#include "mainwindow.hpp"
#include "dialog/login.hpp"
#include "dialog/settings.hpp"
#include "util/settings.hpp"
#include "util/icon.hpp"

#ifdef USE_DBUS
#include "backend/mpris.hpp"
#endif

#include <QApplication>
#include <QMenuBar>
#include <QMenu>
#include <QAction>
#include <QStatusBar>
#include <QLabel>
#include <QLineEdit>
#include <QMessageBox>
#include <QTimer>
#include <QJsonArray>

MainWindow::MainWindow(QobuzBackend *backend, QWidget *parent)
    : QMainWindow(parent)
    , m_backend(backend)
{
    setWindowTitle(QStringLiteral("Qobuz"));
    setMinimumSize(800, 500);
    resize(defaultSize());

    // ---- Queue (owned here, shared with toolbar and track list) ----
    m_queue = new PlayQueue(this);

    // ---- Toolbar ----
    m_toolBar = new MainToolBar(m_backend, m_queue, this);
    addToolBar(Qt::TopToolBarArea, m_toolBar);

    // ---- Central content ----
    m_content = new MainContent(m_backend, m_queue, this);
    setCentralWidget(m_content);

    // ---- Library dock (left) ----
    m_library = new List::Library(m_backend, this);
    m_libraryDock = new QDockWidget(tr("Library"), this);
    m_libraryDock->setObjectName(QStringLiteral("libraryDock"));
    m_libraryDock->setFeatures(QDockWidget::DockWidgetMovable);
    m_libraryDock->setWidget(m_library);
    m_libraryDock->setMinimumWidth(150);
    addDockWidget(Qt::LeftDockWidgetArea, m_libraryDock);

    // ---- Now-playing context dock (left, below library) ----
    m_contextView = new Context::View(m_backend, this);
    addDockWidget(Qt::LeftDockWidgetArea, m_contextView);

    // ---- Queue panel (right) ----
    m_queuePanel = new QueuePanel(m_queue, this);
    m_queuePanel->hide();
    addDockWidget(Qt::RightDockWidgetArea, m_queuePanel);

    // ---- Search side panel (right) ----
    m_sidePanel = new SidePanel::View(m_backend, m_queue, this);
    m_sidePanel->hide();
    addDockWidget(Qt::RightDockWidgetArea, m_sidePanel);

    setupMenuBar();
    statusBar()->showMessage(tr("Ready"));

    // ---- Scrobbler ----
        m_scrobbler = new LastFmScrobbler(this);
        connect(m_backend, &QobuzBackend::trackChanged,
                m_scrobbler, &LastFmScrobbler::onTrackStarted);
        connect(m_backend, &QobuzBackend::positionChanged,
                m_scrobbler, &LastFmScrobbler::onPositionChanged);
        connect(m_backend, &QobuzBackend::trackFinished,
                m_scrobbler, &LastFmScrobbler::onTrackFinished);

        // 1. Scrobble the finished track during a gapless transition
        connect(m_backend, &QobuzBackend::trackTransitioned,
                m_scrobbler, &LastFmScrobbler::onTrackFinished);

    // ---- Gapless Signal ----
        connect(m_backend, &QobuzBackend::positionChanged, this, [this](quint64 pos, quint64 dur) {
            if (!AppSettings::instance().gaplessEnabled() || dur == 0) return;

            // Trigger prefetch if we pass the 50% mark OR are within 60 seconds of the end
            if ((pos > dur / 2) || (dur > 60 && (dur - pos) <= 60)) {
                if (!m_nextTrackPrefetched && m_queue->canGoNext()) {
                    m_nextTrackPrefetched = true; // Lock it so it only fires once

                    const auto upcoming = m_queue->upcomingTracks(1);
                    if (!upcoming.isEmpty()) {
                        const qint64 nextId = static_cast<qint64>(upcoming.first()["id"].toDouble());
                        if (nextId > 0) {
                            m_backend->prefetchTrack(nextId, AppSettings::instance().preferredFormat());
                        }
                    }
                }
            }
        });

