/*
  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License
  as published by the Free Software Foundation; either version
  2 of the License, or (at your option) any later version.
*/

#include <QSqlDatabase>
#include <QSqlQuery>
#include <QHash>

#include <algorithm>

#include "mappingtreemodel.h"
#include "smtreeitem.h"

MappingTreeModel::MappingTreeModel(QStringList &headers, QObject *parent) : SmTreeModel(headers, parent), mForbidden("/"), mType(-1) {
    //init database
    mDb = QSqlDatabase::database("treedb");
    mTypesQ = new QSqlQuery(mDb);
    mTypesQ->prepare("SELECT imappings_type_id, tmappings_type_name FROM mappings_type");
    getMappingTypes();

    //prepare Queries
    mSParentsQ = "SELECT mappings_parents2.imappings_parents_id, mappings_parents2.imapping_id, mappings.tmapping_name, mappings.tscreated FROM mappings_parents2, mappings WHERE  mappings_parents2.iparent_id = :pid AND mappings.imapping_type = :type AND mappings_parents2.imapping_id = mappings.imapping_id ORDER BY mappings.tmapping_name";
    mUpdateTypeQ = new QSqlQuery(mDb);
    mUpdateTypeQ->prepare("UPDATE mappings_type SET tmappings_type_name = :value WHERE imappings_type_id = :id");
    mUpdateChildQ = new QSqlQuery(mDb);
    mUpdateChildQ->prepare("UPDATE mappings SET tmapping_name = :value WHERE imapping_id = :id");
    mAddMappingTypeQ = new QSqlQuery(mDb);
    mAddMappingTypeQ->prepare("INSERT INTO mappings_type (tmappings_type_name) VALUES(:value)");
    mDeleteMappingTypeQ = new QSqlQuery(mDb);
    mDeleteMappingTypeQ->prepare("DELETE FROM mappings_type WHERE imappings_type_id = :id");
    mAddChildQ = new QSqlQuery(mDb);
    mAddChildQ->prepare("INSERT INTO mappings (tmapping_name, imapping_type) VALUES(:name, :type)");
    mSelectChildQ = new QSqlQuery(mDb);
    mSelectChildQ->prepare("SELECT imapping_id, tmapping_name, tscreated FROM mappings WHERE tmapping_name = :name AND imapping_type = :type");
    mAddParentQ = new QSqlQuery(mDb);
    mAddParentQ->prepare("INSERT INTO mappings_parents2 (imapping_id, iparent_id) VALUES(:id, :parentid)");
    mUpdateParentQ = new QSqlQuery(mDb);
    //mUpdateParentQ->prepare("UPDATE mappings_parents SET iparent_id = :pid WHERE imapping_id = :id");
    mUpdateParentQ->prepare("UPDATE mappings_parents2 SET iparent_id = :id where imappings_parents_id = :sid");
    mDeleteMappingParentQ = new QSqlQuery(mDb);
    mDeleteMappingParentQ->prepare("DELETE FROM mappings_parents2 WHERE imappings_parents_id = :id");
    mMappingsQ = new QSqlQuery(mDb);
    mMappingsQ->prepare("SELECT tmapping_name, imapping_id FROM mappings WHERE imapping_type = :type");
}

MappingTreeModel::~MappingTreeModel(){
    delete mTypesQ;
    delete mUpdateTypeQ;
    delete mUpdateChildQ;
    delete mAddMappingTypeQ;
    delete mDeleteMappingTypeQ;
    delete mAddChildQ;
    delete mSelectChildQ;
    delete mAddParentQ;
    delete mUpdateParentQ;
    delete mMappingsQ;
    mDb = QSqlDatabase();
}

QStringList MappingTreeModel::mappingTypeNames() const {
    QStringList retval;
    foreach(mappingType t, mMappingTypes){
        retval << t.name.toString();
    }
    qSort(retval);
    return retval;
}

int MappingTreeModel::mappingTypeIdFromName(const QVariant &name) const{
    foreach(const mappingType t, mMappingTypes){
        if(t.name == name){
            return t.id.toInt();
        }
    }
    return -1;
}

