#include <QRegularExpression>

#include "soundio/soundmanagerconfig.h"

#include "soundio/soundmanagerutil.h"
#include "soundio/sounddevice.h"
#include "soundio/soundmanager.h"
#include "util/cmdlineargs.h"
#include "util/math.h"

// this (7) represents latency values from 1 ms to about 80 ms -- bkgood
const unsigned int SoundManagerConfig::kMaxAudioBufferSizeIndex = 7;

const QString SoundManagerConfig::kDefaultAPI = QStringLiteral("None");
const QString SoundManagerConfig::kEmptyComboBox = QStringLiteral("---");
// Sample Rate even the cheap sound Devices will support most likely
const unsigned int SoundManagerConfig::kFallbackSampleRate = 48000;
const unsigned int SoundManagerConfig::kDefaultDeckCount = 2;
// audioBufferSizeIndex=5 means about 21 ms of latency which is default in trunk r2453 -- bkgood
const int SoundManagerConfig::kDefaultAudioBufferSizeIndex = 5;

const int SoundManagerConfig::kDefaultSyncBuffers = 2;

namespace {
const QString xmlRootElement = "SoundManagerConfig";
const QString xmlAttributeApi = "api";
const QString xmlAttributeSampleRate = "samplerate";
const QString xmlAttributeBufferSize = "latency";
const QString xmlAttributeSyncBuffers = "sync_buffers";
const QString xmlAttributeForceNetworkClock = "force_network_clock";
const QString xmlAttributeDeckCount = "deck_count";

const QString xmlElementSoundDevice = "SoundDevice";
const QString xmlAttributeDeviceName = "name";
const QString xmlAttributeAlsaHwDevice = "alsaHwDevice";
const QString xmlAttributePortAudioIndex = "portAudioIndex";

const QString xmlElementOutput = "output";
const QString xmlElementInput = "input";

const QRegularExpression kLegacyFormatRegex("((\\d*), )(.*) \\((plug)?(hw:(\\d)+(,(\\d)+))?\\)");
} // namespace

SoundManagerConfig::SoundManagerConfig(SoundManager* pSoundManager)
    : m_api(kDefaultAPI),
      m_sampleRate(kFallbackSampleRate),
      m_deckCount(kDefaultDeckCount),
      m_audioBufferSizeIndex(kDefaultAudioBufferSizeIndex),
      m_syncBuffers(2),
      m_forceNetworkClock(false),
      m_iNumMicInputs(0),
      m_bExternalRecordBroadcastConnected(false),
      m_pSoundManager(pSoundManager) {
    m_configFile = QFileInfo(QDir(CmdlineArgs::Instance().getSettingsPath()).filePath(SOUNDMANAGERCONFIG_FILENAME));
}

SoundManagerConfig::~SoundManagerConfig() {
    // don't write to disk here, it's SoundManager's responsibility
    // to save its own configuration -- bkgood
}

/**
 * Read the SoundManagerConfig xml serialization at the predetermined
 * path
 * @returns false if the file can't be read or is invalid XML, true otherwise
 */
bool SoundManagerConfig::readFromDisk() {
    QFile file(m_configFile.absoluteFilePath());
    QDomDocument doc;
    QDomElement rootElement;
    if (!file.open(QIODevice::ReadOnly)) {
        return false;
    }
    if (!doc.setContent(&file)) {
        file.close();
        return false;
    }
    file.close();
    rootElement = doc.documentElement();
    setAPI(rootElement.attribute(xmlAttributeApi));
    setSampleRate(rootElement.attribute(xmlAttributeSampleRate, "0").toUInt());
    // audioBufferSizeIndex is refereed as "latency" in the config file
    setAudioBufferSizeIndex(rootElement.attribute(xmlAttributeBufferSize, "0").toUInt());
    setSyncBuffers(rootElement.attribute(xmlAttributeSyncBuffers, "2").toUInt());
    setForceNetworkClock(rootElement.attribute(xmlAttributeForceNetworkClock,
            "0").toUInt() != 0);
    setDeckCount(rootElement.attribute(xmlAttributeDeckCount,
            QString(kDefaultDeckCount)).toUInt());
    clearOutputs();
    clearInputs();
    QDomNodeList devElements(rootElement.elementsByTagName(xmlElementSoundDevice));

