/*
 * Copyright (C) 2015 Christian Ehringfeld <c.ehringfeld@t-online.de>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include "entityhelper.h"
#include "entity.h"
#include "relation.h"
#include "cache.h"

using namespace CuteEntityManager;
EntityHelper::EntityHelper() {
}

const QHash<QString, Relation> EntityHelper::getNonInheritedRelations(
        const Entity *entity) {
    auto relations = entity->getRelations();
    auto superObject = EntityInstanceFactory::newSuperClassInstance(entity);
    if (superObject) {
        auto superRelations = superObject->getRelations();
        for (auto i = superRelations.constBegin(); i != superRelations.constEnd(); ++i) {
            if (relations.contains(i.key())) {
                relations.remove(i.key());
            }
        }
        delete superObject;
        superObject = nullptr;
    }
    return relations;
}

const QList<const QMetaObject *> EntityHelper::superClasses(
        const Entity *entity, bool
        stopAtSingleTableInheritance) {
    QList<const QMetaObject *> classes = QList<const QMetaObject *>();
    auto superMetaObject = entity->metaObject()->superClass();
    if (entity->getInheritanceStrategy() == InheritanceStrategy::JOINED_TABLE) {
        Entity *e = nullptr;
        while (superMetaObject && QString(superMetaObject->className()) !=
               QString("CuteEntityManager::Entity")) {
            e = EntityInstanceFactory::createInstance(superMetaObject->className());
            if (e) {
                classes.append(superMetaObject);
                superMetaObject = superMetaObject->superClass();
                InheritanceStrategy s = e->getInheritanceStrategy();
                delete e;
                e = nullptr;
                if (stopAtSingleTableInheritance && s == InheritanceStrategy::PER_CLASS_TABLE) {
                    break;
                }
            } else {
                break;
            }
        }
    }
    return classes;
}

const QHash<QString, QMetaProperty> EntityHelper::getMetaProperties(
        const Entity *entity) {
    return EntityHelper::getMetaProperties(entity->metaObject());
}

const QHash<QString, QMetaProperty> EntityHelper::getSuperMetaProperties(
        const Entity *entity) {
    auto superMetaObjectPropertyMap = QHash<QString, QMetaProperty>();
    auto superMeta = entity->metaObject()->superClass();
    if (QString(superMeta->className()) != QString("CuteEntityManager::Entity")
            && entity->getInheritanceStrategy() == InheritanceStrategy::JOINED_TABLE) {
        for (int var = 0; var < superMeta->propertyCount(); ++var) {
            QMetaProperty prop = superMeta->property(var);
            if (prop.isReadable() && prop.isWritable()) {
                superMetaObjectPropertyMap.insert(QString(prop.name()), prop);
            }
        }
    }
    return superMetaObjectPropertyMap;
}

const QHash<QString, QMetaProperty> EntityHelper::getMetaProperties(
        const QMetaObject *object) {
    auto h = QHash<QString, QMetaProperty>();
    for (int var = 0; var < object->propertyCount(); ++var) {
        QMetaProperty m = object->property(var);
        if (m.isValid() && m.name() != QString("objectName")) {
            h.insert(m.name(), m);
        }
    }
    return h;
}

const QHash<QString, QMetaProperty> EntityHelper::getNonInheritedMetaProperties(
        const Entity *entity) {
    auto props = EntityHelper::getMetaProperties(entity);
    auto superObject = EntityInstanceFactory::newSuperClassInstance(entity);
    if (superObject) {
        auto superProps = EntityHelper::getMetaProperties(superObject);
        for (auto iterator = superProps.constBegin(); iterator != superProps.constEnd();
             ++iterator) {
            if (props.contains(iterator.key())) {
                props.remove(iterator.key());
            }
        }
        delete superObject;
        superObject = nullptr;
    }
    return props;
}

const QHash<QString, QMetaProperty> EntityHelper::getInheritedMetaProperties(
        const Entity *entity) {
    auto props = EntityHelper::getMetaProperties(entity);
    auto superObject = EntityInstanceFactory::newSuperClassInstance(entity);
    auto wholeProperties = QHash<QString, QMetaProperty>();
    if (superObject) {
        auto superProps = EntityHelper::getMetaProperties(superObject);
        auto iterator = superProps.constBegin();
        for (auto i = props.constBegin(); i != props.constEnd(); ++i) {
            if (!superProps.contains(iterator.key())) {
                wholeProperties.insert(iterator.key(), iterator.value());
            }
        }
        delete superObject;
        superObject = nullptr;
    }
    return wholeProperties;
}

const QHash<Relation, QMetaProperty> EntityHelper::getRelationProperties(
        const Entity *entity) {
    auto h = QHash<Relation, QMetaProperty>();
    if(entity) {
        auto relations = entity->getRelations();
        for (int var = 0; var < entity->metaObject()->propertyCount(); ++var) {
            QMetaProperty m = entity->metaObject()->property(var);
            if (m.isValid() && relations.contains(QString(m.name()))) {
                h.insert(relations.value(m.name()), m);
            }
        }
    }
    return h;
}

Entity* EntityHelper::copyObject(const Entity *entity) {
    auto metaObject = entity->metaObject();
    auto newInstance = EntityInstanceFactory::createInstance(metaObject);
    if(newInstance) {
        for (int i = 0; i < metaObject->propertyCount(); ++i) {
            auto property = metaObject->property(i);
            if(property.isValid() && property.name() != entity->getPrimaryKey()) {
                property.write(newInstance, property.read(entity));
            }
        }
    }
    return newInstance;
}