    // ---- Backend signals ----
    connect(m_backend, &QobuzBackend::loginSuccess,   this, &MainWindow::onLoginSuccess);
    connect(m_backend, &QobuzBackend::loginError,     this, &MainWindow::onLoginError);
    connect(m_backend, &QobuzBackend::userLoaded, this, [this](const QJsonObject &user) {
        const qint64 id = static_cast<qint64>(user["id"].toDouble());
        if (id > 0) {
            AppSettings::instance().setUserId(id);
            m_library->refresh();  // re-load playlists with correct ownership now
        }
    });
    connect(m_backend, &QobuzBackend::favTracksLoaded,  this, &MainWindow::onFavTracksLoaded);
    connect(m_backend, &QobuzBackend::favAlbumsLoaded,  this, &MainWindow::onFavAlbumsLoaded);
    connect(m_backend, &QobuzBackend::favArtistsLoaded, this, &MainWindow::onFavArtistsLoaded);
    connect(m_backend, &QobuzBackend::albumLoaded,      this, &MainWindow::onAlbumLoaded);
    connect(m_backend, &QobuzBackend::artistLoaded,     this, &MainWindow::onArtistLoaded);
    connect(m_backend, &QobuzBackend::artistReleasesLoaded,
            m_content, &MainContent::updateArtistReleases);
    connect(m_backend, &QobuzBackend::deepShuffleTracksLoaded,
            m_content, &MainContent::onDeepShuffleTracks);
    connect(m_backend, &QobuzBackend::playlistLoaded,   this, &MainWindow::onPlaylistLoaded);
    connect(m_backend, &QobuzBackend::playlistCreated,   this, &MainWindow::onPlaylistCreated);
    connect(m_backend, &QobuzBackend::playlistDeleted,   this, [this](const QJsonObject &) {
        // status bar message is also shown by library's openPlaylistDeleted handler
    });
    connect(m_backend, &QobuzBackend::playlistTrackAdded, this, [this](qint64 playlistId) {
        // Refresh the currently shown playlist if a track was added to it
        if (m_content->tracksList()->playlistId() == playlistId)
            m_backend->getPlaylist(playlistId);
        statusBar()->showMessage(tr("Track added to playlist"), 3000);
    });
    connect(m_backend, &QobuzBackend::trackChanged,   this, &MainWindow::onTrackChanged);
    connect(m_backend, &QobuzBackend::error, this, [this](const QString &msg) {
        statusBar()->showMessage(tr("Error: %1").arg(msg), 6000);
    });

    // ---- Library signals ----
    connect(m_library, &List::Library::userPlaylistsChanged,
            this, &MainWindow::onUserPlaylistsChanged);
    connect(m_library, &List::Library::openPlaylistDeleted,
            this, [this] {
        m_content->showWelcome();
        statusBar()->showMessage(tr("Playlist deleted"), 3000);
    });

    // ---- Library → backend ----
    connect(m_library, &List::Library::favTracksRequested, this, [this] {
        m_backend->getFavTracks();
        statusBar()->showMessage(tr("Loading favorite tracks…"));
    });

#ifdef USE_DBUS
    m_mpris = new Mpris(this);
    connect(m_mpris->player(), &MprisPlayerAdaptor::playRequested, m_backend, [this] {
        if (m_backend->state() == 2) m_backend->resume();
    });
    connect(m_mpris->player(), &MprisPlayerAdaptor::pauseRequested, m_backend, &QobuzBackend::pause);
    connect(m_mpris->player(), &MprisPlayerAdaptor::playPauseRequested, m_backend, [this] {
        if (m_backend->state() == 1)
            m_backend->pause();
        else
            m_backend->resume();
    });
    connect(m_mpris->player(), &MprisPlayerAdaptor::stopRequested, m_backend, &QobuzBackend::stop);
    connect(m_mpris->player(), &MprisPlayerAdaptor::nextRequested, this, [this] {
        if (!m_queue->canGoNext()) return;
        const qint64 id = static_cast<qint64>(m_queue->advance()["id"].toDouble());
        if (id > 0) m_backend->playTrack(id);
    });
    connect(m_mpris->player(), &MprisPlayerAdaptor::previousRequested, this, [this] {
        if (!m_queue->canGoPrev()) return;
        const qint64 id = static_cast<qint64>(m_queue->stepBack()["id"].toDouble());
        if (id > 0) m_backend->playTrack(id);
    });
    connect(m_mpris->player(), &MprisPlayerAdaptor::seekRequested, m_backend, [this](qlonglong offsetMicroseconds) {
        qint64 newPos = m_backend->position() + (offsetMicroseconds / 1000000LL);
        if (newPos < 0) newPos = 0;
        m_backend->seek(newPos);
    });
    connect(m_mpris->player(), &MprisPlayerAdaptor::seekToRequested, m_backend, [this](qlonglong positionMicroseconds) {
        m_backend->seek(positionMicroseconds / 1000000LL);
    });
    connect(m_mpris->player(), &MprisPlayerAdaptor::volumeChangeRequested, m_backend, [this](double vol) {
        m_backend->setVolume(vol * 100);
    });