    VERIFY_OR_DEBUG_ASSERT(m_pSoundManager != nullptr) {
        return false;
    }
    QList<SoundDevicePointer> soundDevices = m_pSoundManager->getDeviceList(m_api, true, true);

    for (int i = 0; i < devElements.count(); ++i) {
        QDomElement devElement(devElements.at(i).toElement());
        if (devElement.isNull()) {
            continue;
        }
        SoundDeviceId deviceIdFromFile;
        deviceIdFromFile.name = devElement.attribute(xmlAttributeDeviceName);
        if (deviceIdFromFile.name.isEmpty()) {
            continue;
        }

        // TODO: remove this ugly hack after Mixxx 2.2.3 is released
        QRegularExpressionMatch match = kLegacyFormatRegex.match(deviceIdFromFile.name);
        if (match.hasMatch()) {
            deviceIdFromFile.name = match.captured(3);
            deviceIdFromFile.alsaHwDevice = match.captured(5);
            deviceIdFromFile.portAudioIndex = match.captured(2).toInt();
        } else {
            deviceIdFromFile.alsaHwDevice = devElement.attribute(xmlAttributeAlsaHwDevice);
            deviceIdFromFile.portAudioIndex = devElement.attribute(xmlAttributePortAudioIndex).toInt();
        }

        int devicesMatchingByName = 0;
        for (const auto& soundDevice : soundDevices) {
            SoundDeviceId hardwareDeviceId = soundDevice->getDeviceId();
            if (hardwareDeviceId.name == deviceIdFromFile.name) {
                devicesMatchingByName++;
            }
        }

        QDomNodeList outElements(devElement.elementsByTagName(xmlElementOutput));
        QDomNodeList inElements(devElement.elementsByTagName(xmlElementInput));

        if (devicesMatchingByName == 0) {
            continue;
        } else if (devicesMatchingByName == 1) {
            // There is only one device with this name, so it is unambiguous
            // which it is. Neither the alsaHwDevice nor portAudioIndex are
            // very reliable as persistent identifiers across restarts of Mixxx.
            // Set deviceIdFromFile's alsaHwDevice and portAudioIndex to match
            // the hardwareDeviceId so operator== works for SoundDeviceId.
            for (const auto& soundDevice : soundDevices) {
                SoundDeviceId hardwareDeviceId = soundDevice->getDeviceId();
                if (hardwareDeviceId.name == deviceIdFromFile.name) {
                    deviceIdFromFile.alsaHwDevice = hardwareDeviceId.alsaHwDevice;
                    deviceIdFromFile.portAudioIndex = hardwareDeviceId.portAudioIndex;
                }
            }
        } else {
            // It is not clear which hardwareDeviceId corresponds to the device
            // listed in the configuration file using only the name.
            if (!deviceIdFromFile.alsaHwDevice.isEmpty()) {
                // If using ALSA, attempt to match based on the ALSA device name.
                // This is reliable between restarts of Mixxx until the user
                // unplugs an audio interface or restarts Linux.
                // NOTE(Be): I am not sure if there is a way to assign a
                // persistent ALSA device name across restarts of Linux for
                // multiple devices with the same name. This might be possible
                // somehow with a udev rule matching device serial numbers, but
                // I have not tested this.
                for (const auto& soundDevice : soundDevices) {
                    SoundDeviceId hardwareDeviceId = soundDevice->getDeviceId();
                    if (hardwareDeviceId.name == deviceIdFromFile.name
                            && hardwareDeviceId.alsaHwDevice == deviceIdFromFile.alsaHwDevice) {
                        deviceIdFromFile.portAudioIndex = hardwareDeviceId.portAudioIndex;
                        break;
                    }
                }
            } else {
                // Check if the one of the matching devices has the configured in and output channels
                for (const auto& soundDevice : soundDevices) {
                    SoundDeviceId hardwareDeviceId = soundDevice->getDeviceId();
                    if (hardwareDeviceId.name == deviceIdFromFile.name &&
                            soundDevice->getNumOutputChannels() >=
                                    outElements.count() &&
                            soundDevice->getNumInputChannels() >=
                                    inElements.count()) {
                        deviceIdFromFile.portAudioIndex = hardwareDeviceId.portAudioIndex;
                        break;
                    }
                }
            }
        }

        for (int j = 0; j < outElements.count(); ++j) {
            QDomElement outElement(outElements.at(j).toElement());
            if (outElement.isNull()) {
                continue;
            }
            AudioOutput out(AudioOutput::fromXML(outElement));
            if (out.getType() == AudioPath::INVALID) {
                continue;
            }
            bool dupe(false);
            for (const AudioOutput& otherOut : qAsConst(m_outputs)) {
                if (out == otherOut
                        && out.getChannelGroup() == otherOut.getChannelGroup()) {
                    dupe = true;
                    break;
                }
            }
            if (dupe) {
                continue;
            }