//caller has ownership of this item!
SmTreeItem *MappingTreeModel::treeFromPaths(const QStringList &paths){
    if(paths.isEmpty()){
        return 0;
    }
    QHash<QString, SmTreeItem*> partsHash;
    SmTreeItem *root = new SmTreeItem(1);
    partsHash.insert(QString(), root);
    SmTreeItem *pItem = root;

    // create tree
    for(int i = 0; i < paths.count(); ++i){
        //split the paths
        QStringList parts = paths.at(i).split(forbidden());
        //process path items
        for(int j = 0; j < parts.count(); ++j){
            if(partsHash.contains(parts.at(j))){
                pItem = partsHash.value(parts.at(j)); //we've already seen this item, set it as new parent
            }else{
                //create a new item, save old root
                SmTreeItem *oldRoot = pItem;
                pItem = new SmTreeItem(QList<QVariant>() << parts.at(j), partsHash.value(parts.at(j)));
                oldRoot->appendChild(pItem);
                partsHash.insert(parts.at(j), pItem);
            }
        }
        pItem = root;
    }
    return root;
}

QVariant MappingTreeModel::data(const QModelIndex &index, int role) const{
    if(!index.isValid()){
        return QVariant();
    }
    SmTreeItem *item = itemAt(index);
    if(role == NameRole){
        return item->data(Name);
    }
    if(role == ParentIdRole){
        return item->data(ParentId);
    }
    if(role == AddedRole){
        return item->data(Added);
    }
    if(role == MyIdRole){
        return item->data(MyId);
    }
    return SmTreeModel::data(index, role);
}

QList<QVariant> MappingTreeModel::childList(const QVariant &value, int column) const{
    QModelIndex itemIdx = findRecursive(value, column, createIndex(0, column, root()));
    SmTreeItem *item = static_cast<SmTreeItem*>(itemIdx.internalPointer());
    if(item){
        if(item->childCount()){
            return getChildListRecursive(item, column);
        }
    }
    return QList<QVariant>() << value;
}

QStringList MappingTreeModel::path(QModelIndex &idx) const{
    if(!idx.isValid()){
        return QStringList();
    }
    QStringList retval;
    SmTreeItem *item = static_cast<SmTreeItem*>(idx.internalPointer());
    do {
        QString d = item->data(MappingTreeModel::Name).toString();
        if(!d.isEmpty()){
            retval << d;
        }
        item = item->parent();
    }while(item);
    std::reverse(retval.begin(), retval.end());
    return retval;
}

QModelIndex MappingTreeModel::indexFromPath(const QString &path, int column) const{
    if(path == "/"){
        return rootIndex();
    }
    QStringList items = path.split("/");
    if(items.isEmpty() || column >= NumFields){
        return QModelIndex();
    }
    QModelIndex retval;
    for(int i = 0; i < items.count(); ++i){
        retval = find(items.at(i), column, retval);
    }
    return retval;
}

bool MappingTreeModel::setData(const QModelIndex &index, const QVariant &value, int role){
    if(!index.isValid()){
        return false;
    }
    SmTreeItem *item = itemAt(index);
    if(role == Qt::EditRole){
        if(index.column() == Name){
            if(value.toString().contains(mForbidden)){
                return false;
            }
        }
        mDb.transaction();
        QSqlQuery *q = 0;
        if(item == root()){
            q = mUpdateTypeQ;
        }else{
            q = mUpdateChildQ;
        }
        q->bindValue(":value", value);
        q->bindValue(":id", item->data(ParentId));
        if(q->exec()){
            item->setData(Name, value);
            emit dataChanged(index, index);
            mDb.commit();
            return true;
        }
        mDb.rollback();
    }
    if(role == NameRole){
        if(value.toString().contains(mForbidden)){
            return false;
        }
        item->setData(Name, value);
    }
    if(role == ParentIdRole){
        item->setData(ParentId, value);
    }
    if(role == AddedRole){
        item->setData(Added, value);
    }
    if(role == MyIdRole){
        item->setData(MyId, value);
    }
    return true;
}

