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#include "appparser.h"
#include "applog.h"

#include <QtCore/QFile>
#include <QtCore/QJsonDocument>
#include <QtCore/QJsonObject>

Q_LOGGING_CATEGORY(apps, "launcher.apps")


static QString doReadString(const QJsonValue& value, bool *ok)
{
    if (value.type() != QJsonValue::String) {
        *ok = false;
        return QString();
    }
    return value.toString();
}

static int doReadInt(const QJsonValue& value, bool *ok)
{
    if (value.type() != QJsonValue::Double) {
        *ok = false;
        return 0;
    }
    return value.toInt();
}

static QString readString(const QJsonObject& object, const QString& key, bool *ok)
{
    return doReadString(object.value(key), ok);
}

static QString readStringOptional(const QJsonObject& object, const QString& key, bool *ok)
{
    auto item = object.value(key);
    if (item.type() == QJsonValue::Undefined)
        return QString();
    return doReadString(item, ok);
}

static int readInt(const QJsonObject& object, const QString& key, bool *ok)
{
    return doReadInt(object.value(key), ok);
}

static QVariantMap readExtensions(const QJsonObject& object, const QString& prefixKey)
{
    QVariantMap map;

    for (auto it = object.constBegin(); it != object.constEnd(); ++it) {
        if (!it.key().startsWith(prefixKey))
            continue;
        map[it.key()] = it.value().toVariant();
    }
    return map;
}

AppEntry AppParser::parseData(const QByteArray& content, const QString& fileName, bool *ok)
{
    *ok = true;
    QJsonParseError error;

    QJsonDocument doc = QJsonDocument::fromJson(content, &error);
    if (error.error != QJsonParseError::NoError) {
        qCWarning(apps) << "Failed to parse json: " << error.errorString();
        *ok = false;
        return AppEntry::empty();
    }

    if (!doc.isObject()) {
        qCWarning(apps) << "Parsed document is not an object";
        *ok = false;
        return AppEntry::empty();
    }

    auto root = doc.object();

    QString type = readString(root, QStringLiteral("Type"), ok);
    if (type != QStringLiteral("Application")) {
        qCWarning(apps) << "Unknown type" << type;
        *ok = false;
    }

    int version = readInt(root, QStringLiteral("Version"), ok);
    if (version != 1) {
        qCWarning(apps) << "Version number should be 1... Consider to fix that" << version;
    }

    QString iconName = readString(root, QStringLiteral("Icon"), ok);
    QString appName = readString(root, QStringLiteral("Name"), ok);
    QString appId = readString(root, QStringLiteral("Id"), ok);
    QString executableName = readString(root, QStringLiteral("Exec"), ok);
    QString executablePath = readStringOptional(root, QStringLiteral("Path"), ok);
    QVariantMap extensions = readExtensions(root, QStringLiteral("X-"));
    if (!*ok)
        return AppEntry::empty();

    return AppEntry{iconName, appName, appId, executableName, executablePath, fileName, extensions};
}

AppEntry AppParser::parseFile(const QString& fileName, bool *ok)
{
    qCDebug(apps) << "Trying to parse" << fileName;

    QFile file(fileName);
    if (!file.open(QFile::ReadOnly)) {
        qCWarning(apps) << "Failed to open" << fileName;
        *ok = false;
        return AppEntry::empty();
    }

    auto entry = parseData(file.readAll(), fileName, ok);
    file.close();
    if (!*ok) {
        qCWarning(apps) << "Failed to parse" << fileName;
        return AppEntry::empty();
    }
    return entry;
}