#include "AppController.h"
#include <QJsonArray>
#include <QFile>
#include <QFileInfo>
#include <QDir>
#include <QStandardPaths>
#include <QUrl>
#include <QDebug>
#include <QMimeDatabase>

AppController::AppController(QObject* parent)
    : QObject(parent)
    , m_settings(new LocalSend::Settings(this))
    , m_security(new LocalSend::SecurityContext(this))
    , m_discovery(new LocalSend::DiscoveryManager(this))
    , m_server(new LocalSend::HttpServer(this))
    , m_sessions(new LocalSend::SessionManager(this))
    , m_httpClient(new LocalSend::HttpClient(this))
{
}

AppController::~AppController()
{
    stopDiscovery();
}

void AppController::initialize()
{
    m_security->initialize();
    
    LocalSend::InfoDto info = buildInfoDto();
    m_server->setLocalInfo(info, m_security->fingerprint());
    m_discovery->setLocalInfo(info, m_security->fingerprint(), m_settings->port(), 
                               m_settings->https() ? LocalSend::ProtocolType::Https : LocalSend::ProtocolType::Http);
    
    if (m_server->start(m_settings->port(), m_settings->https())) {
        emit serverRunningChanged();
    }
    
    connect(m_discovery, &LocalSend::DiscoveryManager::deviceDiscovered,
            this, &AppController::onDeviceDiscovered);
    connect(m_discovery, &LocalSend::DiscoveryManager::deviceLost,
            this, &AppController::onDeviceLost);
    connect(m_server, &LocalSend::HttpServer::registerRequest,
            this, &AppController::onRegisterRequest);
    connect(m_server, &LocalSend::HttpServer::prepareUploadRequest,
            this, &AppController::onPrepareUploadRequest);
    connect(m_server, &LocalSend::HttpServer::uploadRequest,
            this, &AppController::onUploadRequest);
    connect(m_sessions, &LocalSend::SessionManager::receiveSessionAccepted,
            this, &AppController::onSessionAccepted);
    connect(m_sessions, &LocalSend::SessionManager::receiveSessionDeclined,
            this, &AppController::onSessionDeclined);
    connect(m_sessions, &LocalSend::SessionManager::receiveProgress,
            this, &AppController::onReceiveProgress);
    connect(m_sessions, &LocalSend::SessionManager::receiveSessionCompleted,
            this, &AppController::onReceiveCompleted);
    
    connect(m_httpClient, &LocalSend::HttpClient::prepareUploadResponse,
            this, &AppController::onPrepareUploadResponse);
    connect(m_httpClient, &LocalSend::HttpClient::prepareUploadError,
            this, &AppController::onPrepareUploadError);
    connect(m_httpClient, &LocalSend::HttpClient::uploadProgress,
            this, &AppController::onUploadProgress);
    connect(m_httpClient, &LocalSend::HttpClient::uploadCompleted,
            this, &AppController::onUploadCompleted);
    connect(m_httpClient, &LocalSend::HttpClient::uploadError,
            this, &AppController::onUploadError);
    
    startDiscovery();
}

LocalSend::InfoDto AppController::buildInfoDto() const
{
    LocalSend::InfoDto info;
    info.alias = m_settings->alias();
    info.version = m_settings->version();
    info.deviceModel = m_settings->deviceModel();
    info.deviceType = m_settings->deviceType();
    info.download = false;
    return info;
}

QString AppController::alias() const
{
    return m_settings->alias();
}

void AppController::setAlias(const QString& alias)
{
    if (m_settings->alias() != alias) {
        m_settings->setAlias(alias);
        emit aliasChanged();
    }
}

quint16 AppController::port() const
{
    return m_settings->port();
}

void AppController::setPort(quint16 port)
{
    if (m_settings->port() != port) {
        m_settings->setPort(port);
        emit portChanged();
    }
}

QString AppController::downloadPath() const
{
    return m_settings->downloadDir();
}

void AppController::setDownloadPath(const QString& path)
{
    if (m_settings->downloadDir() != path) {
        m_settings->setDownloadDir(path);
        emit downloadPathChanged();
    }
}

bool AppController::quickSave() const
{
    return m_settings->quickSave();
}

void AppController::setQuickSave(bool enabled)
{
    if (m_settings->quickSave() != enabled) {
        m_settings->setQuickSave(enabled);
        emit quickSaveChanged();
    }
}

