/*
 * Copyright (C) 2020-2022 Roy Qu (royqh1979@gmail.com)
 *
 * 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 3 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
#include "searchresultview.h"
#include <QApplication>
#include <QPainter>
#include <QStyledItemDelegate>
#include "mainwindow.h"

PSearchResults SearchResultModel::addSearchResults(const QString &keyword, SynSearchOptions options, SearchFileScope scope)
{
    int index=-1;
    for (int i=0;i<mSearchResults.size();i++) {
        PSearchResults results = mSearchResults[i];
        if (results->keyword == keyword && results->scope == scope
                && results->searchType == SearchType::Search) {
            index=i;
            break;
        }
    }
    if (index>=0) {
        mSearchResults.removeAt(index);
    }
    if (mSearchResults.size()>=MAX_SEARCH_RESULTS) {
        mSearchResults.pop_back();
    }
    PSearchResults results = std::make_shared<SearchResults>();
    results->keyword = keyword;
    results->options = options;
    results->scope = scope;
    results->searchType = SearchType::Search;
    mSearchResults.push_front(results);
    mCurrentIndex = 0;
    return results;
}

PSearchResults SearchResultModel::addSearchResults(
        const QString& keyword,
        const QString& symbolFullname,
        SearchFileScope scope)
{
    int index=-1;
    for (int i=0;i<mSearchResults.size();i++) {
        PSearchResults results = mSearchResults[i];
        if (results->searchType == SearchType::FindOccurences
                && results->scope == scope
                && results->statementFullname == symbolFullname
                ) {
            index=i;
            break;
        }
    }
    if (index>=0) {
        mSearchResults.removeAt(index);
    }
    if (mSearchResults.size()>=MAX_SEARCH_RESULTS) {
        mSearchResults.pop_back();
    }
    PSearchResults results = std::make_shared<SearchResults>();
    results->keyword = keyword;
    results->statementFullname = symbolFullname;
    results->filename = "";
    results->searchType = SearchType::FindOccurences;
    results->scope = scope;
    mSearchResults.push_front(results);
    mCurrentIndex = 0;
    return results;
}

PSearchResults SearchResultModel::results(int index)
{
    if (index<0 || index>=mSearchResults.size()) {
        return PSearchResults();
    }
    return mSearchResults[index];
}

void SearchResultModel::notifySearchResultsUpdated()
{
    emit modelChanged();
}

SearchResultModel::SearchResultModel(QObject* parent):
    QObject(parent),
    mCurrentIndex(-1)
{

}

int SearchResultModel::currentIndex() const
{
    return mCurrentIndex;
}

int SearchResultModel::resultsCount() const
{
    return mSearchResults.count();
}

PSearchResults SearchResultModel::currentResults()
{
    return results(mCurrentIndex);
}

void SearchResultModel::setCurrentIndex(int index)
{
    if (index!=mCurrentIndex &&
            index>=0 && index<mSearchResults.size()) {
        mCurrentIndex = index;
        emit currentChanged(mCurrentIndex);
    }
}

void SearchResultModel::clear()
{
    mCurrentIndex = -1;
    mSearchResults.clear();
    emit modelChanged();
}

void SearchResultModel::removeSearchResults(int index)
{
    mSearchResults.removeAt(index);
    emit modelChanged();
}

SearchResultTreeModel::SearchResultTreeModel(SearchResultModel *model, QObject *parent):
    QAbstractItemModel(parent),
    mSearchResultModel(model),
    mSelectable(false)
{
    connect(mSearchResultModel,&SearchResultModel::currentChanged,
            this,&SearchResultTreeModel::onResultModelChanged);
    connect(mSearchResultModel,&SearchResultModel::modelChanged,
            this,&SearchResultTreeModel::onResultModelChanged);
}

QModelIndex SearchResultTreeModel::index(int row, int column, const QModelIndex &parent) const
{
    if (!hasIndex(row,column,parent))
        return QModelIndex();

    PSearchResults results = mSearchResultModel->currentResults();
    if (!results)
        return QModelIndex();
    SearchResultTreeItem *parentItem=nullptr;
    PSearchResultTreeItem childItem;
    if (!parent.isValid()) {
        parentItem = nullptr;
        childItem = results->results[row];
    } else {
        parentItem = static_cast<SearchResultTreeItem *>(parent.internalPointer());
        childItem = parentItem->results[row];
    }
    if (childItem)
        return createIndex(row,column,childItem.get());
    return QModelIndex();
}