bool MappingTreeModel::move(const QModelIndex &source, const QModelIndex &dest){
    QVariant sourceId = source.data(MyIdRole);
    QVariant destId = dest.data(ParentIdRole);
    mDb.transaction();
    mUpdateParentQ->bindValue(":id", destId);
    mUpdateParentQ->bindValue(":sid", sourceId);
    if(mUpdateParentQ->exec()){
        // well, well, I tried to make this work with removeRows and insertRows,
        // but qt has a mind of its own there. So take the easy way out. Also,
        // it's way faster!
        mDb.commit();
        populate();
        return true;
    }
    mLastError = mUpdateParentQ->lastError();
    mDb.rollback();
    return false;
}

bool MappingTreeModel::addMappingType(const QString &type){
    mAddMappingTypeQ->bindValue(":value", type);
    mDb.transaction();
    if(mAddMappingTypeQ->exec()){
        mDb.commit();
        getMappingTypes();
        return true;
    }
    mDb.rollback();
    return false;
}

bool MappingTreeModel::deleteMappingType(int typeId){
    mDeleteMappingTypeQ->bindValue(":id", typeId);
    mDb.transaction();
    if(mDeleteMappingTypeQ->exec()){
        mDb.commit();
        getMappingTypes();
        return true;
    }
    mDb.rollback();
    return false;
}

bool MappingTreeModel::addChild(const QVariant &name, const QModelIndex &parent){
    if(!parent.isValid()){
        return false;
    }
    if(name.toString().contains(mForbidden)){
        return false;
    }
    //check if we already have a mapping with this name
    int id = mMappings.value(name.toString(), -1);
    if(id == -1){
        id = addChild(name.toString(), mType);
    }
    //now check if we already have a mapping with the same parent
    mDb.transaction();
    mAddParentQ->bindValue(":id", id);
    // seems we're a child of root
    //QVariant ppId = parent.data(ParentIdRole).isValid() ? parent.data(ParentIdRole) : -1;
    mAddParentQ->bindValue(":parentid", parent.data(ParentIdRole));
    if(mAddParentQ->exec()){
        mDb.commit();
        populate();
        return true;
    }
    mLastError = mAddParentQ->lastError();
    mDb.rollback();
    return false;
    //we're good now... db makes sure we're unique
    SmTreeItem *pItem = itemAt(parent);
    int where = lowerBound(pItem, name, Name);
    if(insertRows(where, 1, parent)){
        QSqlQuery pIdQuery = QSqlQuery("SELECT currval('mappings_parents_id__seq')", mDb);
        int parentId = -1;
        while(pIdQuery.next()){
            parentId = pIdQuery.value(0).toInt();
        }
        QModelIndex newIdx = index(where, 0, parent);
        setData(newIdx, name, NameRole);
        setData(newIdx, id, ParentIdRole);
        setData(newIdx, parentId, MyIdRole);
        mDb.commit();
        return true;
    }
    return false;
}

bool MappingTreeModel::deleteChild(const QModelIndex &idx){
    if(!idx.isValid()){
        return false;
    }
    SmTreeItem *item = itemAt(idx);
    if(item->childCount() > 0){
        return false;
    }
    mDeleteMappingParentQ->bindValue(":id", item->data(MyId));
    if(mDeleteMappingParentQ->exec()){
        removeRows(idx.row(), 1, idx.parent());
        return true;
    }
    mLastError = mDeleteMappingParentQ->lastError();
    return false;
}

MappingData MappingTreeModel::mappingDataFromIndex(QModelIndex &idx) const{
    MappingData retval = { -1, QString(), QList<QStringList>() };
    if(!idx.isValid()){
        return retval;
    }
    retval.id = idx.data(MappingTreeModel::MyIdRole).toInt();
    retval.name = idx.data(MappingTreeModel::NameRole).toString();
    retval.path << path(idx);
    return retval;
}