    connect(m_backend, &QobuzBackend::stateChanged, this, [this](const QString &state) {
        if (state == "playing") m_mpris->player()->setPlaybackStatus("Playing");
        else if (state == "paused") m_mpris->player()->setPlaybackStatus("Paused");
        else m_mpris->player()->setPlaybackStatus("Stopped");
    });
    connect(m_backend, &QobuzBackend::positionChanged, this, [this](quint64 pos) {
        m_mpris->player()->updatePosition(pos);
    });
#endif

    connect(m_library, &List::Library::favAlbumsRequested, this, [this] {
        m_backend->getFavAlbums();
        statusBar()->showMessage(tr("Loading favorite albums…"));
    });
    connect(m_library, &List::Library::favArtistsRequested, this, [this] {
        m_showFavArtistsOnLoad = true;
        m_backend->getFavArtists();
        statusBar()->showMessage(tr("Loading favorite artists…"));
    });
    connect(m_library, &List::Library::playlistRequested,
            this, [this](qint64 id, const QString &name) {
        m_backend->getPlaylist(id);
        statusBar()->showMessage(tr("Loading playlist: %1…").arg(name));
    });
    connect(m_library, &List::Library::browseGenresRequested, this, [this] {
        m_content->showGenreBrowser();
        statusBar()->showMessage(tr("Browse Genres"));
    });

    // ---- Track list → playback / playlist management ----
    connect(m_content->tracksList(), &List::Tracks::playTrackRequested,
            this, &MainWindow::onPlayTrackRequested);
    connect(m_content->tracksList(), &List::Tracks::addToPlaylistRequested,
            this, [this](qint64 trackId, qint64 playlistId) {
        m_backend->addTrackToPlaylist(playlistId, trackId);
        statusBar()->showMessage(tr("Adding track to playlist…"), 3000);
    });
    connect(m_content->tracksList(), &List::Tracks::removeFromPlaylistRequested,
            this, [this](qint64 playlistId, qint64 playlistTrackId) {
        m_backend->deleteTrackFromPlaylist(playlistId, playlistTrackId);
        statusBar()->showMessage(tr("Removing track from playlist…"), 3000);
    });

    // ---- Search panel ----
    connect(m_sidePanel, &SidePanel::View::albumSelected,
            this, &MainWindow::onSearchAlbumSelected);
    connect(m_sidePanel, &SidePanel::View::artistSelected,
            this, &MainWindow::onSearchArtistSelected);
    connect(m_sidePanel, &SidePanel::View::trackPlayRequested,
            this, &MainWindow::onPlayTrackRequested);
    connect(m_sidePanel, &SidePanel::View::addToPlaylistRequested,
            this, [this](qint64 trackId, qint64 playlistId) {
        m_backend->addTrackToPlaylist(playlistId, trackId);
        statusBar()->showMessage(tr("Adding track to playlist..."), 3000);
    });

    // ---- Album / artist navigation from content views ----
    connect(m_content, &MainContent::albumRequested,
            this, &MainWindow::onSearchAlbumSelected);
    connect(m_content, &MainContent::artistRequested,
            this, &MainWindow::onSearchArtistSelected);
    connect(m_content, &MainContent::playTrackRequested,
            this, &MainWindow::onPlayTrackRequested);

    // ---- Queue panel ----
    connect(m_queuePanel, &QueuePanel::skipToTrackRequested,
            this, &MainWindow::onPlayTrackRequested);

    // ---- Toolbar toggles ----
    connect(m_toolBar, &MainToolBar::searchToggled, this, &MainWindow::onSearchToggled);
    connect(m_toolBar, &MainToolBar::queueToggled,
            this, [this](bool v) { m_queuePanel->setVisible(v); });

    connect(m_toolBar, &MainToolBar::albumRequested,  this, &MainWindow::onSearchAlbumSelected);
    connect(m_toolBar, &MainToolBar::artistRequested, this, &MainWindow::onSearchArtistSelected);