            addOutput(deviceIdFromFile, out);
        }
        for (int j = 0; j < inElements.count(); ++j) {
            QDomElement inElement(inElements.at(j).toElement());
            if (inElement.isNull()) {
                continue;
            }
            AudioInput in(AudioInput::fromXML(inElement));
            if (in.getType() == AudioPath::INVALID) {
                continue;
            }
            bool dupe(false);
            for (const AudioInput& otherIn : qAsConst(m_inputs)) {
                if (in == otherIn
                        && in.getChannelGroup() == otherIn.getChannelGroup()) {
                    dupe = true;
                    break;
                }
            }
            if (dupe) {
                continue;
            }
            addInput(deviceIdFromFile, in);
        }
    }
    return true;
}

bool SoundManagerConfig::writeToDisk() const {
    QDomDocument doc(xmlRootElement);
    QDomElement docElement(doc.createElement(xmlRootElement));
    docElement.setAttribute(xmlAttributeApi, m_api);
    docElement.setAttribute(xmlAttributeSampleRate, m_sampleRate);
    docElement.setAttribute(xmlAttributeBufferSize, m_audioBufferSizeIndex);
    docElement.setAttribute(xmlAttributeSyncBuffers, m_syncBuffers);
    docElement.setAttribute(xmlAttributeForceNetworkClock, m_forceNetworkClock);
    docElement.setAttribute(xmlAttributeDeckCount, m_deckCount);
    doc.appendChild(docElement);

    const QSet<SoundDeviceId> deviceIds = getDevices();
    for (const auto& deviceId : deviceIds) {
        QDomElement devElement(doc.createElement(xmlElementSoundDevice));
        devElement.setAttribute(xmlAttributeDeviceName, deviceId.name);
        devElement.setAttribute(xmlAttributePortAudioIndex, deviceId.portAudioIndex);
        if (m_api == MIXXX_PORTAUDIO_ALSA_STRING) {
            devElement.setAttribute(xmlAttributeAlsaHwDevice, deviceId.alsaHwDevice);
        }

        for (auto it = m_inputs.constFind(deviceId);
                it != m_inputs.constEnd() && it.key() == deviceId;
                ++it) {
            QDomElement inElement(doc.createElement(xmlElementInput));
            it.value().toXML(&inElement);
            devElement.appendChild(inElement);
        }

        for (auto it = m_outputs.constFind(deviceId);
                it != m_outputs.constEnd() && it.key() == deviceId;
                ++it) {
            QDomElement outElement(doc.createElement(xmlElementOutput));
            it.value().toXML(&outElement);
            devElement.appendChild(outElement);
        }
        docElement.appendChild(devElement);
    }

    QFile file(m_configFile.absoluteFilePath());
    if (!file.open(QIODevice::Truncate | QIODevice::WriteOnly)) {
        return false;
    }
    file.write(doc.toString().toUtf8());
    file.close();
    return true;
}

QString SoundManagerConfig::getAPI() const {
    return m_api;
}

void SoundManagerConfig::setAPI(const QString &api) {
    // SoundManagerConfig doesn't necessarily have access to a SoundManager
    // instance, so I can't check for input validity here -- bkgood
    m_api = api;
}

/**
 * Checks that the API in the object is valid according to the list of APIs
 * given by SoundManager.
 * @returns false if the API is not found in SoundManager's list, otherwise
 *          true
 */
bool SoundManagerConfig::checkAPI() {
    VERIFY_OR_DEBUG_ASSERT(m_pSoundManager != nullptr) {
        return false;
    }
    if (!m_pSoundManager->getHostAPIList().contains(m_api) && m_api != kDefaultAPI) {
        return false;
    }
    return true;
}

unsigned int SoundManagerConfig::getSampleRate() const {
    return m_sampleRate;
}

void SoundManagerConfig::setSampleRate(unsigned int sampleRate) {
    // making sure we don't divide by zero elsewhere
    m_sampleRate = sampleRate != 0 ? sampleRate : kFallbackSampleRate;
}


unsigned int SoundManagerConfig::getSyncBuffers() const {
    return m_syncBuffers;
}

void SoundManagerConfig::setSyncBuffers(unsigned int syncBuffers) {
    // making sure we don't divide by zero elsewhere
    m_syncBuffers = qMin(syncBuffers, (unsigned int)2);
}

bool SoundManagerConfig::getForceNetworkClock() const {
    return m_forceNetworkClock;
}

void SoundManagerConfig::setForceNetworkClock(bool force) {
    m_forceNetworkClock = force;
}

