#include <windows.h>
#include <QApplication>
#include <QCoreApplication>
#include <QDebug>
#include <QDir>
#include <QDirIterator>
#include <QElapsedTimer>
#include <QFile>
#include <QMessageBox>
#include <QProcess>
#include <QProgressDialog>
#include <QSaveFile>
#include <QStorageInfo>
#include <QTextCodec>
#include <QThread>
#include "UpdaterLogic.h"
#include "UpdateTransaction.h"
#include "FileHelper.h"
#include "ConfigHelper.h"

int main(int argc, char* argv[])
{
    SetConsoleOutputCP(65001);
    QTextCodec::setCodecForLocale(QTextCodec::codecForName("UTF-8"));
    QApplication app(argc, argv);
    QApplication::setApplicationName("Marsco Updater");

    if (argc < 5) {
        QMessageBox::critical(nullptr, "更新器参数错误", "更新器缺少应用、渠道或目标版本参数，请从 Launcher 启动。");
        return -1;
    }

    const QString appId = argv[1];
    const QString channel = argv[2];
    const QString targetVersion = argv[3];
    const int targetVersionId = QString(argv[4]).toInt();
    QString bootstrapResult;
    for (int i = 5; i < argc; ++i) {
        const QString arg = argv[i];
        if (arg.startsWith("--bootstrap-resume="))
            bootstrapResult = arg.mid(QString("--bootstrap-resume=").size());
    }
    const bool resumingFromBootstrap = !bootstrapResult.isEmpty();
    const QString targetDir = QApplication::applicationDirPath();

    ConfigHelper& config = ConfigHelper::instance();
    QString fromVersion = config.getValue("App", "current_version");
    QString deviceId = config.getValue("Update", "device_id");
    if (deviceId.isEmpty()) deviceId = "unknown_device";

    if (!resumingFromBootstrap) {
        QString restoredVersion;
        QString recoveryError;
        if (!UpdateTransaction::recoverInterrupted(targetDir, &restoredVersion, &recoveryError)) {
            QMessageBox::critical(nullptr, "更新恢复失败",
                QString("检测到上次更新未完成，但无法恢复旧版本：%1\n请不要继续运行软件，并联系管理员。").arg(recoveryError));
            return -1;
        }
        if (!restoredVersion.isEmpty() && restoredVersion != fromVersion) {
            if (!config.setValue("App", "current_version", restoredVersion)) {
                QMessageBox::critical(nullptr, "更新恢复失败", "旧文件已经恢复，但无法恢复版本状态，请检查配置目录写入权限。");
                return -1;
            }
            fromVersion = restoredVersion;
        }
    }

    QProgressDialog progress("正在准备更新...", QString(), 0, 100);
    progress.setWindowTitle(QString("正在更新到 %1").arg(targetVersion));
    progress.setCancelButton(nullptr);
    progress.setWindowModality(Qt::ApplicationModal);
    progress.setMinimumDuration(0);
    progress.setAutoClose(false);
    progress.setValue(2);
    progress.show();
    QApplication::processEvents();