    // Apply playback options from saved settings
    m_backend->setReplayGain(AppSettings::instance().replayGainEnabled());
    m_backend->setGapless(AppSettings::instance().gaplessEnabled());

    tryRestoreSession();
}

void MainWindow::setupMenuBar()
{
    auto *fileMenu = menuBar()->addMenu(tr("&File"));
    fileMenu->addAction(Icon::get("im-user-away"), tr("&Sign in…"),
                        this, &MainWindow::showLoginDialog);
    fileMenu->addSeparator();
    fileMenu->addAction(Icon::settings(), tr("&Settings…"),
                        this, &MainWindow::showSettingsDialog);
    fileMenu->addSeparator();
    auto *quitAction = fileMenu->addAction(Icon::get("application-exit"), tr("&Quit"),
                                           qApp, &QApplication::quit);
    quitAction->setShortcut(QKeySequence::Quit);

    auto *viewMenu = menuBar()->addMenu(tr("&View"));
    viewMenu->addAction(m_libraryDock->toggleViewAction());
    viewMenu->addAction(m_contextView->toggleViewAction());
    viewMenu->addAction(m_queuePanel->toggleViewAction());
    viewMenu->addAction(m_sidePanel->toggleViewAction());

    auto *helpMenu = menuBar()->addMenu(tr("&Help"));
    helpMenu->addAction(Icon::get("help-about"), tr("&About"), this, [this] {
        QMessageBox::about(this, tr("About Qobuz"),
            tr("<h3>qobuz-qt</h3>"
               "<p>A lightweight Qt client for the Qobuz streaming service.</p>"
               "<p>Audio engine: <b>Symphonia</b> (Rust) via CPAL/ALSA.<br>"
               "Icons: <b>spotify-qt</b> (dark variant).</p>"));
    });
}

void MainWindow::tryRestoreSession()
{
    const QString token = AppSettings::instance().authToken();
    if (!token.isEmpty()) {
        m_backend->setToken(token);
        if (AppSettings::instance().userId() == 0)
            m_backend->getUser();  // userLoaded will call m_library->refresh()
        else
            m_library->refresh();
        // Preload fav artists so the artist page fav button works immediately
        m_backend->getFavArtists();
        const QString name = AppSettings::instance().displayName();
        statusBar()->showMessage(tr("Signed in as %1").arg(
            name.isEmpty() ? AppSettings::instance().userEmail() : name));
    } else {
        QTimer::singleShot(200, this, &MainWindow::showLoginDialog);
    }
}

// ---- slots ----

void MainWindow::showLoginDialog()
{
    auto *dlg = new LoginDialog(this);
    dlg->setAttribute(Qt::WA_DeleteOnClose);

    connect(dlg, &LoginDialog::loginRequested,
            this, [this, dlg](const QString &email, const QString &password) {
        dlg->setBusy(true);
        m_backend->login(email, password);
    });
    connect(m_backend, &QobuzBackend::loginSuccess, dlg, [dlg](const QString &, const QJsonObject &) {
        dlg->accept();
    });
    connect(m_backend, &QobuzBackend::loginError, dlg, [dlg](const QString &err) {
        dlg->setError(err);
    });

    dlg->exec();
}

void MainWindow::showSettingsDialog()
{
    SettingsDialog dlg(this);
    dlg.exec();
}

void MainWindow::onLoginSuccess(const QString &token, const QJsonObject &user)
{
    AppSettings::instance().setAuthToken(token);
    const QString displayName = user["display_name"].toString();
    const QString email       = user["email"].toString();
    AppSettings::instance().setDisplayName(displayName);
    AppSettings::instance().setUserEmail(email);
    const qint64 userId = static_cast<qint64>(user["id"].toDouble());
    if (userId > 0)
        AppSettings::instance().setUserId(userId);
    statusBar()->showMessage(tr("Signed in as %1").arg(
        displayName.isEmpty() ? email : displayName));
    m_library->refresh();
}

void MainWindow::onLoginError(const QString &error)
{
    statusBar()->showMessage(tr("Login failed: %1").arg(error), 6000);
}

void MainWindow::onTrackChanged(const QJsonObject &track)
{
    m_nextTrackPrefetched = false;
    // Update playing row highlight in the track list
    const qint64 id = static_cast<qint64>(track["id"].toDouble());
    m_content->tracksList()->setPlayingTrackId(id);

    // Update status bar with track name
    const QString title  = track["title"].toString();
    const QString artist = track["performer"].toObject()["name"].toString().isEmpty()
        ? track["album"].toObject()["artist"].toObject()["name"].toString()
        : track["performer"].toObject()["name"].toString();
    statusBar()->showMessage(
        artist.isEmpty() ? title : QStringLiteral("▶  %1 — %2").arg(artist, title));

#ifdef USE_DBUS
    QVariantMap metadata;
    metadata["mpris:trackid"] = QVariant::fromValue(QDBusObjectPath(QString("/org/qobuz/track/%1").arg(id)));
    metadata["mpris:length"] = QVariant::fromValue(qlonglong(track["duration"].toDouble() * 1000000LL));
    metadata["xesam:title"]  = title;

