit nowPlayingHidden();
        return;
    }
    else
        show();

    for(NowPlayingItem *item : m_items) {
        item->update(file);
    }
}

void NowPlaying::slotReloadCurrentItem()
{
    for(NowPlayingItem *item : m_items) {
        item->update(m_file);
    }
}

////////////////////////////////////////////////////////////////////////////////
// CoverItem
////////////////////////////////////////////////////////////////////////////////

CoverItem::CoverItem(NowPlaying *parent) :
    QLabel(parent),
    NowPlayingItem(parent)
{
    setObjectName(QLatin1String("CoverItem"));
    const QMargins margins = parent->layout()->contentsMargins();

    setFixedHeight(parent->height() - (margins.top() + margins.bottom()));
    setContentsMargins(1, 1, 1, 1);
    setAcceptDrops(true);
}

void CoverItem::update(const FileHandle &file)
{
    m_file = file;

    if(!file.isNull() && file.coverInfo()->hasCover()) {
        show();

        const auto pixRatio = this->devicePixelRatioF();
        const QSizeF logicalSize = QSizeF(this->height(), this->height());
        const QSizeF scaledSize = logicalSize * pixRatio;
        QPixmap pix =
            file.coverInfo()->pixmap(CoverInfo::FullSize)
            .scaled(scaledSize.toSize(), Qt::KeepAspectRatio, Qt::SmoothTransformation);

        if (!qFuzzyCompare(pixRatio, 1.0)) {
            pix.setDevicePixelRatio(pixRatio);
        }

        setPixmap(pix);
    }
    else
        hide();
}

void CoverItem::mouseReleaseEvent(QMouseEvent *event)
{
    if(m_dragging) {
        m_dragging = false;
        return;
    }

    if(rect().contains(event->position().toPoint()) &&
       event->button() == Qt::LeftButton &&
       m_file.coverInfo()->hasCover())
    {
        m_file.coverInfo()->popup();
    }

    QLabel::mousePressEvent(event);
}

void CoverItem::mousePressEvent(QMouseEvent *e)
{
    m_dragging = false;
    m_dragStart = e->globalPosition().toPoint();
}

void CoverItem::mouseMoveEvent(QMouseEvent *e)
{
    if(m_dragging)
        return;

    QPoint diff = m_dragStart - e->globalPosition().toPoint();
    if(diff.manhattanLength() > QApplication::startDragDistance()) {

        // Start a drag.

        m_dragging = true;

        // TODO: Restore CoverDrag and include ability to DnD image data
        // rather than a cover ID.
#if 0
        QDrag *drag = new QDrag(this);
        CoverDrag *data = new CoverDrag(m_file.coverInfo()->coverId());

        drag->setMimeData(data);
        drag->exec(Qt::CopyAction);
#endif
    }
}

void CoverItem::dragEnterEvent(QDragEnterEvent *e)
{
    e->setAccepted(false);
}

void CoverItem::dropEvent(QDropEvent *e)
{
    qCWarning(JUK_LOG) << "Dropping covers is not currently supported.";
    Q_UNUSED(e);

#if 0
    QImage image;
    QList<QUrl> urls;
    coverKey key;

    if(e->source() == this)
        return;

    if(e->mimeData()->hasImage()) {
        m_file.coverInfo()->setCover(qvariant_cast<QImage>(e->mimeData()->imageData()));
        update(m_file);
    }
    else {
        urls = e->mimeData()->urls();
        if(urls.isEmpty())
            return;

        auto getJob = KIO::storedGet(urls.front());
        KJobWidgets::setWindow(getJob, this);
        if(getJob->exec()) {
            if(image.loadFromData(getJob->data())) {
                m_file.coverInfo()->setCover(image);
                update(m_file);
            }
            else
                qCCritical(JUK_LOG) << "Unable to load image from " << urls.front();
        }
        else
            qCCritical(JUK_LOG) << "Unable to download " << urls.front();
    }
#endif
}

////////////////////////////////////////////////////////////////////////////////
// TrackItem
////////////////////////////////////////////////////////////////////////////////

TrackItem::TrackItem(NowPlaying *parent) :
    QWidget(parent),
    NowPlayingItem(parent)
{
    setObjectName(QLatin1String("TrackItem"));
    const QMargins margins = parent->layout()->contentsMargins();
    setFixedHeight(parent->height() - (margins.top() + margins.bottom()));
    setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);

    QVBoxLayout *layout = new QVBoxLayout(this);

    m_label = new QLabel(this);
    m_label->setWordWrap(true);

    m_label->setTextInteractionFlags(Qt::LinksAccessibleByMouse|Qt::LinksAccessibleByKeyboard|Qt::TextSelectableByMouse);

    layout->addStretch();
    layout->addWidget(m_label, 1);
    layout->addStretch();

    connect(m_label, SIGNAL(linkActivated(QString)), this,
            SLOT(slotOpenLink(QString)));

    // Ensure that if we're filtering results, that the filtering is cleared if we
    // hide the now playing bar so that the user can select tracks normally.

    connect(parent, SIGNAL(nowPlayingHidden()), SLOT(slotClearShowMore()));
}

void TrackItem::update(const FileHandle &file)
{
    m_file = file;
    QTimer::singleShot(0, this, SLOT(slotUpdate()));
}

void TrackItem::slotOpenLink(const QString &link)
{
    PlaylistCollection *collection = parentManager()->collection();

    if(link == "artist")
        collection->showMore(m_file.tag()->artist());
    else if(link == "album")
        collection->showMore(QString(), m_file.tag()->album());
    else if(link == "clear")
        collection->clearShowMore();

    update(m_file);
}

void TrackItem::slotUpdate()
{
    if(m_file.isNull()) {
        m_label->setText(QString());
        return;
    }

    const QString title  = m_file.tag()->title().toHtmlEscaped();
    const QString artist = m_file.tag()->artist().toHtmlEscaped();
    const QString album  = m_file.tag()->album().toHtmlEscaped();
    const QString separator =
        (artist.isEmpty() || album.isEmpty())
        ? QString() : QString(" - ");

    // This block-o-nastiness makes the font smaller and smaller until it actually fits.

    int size = 4;
    QString format =
        "<font size=\"+%1\"><b>%2</b></font>"
        "<br />"
        "<font size=\"+%3\"><b><a href=\"artist\">%4</a>%5<a href=\"album\">%6</a></b>";

    if(parentManager()->collection()->showMoreActive())
        format.append(QString(" (<a href=\"clear\">%1</a>)").arg(i18n("back to playlist")));

    format.append("</font>");
    int parentHeight = parentManager()->contentsRect().height();
    int neededHeight = 0;

    do {
        m_label->setText(format.arg(size).arg(title).arg(size - 2)
                         .arg(artist, separator, album));
        --size;
        neededHeight = m_label->heightForWidth(m_label->width());
    } while(neededHeight > parentHeight && size >= -1);

    m_label->setFixedHeight(qMin(neededHeight, parentHeight));
}

void TrackItem::slotClearShowMore()
{
    PlaylistCollection *collection = parentManager()->collection();
    Q_ASSERT(collection);
    collection->clearShowMore();
}

// vim: set et sw=4 tw=0 sta: