#include "ScreenshotsPage.h"
#include "ui_ScreenshotsPage.h"

#include <QModelIndex>
#include <QMutableListIterator>
#include <QMap>
#include <QSet>
#include <QFileIconProvider>
#include <QFileSystemModel>
#include <QStyledItemDelegate>
#include <QLineEdit>
#include <QEvent>
#include <QPainter>
#include <QClipboard>
#include <QKeyEvent>
#include <QMenu>

#include <MultiMC.h>

#include "dialogs/ProgressDialog.h"
#include "dialogs/CustomMessageBox.h"
#include "net/NetJob.h"
#include "screenshots/ImgurUpload.h"
#include "screenshots/ImgurAlbumCreation.h"
#include "tasks/SequentialTask.h"

#include "RWStorage.h"
#include <FileSystem.h>
#include <DesktopServices.h>

typedef RWStorage<QString, QIcon> SharedIconCache;
typedef std::shared_ptr<SharedIconCache> SharedIconCachePtr;

class ThumbnailingResult : public QObject
{
    Q_OBJECT
public slots:
    inline void emitResultsReady(const QString &path) { emit resultsReady(path); }
    inline void emitResultsFailed(const QString &path) { emit resultsFailed(path); }
signals:
    void resultsReady(const QString &path);
    void resultsFailed(const QString &path);
};

class ThumbnailRunnable : public QRunnable
{
public:
    ThumbnailRunnable(QString path, SharedIconCachePtr cache)
    {
        m_path = path;
        m_cache = cache;
    }
    void run()
    {
        QFileInfo info(m_path);
        if (info.isDir())
            return;
        if ((info.suffix().compare("png", Qt::CaseInsensitive) != 0))
            return;
        int tries = 5;
        while (tries)
        {
            if (!m_cache->stale(m_path))
                return;
            QImage image(m_path);
            if (image.isNull())
            {
                QThread::msleep(500);
                tries--;
                continue;
            }
            QImage small;
            if (image.width() > image.height())
                small = image.scaledToWidth(512).scaledToWidth(256, Qt::SmoothTransformation);
            else
                small = image.scaledToHeight(512).scaledToHeight(256, Qt::SmoothTransformation);
            QPoint offset((256 - small.width()) / 2, (256 - small.height()) / 2);
            QImage square(QSize(256, 256), QImage::Format_ARGB32);
            square.fill(Qt::transparent);

            QPainter painter(&square);
            painter.drawImage(offset, small);
            painter.end();

            QIcon icon(QPixmap::fromImage(square));
            m_cache->add(m_path, icon);
            m_resultEmitter.emitResultsReady(m_path);
            return;
        }
        m_resultEmitter.emitResultsFailed(m_path);
    }
    QString m_path;
    SharedIconCachePtr m_cache;
    ThumbnailingResult m_resultEmitter;
};

// this is about as elegant and well written as a bag of bricks with scribbles done by insane
// asylum patients.
class FilterModel : public QIdentityProxyModel
{
    Q_OBJECT
public:
    explicit FilterModel(QObject *parent = 0) : QIdentityProxyModel(parent)
    {
        m_thumbnailingPool.setMaxThreadCount(4);
        m_thumbnailCache = std::make_shared<SharedIconCache>();
        m_thumbnailCache->add("placeholder", MMC->getThemedIcon("screenshot-placeholder"));
        connect(&watcher, SIGNAL(fileChanged(QString)), SLOT(fileChanged(QString)));
        // FIXME: the watched file set is not updated when files are removed
    }
    virtual ~FilterModel() { m_thumbnailingPool.waitForDone(500); }
    virtual QVariant data(const QModelIndex &proxyIndex, int role = Qt::DisplayRole) const
    {
        auto model = sourceModel();
        if (!model)
            return QVariant();
        if (role == Qt::DisplayRole || role == Qt::EditRole)
        {
            QVariant result = sourceModel()->data(mapToSource(proxyIndex), role);
            return result.toString().remove(QRegExp("\\.png$"));
        }
        if (role == Qt::DecorationRole)
        {
            QVariant result =
                sourceModel()->data(mapToSource(proxyIndex), QFileSystemModel::FilePathRole);
            QString filePath = result.toString();
            QIcon temp;
            if (!watched.contains(filePath))
            {
                ((QFileSystemWatcher &)watcher).addPath(filePath);
                ((QSet<QString> &)watched).insert(filePath);
            }
            if (m_thumbnailCache->get(filePath, temp))
            {
                return temp;
            }
            if (!m_failed.contains(filePath))
            {
                ((FilterModel *)this)->thumbnailImage(filePath);
            }
            return (m_thumbnailCache->get("placeholder"));
        }
        return sourceModel()->data(mapToSource(proxyIndex), role);
    }
    virtual bool setData(const QModelIndex &index, const QVariant &value,
                         int role = Qt::EditRole)
    {
        auto model = sourceModel();
        if (!model)
            return false;
        if (role != Qt::EditRole)
            return false;
        // FIXME: this is a workaround for a bug in QFileSystemModel, where it doesn't
        // sort after renames
        {
            ((QFileSystemModel *)model)->setNameFilterDisables(true);
            ((QFileSystemModel *)model)->setNameFilterDisables(false);
        }
        return model->setData(mapToSource(index), value.toString() + ".png", role);
    }

private:
    void thumbnailImage(QString path)
    {
        auto runnable = new ThumbnailRunnable(path, m_thumbnailCache);
        connect(&(runnable->m_resultEmitter), SIGNAL(resultsReady(QString)),
                SLOT(thumbnailReady(QString)));
        connect(&(runnable->m_resultEmitter), SIGNAL(resultsFailed(QString)),
                SLOT(thumbnailFailed(QString)));
        ((QThreadPool &)m_thumbnailingPool).start(runnable);
    }
private slots:
    void thumbnailReady(QString path) { emit layoutChanged(); }
    void thumbnailFailed(QString path) { m_failed.insert(path); }
    void fileChanged(QString filepath)
    {
        m_thumbnailCache->setStale(filepath);
        thumbnailImage(filepath);
        // reinsert the path...
        watcher.removePath(filepath);
        watcher.addPath(filepath);
    }

private:
    SharedIconCachePtr m_thumbnailCache;
    QThreadPool m_thumbnailingPool;
    QSet<QString> m_failed;
    QSet<QString> watched;
    QFileSystemWatcher watcher;
};

class CenteredEditingDelegate : public QStyledItemDelegate
{
public:
    explicit CenteredEditingDelegate(QObject *parent = 0) : QStyledItemDelegate(parent) {}
    virtual ~CenteredEditingDelegate() {}
    virtual QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option,
                                  const QModelIndex &index) const
    {
        auto widget = QStyledItemDelegate::createEditor(parent, option, index);
        auto foo = dynamic_cast<QLineEdit *>(widget);
        if (foo)
        {
            foo->setAlignment(Qt::AlignHCenter);
            foo->setFrame(true);
            foo->setMaximumWidth(192);
        }
        return widget;
    }
};

ScreenshotsPage::ScreenshotsPage(QString path, QWidget *parent)
    : QMainWindow(parent), ui(new Ui::ScreenshotsPage)
{
    m_model.reset(new QFileSystemModel());
    m_filterModel.reset(new FilterModel());
    m_filterModel->setSourceModel(m_model.get());
    m_model->setFilter(QDir::Files | QDir::Writable | QDir::Readable);
    m_model->setReadOnly(false);
    m_model->setNameFilters({"*.png"});
    m_model->setNameFilterDisables(false);
    m_folder = path;
    m_valid = FS::ensureFolderPathExists(m_folder);

    ui->setupUi(this);
    ui->toolBar->insertSpacer(ui->actionView_Folder);

    ui->listView->setIconSize(QSize(128, 128));
    ui->listView->setGridSize(QSize(192, 160));
    ui->listView->setSpacing(9);
    // ui->listView->setUniformItemSizes(true);
    ui->listView->setLayoutMode(QListView::Batched);
    ui->listView->setViewMode(QListView::IconMode);
    ui->listView->setResizeMode(QListView::Adjust);
    ui->listView->installEventFilter(this);
    ui->listView->setEditTriggers(0);
    ui->listView->setItemDelegate(new CenteredEditingDelegate(this));
    ui->listView->setContextMenuPolicy(Qt::CustomContextMenu);
    connect(ui->listView, &QListView::customContextMenuRequested, this, &ScreenshotsPage::ShowContextMenu);
    connect(ui->listView, SIGNAL(activated(QModelIndex)), SLOT(onItemActivated(QModelIndex)));
}

bool ScreenshotsPage::eventFilter(QObject *obj, QEvent *evt)
{
    if (obj != ui->listView)
        return QWidget::eventFilter(obj, evt);
    if (evt->type() != QEvent::KeyPress)
    {
        return QWidget::eventFilter(obj, evt);
    }
    QKeyEvent *keyEvent = static_cast<QKeyEvent *>(evt);
    switch (keyEvent->key())
    {
    case Qt::Key_Delete:
        on_actionDelete_triggered();
        return true;
    case Qt::Key_F2:
        on_actionRename_triggered();
        return true;
    default:
        break;
    }
    return QWidget::eventFilter(obj, evt);
}

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

void ScreenshotsPage::ShowContextMenu(const QPoint& pos)
{
    auto menu = ui->toolBar->createContextMenu(this, tr("Context menu"));
    menu->exec(ui->listView->mapToGlobal(pos));
    delete menu;
}