    UpdaterLogic logic;
    UpdateTransaction transaction(targetDir, fromVersion, targetVersion, targetVersionId);
    const auto setProgress = [&](int value, const QString& message) {
        progress.setValue(value);
        progress.setLabelText(message);
        QApplication::processEvents();
    };
    const auto formatBytes = [](qint64 bytes) {
        const double value = static_cast<double>(bytes);
        if (bytes >= 1024LL * 1024 * 1024)
            return QString::number(value / (1024.0 * 1024 * 1024), 'f', 2) + " GB";
        if (bytes >= 1024LL * 1024)
            return QString::number(value / (1024.0 * 1024), 'f', 2) + " MB";
        if (bytes >= 1024)
            return QString::number(value / 1024.0, 'f', 1) + " KB";
        return QString::number(bytes) + " B";
    };
    QObject::connect(&logic, &UpdaterLogic::downloadProgress,
        [&](qint64 received, qint64 total, const QString& path, double bytesPerSecond) {
            const int value = total > 0 ? 30 + static_cast<int>(30 * received / total) : 60;
            const QString fileText = path.isEmpty() ? QString("正在准备下载...")
                                                    : QString("正在下载：%1").arg(path);
            progress.setValue(value);
            progress.setLabelText(QString("%1\n%2 / %3 · %4/s")
                .arg(fileText, formatBytes(received), formatBytes(total),
                     formatBytes(static_cast<qint64>(bytesPerSecond))));
            QApplication::processEvents();
        });
    const auto fail = [&](const QString& title, const QString& message,
                          const QString& errorCode = QString("update_failed")) {
        transaction.markFailed(errorCode, message);
        logic.reportResult(deviceId, fromVersion, targetVersion, false);
        progress.close();
        QMessageBox::critical(nullptr, title, message);
        return -1;
    };
    const QString mainAppPath = QDir(targetDir).filePath("MainApp.exe");
    const QString updaterPath = QDir(targetDir).filePath("Updater.exe");
    const QString bootstrapPath = QDir(targetDir).filePath("Bootstrap.exe");
    const QString launchToken = config.getValue("App", "launch_token");
    const auto launchMainApp = [&](const QString& healthFile = QString()) {
        QStringList args{QString("--launcher-token=%1").arg(launchToken)};
        if (!healthFile.isEmpty()) args.append(QString("--health-file=%1").arg(healthFile));
        return QProcess::startDetached(mainAppPath, args);
    };
    const auto bootstrapPlanFile = [&]() {
        return QDir(targetDir).filePath("update/bootstrap_plan_" + transaction.transactionId() + ".txt");
    };
    const auto launchBootstrap = [&](const QString& mode) {
        const QStringList args{
            bootstrapPlanFile(), targetDir, transaction.stagingDir(), transaction.backupDir(), updaterPath,
            QString::number(QCoreApplication::applicationPid()), appId, channel,
            targetVersion, QString::number(targetVersionId), mode
        };
        return QFile::exists(bootstrapPath) && QProcess::startDetached(bootstrapPath, args);
    };
    const auto delegateRollback = [&](const QString& title, const QString& reason) {
        FileHelper::killProcess("MainApp.exe");
        transaction.markRollbackRequired(reason);
        progress.setLabelText("正在将回滚工作移交给 Bootstrap...");
        QApplication::processEvents();
        if (launchBootstrap("rollback")) {
            progress.close();
            return 0;
        }
        logic.reportResult(deviceId, fromVersion, targetVersion, false);
        progress.close();
        QMessageBox::critical(nullptr, title,
            reason + "\n\n无法启动 Bootstrap 执行回滚。请不要继续运行软件，并联系管理员。");
        return -1;
    };

    if (resumingFromBootstrap) {
        QString resumeError;
        if (!transaction.resumeExisting(&resumeError)) {
            logic.reportResult(deviceId, fromVersion, targetVersion, false);
            progress.close();
            QMessageBox::critical(nullptr, "事务续办失败",
                QString("无法读取 Bootstrap 更新事务：%1").arg(resumeError));
            return -1;
        }
        fromVersion = transaction.fromVersion();
        if (bootstrapResult == "rolledback") {
            const bool stateOk = config.setValue("App", "current_version", fromVersion);
            transaction.markRolledBack();
            logic.reportResult(deviceId, fromVersion, targetVersion, false);
            if (stateOk) launchMainApp();
            progress.close();
            QMessageBox::warning(nullptr, "更新已回滚",
                stateOk ? "新版本安装或启动失败，已自动恢复并启动旧版本。"
                        : "旧文件已经恢复，但旧版本号写回失败，请检查配置目录权限。");
            return stateOk ? 0 : -1;
        }
        if (bootstrapResult != "success") {
            logic.reportResult(deviceId, fromVersion, targetVersion, false);
            progress.close();
            QMessageBox::critical(nullptr, "自动回滚失败",
                "Bootstrap 无法完整恢复旧版本。请不要继续运行软件，并联系管理员。");
            return -1;
        }
    } else if (!transaction.initialize()) {
        return fail("更新准备失败", "无法创建更新事务目录或保存事务状态。", "transaction_init_failed");
    }