    QJsonObject album = track["album"].toObject();
    metadata["xesam:album"]  = album["title"].toString();

    if (!artist.isEmpty()) {
        metadata["xesam:artist"] = QStringList{artist};
    }

    if (album.contains("image") && album["image"].toObject().contains("large")) {
        metadata["mpris:artUrl"] = album["image"].toObject()["large"].toString();
    }

    m_mpris->player()->setMetadata(metadata);
#endif
}

void MainWindow::onFavTracksLoaded(const QJsonObject &result)
{
    // Cache fav IDs so the star indicator and context menu stay in sync
    QSet<qint64> ids;
    const QJsonArray items = result["items"].toArray();
    for (const QJsonValue &v : items) {
        const qint64 id = static_cast<qint64>(v.toObject()["id"].toDouble());
        if (id > 0) ids.insert(id);
    }
    m_content->tracksList()->setFavTrackIds(ids);

    m_content->showFavTracks(result);
    statusBar()->showMessage(
        tr("%1 favorite tracks").arg(result["total"].toInt()), 4000);
}

void MainWindow::onFavAlbumsLoaded(const QJsonObject &result)
{
    m_content->showFavAlbums(result);
    statusBar()->showMessage(
        tr("%1 favorite albums").arg(result["total"].toInt()), 4000);
}

void MainWindow::onFavArtistsLoaded(const QJsonObject &result)
{
    // Always cache fav artist IDs (needed by the artist page fav button)
    m_favArtistIds.clear();
    const QJsonArray items = result["items"].toArray();
    for (const QJsonValue &v : items) {
        const qint64 id = static_cast<qint64>(v.toObject()["id"].toDouble());
        if (id > 0) m_favArtistIds.insert(id);
    }
    m_content->setFavArtistIds(m_favArtistIds);

    // Only navigate to the fav artists page if the user explicitly requested it
    if (m_showFavArtistsOnLoad) {
        m_showFavArtistsOnLoad = false;
        m_content->showFavArtists(result);
        statusBar()->showMessage(
            tr("%1 favorite artists").arg(result["total"].toInt()), 4000);
    }
}

void MainWindow::onAlbumLoaded(const QJsonObject &album)
{
    m_content->showAlbum(album);
    statusBar()->showMessage(
        tr("Album: %1").arg(album["title"].toString()), 4000);
}

void MainWindow::onArtistLoaded(const QJsonObject &artist)
{
    m_content->showArtist(artist);
    // Fire release requests only after the artist page is shown — avoids the
    // race where a fast-responding release request arrives before setArtist()
    // clears the sections, causing setArtist() to wipe out the data.
    const qint64 artistId = static_cast<qint64>(artist["id"].toDouble());
    for (const char *type : {"album", "epSingle", "live", "compilation"})
        m_backend->getArtistReleases(artistId, QString::fromLatin1(type));
    statusBar()->showMessage(
        tr("Artist: %1").arg(artist["name"].toObject()["display"].toString()), 4000);
}

void MainWindow::onPlaylistLoaded(const QJsonObject &playlist)
{
    m_content->showPlaylist(playlist);
    statusBar()->showMessage(
        tr("Playlist: %1").arg(playlist["name"].toString()), 4000);
}

void MainWindow::onPlayTrackRequested(qint64 trackId)
{
    m_backend->playTrack(trackId, AppSettings::instance().preferredFormat());
}

void MainWindow::onSearchAlbumSelected(const QString &albumId)
{
    m_backend->getAlbum(albumId);
    statusBar()->showMessage(tr("Loading album…"));
}

void MainWindow::onSearchArtistSelected(qint64 artistId)
{
    m_backend->getArtist(artistId);
    statusBar()->showMessage(tr("Loading artist…"));
}

void MainWindow::onSearchToggled(bool visible)
{
    m_sidePanel->setVisible(visible);
}

void MainWindow::onPlaylistCreated(const QJsonObject &playlist)
{
    const QString name = playlist["name"].toString();
    statusBar()->showMessage(tr("Playlist '%1' created").arg(name), 4000);
    // Open the new playlist immediately
    const qint64 id = static_cast<qint64>(playlist["id"].toDouble());
    if (id > 0)
        m_backend->getPlaylist(id);
}

void MainWindow::onUserPlaylistsChanged(const QVector<QPair<qint64, QString>> &playlists)
{
    m_userPlaylists = playlists;
    m_content->tracksList()->setUserPlaylists(playlists);
    m_sidePanel->searchTab()->setUserPlaylists(playlists);
}