QVariantList AppController::devices() const
{
    QVariantList result;
    for (const LocalSend::Device& device : m_devices) {
        QVariantMap map;
        map[QStringLiteral("ip")] = device.ip;
        map[QStringLiteral("port")] = device.port;
        map[QStringLiteral("alias")] = device.alias;
        map[QStringLiteral("fingerprint")] = device.fingerprint;
        map[QStringLiteral("deviceModel")] = device.deviceModel;
        map[QStringLiteral("deviceType")] = LocalSend::deviceTypeToString(device.deviceType);
        result.append(map);
    }
    return result;
}

bool AppController::serverRunning() const
{
    return m_server->isRunning();
}

void AppController::startDiscovery()
{
    m_discovery->start();
}

void AppController::stopDiscovery()
{
    m_discovery->stop();
}

void AppController::refreshDevices()
{
    m_discovery->startScan();
}

void AppController::acceptReceive(const QString& sessionId)
{
    qDebug() << "[AppController] acceptReceive called with sessionId:" << sessionId;
    
    LocalSend::ReceiveSession session = m_sessions->receiveSession(sessionId);
    if (session.sessionId.isEmpty()) {
        qWarning() << "[AppController] Session not found for sessionId:" << sessionId;
        return;
    }
    
    QString baseDir = downloadPath();
    QDir dir(baseDir);
    if (!dir.exists()) {
        dir.mkpath(QStringLiteral("."));
    }
    
    QMap<QString, QString> destinationPaths;
    for (auto it = session.files.constBegin(); it != session.files.constEnd(); ++it) {
        QString filePath = generateUniqueFilePath(baseDir, it->file.fileName);
        destinationPaths.insert(it.key(), filePath);
        qDebug() << "[AppController] File" << it.key() << "->" << filePath;
    }
    
    m_sessions->acceptReceiveSession(sessionId, destinationPaths);
}

void AppController::declineReceive(const QString& sessionId)
{
    qDebug() << "[AppController] declineReceive called with sessionId:" << sessionId;
    m_sessions->declineReceiveSession(sessionId);
}

QString AppController::generateUniqueFilePath(const QString& baseDir, const QString& fileName) const
{
    QString filePath = baseDir + QDir::separator() + fileName;
    QFileInfo info(filePath);
    
    if (!info.exists()) {
        return filePath;
    }
    
    QString baseName = info.completeBaseName();
    QString suffix = info.suffix();
    
    int counter = 1;
    while (info.exists()) {
        QString newName = QString(QStringLiteral("%1 (%2)")).arg(baseName).arg(counter);
        if (!suffix.isEmpty()) {
            newName += QStringLiteral(".") + suffix;
        }
        filePath = baseDir + QDir::separator() + newName;
        info.setFile(filePath);
        counter++;
    }
    
    return filePath;
}

void AppController::onDeviceDiscovered(const LocalSend::Device& device)
{
    m_devices.insert(device.fingerprint, device);
    emit devicesChanged();
}

void AppController::onDeviceLost(const QString& fingerprint)
{
    m_devices.remove(fingerprint);
    emit devicesChanged();
}

void AppController::onRegisterRequest(const LocalSend::RegisterDto& dto, const QHostAddress& sender)
{
    qDebug() << "[AppController] onRegisterRequest from:" << sender.toString() 
             << "alias:" << dto.alias << "fingerprint:" << dto.fingerprint;
    
    LocalSend::Device device;
    device.ip = sender.toString();
    device.port = dto.port;
    device.protocol = dto.protocol;
    device.alias = dto.alias;
    device.fingerprint = dto.fingerprint;
    device.deviceModel = dto.deviceModel;
    device.deviceType = dto.deviceType;
    device.version = dto.version;
    device.download = dto.download;
    device.lastSeen = QDateTime::currentDateTime();
    
    m_devices.insert(device.fingerprint, device);
    emit devicesChanged();
}

void AppController::onPrepareUploadRequest(const QString& httpSessionId, 
                                            const LocalSend::PrepareUploadRequestDto& dto, 
                                            const QHostAddress& sender)
{
    qDebug() << "[AppController] onPrepareUploadRequest received, httpSessionId:" << httpSessionId;
    