QModelIndex SearchResultTreeModel::parent(const QModelIndex &child) const
{
    if (!child.isValid())
        return QModelIndex();
    SearchResultTreeItem* item = static_cast<SearchResultTreeItem *>(child.internalPointer());
    if (!item) {
        return QModelIndex();
    } else {
        if (item->parent==nullptr)
            return QModelIndex();
        SearchResultTreeItem* parent = item->parent;
        int row = -1;
        for (int i=0;i<parent->results.count();i++) {
            if (parent->results[i].get()==item) {
                row = i;
                break;
            }
        }
        return createIndex(row,0,parent);
    }
}

int SearchResultTreeModel::rowCount(const QModelIndex &parent) const
{
    if (!parent.isValid()){ //root
        PSearchResults searchResults = mSearchResultModel->currentResults();
        if (!searchResults)
            return 0;
        return searchResults->results.count();
    }
    SearchResultTreeItem* item = static_cast<SearchResultTreeItem *>(parent.internalPointer());    if (!item)
        return 0;
    return item->results.count();
}

int SearchResultTreeModel::columnCount(const QModelIndex &) const
{
    return 1;
}

QVariant SearchResultTreeModel::data(const QModelIndex &index, int role) const
{
    if (!index.isValid()){
        return QVariant();
    }
    SearchResultTreeItem *item = static_cast<SearchResultTreeItem *>(index.internalPointer());
    if (!item)
        return QVariant();
    if (role == Qt::DisplayRole) {

        PSearchResults results = mSearchResultModel->currentResults();

         if (!results || !index.isValid() ) {
             // This is nothing this function is supposed to handle
             return QVariant();
         }

         if (item->parent==nullptr) { //is filename
             return QString("%1(%2)").arg(item->filename)
                     .arg(item->results.count());
         } else {
             return QString("%1 %2: %3").arg(tr("Line")).arg(item->line)
                 .arg(item->text);
         }
    }
    if (role == Qt::CheckStateRole && mSelectable) {

        PSearchResults results = mSearchResultModel->currentResults();

         if (!results || !index.isValid() ) {
             // This is nothing this function is supposed to handle
             return QVariant();
         }

         if (item->parent==nullptr) { //is filename
             return QVariant();
         } else {
             return (item->selected)?Qt::Checked:Qt::Unchecked;
         }
    }
    return QVariant();

}

SearchResultModel *SearchResultTreeModel::searchResultModel() const
{
    return mSearchResultModel;
}

bool SearchResultTreeModel::getItemFileAndLineChar(const QModelIndex &index, QString &filename, int &line, int &startChar)
{
    if (!index.isValid()){
        return false;
    }
    SearchResultTreeItem *item = static_cast<SearchResultTreeItem *>(index.internalPointer());
    if (!item)
        return false;

    PSearchResults results = mSearchResultModel->currentResults();

    if (!results ) {
        // This is nothing this function is supposed to handle
        return false;
    }

    SearchResultTreeItem *parent = item->parent;
    if (parent==nullptr) { //is filename
        return false;
    } else {
        filename = parent->filename;
        line = item->line;
        startChar = item->start;
        return true;
    }
    return false;
}

void SearchResultTreeModel::onResultModelChanged()
{
    beginResetModel();
    endResetModel();
}

Qt::ItemFlags SearchResultTreeModel::flags(const QModelIndex &) const
{
    Qt::ItemFlags flags=Qt::ItemIsEnabled | Qt::ItemIsSelectable;
    if (mSelectable) {
        flags.setFlag(Qt::ItemIsUserCheckable);
    }
    return flags;
}

bool SearchResultTreeModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
    if (!index.isValid()){
        return false;
    }
    SearchResultTreeItem *item = static_cast<SearchResultTreeItem *>(index.internalPointer());
    if (!item)
        return false;
    if (role == Qt::CheckStateRole && mSelectable) {
        PSearchResults results = mSearchResultModel->currentResults();

         if (!results || !index.isValid() ) {
             // This is nothing this function is supposed to handle
             return false;
         }

         if (item->parent==nullptr) { //is filename
             return false;
         } else {
             item->selected = value.toBool();
             return true;
         }
    }
    return false;

}

bool SearchResultTreeModel::selectable() const
{
    return mSelectable;
}

void SearchResultTreeModel::setSelectable(bool newSelectable)
{
    if (newSelectable!=mSelectable) {
        mSelectable = newSelectable;
    }
    beginResetModel();
    if (mSelectable) {
        //select all items by default
        PSearchResults results = mSearchResultModel->currentResults();
        if (results) {
            foreach (const PSearchResultTreeItem& file, results->results) {
                file->selected = false;
                foreach (const PSearchResultTreeItem& item, file->results) {
                    item->selected = true;
                }
            }
        }
    }
    endResetModel();
}

