QJsonUtils.h

#pragma once

// QT include
#include <QString>
#include <QStringList>
#include <QJsonObject>
#include <QJsonValue>
#include <QJsonArray>

class QJsonUtils
{
public:

    static void modify(QJsonObject& value, QStringList path, const QJsonValue& newValue = QJsonValue::Null, QString propertyName = "")
    {
        QJsonObject result;

        if (!path.isEmpty())
        {
            if (path.first() == "[root]")
                path.removeFirst();
            
            for (QStringList::iterator it = path.begin(); it != path.end(); ++it)
            {
                QString current = *it;
                if (current.left(1) == ".")
                    *it = current.mid(1, current.size()-1);
            }
            
            if (!value.isEmpty())
                modifyValue(value, result, path, newValue, propertyName);
            else if (newValue != QJsonValue::Null && !propertyName.isEmpty())
                result[propertyName] = newValue;
        }

        value = result;
    }

    static QJsonValue create(QJsonValue schema, bool ignoreRequired = false)
    {
        return createValue(schema, ignoreRequired);
    }

private:

    static QJsonValue createValue(QJsonValue schema, bool ignoreRequired)
    {
        QJsonObject result;
        QJsonObject obj = schema.toObject();
        
        if (obj.find("type") != obj.end() && obj.find("type").value().isString())
        {
            QJsonValue ret = QJsonValue::Null;
            
            if (obj.find("type").value().toString() == "object" && ( obj.find("required").value().toBool() || ignoreRequired ) )
                ret = createValue(obj["properties"], ignoreRequired);
            else if (obj.find("type").value().toString() == "array" && ( obj.find("required").value().toBool() || ignoreRequired ) )
            {
                QJsonArray array;
                
                if (obj.find("default") != obj.end())
                    ret = obj.find("default").value();
                else
                {
                    ret = createValue(obj["items"], ignoreRequired);

                    if (!ret.toObject().isEmpty())
                        array.append(ret);
                    ret = array;
                }
            }
            else if ( obj.find("required").value().toBool() || ignoreRequired )
                if (obj.find("default") != obj.end())
                    ret = obj.find("default").value();
            
            return ret;
        }
        else
        {
            for (QJsonObject::const_iterator i = obj.begin(); i != obj.end(); ++i)
            {
                QString attribute = i.key();
                const QJsonValue & attributeValue = *i;
                QJsonValue subValue = obj[attribute];

                if (attributeValue.toObject().find("type") != attributeValue.toObject().end())
                {
                    if (attributeValue.toObject().find("type").value().toString() == "object" && ( attributeValue.toObject().find("required").value().toBool() || ignoreRequired ) )
                    {
                        if (obj.contains("properties"))
                            result[attribute] = createValue(obj["properties"], ignoreRequired);
                        else
                            result[attribute] = createValue(subValue, ignoreRequired);
                    }
                    else if (attributeValue.toObject().find("type").value().toString() == "array" && ( attributeValue.toObject().find("required").value().toBool() || ignoreRequired ) )
                    {
                        QJsonArray array;

                        if (attributeValue.toObject().find("default") != attributeValue.toObject().end())
                            result[attribute] = attributeValue.toObject().find("default").value();
                        else
                        {
                            QJsonValue retEmpty;
                            retEmpty = createValue(attributeValue.toObject()["items"], ignoreRequired);
                            
                            if (!retEmpty.toObject().isEmpty())
                                array.append(retEmpty);
                            result[attribute] = array;
                        }
                    }
                    else if ( attributeValue.toObject().find("required").value().toBool() || ignoreRequired )
                    {
                        if (attributeValue.toObject().find("default") != attributeValue.toObject().end())
                            result[attribute] = attributeValue.toObject().find("default").value();
                        else
                            result[attribute] = QJsonValue::Null;
                    }
                }
            }
        }

        return result;
    }

    static void modifyValue(QJsonValue source, QJsonObject& target, QStringList path, const QJsonValue& newValue, QString& property)
    {
        QJsonObject obj = source.toObject();

        if (!obj.isEmpty())
        {
            for (QJsonObject::iterator i = obj.begin(); i != obj.end(); ++i)
            {
                QString propertyName = i.key();
                QJsonValue subValue = obj[propertyName];

                if (subValue.isObject())
                {
                    if (!path.isEmpty())
                    {
                        if (propertyName == path.first())
                        {
                            path.removeFirst();

                            if (!path.isEmpty())
                            {
                                QJsonObject obj;
                                modifyValue(subValue, obj, path, newValue, property);
                                subValue = obj;
                            }
                            else if (newValue != QJsonValue::Null)
                                subValue = newValue;
                            else
                                continue;

                            if (!subValue.toObject().isEmpty())
                                target[propertyName] = subValue;
                        }
                        else
                        {
                            if (path.first() == property && newValue != QJsonValue::Null)
                            {
                                target[property] = newValue;
                                property = QString();
                            }

                            target[propertyName] = subValue;
                        }
                    }
                    else
                        if (!subValue.toObject().isEmpty())
                            target[propertyName] = subValue;
                }
                else if (subValue.isArray())
                {
                    if (!path.isEmpty())
                    {
                        if (propertyName == path.first())
                        {
                            path.removeFirst();

                            int arrayLevel = -1;
                            if (!path.isEmpty())
                            {
                                if ((path.first().left(1) == "[") && (path.first().right(1) == "]"))
                                {
                                    arrayLevel = path.first().mid(1, path.first().size()-2).toInt();
                                    path.removeFirst();
                                }
                            }

                            QJsonArray array = subValue.toArray();
                            QJsonArray json_array;

                            for (QJsonArray::iterator i = array.begin(); i != array.end(); ++i)
                            {
                                if (!path.isEmpty())
                                {
                                    QJsonObject arr;
                                    modifyValue(*i, arr, path, newValue, property);
                                    subValue = arr;
                                }
                                else if (newValue != QJsonValue::Null)
                                    subValue = newValue;
                                else
                                    continue;
                                
                                if (!subValue.toObject().isEmpty())
                                    json_array.append(subValue);
                                else if (newValue != QJsonValue::Null && arrayLevel != -1)
                                    json_array.append( (i - array.begin() == arrayLevel) ? subValue : *i );
                            }

                            if (!json_array.isEmpty())
                                target[propertyName] = json_array;
                            else if (newValue != QJsonValue::Null && arrayLevel == -1)
                                target[propertyName] = newValue;
                        }
                        else
                        {
                            if (path.first() == property && newValue != QJsonValue::Null)
                            {
                                target[property] = newValue;
                                property = QString();
                            }

                            target[propertyName] = subValue;
                        }
                    }
                    else
                        if (!subValue.toArray().isEmpty())
                            target[propertyName] = subValue;
                }
                else
                {
                    if (!path.isEmpty())
                    {
                        if (propertyName == path.first())
                        {
                            path.removeFirst();

                            if (path.isEmpty())
                            {
                                if (newValue != QJsonValue::Null && property.isEmpty())
                                    subValue = newValue;
                                else
                                    continue;
                            }

                            target[propertyName] = subValue;
                        }
                        else
                        {
                            if (path.first() == property && newValue != QJsonValue::Null)
                            {
                                target[property] = newValue;
                                property = QString();
                            }

                            target[propertyName] = subValue;
                        }
                    }
                    else
                        target[propertyName] = subValue;
                }
            }
        }
        else if (newValue != QJsonValue::Null && !property.isEmpty())
        {
            target[property] = newValue;
            property = QString();
        }
    }
};