    LocalSend::Device device;
    device.ip = sender.toString();
    device.alias = dto.info.alias;
    device.fingerprint = dto.info.fingerprint;
    device.deviceModel = dto.info.deviceModel;
    device.deviceType = dto.info.deviceType;
    device.version = dto.info.version;
    
    QString sessionId = m_sessions->createReceiveSession(device, dto.files, httpSessionId);
    qDebug() << "[AppController] Created receive session, sessionId:" << sessionId;
    
    QVariantList filesList;
    for (auto it = dto.files.constBegin(); it != dto.files.constEnd(); ++it) {
        QVariantMap file;
        file[QStringLiteral("id")] = it.key();
        file[QStringLiteral("fileName")] = it.value().fileName;
        file[QStringLiteral("size")] = it.value().size;
        file[QStringLiteral("fileType")] = it.value().fileType;
        filesList.append(file);
    }
    
    emit receiveRequest(sessionId, dto.info.alias, sender.toString(), filesList);
}

void AppController::onUploadRequest(const QString& sessionId, const QString& fileId, 
                                     const QString& token, const QByteArray& data)
{
    LocalSend::ReceiveSession session = m_sessions->receiveSession(sessionId);
    if (session.sessionId.isEmpty()) {
        return;
    }
    
    if (!session.files.contains(fileId)) {
        return;
    }
    
    const LocalSend::FileTransfer& transfer = session.files[fileId];
    if (transfer.token != token) {
        emit receiveError(sessionId, QStringLiteral("Invalid token"));
        return;
    }
    
    QString filePath = transfer.destinationPath;
    if (filePath.isEmpty()) {
        emit receiveError(sessionId, QStringLiteral("No destination path"));
        return;
    }
    
    QFile file(filePath);
    if (!file.open(QIODevice::WriteOnly)) {
        emit receiveError(sessionId, QStringLiteral("Cannot open file: ") + file.errorString());
        return;
    }
    
    qint64 written = file.write(data);
    file.close();
    
    if (written != data.size()) {
        m_sessions->failReceiveFile(sessionId, fileId);
        emit receiveError(sessionId, QStringLiteral("Write error"));
        return;
    }
    
    m_sessions->updateReceiveProgress(sessionId, fileId, written);
    
    if (written >= transfer.file.size) {
        m_sessions->completeReceiveFile(sessionId, fileId);
    }
}

void AppController::onSessionAccepted(const QString& sessionId, const QMap<QString, QString>& tokens)
{
    qDebug() << "[AppController] onSessionAccepted, sessionId:" << sessionId;
    qDebug() << "[AppController] Tokens:" << tokens;
    m_server->respondToPrepareUpload(sessionId, true, tokens);
}

void AppController::onSessionDeclined(const QString& sessionId)
{
    qDebug() << "[AppController] onSessionDeclined, sessionId:" << sessionId;
    m_server->respondToPrepareUpload(sessionId, false);
}

void AppController::onReceiveProgress(const QString& sessionId, const QString& fileId, double progress)
{
    emit receiveProgress(sessionId, fileId, progress);
}

void AppController::onReceiveCompleted(const QString& sessionId)
{
    emit receiveCompleted(sessionId);
}

bool AppController::sending() const
{
    return !m_currentSendSessionId.isEmpty();
}

double AppController::sendProgress() const
{
    return m_sendProgress;
}

QVariantList AppController::pendingFiles() const
{
    return m_pendingFilesList;
}

bool AppController::hasPendingFiles() const
{
    return !m_pendingFilesList.isEmpty();
}

void AppController::addFiles(const QStringList& filePaths)
{
    QMimeDatabase mimeDb;
    for (const QString& rawPath : filePaths) {
        QString filePath = rawPath;
        if (filePath.startsWith(QStringLiteral("file://"))) {
            filePath = filePath.mid(7);
        }
        QFileInfo info(filePath);
        if (!info.exists() || info.isDir()) {
            continue;
        }
        QVariantMap file;
        file[QStringLiteral("path")] = info.absoluteFilePath();
        file[QStringLiteral("fileName")] = info.fileName();
        file[QStringLiteral("size")] = info.size();
        file[QStringLiteral("fileType")] = mimeDb.mimeTypeForFile(info).name();
        m_pendingFilesList.append(file);
        m_pendingSendPaths.append(info.absoluteFilePath());
    }
    emit pendingFilesChanged();
}