    setProgress(resumingFromBootstrap ? 72 : 10, "正在获取并验证版本清单...");
    logic.getManifest(appId, channel, targetVersion, targetVersionId);
    if (!logic.verifyManifestSignature()) {
        if (resumingFromBootstrap)
            return delegateRollback("安全验证失败", "Bootstrap 安装后无法重新验证版本清单签名。");
        return fail("安全验证失败", "版本清单签名无效，更新已停止。请联系管理员。", "manifest_signature_invalid");
    }
    const QString manifestCacheDir = QDir(targetDir).filePath("update/manifest_cache");
    QStringList obsoletePaths;
    if (!resumingFromBootstrap && fromVersion != targetVersion) {
        UpdaterLogic oldManifestLogic;
        if (oldManifestLogic.loadManifestCache(manifestCacheDir, fromVersion)
            && oldManifestLogic.getManifest().value("version").toString() == fromVersion
            && oldManifestLogic.verifyManifestSignature()) {
            obsoletePaths = logic.obsoleteFilesComparedTo(oldManifestLogic.getManifest());
            qDebug() << "Obsolete files from signed previous manifest:" << obsoletePaths;
        } else {
            qDebug() << "No valid signed previous manifest cache; obsolete deletion skipped for safety";
        }
    }
    if (!logic.saveManifestCache(manifestCacheDir)) {
        if (resumingFromBootstrap)
            return delegateRollback("清单缓存失败", "无法保存新版本 Manifest 缓存。");
        return fail("清单缓存失败", "无法保存新版本 Manifest 缓存，更新已停止。", "manifest_cache_failed");
    }

    if (!resumingFromBootstrap) {
        setProgress(25, "正在获取安全下载地址...");
        logic.getDownloadUrl(appId, channel, targetVersion, targetVersionId);
        if (logic.getFileList().isEmpty())
            return fail("没有可更新文件", "服务器没有返回任何版本文件，更新已停止。", "empty_file_list");

        QStorageInfo storage(targetDir);
        storage.refresh();
        const qint64 requiredBytes = logic.estimateAdditionalDiskBytes(targetDir, obsoletePaths);
        const qint64 availableBytes = storage.bytesAvailable();
        if (!storage.isValid() || !storage.isReady() || availableBytes < requiredBytes) {
            return fail("磁盘空间不足",
                QString("更新至少需要 %1 可用空间，安装盘当前仅剩 %2。\n"
                        "所需空间已包含下载文件、旧版本备份和安全余量。")
                    .arg(formatBytes(requiredBytes), formatBytes(qMax<qint64>(0, availableBytes))),
                "disk_space_insufficient");
        }

        const QString stagingDir = transaction.stagingDir();
        setProgress(30, QString("正在下载并校验 %1 个版本文件...").arg(logic.getFileList().size()));
        if (!logic.downloadAllFiles(stagingDir, targetDir))
            return fail("下载失败", "部分文件下载失败或 SHA-256 校验未通过，请检查网络后重试。", "download_failed");

        setProgress(58, "正在校验完整版本文件...");
        if (!logic.validateLocalFiles(stagingDir, targetDir))
            return fail("文件校验失败", "暂存文件与版本清单不一致，更新已停止。", "staging_verify_failed");

        QStringList changedPaths;
        QDir stagingRoot(stagingDir);
        QDirIterator stagingFiles(stagingDir, QDir::Files, QDirIterator::Subdirectories);
        while (stagingFiles.hasNext())
            changedPaths.append(QDir::fromNativeSeparators(stagingRoot.relativeFilePath(stagingFiles.next())));
        for (const QString& path : changedPaths) {
            if (path.compare("Bootstrap.exe", Qt::CaseInsensitive) == 0)
                return fail("Bootstrap 无法自更新", "本次版本包含新的 Bootstrap.exe。请使用安装包升级 Bootstrap，再重新发布业务版本。", "bootstrap_self_update_blocked");
        }
        if (!transaction.recordVerifiedFiles(changedPaths, obsoletePaths))
            return fail("事务记录失败", "无法保存已校验或待删除文件列表，更新已停止。", "transaction_record_failed");