/**
 * Checks that the sample rate in the object is valid according to the list of
 * sample rates given by SoundManager.
 * @returns false if the sample rate is not found in SoundManager's list,
 *          otherwise true
 */
bool SoundManagerConfig::checkSampleRate(const SoundManager &soundManager) {
    if (!soundManager.getSampleRates(m_api).contains(m_sampleRate)) {
        return false;
    }
    return true;
}

unsigned int SoundManagerConfig::getDeckCount() const {
    return m_deckCount;
}

void SoundManagerConfig::setDeckCount(unsigned int deckCount) {
    m_deckCount = deckCount;
}

void SoundManagerConfig::setCorrectDeckCount(int configuredDeckCount) {
    int minimum_deck_count = 0;

    const QSet<SoundDeviceId> deviceIds = getDevices();
    for (const auto& deviceId : deviceIds) {
        for (auto it = m_inputs.constFind(deviceId);
                it != m_inputs.constEnd() && it.key() == deviceId;
                ++it) {
            const int index = it.value().getIndex();
            const AudioPathType type = it.value().getType();
            if ((type == AudioInput::DECK ||
                        type == AudioInput::VINYLCONTROL ||
                        type == AudioInput::AUXILIARY) &&
                    index + 1 > minimum_deck_count) {
                qDebug() << "Found an input connection above current deck count";
                minimum_deck_count = index + 1;
            }
        }
        for (auto it = m_outputs.constFind(deviceId);
                it != m_outputs.constEnd() && it.key() == deviceId;
                ++it) {
            const int index = it.value().getIndex();
            const AudioPathType type = it.value().getType();
            if (type == AudioOutput::DECK && index + 1 > minimum_deck_count) {
                qDebug() << "Found an output connection above current deck count";
                minimum_deck_count = index + 1;
            }
        }
    }

    if (minimum_deck_count > configuredDeckCount) {
        m_deckCount = minimum_deck_count;
    } else {
        m_deckCount = configuredDeckCount;
    }
}

unsigned int SoundManagerConfig::getAudioBufferSizeIndex() const {
    return m_audioBufferSizeIndex;
}

// FIXME: This is incorrect when using JACK as the sound API!
// m_audioBufferSizeIndex does not reflect JACK's buffer size.
unsigned int SoundManagerConfig::getFramesPerBuffer() const {
    // endless loop otherwise
    unsigned int audioBufferSizeIndex = m_audioBufferSizeIndex;
    VERIFY_OR_DEBUG_ASSERT(audioBufferSizeIndex > 0) {
        audioBufferSizeIndex = kDefaultAudioBufferSizeIndex;
    }
    unsigned int framesPerBuffer = 1;
    double sampleRate = m_sampleRate; // need this to avoid int division
    // first, get to the framesPerBuffer value corresponding to latency index 1
    for (; framesPerBuffer / sampleRate * 1000 < 1.0; framesPerBuffer *= 2) {
    }
    // then, keep going until we get to our desired latency index (if not 1)
    for (unsigned int latencyIndex = 1; latencyIndex < audioBufferSizeIndex; ++latencyIndex) {
        framesPerBuffer <<= 1; // *= 2
    }
    return framesPerBuffer;
}

// FIXME: This is incorrect when using JACK as the sound API!
// m_audioBufferSizeIndex does not reflect JACK's buffer size.
double SoundManagerConfig::getProcessingLatency() const {
    return static_cast<double>(getFramesPerBuffer()) / m_sampleRate * 1000.0;
}


// Set the audio buffer size
// @warning This IS NOT a value in milliseconds, or a number of frames per
// buffer. It is an index, where 1 is the first power-of-two buffer size (in
// frames) which corresponds to a latency greater than or equal to 1 ms, 2 is
// the second, etc. This is so that latency values are roughly equivalent
// between different sample rates.
void SoundManagerConfig::setAudioBufferSizeIndex(unsigned int sizeIndex) {
    // latency should be either the min of kMaxAudioBufferSizeIndex and the passed value
    // if it's 0, pretend it was 1 -- bkgood
    m_audioBufferSizeIndex = sizeIndex != 0 ? math_min(sizeIndex, kMaxAudioBufferSizeIndex) : 1;
}

void SoundManagerConfig::addOutput(const SoundDeviceId &device, const AudioOutput &out) {
    m_outputs.insert(device, out);
}

void SoundManagerConfig::addInput(const SoundDeviceId &device, const AudioInput &in) {
    m_inputs.insert(device, in);
    if (in.getType() == AudioPath::MICROPHONE) {
        m_iNumMicInputs++;
    } else if (in.getType() == AudioPath::RECORD_BROADCAST) {
        m_bExternalRecordBroadcastConnected = true;
    }
}