void AppController::removePendingFile(int index)
{
    if (index < 0 || index >= m_pendingFilesList.size()) {
        return;
    }
    m_pendingFilesList.removeAt(index);
    m_pendingSendPaths.removeAt(index);
    emit pendingFilesChanged();
}

void AppController::clearPendingFiles()
{
    m_pendingFilesList.clear();
    m_pendingSendPaths.clear();
    emit pendingFilesChanged();
}

void AppController::sendTo(const QString& deviceFingerprint)
{
    if (m_pendingSendPaths.isEmpty()) {
        emit sendError(QStringLiteral("No files selected"));
        return;
    }
    sendFiles(deviceFingerprint, m_pendingSendPaths);
}

void AppController::sendFiles(const QString& deviceFingerprint, const QStringList& filePaths)
{
    if (!m_devices.contains(deviceFingerprint)) {
        emit sendError(QStringLiteral("Device not found"));
        return;
    }
    
    if (filePaths.isEmpty()) {
        emit sendError(QStringLiteral("No files selected"));
        return;
    }
    
    if (sending()) {
        emit sendError(QStringLiteral("Already sending files"));
        return;
    }
    
    m_currentSendDeviceFingerprint = deviceFingerprint;
    m_pendingSendPaths = filePaths;
    m_currentFileIndex = 0;
    m_sendProgress = 0.0;
    emit sendingChanged();
    emit sendProgressChanged();
    
    qDebug() << "[AppController] sendFiles: device=" << deviceFingerprint 
             << "files=" << filePaths.size();
    
    LocalSend::Device target = m_devices[deviceFingerprint];
    
    QMap<QString, LocalSend::FileDto> files;
    QMimeDatabase mimeDb;
    
    for (int i = 0; i < filePaths.size(); ++i) {
        QString filePath = filePaths[i];
        QFileInfo info(filePath);
        
        if (!info.exists()) {
            emit sendError(QStringLiteral("File not found: ") + filePath);
            m_currentSendSessionId.clear();
            emit sendingChanged();
            return;
        }
        
        LocalSend::FileDto fileDto;
        fileDto.id = QString::number(i);
        fileDto.fileName = info.fileName();
        fileDto.size = info.size();
        fileDto.fileType = mimeDb.mimeTypeForFile(filePath).name();
        files.insert(fileDto.id, fileDto);
    }
    
    m_currentSendSessionId = m_sessions->createSendSession(target, files, 
        [filePaths]() {
            QMap<QString, QString> paths;
            for (int i = 0; i < filePaths.size(); ++i) {
                paths.insert(QString::number(i), filePaths[i]);
            }
            return paths;
        }()
    );
    
    LocalSend::PrepareUploadRequestDto request;
    request.info = buildRegisterDto();
    request.files = files;
    
    qDebug() << "[AppController] Sending prepare-upload request to" << target.ip;
    m_httpClient->prepareUpload(target, request);
}

void AppController::cancelSend()
{
    if (m_currentSendSessionId.isEmpty()) {
        return;
    }
    
    LocalSend::Device target = m_devices.value(m_currentSendDeviceFingerprint);
    m_httpClient->cancel(target, m_currentSendSessionId);
    
    m_sessions->cancelSendSession(m_currentSendSessionId);
    m_currentSendSessionId.clear();
    m_pendingSendPaths.clear();
    m_pendingFilesList.clear();
    m_sendProgress = 0.0;
    emit sendingChanged();
    emit sendProgressChanged();
}

void AppController::onPrepareUploadResponse(const LocalSend::PrepareUploadResponseDto& response)
{
    qDebug() << "[AppController] onPrepareUploadResponse: sessionId=" << response.sessionId
             << "files=" << response.files.size();
    
