#include "analyzer/analyzerbeats.h"

#include <QHash>
#include <QString>
#include <QVector>
#include <QtDebug>

#include "analyzer/constants.h"
#include "analyzer/plugins/analyzerqueenmarybeats.h"
#include "analyzer/plugins/analyzersoundtouchbeats.h"
#include "library/rekordbox/rekordboxconstants.h"
#include "track/beatfactory.h"
#include "track/beatmap.h"
#include "track/beatutils.h"
#include "track/track.h"

// static
QList<mixxx::AnalyzerPluginInfo> AnalyzerBeats::availablePlugins() {
    QList<mixxx::AnalyzerPluginInfo> plugins;
    // First one below is the default
    plugins.append(mixxx::AnalyzerQueenMaryBeats::pluginInfo());
    plugins.append(mixxx::AnalyzerSoundTouchBeats::pluginInfo());
    return plugins;
}

// static
mixxx::AnalyzerPluginInfo AnalyzerBeats::defaultPlugin() {
    const auto plugins = availablePlugins();
    DEBUG_ASSERT(!plugins.isEmpty());
    return plugins.at(0);
}

AnalyzerBeats::AnalyzerBeats(UserSettingsPointer pConfig, bool enforceBpmDetection)
        : m_bpmSettings(pConfig),
          m_enforceBpmDetection(enforceBpmDetection),
          m_bPreferencesReanalyzeOldBpm(false),
          m_bPreferencesReanalyzeImported(false),
          m_bPreferencesFixedTempo(true),
          m_bPreferencesFastAnalysis(false),
          m_totalSamples(0),
          m_iMaxSamplesToProcess(0),
          m_iCurrentSample(0) {
}

bool AnalyzerBeats::initialize(TrackPointer pTrack, int sampleRate, int totalSamples) {
    if (totalSamples == 0) {
        return false;
    }

    bool bPreferencesBeatDetectionEnabled =
            m_enforceBpmDetection || m_bpmSettings.getBpmDetectionEnabled();
    if (!bPreferencesBeatDetectionEnabled) {
        qDebug() << "Beat calculation is deactivated";
        return false;
    }

    bool bpmLock = pTrack->isBpmLocked();
    if (bpmLock) {
        qDebug() << "Track is BpmLocked: Beat calculation will not start";
        return false;
    }

    m_bPreferencesFixedTempo = m_bpmSettings.getFixedTempoAssumption();
    m_bPreferencesReanalyzeOldBpm = m_bpmSettings.getReanalyzeWhenSettingsChange();
    m_bPreferencesReanalyzeImported = m_bpmSettings.getReanalyzeImported();
    m_bPreferencesFastAnalysis = m_bpmSettings.getFastAnalysis();

    const auto plugins = availablePlugins();
    if (!plugins.isEmpty()) {
        m_pluginId = defaultPlugin().id;
        QString pluginId = m_bpmSettings.getBeatPluginId();
        for (const auto& info : plugins) {
            if (info.id == pluginId) {
                m_pluginId = pluginId; // configured Plug-In available
                break;
            }
        }
    }

    qDebug() << "AnalyzerBeats preference settings:"
             << "\nPlugin:" << m_pluginId
             << "\nFixed tempo assumption:" << m_bPreferencesFixedTempo
             << "\nRe-analyze when settings change:" << m_bPreferencesReanalyzeOldBpm
             << "\nFast analysis:" << m_bPreferencesFastAnalysis;

    m_sampleRate = sampleRate;
    m_totalSamples = totalSamples;
    // In fast analysis mode, skip processing after
    // kFastAnalysisSecondsToAnalyze seconds are analyzed.
    if (m_bPreferencesFastAnalysis) {
        m_iMaxSamplesToProcess =
                mixxx::kFastAnalysisSecondsToAnalyze * m_sampleRate * mixxx::kAnalysisChannels;
    } else {
        m_iMaxSamplesToProcess = m_totalSamples;
    }
    m_iCurrentSample = 0;

    // if we can load a stored track don't reanalyze it
    bool bShouldAnalyze = shouldAnalyze(pTrack);

    DEBUG_ASSERT(!m_pPlugin);
    if (bShouldAnalyze) {
        if (m_pluginId == mixxx::AnalyzerQueenMaryBeats::pluginInfo().id) {
            m_pPlugin = std::make_unique<mixxx::AnalyzerQueenMaryBeats>();
        } else if (m_pluginId == mixxx::AnalyzerSoundTouchBeats::pluginInfo().id) {
            m_pPlugin = std::make_unique<mixxx::AnalyzerSoundTouchBeats>();
        } else {
            // This must not happen, because we have already verified above
            // that the PlugInId is valid
            DEBUG_ASSERT(false);
        }

        if (m_pPlugin) {
            if (m_pPlugin->initialize(sampleRate)) {
                qDebug() << "Beat calculation started with plugin" << m_pluginId;
            } else {
                qDebug() << "Beat calculation will not start.";
                m_pPlugin.reset();
                bShouldAnalyze = false;
            }
        } else {
            bShouldAnalyze = false;
        }
    }
    return bShouldAnalyze;
}

bool AnalyzerBeats::shouldAnalyze(TrackPointer pTrack) const {
    bool bpmLock = pTrack->isBpmLocked();
    if (bpmLock) {
        qDebug() << "Track is BpmLocked: Beat calculation will not start";
        return false;
    }

