/*
  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 <QPushButton>
#include <QHBoxLayout>
#include <QVBoxLayout>
#include <QSettings>

#include "mappingeditwidget.h"
#include "mappingtreewidget.h"
#include "mappingtreeresultview.h"
#include "mappingtreeresultmodel.h"
#include "mappingtreeview.h"
#include "mappingtreeproxy.h"
#include "mappingdata.h"

MappingEditWidget::MappingEditWidget(QWidget *parent) : QWidget(parent){
    //the views
    mMappingTree = new MappingTreeWidget;
    mMappingResult = new MappingTreeResultView;
    mResultModel = new MappingTreeResultModel(QStringList() << tr("Name") << tr("MappingId") << tr("ParentId") << tr("MyId"), this);
    mMappingResult->setModel(mResultModel);
    mMappingResult->setAlternatingRowColors(true);
    mMappingResult->setColumnHidden(1, true);
    mMappingResult->setColumnHidden(2, true);
    mMappingResult->setColumnHidden(3, true);
    connect(mMappingTree->mappingTreeView(), &MappingTreeView::addMapping, this, &MappingEditWidget::addMapping);
    connect(mMappingTree->mappingTreeView(), &MappingTreeView::clearMappings, this, &MappingEditWidget::clearMapping);
    connect(mMappingTree->mappingTreeView(), &MappingTreeView::shiftFocus, this, &MappingEditWidget::shiftFocusResult);
    connect(mMappingResult, &MappingTreeResultView::shiftFocus, this, &MappingEditWidget::shiftFocusMappings);
    connect(mMappingResult, &MappingTreeResultView::removeMapping, this, &MappingEditWidget::removeMapping);
    connect(mMappingResult->selectionModel(), &QItemSelectionModel::currentChanged, this, &MappingEditWidget::resultSelectionChanged);

    //buttons
    mAddMapping = new QPushButton(tr(">>"));
    connect(mAddMapping, &QPushButton::clicked, this, &MappingEditWidget::addMapping);
    mRemoveMapping = new QPushButton(tr("<<"));
    connect(mRemoveMapping, &QPushButton::clicked, this, &MappingEditWidget::removeMapping);
    mClearMapping = new QPushButton(tr("&Clear"));
    connect(mClearMapping, &QPushButton::clicked, this, &MappingEditWidget::clearMapping);
    mAddTree = new QPushButton(tr(">>>>"));
    connect(mAddTree, &QPushButton::clicked, this, &MappingEditWidget::addTree);

    //layout
    QHBoxLayout *mainLayout = new QHBoxLayout;
    mainLayout->addWidget(mMappingTree);
    QVBoxLayout *buttonLayout = new QVBoxLayout;
    buttonLayout->addStretch();
    buttonLayout->addWidget(mAddMapping);
    buttonLayout->addWidget(mRemoveMapping);
    buttonLayout->addWidget(mClearMapping);
    buttonLayout->addWidget(mAddTree);
    buttonLayout->addStretch();
    mainLayout->addLayout(buttonLayout);
    mainLayout->addWidget(mMappingResult);
    setLayout(mainLayout);
    mMappingTree->mappingTreeView()->setFocus();
}

void MappingEditWidget::addMapping(){
    MappingData selected = mMappingTree->selectedItem();
    mResultModel->addItem(selected);
    mMappingResult->expandAll();
    mMappingTree->mappingTreeView()->setFocus();
}

void MappingEditWidget::addTree(){
    QList<MappingData> retval = mMappingTree->selectedTree();
    for(const MappingData &md : retval){
        mResultModel->addItem(md);
    }
    mMappingResult->expandAll();
    mMappingTree->mappingTreeView()->setFocus();
}

void MappingEditWidget::removeMapping(){
    QModelIndexList sel = mMappingResult->selectionModel()->selectedRows();
    if(sel.isEmpty()){
        return;
    }
    QModelIndex firstIdx = sel.first();
    if(firstIdx.isValid()){
        mResultModel->removeItem(firstIdx);
    }
    mMappingResult->expandAll();
    mMappingTree->mappingTreeView()->setFocus();
}

void MappingEditWidget::clearMapping(){
    mResultModel->clearData();
    mMappingTree->mappingTreeView()->setFocus();
}

void MappingEditWidget::setMappings(const QList<MappingData> &mappings){
    if(mappings.isEmpty()){
        return;
    }
    mResultModel->clearData();
    for(const MappingData &d : mappings){
        mResultModel->addItem(d);
    }
    mMappingResult->expandAll();
}

void MappingEditWidget::expandAllResults(){
    mMappingResult->expandAll();
}

void MappingEditWidget::shiftFocusResult(){
    mMappingResult->setFocus();
}

void MappingEditWidget::shiftFocusMappings(){
    mMappingTree->mappingTreeView()->setFocus();
}

void MappingEditWidget::saveMappings(QString where){
    const QList<MappingData> mappingData = model()->mappingData();
    QByteArray saveVal;
    QDataStream in(&saveVal, QIODevice::WriteOnly);
    for(const MappingData &md : mappingData){
        in << md;
    }
    QSettings s;
    s.setValue(where, saveVal);
}

void MappingEditWidget::loadMappings(QString from){
    QSettings s;
    QByteArray val = s.value(from).toByteArray();
    QDataStream out(&val, QIODevice::ReadOnly);
    MappingData md;
    while(!out.atEnd()){
        out >> md;
        model()->addItem(md);
    }
    expandAllResults();
}

void MappingEditWidget::resultSelectionChanged(const QModelIndex &current, const QModelIndex &previous){
    Q_UNUSED(previous)
    QStringList path;
    QModelIndex c = current;
    // gather elements from leaf to root
    while(c != QModelIndex()){
        path << c.data().toString();
        c = c.parent();
    }
    std::reverse(path.begin(), path.end());
    MappingTreeModel *srcModel = mMappingTree->mappingTreeModel();
    QModelIndex srcIdx = srcModel->rootIndex();
    // now search the source tree starting at the top,
    // that's why we reversed the QStringList above
    for(const QString &p : path){
        srcIdx = srcModel->find(p, 0, srcIdx);
        if(!srcIdx.isValid()){
            return;
        }
    }
    // yes, we have a valid index. Map it to the Proxy...
    QModelIndex real = mMappingTree->mappingTreeProxy()->mapFromSource(srcIdx);
    // select it and make sure it's visible!
    mMappingTree->mappingTreeView()->selectionModel()->select(real, QItemSelectionModel::ClearAndSelect | QItemSelectionModel::Rows);
    mMappingTree->mappingTreeView()->scrollTo(real, QAbstractItemView::PositionAtCenter);
}