QMenu * ScreenshotsPage::createPopupMenu()
{
    QMenu* filteredMenu = QMainWindow::createPopupMenu();
    filteredMenu->removeAction( ui->toolBar->toggleViewAction() );
    return filteredMenu;
}

void ScreenshotsPage::onItemActivated(QModelIndex index)
{
    if (!index.isValid())
        return;
    auto info = m_model->fileInfo(index);
    QString fileName = info.absoluteFilePath();
    DesktopServices::openFile(info.absoluteFilePath());
}

void ScreenshotsPage::on_actionView_Folder_triggered()
{
    DesktopServices::openDirectory(m_folder, true);
}

void ScreenshotsPage::on_actionUpload_triggered()
{
    auto selection = ui->listView->selectionModel()->selectedRows();
    if (selection.isEmpty())
        return;

    QList<ScreenshotPtr> uploaded;
    auto job = NetJobPtr(new NetJob("Screenshot Upload"));
    if(selection.size() < 2)
    {
        auto item = selection.at(0);
        auto info = m_model->fileInfo(item);
        auto screenshot = std::make_shared<ScreenShot>(info);
        job->addNetAction(ImgurUpload::make(screenshot));

        m_uploadActive = true;
        ProgressDialog dialog(this);
        if(dialog.execWithTask(job.get()) != QDialog::Accepted)
        {
            CustomMessageBox::selectable(this, tr("Failed to upload screenshots!"),
                                         tr("Unknown error"), QMessageBox::Warning)->exec();
        }
        else
        {
            auto link = screenshot->m_url;
            QClipboard *clipboard = QApplication::clipboard();
            clipboard->setText(link);
            CustomMessageBox::selectable(
                    this,
                    tr("Upload finished"),
                    tr("The <a href=\"%1\">link  to the uploaded screenshot</a> has been placed in your clipboard.")
                        .arg(link),
                    QMessageBox::Information
            )->exec();
        }

        m_uploadActive = false;
        return;
    }

    for (auto item : selection)
    {
        auto info = m_model->fileInfo(item);
        auto screenshot = std::make_shared<ScreenShot>(info);
        uploaded.push_back(screenshot);
        job->addNetAction(ImgurUpload::make(screenshot));
    }
    SequentialTask task;
    auto albumTask = NetJobPtr(new NetJob("Imgur Album Creation"));
    auto imgurAlbum = ImgurAlbumCreation::make(uploaded);
    albumTask->addNetAction(imgurAlbum);
    task.addTask(job.unwrap());
    task.addTask(albumTask.unwrap());
    m_uploadActive = true;
    ProgressDialog prog(this);
    if (prog.execWithTask(&task) != QDialog::Accepted)
    {
        CustomMessageBox::selectable(this, tr("Failed to upload screenshots!"),
                                     tr("Unknown error"), QMessageBox::Warning)->exec();
    }
    else
    {
        auto link = QString("https://imgur.com/a/%1").arg(imgurAlbum->id());
        QClipboard *clipboard = QApplication::clipboard();
        clipboard->setText(link);
        CustomMessageBox::selectable(
            this,
            tr("Upload finished"),
            tr("The <a href=\"%1\">link  to the uploaded album</a> has been placed in your clipboard.") .arg(link),
            QMessageBox::Information
        )->exec();
    }
    m_uploadActive = false;
}

void ScreenshotsPage::on_actionDelete_triggered()
{
    auto mbox = CustomMessageBox::selectable(
        this, tr("Are you sure?"), tr("This will delete all selected screenshots."),
        QMessageBox::Warning, QMessageBox::Yes | QMessageBox::No);
    std::unique_ptr<QMessageBox> box(mbox);

    if (box->exec() != QMessageBox::Yes)
        return;

    auto selected = ui->listView->selectionModel()->selectedIndexes();
    for (auto item : selected)
    {
        m_model->remove(item);
    }
}

void ScreenshotsPage::on_actionRename_triggered()
{
    auto selection = ui->listView->selectionModel()->selectedIndexes();
    if (selection.isEmpty())
        return;
    ui->listView->edit(selection[0]);
    // TODO: mass renaming
}

void ScreenshotsPage::openedImpl()
{
    if(!m_valid)
    {
        m_valid = FS::ensureFolderPathExists(m_folder);
    }
    if (m_valid)
    {
        QString path = QDir(m_folder).absolutePath();
        auto idx = m_model->setRootPath(path);
        if(idx.isValid())
        {
            ui->listView->setModel(m_filterModel.get());
            ui->listView->setRootIndex(m_filterModel->mapFromSource(idx));
        }
        else
        {
            ui->listView->setModel(nullptr);
        }
    }
}

#include "ScreenshotsPage.moc"