    QString pluginID = m_bpmSettings.getBeatPluginId();
    if (pluginID.isEmpty()) {
        pluginID = defaultPlugin().id;
    }

    // If the track already has a Beats object then we need to decide whether to
    // analyze this track or not.
    const mixxx::BeatsPointer pBeats = pTrack->getBeats();
    if (!pBeats) {
        return true;
    }
    if (!mixxx::Bpm::isValidValue(pBeats->getBpm())) {
        // Tracks with an invalid bpm <= 0 should be re-analyzed,
        // independent of the preference settings. We expect that
        // all tracks have a bpm > 0 when analyzed. Users that want
        // to keep their zero bpm tracks could lock them to prevent
        // this re-analysis (see the check above).
        qDebug() << "Re-analyzing track with invalid BPM despite preference settings.";
        return true;
    }

    QString subVersion = pBeats->getSubVersion();
    if (subVersion == mixxx::rekordboxconstants::beatsSubversion) {
        return m_bPreferencesReanalyzeImported;
    }

    if (subVersion.isEmpty() && pBeats->findNextBeat(0) <= 0.0 &&
            m_pluginId != mixxx::AnalyzerSoundTouchBeats::pluginInfo().id) {
        // This happens if the beat grid was created from the metadata BPM value.
        qDebug() << "First beat is 0 for grid so analyzing track to find first beat.";
        return true;
    }

    QString version = pBeats->getVersion();
    QHash<QString, QString> extraVersionInfo = getExtraVersionInfo(
            pluginID,
            m_bPreferencesFastAnalysis);
    QString newVersion = BeatFactory::getPreferredVersion(
            m_bPreferencesFixedTempo);
    QString newSubVersion = BeatFactory::getPreferredSubVersion(
            extraVersionInfo);

    if (version == newVersion && subVersion == newSubVersion) {
        // If the version and settings have not changed then if the world is
        // sane, re-analyzing will do nothing.
        return false;
    }
    // Beat grid exists but version and settings differ
    if (!m_bPreferencesReanalyzeOldBpm) {
        qDebug() << "Beat calculation skips analyzing because the track has"
                << "a BPM computed by a previous Mixxx version and user"
                << "preferences indicate we should not change it.";
        return false;
    }

    return true;
}

bool AnalyzerBeats::processSamples(const CSAMPLE *pIn, const int iLen) {
    VERIFY_OR_DEBUG_ASSERT(m_pPlugin) {
        return false;
    }

    m_iCurrentSample += iLen;
    if (m_iCurrentSample > m_iMaxSamplesToProcess) {
        return true; // silently ignore all remaining samples
    }

    return m_pPlugin->processSamples(pIn, iLen);
}

void AnalyzerBeats::cleanup() {
    m_pPlugin.reset();
}

void AnalyzerBeats::storeResults(TrackPointer pTrack) {
    VERIFY_OR_DEBUG_ASSERT(m_pPlugin) {
        return;
    }

    if (!m_pPlugin->finalize()) {
        qWarning() << "Beat/BPM analysis failed";
        return;
    }

    mixxx::BeatsPointer pBeats;
    if (m_pPlugin->supportsBeatTracking()) {
        QVector<double> beats = m_pPlugin->getBeats();
        QHash<QString, QString> extraVersionInfo = getExtraVersionInfo(
                m_pluginId, m_bPreferencesFastAnalysis);
        pBeats = BeatFactory::makePreferredBeats(
                beats,
                extraVersionInfo,
                m_bPreferencesFixedTempo,
                m_sampleRate);
        qDebug() << "AnalyzerBeats plugin detected" << beats.size()
                 << "beats. Average BPM:" << (pBeats ? pBeats->getBpm() : 0.0);
    } else {
        float bpm = m_pPlugin->getBpm();
        qDebug() << "AnalyzerBeats plugin detected constant BPM: " << bpm;
        pBeats = BeatFactory::makeBeatGrid(m_sampleRate, bpm, 0.0f);
    }

    pTrack->trySetBeats(pBeats);
}

// static
QHash<QString, QString> AnalyzerBeats::getExtraVersionInfo(
        const QString& pluginId, bool bPreferencesFastAnalysis) {
    QHash<QString, QString> extraVersionInfo;
    extraVersionInfo["vamp_plugin_id"] = pluginId;
    if (bPreferencesFastAnalysis) {
        extraVersionInfo["fast_analysis"] = "1";
    }
    return extraVersionInfo;
}