QMultiHash<SoundDeviceId, AudioOutput> SoundManagerConfig::getOutputs() const {
    return m_outputs;
}

QMultiHash<SoundDeviceId, AudioInput> SoundManagerConfig::getInputs() const {
    return m_inputs;
}

void SoundManagerConfig::clearOutputs() {
    m_outputs.clear();
}

void SoundManagerConfig::clearInputs() {
    m_inputs.clear();
    m_iNumMicInputs = 0;
    m_bExternalRecordBroadcastConnected = false;
}

bool SoundManagerConfig::hasMicInputs() {
    return m_iNumMicInputs;
}

bool SoundManagerConfig::hasExternalRecordBroadcast() {
    return m_bExternalRecordBroadcastConnected;
}

/**
 * Loads default values for API, master output, sample rate and/or latency.
 * @param soundManager pointer to SoundManager instance to load data from
 * @param flags Bitfield to determine which defaults to load, use something
 *              like SoundManagerConfig::API | SoundManagerConfig::DEVICES to
 *              load default API and master device.
 */
void SoundManagerConfig::loadDefaults(SoundManager *soundManager, unsigned int flags) {
    if (flags & SoundManagerConfig::API) {
        QList<QString> apiList = soundManager->getHostAPIList();
        if (!apiList.isEmpty()) {
#ifdef __LINUX__
            //Check for JACK and use that if it's available, otherwise use ALSA
            if (apiList.contains(MIXXX_PORTAUDIO_JACK_STRING)) {
                m_api = MIXXX_PORTAUDIO_JACK_STRING;
            } else {
                m_api = MIXXX_PORTAUDIO_ALSA_STRING;
            }
#endif
#ifdef __WINDOWS__
            //Existence of ASIO doesn't necessarily mean you've got ASIO devices
            //Do something more advanced one day if you like - Adam
            // hoping this counts as more advanced, tests if ASIO is an option
            // and then that we have at least one ASIO output device -- bkgood
            if (apiList.contains(MIXXX_PORTAUDIO_ASIO_STRING)
                   && !soundManager->getDeviceList(
                       MIXXX_PORTAUDIO_ASIO_STRING, true, false).isEmpty()) {
                m_api = MIXXX_PORTAUDIO_ASIO_STRING;
            } else {
                m_api = MIXXX_PORTAUDIO_DIRECTSOUND_STRING;
            }
#endif
#ifdef __APPLE__
            m_api = MIXXX_PORTAUDIO_COREAUDIO_STRING;
#endif
        }
    }

    unsigned int defaultSampleRate = kFallbackSampleRate;
    if (flags & SoundManagerConfig::DEVICES) {
        clearOutputs();
        clearInputs();
        QList<SoundDevicePointer> outputDevices = soundManager->getDeviceList(m_api, true, false);
        if (!outputDevices.isEmpty()) {
            for (const auto& pDevice: outputDevices) {
                if (pDevice->getNumOutputChannels() < 2) {
                    continue;
                }
                AudioOutput masterOut(AudioPath::MASTER, 0, 2, 0);
                addOutput(pDevice->getDeviceId(), masterOut);
                defaultSampleRate = pDevice->getDefaultSampleRate();
                break;
            }
        }
    }
    if (flags & SoundManagerConfig::OTHER) {
        QList<unsigned int> sampleRates = soundManager->getSampleRates(m_api);
        if (sampleRates.contains(defaultSampleRate)) {
            m_sampleRate = defaultSampleRate;
        } else if (sampleRates.contains(kFallbackSampleRate)) {
            m_sampleRate = kFallbackSampleRate;
        } else if (!sampleRates.isEmpty()) {
            m_sampleRate = sampleRates.first();
        } else {
            qWarning() << "got empty sample rate list from SoundManager, this is a bug";
            m_sampleRate = kFallbackSampleRate;
        }
        m_audioBufferSizeIndex = kDefaultAudioBufferSizeIndex;
    }

    m_syncBuffers = kDefaultSyncBuffers;
    m_forceNetworkClock = false;
}

QSet<SoundDeviceId> SoundManagerConfig::getDevices() const {
    QSet<SoundDeviceId> devices;
    devices.reserve(m_outputs.size() + m_inputs.size());
    for (auto it = m_outputs.constBegin(); it != m_outputs.constEnd(); ++it) {
        devices.insert(it.key());
    }
    for (auto it = m_inputs.constBegin(); it != m_inputs.constEnd(); ++it) {
        devices.insert(it.key());
    }
    return devices;
}
