pollymc/api/logic/minecraft/AssetsUtils.cpp

/* Copyright 2013-2018 MultiMC Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <QFileInfo>
#include <QDir>
#include <QDirIterator>
#include <QCryptographicHash>
#include <QJsonParseError>
#include <QJsonDocument>
#include <QJsonObject>
#include <QVariant>
#include <QDebug>

#include "AssetsUtils.h"
#include "FileSystem.h"
#include "net/Download.h"
#include "net/ChecksumValidator.h"


namespace AssetsUtils
{

/*
 * Returns true on success, with index populated
 * index is undefined otherwise
 */
bool loadAssetsIndexJson(QString assetsId, QString path, AssetsIndex *index)
{
    /*
    {
      "objects": {
        "icons/icon_16x16.png": {
          "hash": "bdf48ef6b5d0d23bbb02e17d04865216179f510a",
          "size": 3665
        },
        ...
        }
      }
    }
    */

    QFile file(path);

    // Try to open the file and fail if we can't.
    // TODO: We should probably report this error to the user.
    if (!file.open(QIODevice::ReadOnly))
    {
        qCritical() << "Failed to read assets index file" << path;
        return false;
    }
    index->id = assetsId;

    // Read the file and close it.
    QByteArray jsonData = file.readAll();
    file.close();

    QJsonParseError parseError;
    QJsonDocument jsonDoc = QJsonDocument::fromJson(jsonData, &parseError);

    // Fail if the JSON is invalid.
    if (parseError.error != QJsonParseError::NoError)
    {
        qCritical() << "Failed to parse assets index file:" << parseError.errorString()
                     << "at offset " << QString::number(parseError.offset);
        return false;
    }

    // Make sure the root is an object.
    if (!jsonDoc.isObject())
    {
        qCritical() << "Invalid assets index JSON: Root should be an array.";
        return false;
    }

    QJsonObject root = jsonDoc.object();

    QJsonValue isVirtual = root.value("virtual");
    if (!isVirtual.isUndefined())
    {
        index->isVirtual = isVirtual.toBool(false);
    }

    QJsonValue objects = root.value("objects");
    QVariantMap map = objects.toVariant().toMap();

    for (QVariantMap::const_iterator iter = map.begin(); iter != map.end(); ++iter)
    {
        // qDebug() << iter.key();

        QVariant variant = iter.value();
        QVariantMap nested_objects = variant.toMap();

        AssetObject object;

        for (QVariantMap::const_iterator nested_iter = nested_objects.begin();
             nested_iter != nested_objects.end(); ++nested_iter)
        {
            // qDebug() << nested_iter.key() << nested_iter.value().toString();
            QString key = nested_iter.key();
            QVariant value = nested_iter.value();

            if (key == "hash")
            {
                object.hash = value.toString();
            }
            else if (key == "size")
            {
                object.size = value.toDouble();
            }
        }

        index->objects.insert(iter.key(), object);
    }

    return true;
}

QDir reconstructAssets(QString assetsId)
{
    QDir assetsDir = QDir("assets/");
    QDir indexDir = QDir(FS::PathCombine(assetsDir.path(), "indexes"));
    QDir objectDir = QDir(FS::PathCombine(assetsDir.path(), "objects"));
    QDir virtualDir = QDir(FS::PathCombine(assetsDir.path(), "virtual"));

    QString indexPath = FS::PathCombine(indexDir.path(), assetsId + ".json");
    QFile indexFile(indexPath);
    QDir virtualRoot(FS::PathCombine(virtualDir.path(), assetsId));

    if (!indexFile.exists())
    {
        qCritical() << "No assets index file" << indexPath << "; can't reconstruct assets";
        return virtualRoot;
    }

    qDebug() << "reconstructAssets" << assetsDir.path() << indexDir.path()
                 << objectDir.path() << virtualDir.path() << virtualRoot.path();

    AssetsIndex index;
    bool loadAssetsIndex = AssetsUtils::loadAssetsIndexJson(assetsId, indexPath, &index);

    if (loadAssetsIndex && index.isVirtual)
    {
        qDebug() << "Reconstructing virtual assets folder at" << virtualRoot.path();

        for (QString map : index.objects.keys())
        {
            AssetObject asset_object = index.objects.value(map);
            QString target_path = FS::PathCombine(virtualRoot.path(), map);
            QFile target(target_path);

            QString tlk = asset_object.hash.left(2);

            QString original_path = FS::PathCombine(objectDir.path(), tlk, asset_object.hash);
            QFile original(original_path);
            if (!original.exists())
                continue;
            if (!target.exists())
            {
                QFileInfo info(target_path);
                QDir target_dir = info.dir();
                // qDebug() << target_dir;
                if (!target_dir.exists())
                    QDir("").mkpath(target_dir.path());

                bool couldCopy = original.copy(target_path);
                qDebug() << " Copying" << original_path << "to" << target_path
                             << QString::number(couldCopy); // << original.errorString();
            }
        }

        // TODO: Write last used time to virtualRoot/.lastused
    }

    return virtualRoot;
}

}

NetActionPtr AssetObject::getDownloadAction()
{
    QFileInfo objectFile(getLocalPath());
    if ((!objectFile.isFile()) || (objectFile.size() != size))
    {
        auto objectDL = Net::Download::makeFile(getUrl(), objectFile.filePath());
        if(hash.size())
        {
            auto rawHash = QByteArray::fromHex(hash.toLatin1());
            objectDL->addValidator(new Net::ChecksumValidator(QCryptographicHash::Sha1, rawHash));
        }
        objectDL->m_total_progress = size;
        return objectDL;
    }
    return nullptr;
}

QString AssetObject::getLocalPath()
{
    return "assets/objects/" + getRelPath();
}

QUrl AssetObject::getUrl()
{
    return QUrl("http://resources.download.minecraft.net/" + getRelPath());
}

QString AssetObject::getRelPath()
{
    return hash.left(2) + "/" + hash;
}

NetJobPtr AssetsIndex::getDownloadJob()
{
    auto job = new NetJob(QObject::tr("Assets for %1").arg(id));
    for (auto &object : objects.values())
    {
        auto dl = object.getDownloadAction();
        if(dl)
        {
            job->addNetAction(dl);
        }
    }
    if(job->size())
        return job;
    return nullptr;
}