        setProgress(66, "正在关闭主程序...");
        if (!FileHelper::killProcess("MainApp.exe"))
            return fail("无法关闭主程序", "MainApp.exe 仍在运行，请手动关闭后重试。", "mainapp_close_failed");

        setProgress(72, QString("正在备份 %1 个待变更文件（其中删除 %2 个）...")
            .arg(changedPaths.size() + obsoletePaths.size()).arg(obsoletePaths.size()));
        if (!transaction.backupCurrentFiles())
            return fail("备份失败", "无法备份当前版本文件，尚未安装新版本。请检查磁盘空间和目录权限。", "backup_failed");

        const QString planFile = bootstrapPlanFile();
        QSaveFile plan(planFile);
        if (!plan.open(QIODevice::WriteOnly))
            return fail("接管准备失败", "无法创建 Bootstrap 文件计划。", "bootstrap_plan_failed");
        const auto writePlanItem = [&](char operation, const QString& path) {
            const QByteArray line = QByteArray(1, operation) + '\t' + path.toUtf8() + '\n';
            return plan.write(line) == line.size();
        };
        for (const QString& path : changedPaths) {
            if (!writePlanItem('C', path)) {
                plan.cancelWriting();
                return fail("接管准备失败", "无法写入 Bootstrap 复制计划。", "bootstrap_plan_failed");
            }
        }
        for (const QString& path : obsoletePaths) {
            if (!writePlanItem('D', path)) {
                plan.cancelWriting();
                return fail("接管准备失败", "无法写入 Bootstrap 删除计划。", "bootstrap_plan_failed");
            }
        }
        if (!plan.commit() || !transaction.markAwaitingBootstrap())
            return fail("接管准备失败", "无法提交 Bootstrap 文件计划或事务状态。", "bootstrap_plan_failed");

        setProgress(78, "正在将安装工作移交给 Bootstrap...");
        if (!launchBootstrap("install"))
            return fail("Bootstrap 启动失败", QString("无法启动独立更新接管程序：%1").arg(bootstrapPath), "bootstrap_start_failed");
        progress.close();
        return 0;
    }

    setProgress(82, "正在校验 Bootstrap 安装结果...");
    if (!transaction.markPostVerify() || !logic.validateLocalFiles(targetDir))
        return delegateRollback("安装校验失败", "新版本文件安装后校验未通过。");
    for (const QString& path : transaction.obsoletePaths()) {
        if (QFile::exists(QDir(targetDir).filePath(path)))
            return delegateRollback("废弃文件清理失败", QString("废弃文件仍然存在：%1").arg(path));
    }

    setProgress(89, "正在保存新版本状态...");
    if (!config.setValue("App", "current_version", targetVersion)
        || config.getValue("App", "current_version") != targetVersion)
        return delegateRollback("状态保存失败", "无法保存当前版本号。");

    const QString healthFile = transaction.healthFile();
    QFile::remove(healthFile);
    setProgress(94, "正在启动新版本并等待健康确认...");
    if (!launchMainApp(healthFile))
        return delegateRollback("启动失败", "MainApp.exe 无法启动。");

    QElapsedTimer healthTimer;
    healthTimer.start();
    while (healthTimer.elapsed() < 15000 && !QFile::exists(healthFile)) {
        QApplication::processEvents();
        QThread::msleep(100);
    }
    if (!QFile::exists(healthFile))
        return delegateRollback("启动确认失败", "新版本在 15 秒内没有完成启动健康确认。");

    setProgress(99, "正在提交更新事务...");
    if (!transaction.commit())
        return delegateRollback("事务提交失败", "新版本已经启动，但无法提交更新事务。");

    QFile::remove(healthFile);
    QFile::remove(bootstrapPlanFile());
    logic.reportResult(deviceId, fromVersion, targetVersion, true);
    progress.setValue(100);
    progress.close();
    QMessageBox::information(nullptr, "更新完成", QString("软件已成功更新到 %1，并通过启动健康检查。").arg(targetVersion));
    return 0;
}