// SPDX-FileCopyrightText: 2023 Joshua Goins <josh@redstrate.com>
// SPDX-License-Identifier: GPL-3.0-or-later

#include "patcher.h"

#include <KLocalizedString>
#include <QDir>
#include <QFile>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QStandardPaths>
#include <QtConcurrent>
#include <physis.hpp>
#include <qcorofuture.h>

#include "launchercore.h"

Patcher::Patcher(LauncherCore &launcher, const QString &baseDirectory, BootData &bootData, QObject *parent)
    : QObject(parent)
    , m_baseDirectory(baseDirectory)
    , m_bootData(&bootData)
    , m_launcher(launcher)
{
    setupDirectories();

    Q_EMIT m_launcher.stageChanged(i18n("Checking the FINAL FANTASY XIV Updater/Launcher version."));
}

Patcher::Patcher(LauncherCore &launcher, const QString &baseDirectory, GameData &gameData, QObject *parent)
    : QObject(parent)
    , m_baseDirectory(baseDirectory)
    , m_gameData(&gameData)
    , m_launcher(launcher)
{
    setupDirectories();

    Q_EMIT m_launcher.stageChanged(i18n("Checking the FINAL FANTASY XIV Game version."));
}

QCoro::Task<> Patcher::patch(const QString &patchList)
{
    if (patchList.isEmpty()) {
        co_return;
    }

    Q_EMIT m_launcher.stageIndeterminate();
    Q_EMIT m_launcher.stageChanged(i18n("Checking the %1 version.", getBaseString()));

    const QStringList parts = patchList.split("\r\n");

    m_remainingPatches = parts.size() - 7;
    m_patchQueue.resize(m_remainingPatches);

    QFutureSynchronizer<void> synchronizer;

    int patchIndex = 0;

    for (int i = 5; i < parts.size() - 2; i++) {
        const QStringList patchParts = parts[i].split(QLatin1Char('\t'));

        const int length = patchParts[0].toInt();
        const int ourIndex = patchIndex++;

        const QString &version = patchParts[4];
        const long hashBlockSize = patchParts.size() == 9 ? patchParts[6].toLong() : 0;

        const QString &name = version;
        const QStringList hashes = patchParts.size() == 9 ? (patchParts[7].split(QLatin1Char(','))) : QStringList();
        const QString &url = patchParts[patchParts.size() == 9 ? 8 : 5];
        const QString filename = QStringLiteral("%1.patch").arg(name);

        auto url_parts = url.split(QLatin1Char('/'));
        const QString repository = url_parts[url_parts.size() - 3];

        const QDir repositoryDir = m_patchesDir.absoluteFilePath(repository);

        if (!QDir().exists(repositoryDir.absolutePath()))
            QDir().mkpath(repositoryDir.absolutePath());

        const QString patchPath = repositoryDir.absoluteFilePath(filename);

        const QueuedPatch patch{name, repository, version, patchPath, hashes, hashBlockSize, length, isBoot()};

        m_patchQueue[ourIndex] = patch;

        if (!QFile::exists(patchPath)) {
            auto patchReply = m_launcher.mgr->get(QNetworkRequest(url));

            connect(patchReply, &QNetworkReply::downloadProgress, this, [this, patch](int received, int total) {
                Q_EMIT m_launcher.stageChanged(i18n("Updating %1.\nDownloading %2", getBaseString(), patch.getVersion()));
                Q_EMIT m_launcher.stageDeterminate(0, total, received);
            });

            synchronizer.addFuture(QtFuture::connect(patchReply, &QNetworkReply::finished).then([patchPath, patchReply] {
                QFile file(patchPath);
                file.open(QIODevice::WriteOnly);
                file.write(patchReply->readAll());
                file.close();
            }));
        } else {
            qDebug() << "Found existing patch: " << name;
        }
    }

    co_await QtConcurrent::run([&synchronizer] {
        synchronizer.waitForFinished();
    });

    // This must happen synchronously
    size_t i = 0;
    for (const auto &patch : m_patchQueue) {
        Q_EMIT m_launcher.stageChanged(i18n("Updating %1.\nInstalling %2", getBaseString(), patch.getVersion()));
        Q_EMIT m_launcher.stageDeterminate(0, m_patchQueue.size(), i++);

        processPatch(patch);
    }
}

void Patcher::processPatch(const QueuedPatch &patch)
{
    // Perform hash checking
    if (!patch.hashes.isEmpty()) {
        auto f = QFile(patch.path);
        f.open(QIODevice::ReadOnly);

        Q_ASSERT(patch.length == f.size());

        const int parts = std::ceil(static_cast<double>(patch.length) / static_cast<double>(patch.hashBlockSize));
        QByteArray block;
        block.resize(patch.hashBlockSize);

        for (int i = 0; i < parts; i++) {
            const auto read = f.read(patch.hashBlockSize);

            if (read.length() <= patch.hashBlockSize) {
                block = read;
            }

            QCryptographicHash hash(QCryptographicHash::Sha1);
            hash.addData(block);

            Q_ASSERT(hash.result().toHex() == patch.hashes[i]);
        }
    }

    if (isBoot()) {
        physis_bootdata_apply_patch(m_bootData, patch.path.toStdString().c_str());
    } else {
        physis_gamedata_apply_patch(m_gameData, patch.path.toStdString().c_str());
    }

    QString verFilePath;
    if (isBoot()) {
        verFilePath = m_baseDirectory + QStringLiteral("/ffxivboot.ver");
    } else {
        if (patch.repository == QLatin1String("game")) {
            verFilePath = m_baseDirectory + QStringLiteral("/ffxivgame.ver");
        } else {
            verFilePath = m_baseDirectory + QStringLiteral("/sqpack/") + patch.repository + QStringLiteral("/") + patch.repository + QStringLiteral(".ver");
        }
    }

    QFile verFile(verFilePath);
    verFile.open(QIODevice::WriteOnly | QIODevice::Text);
    verFile.write(patch.version.toUtf8());
    verFile.close();
}

void Patcher::setupDirectories()
{
    QDir dataDir;
    if (m_launcher.keepPatches()) {
        dataDir.setPath(QStandardPaths::writableLocation(QStandardPaths::AppDataLocation));
    } else {
        dataDir.setPath(QStandardPaths::writableLocation(QStandardPaths::TempLocation));
    }

    m_patchesDir.setPath(dataDir.absoluteFilePath(QStringLiteral("patches")));
}

QString Patcher::getBaseString() const
{
    if (isBoot()) {
        return i18n("FINAL FANTASY XIV Update/Launcher");
    } else {
        return i18n("FINAL FANTASY XIV Game");
    }
}