Entity *EntityHelper::getBaseClassObject(const QSharedPointer<Entity> &entity,
                                         QString attributeName) {
    auto superObject = EntityInstanceFactory::createInstance(entity->metaObject());
    auto objectBefore = superObject;
    bool first = true;
    while(superObject) {
        auto props = EntityHelper::getMetaProperties(superObject);
        if(!props.contains(attributeName) ||
                superObject->getInheritanceStrategy() == InheritanceStrategy::PER_CLASS_TABLE) {
            break;
        } else if(!first) {
            delete objectBefore;
            objectBefore = nullptr;
        } else {
            first = false;
        }
        objectBefore = superObject;
        superObject = EntityInstanceFactory::newSuperClassInstance(superObject);
    }
    return objectBefore;
}

const char *EntityHelper::getClassname(const Entity *entity) {
    return entity->metaObject()->className();
}

const QString EntityHelper::getClassName(const Entity *entity) {
    return QString(entity->metaObject()->className());
}

void EntityHelper::addEntityToListProperty(const QSharedPointer<Entity>
                                           &entity, QSharedPointer<Entity> add, const QMetaProperty &property) {
    QVariant var = property.read(entity.data());
    QList<QSharedPointer<Entity>> list = (!var.isNull() && var.data() &&
                                          var.canConvert<QList<QVariant>>() ? EntityInstanceFactory::castQVariantList(
                                                                                  var) : QList<QSharedPointer<Entity>>());
    if (!list.contains(add)) {
        list.append(add);
        EntityHelper::setListProperty(entity, list, property);
    }
}

void EntityHelper::removeEntityFromListProperty(const QSharedPointer<Entity>
                                                &entity, QSharedPointer<Entity> remove, const QMetaProperty &property) {
    QVariant var = property.read(entity.data());
    if (!var.isNull() && var.canConvert<QList<QVariant>>()) {
        auto list = EntityInstanceFactory::castQVariantList(var);
        for (int i = 0; i < list.size(); ++i) {
            auto e = list.at(i);
            if (e->getId() == remove->getId()) {
                list.removeAt(i);
                break;
            }
        }
        EntityHelper::setListProperty(entity, list, property);
    }
}

void EntityHelper::clearEntityListProperty(const QSharedPointer<Entity> &entity,
                                           const QMetaProperty &property) {
    QVariant var = property.read(entity.data());
    if (var.canConvert<QList<QVariant>>()) {
        auto list = EntityInstanceFactory::castQVariantList(var);
        list.clear();
        EntityHelper::setListProperty(entity, list, property);
    }
}

void EntityHelper::setProperty(const QSharedPointer<Entity> &entity,
                               QSharedPointer<Entity> value,
                               const QMetaProperty &property) {
    if (value && value->getProperty(value->getPrimaryKey()).toLongLong()
            > -1) {
        auto i = EntityInstanceFactory::createInstance(EntityInstanceFactory::extractEntityType(property.typeName()));
        if(i) {
            i->setProperty(entity, value, property);
            delete i;
        }
    }
}

void EntityHelper::setFoundProperty(const QSharedPointer<Entity> &entity,
                               QSharedPointer<Entity> value,
                               const QMetaProperty &property) {
    if (value && value->getProperty(value->getPrimaryKey()).toLongLong()
            > -1) {
        auto i = EntityInstanceFactory::createInstance(EntityInstanceFactory::extractEntityType(property.typeName()));
        if(i) {
            i->setFoundProperty(entity, value, property);
            delete i;
        }
    }
}

void EntityHelper::setListProperty(const QSharedPointer<Entity> &entity,
                                   QList<QSharedPointer<Entity>> &value, const QMetaProperty &property) {
    auto i = EntityInstanceFactory::createInstance(EntityInstanceFactory::extractEntityType(property.typeName()));
    if(i) {
        i->setListProperty(entity, value, property);
        delete i;
    }
}


QMetaProperty EntityHelper::mappedProperty(const Relation &r,
                                           const QSharedPointer<Entity> &foreignEntity) {
    QMetaProperty prop;
    auto props = EntityHelper::getMetaProperties(foreignEntity.data());
    if (!r.getMappedBy().isEmpty() && props.contains(r.getMappedBy())) {
        prop = props.value(r.getMappedBy());
    } else {
        auto relations = foreignEntity->getRelations();
        for (auto iterator = relations.constBegin(); iterator != relations.constEnd();
             ++iterator) {
            auto rel = iterator.value();
            if (rel.getMappedBy() == r.getPropertyName()) {
                prop = props.value(rel.getPropertyName());
                break;
            }
        }
    }
    return prop;
}

QHash<QString, QVariant> EntityHelper::getEntityAttributes(
        const QHash<QString, QMetaProperty>
        &props,
        const QSharedPointer<Entity> &entity) {
    auto map = QHash<QString, QVariant>();
    auto transientAttrs = entity->getTransientAttributes();
    auto relations = entity->getRelations();
    auto i = props.constBegin();
    while (i != props.constEnd()) {
        if (!transientAttrs.contains(i.key()) && !relations.contains(i.key())) {
            if(i.value().isEnumType()) {
                map.insert(i.key(), i.value().read(entity.data()).toInt());
            } else {
                map.insert(i.key(), i.value().read(entity.data()));
            }
        }
        ++i;
    }
    return map;
}

const QList<qint64> EntityHelper::getIds(QList<QSharedPointer<Entity> > entities) {
    QList<qint64> l = QList<qint64>();
    for(int i=0; i<entities.size(); ++i) {
        auto e = entities.at(i);
        l.append(e->getId());
    }
    return l;
}

const QVariant EntityHelper::getIdsAsVariant(QList<QSharedPointer<Entity> > entities) {
    QVariant var;
    var.setValue<QList<qint64>>(EntityHelper::getIds(entities));
    return var;
}