QStringList MappingTreeModel::paths() const{
    QStringList retval = QStringList() << "/";
    retval << getPathsRecursive(root());
    return retval;
}

void MappingTreeModel::populate(){
    if(mType == -1){
        return;
    }
    // get nodes with root as parent
    QSqlQuery rootQ(mDb);
    rootQ.prepare(mSParentsQ);
    rootQ.bindValue(":type", mType);
    rootQ.bindValue(":pid", -1);
    if(rootQ.exec()){
        SmTreeItem *rootItem = new SmTreeItem(NumFields);
        rootItem->setData(MyId, -1);
        rootItem->setData(ParentId, -1);
        while(rootQ.next()){
            QList<QVariant> childData;
            childData << rootQ.value(2) << rootQ.value(1) << rootQ.value(3) << rootQ.value(0);
            SmTreeItem *childItem = new SmTreeItem(childData, rootItem);
            rootItem->appendChild(childItem);
            getChildrenRecursive(childItem);
        }
        setRoot(rootItem);
        emit needExpansion();
    }
}

void MappingTreeModel::setType(int type){
    mType = type;
    getMappings();
}

void MappingTreeModel::getMappings(){
    mMappingsQ->bindValue(":type", mType);
    if(mMappingsQ->exec()){
        mMappings.clear();
        while(mMappingsQ->next()){
            mMappings.insert(mMappingsQ->value(0).toString(), mMappingsQ->value(1).toInt());
        }
    }
}

int MappingTreeModel::addChild(const QString &name, int type){
    mAddChildQ->bindValue(":name", name);
    mAddChildQ->bindValue(":type", type);
    if(mAddChildQ->exec()){
        mSelectChildQ->bindValue(":name", name);
        mSelectChildQ->bindValue(":type", type);
        int c = 0;
        mSelectChildQ->exec();
        while(mSelectChildQ->next()){
            ++c;
            mMappings.insert(mSelectChildQ->value(1).toString(), mSelectChildQ->value(0).toInt());
        }
        if(c > 1){
            qWarning("addChild yielded more than 1 result!");
        }
    }
    return mMappings.value(name);
}

void MappingTreeModel::getMappingTypes(){
    bool qRes = mTypesQ->exec();
    if(qRes){
        mMappingTypes.clear();
        while(mTypesQ->next()){
            mappingType t;
            t.id = mTypesQ->value(0);
            t.name = mTypesQ->value(1);
            mMappingTypes << t;
        }
        emit mappingTypesChanged();
    }
}

#include <QDebug>

void MappingTreeModel::getChildrenRecursive(SmTreeItem *item){
    static QList<QVariant> seenIds;
    QSqlQuery cq(mDb);
    cq.prepare(mSParentsQ);
    cq.bindValue(":type", mType);
    cq.bindValue(":pid", item->data(ParentId));
    if(cq.exec()){
        while(cq.next()){
            QList<QVariant> childData;
            childData << cq.value(2) << cq.value(1) << cq.value(3) << cq.value(0);
            if(seenIds.contains(item->data(MyId))){
                qDebug() << "already seen" << childData.value(0);
                continue;
            }
            seenIds << item->data(MyId);
            SmTreeItem *child = new SmTreeItem(childData, item);
            item->appendChild(child);
            getChildrenRecursive(child);
        }
    }
}

QStringList MappingTreeModel::getPathsRecursive(SmTreeItem *parent) const{
    QStringList retval;
    if(!basePath(parent).isEmpty()){
        retval << basePath(parent);
    }
    for(int i = 0; i < parent->childCount(); ++i){
        if(parent->child(i)->childCount()){
            retval << getPathsRecursive(parent->child(i));
        }else{
            retval << QString("%1/%2").arg(basePath(parent)).arg(parent->child(i)->data(Name).toString());
        }
    }
    return retval;
}