    LocalSend::SendSession session = m_sessions->sendSession(m_currentSendSessionId);
    if (session.sessionId.isEmpty()) {
        emit sendError(QStringLiteral("Session not found"));
        m_currentSendSessionId.clear();
        emit sendingChanged();
        return;
    }
    
    if (response.files.isEmpty()) {
        emit sendError(QStringLiteral("Receiver declined the transfer"));
        m_currentSendSessionId.clear();
        emit sendingChanged();
        return;
    }
    
    m_sessions->setSendSessionTokens(m_currentSendSessionId, response.sessionId, response.files);
    
    m_currentSendSessionId = response.sessionId;
    m_sessions->startSendSession(m_currentSendSessionId);
    
    m_currentFileIndex = 0;
    sendNextFile();
}

void AppController::onPrepareUploadError(const QString& error)
{
    qWarning() << "[AppController] onPrepareUploadError:" << error;
    emit sendError(error);
    m_currentSendSessionId.clear();
    emit sendingChanged();
}

void AppController::onUploadProgress(qint64 sent, qint64 total)
{
    if (total > 0) {
        double fileProgress = static_cast<double>(sent) / total;
        int totalFiles = m_pendingSendPaths.size();
        double overallProgress = (m_currentFileIndex + fileProgress) / totalFiles;
        m_sendProgress = overallProgress * 100.0;
        emit sendProgressChanged();
    }
}

void AppController::onUploadCompleted()
{
    qDebug() << "[AppController] onUploadCompleted, file index:" << m_currentFileIndex;
    
    m_sessions->completeSendFile(m_currentSendSessionId, m_currentSendFileId);
    
    m_currentFileIndex++;
    
    if (m_currentFileIndex < m_pendingSendPaths.size()) {
        sendNextFile();
    } else {
        qDebug() << "[AppController] All files sent successfully";
        m_sendProgress = 100.0;
        emit sendProgressChanged();
        emit sendCompleted(m_currentSendSessionId);
        m_currentSendSessionId.clear();
        m_pendingFilesList.clear();
        m_pendingSendPaths.clear();
        emit sendingChanged();
        emit pendingFilesChanged();
    }
}

void AppController::onUploadError(const QString& error)
{
    qWarning() << "[AppController] onUploadError:" << error;
    emit sendError(error);
    m_sessions->failSendFile(m_currentSendSessionId, m_currentSendFileId);
    m_currentSendSessionId.clear();
    emit sendingChanged();
}

void AppController::sendNextFile()
{
    if (m_currentFileIndex >= m_pendingSendPaths.size()) {
        return;
    }
    
    LocalSend::SendSession session = m_sessions->sendSession(m_currentSendSessionId);
    if (session.sessionId.isEmpty()) {
        qWarning() << "[AppController] Session not found:" << m_currentSendSessionId;
        return;
    }
    
    QString fileId = QString::number(m_currentFileIndex);
    if (!session.files.contains(fileId)) {
        qWarning() << "[AppController] File not found in session:" << fileId;
        return;
    }
    
    m_currentSendFileId = fileId;
    QString filePath = m_pendingSendPaths[m_currentFileIndex];
    QString token = session.files[fileId].token;
    
    LocalSend::Device target = m_devices.value(m_currentSendDeviceFingerprint);
    
    qDebug() << "[AppController] Uploading file" << fileId << ":" << filePath 
             << "token:" << token << "to" << target.ip;
    
    if (token.isEmpty()) {
        emit sendError(QStringLiteral("No token for file: ") + fileId);
        m_currentSendSessionId.clear();
        emit sendingChanged();
        return;
    }
    
    m_httpClient->uploadFile(target, m_currentSendSessionId, fileId, token, filePath);
}

LocalSend::RegisterDto AppController::buildRegisterDto() const
{
    LocalSend::RegisterDto dto;
    dto.alias = m_settings->alias();
    dto.version = m_settings->version();
    dto.deviceModel = m_settings->deviceModel();
    dto.deviceType = m_settings->deviceType();
    dto.fingerprint = m_security->fingerprint();
    dto.port = m_settings->port();
    dto.protocol = m_settings->https() ? LocalSend::ProtocolType::Https : LocalSend::ProtocolType::Http;
    dto.download = false;
    return dto;
}