SearchResultListModel::SearchResultListModel(SearchResultModel *model, QObject *parent):
    QAbstractListModel(parent),
    mSearchResultModel(model)
{
    connect(mSearchResultModel, &SearchResultModel::modelChanged,
            this, &SearchResultListModel::onResultModelChanged);
}

int SearchResultListModel::rowCount(const QModelIndex &) const
{
    return mSearchResultModel->resultsCount();
}

QVariant SearchResultListModel::data(const QModelIndex &index, int role) const
{
    if (!index.isValid())
        return QVariant();
    if (role == Qt::DisplayRole) {
        PSearchResults results = mSearchResultModel->results(index.row());
        if (!results)
            return QVariant();
        if (results->searchType == SearchType::Search) {
            switch (results->scope) {
            case SearchFileScope::currentFile:
                return tr("Current File:") + QString(" \"%1\"").arg(results->keyword);
            case SearchFileScope::wholeProject:
                return tr("Files In Project:") + QString(" \"%1\"").arg(results->keyword);
            case SearchFileScope::openedFiles:
                return tr("Open Files:") + QString(" \"%1\"").arg(results->keyword);
            }
        } else if (results->searchType == SearchType::FindOccurences) {
            if (results->scope == SearchFileScope::currentFile) {
                return tr("Find Usages in Current File: '%1'")
                    .arg(results->keyword);
            } else {
                return tr("Find Usages in Project: '%1'")
                    .arg(results->keyword);
            }
        }
    }
    return QVariant();
}

void SearchResultListModel::onResultModelChanged()
{
    beginResetModel();
    endResetModel();
}

/**
 *
 * see https://stackoverflow.com/questions/1956542/how-to-make-item-view-render-rich-html-text-in-qt/66412883#66412883
 */
SearchResultTreeViewDelegate::SearchResultTreeViewDelegate(PSearchResultTreeModel model, QObject *parent):
    QStyledItemDelegate(parent),
    mModel(model)
{

}

void SearchResultTreeViewDelegate::paint(QPainter *painter, const QStyleOptionViewItem &optIn, const QModelIndex &index) const
{
    QStyleOptionViewItem option = optIn;
    initStyleOption(&option,index);
    PSearchResults results = mModel->searchResultModel()->currentResults();

     if (!results || !index.isValid() ) {
         // This is nothing this function is supposed to handle
         return;
     }

     QStyle *style = option.widget ? option.widget->style() : QApplication::style();

     // Painting item without text (this takes care of painting e.g. the highlighted for selected
     // or hovered over items in an ItemView)
     option.text = QString();
     style->drawControl(QStyle::CE_ItemViewItem, &option, painter, option.widget);
     SearchResultTreeItem* item = static_cast<SearchResultTreeItem *>(index.internalPointer());

     QString fullText;
     if (item->parent==nullptr) { //is filename
         fullText = QString("%1(%2)").arg(item->filename)
                     .arg(item->results.count());
     } else {
         fullText = QString("%1 %2: %3").arg(tr("Line")).arg(item->line)
             .arg(item->text);
     }
     // Figure out where to render the text in order to follow the requested alignment
     option.text = fullText;
     QRect textRect = style->subElementRect(QStyle::SE_ItemViewItemText, &option);

     QFontMetrics metrics = option.fontMetrics;
     int x=textRect.left();
     int y=textRect.top() + metrics.ascent();
     if (item->parent==nullptr) { //is filename
        painter->drawText(x,y,fullText);
     } else {
         QString s = item->text.mid(0,item->start-1);
         QString text = QString("%1 %2: %3").arg(tr("Line")).arg(item->line)
                 .arg(s);
         painter->drawText(x,y,text);
         x+=metrics.horizontalAdvance(text);
         QFont font = option.font;
         font.setBold(true);
         text=item->text.mid(item->start-1,item->len);
         int width = metrics.horizontalAdvance(text);
         QFont oldFont = painter->font();
         QPen oldPen = painter->pen();
         painter->setPen(qApp->palette().color(QPalette::ColorRole::HighlightedText));
         painter->setFont(font);
         QRect rect = textRect;
         rect.setLeft(x);
         rect.setWidth(width);
         painter->fillRect(rect,qApp->palette().color(QPalette::ColorRole::Highlight));
         painter->drawText(x,y,text);
         metrics = QFontMetrics(font);
         x+=width;
         painter->setFont(oldFont);
         painter->setPen(oldPen);

         text = item->text.mid(item->start-1+item->len);
         painter->drawText(x,y,text);
     }


}