QList<QVariant> MappingTreeModel::getChildListRecursive(SmTreeItem *item, int column) const{
    QList<QVariant> retval;
    if(!item){
        return retval;
    }
    for(int i = 0; i < item->childCount(); ++i){
        if(item->child(i)->childCount()){
            retval << getChildListRecursive(item->child(i), column);
        }else{
            retval << item->child(i)->data(column);
        }
    }
    return retval;
}

QString MappingTreeModel::basePath(SmTreeItem *item) const{
    QStringList pItems;
    SmTreeItem *cur = item;
    while(cur != root()){
        pItems << cur->data(Name).toString();
        cur = cur->parent();
    }
    if(pItems.isEmpty()){
        return QString();
    }
    std::reverse(pItems.begin(), pItems.end());
    return pItems.join("/");
}

int MappingTreeModel::lowerBound(SmTreeItem *item, const QVariant &value, int column) const {
    for(int i = 0; i < item->childCount(); ++i){
        SmTreeItem *child = item->child(i);
        if(child->data(column).toString() > value.toString()){
            return i;
        }
    }
    return item->childCount();
}

MappingTreeResultModel::MappingTreeResultModel(const QStringList &headers, QObject *parent) : SmTreeModel(headers, parent) { }

Qt::ItemFlags MappingTreeResultModel::flags(const QModelIndex &index) const {
    Q_UNUSED(index);
    return (Qt::ItemIsEnabled | Qt::ItemIsSelectable);
}

bool MappingTreeResultModel::setData(const QModelIndex &index, const QVariant &value, int role){
    SmTreeItem *item = itemAt(index);
    if(role == NameRole){
        item->setData(Name, value);
        return true;
    }
    if(role == IdRole){
        item->setData(Id, value);
        return true;
    }
    return SmTreeModel::setData(index, value, role);
}

void MappingTreeResultModel::addItem(const MappingData &data){
    SmTreeItem *curItem = root();
    QList<QStringList> paths = data.path;
    foreach(QStringList p, paths){
        for(int i = 0; i < p.count(); ++i){
            int childPos = hasChild(curItem, p.at(i));
            if(childPos != -1){
                //child already exists
                curItem = curItem->child(childPos);
                continue;
            }else{
                //insert child
                int id = -1;
                if(i == p.count() - 1){
                    id = data.id;
                }
                QModelIndex curIdx = insertChild(p.at(i), id, curItem);
                curItem = itemAt(curIdx);
            }
        }
    }
}

QModelIndex MappingTreeResultModel::insertChild(const QVariant &data, int id, SmTreeItem *parent){
    QModelIndex parentIdx;
    int row = parent->childCount();
    if(parent != root()){
        for(int i = 0; i < parent->childCount(); ++i){
            if(parent->child(i)->data(0).toString() > data.toString()){
                row = i;
            }
        }
        parentIdx = createIndex(0, 0, parent);
    }
    insertRows(row, 1, parentIdx);
    QModelIndex newIdx = index(row, 0, parentIdx);
    setData(newIdx, data, NameRole);
    setData(newIdx, id, IdRole);
    return newIdx;
}

QList<int> MappingTreeResultModel::mappingsIds() const {
    return mappingIdsRecursive(root());
}

void MappingTreeResultModel::clearData(){
    setRoot(new SmTreeItem(NumFields));
}

int MappingTreeResultModel::hasChild(SmTreeItem *item, const QVariant &name, int column) const{
    for(int i = 0; i < item->childCount(); ++i){
        if(item->child(i)->data(column) == name){
            return i;
        }
    }
    return -1;
}

QList<int> MappingTreeResultModel::mappingIdsRecursive(SmTreeItem *parent) const {
    QList<int> retval;
    if(!parent->childCount()){
        return retval;
    }
    for(int i = 0; i < parent->childCount(); ++i){
        SmTreeItem *child = parent->child(i);
        int id = child->data(Id).toInt();
        if(id != -1){
            retval << id;
        }
        retval << mappingIdsRecursive(child);
    }
    return retval;
}