/*
  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 <QString>
#include <QSqlQuery>

#include "listmodel.h"
#include "listitem.h"

ListModel::ListModel(const QString table, QObject *parent) : QAbstractItemModel(parent), mTable(table){
	QString updateQuery = QString("UPDATE %1 SET t%1name = :name WHERE i%1id = :id").arg(mTable);
	mUpdateQuery = new QSqlQuery(updateQuery);
	QString insertQuery = QString("INSERT INTO %1(t%1name) VALUES(:name)").arg(mTable);
	mInsertQuery = new QSqlQuery(insertQuery);
	QString deleteQuery = QString("DELETE FROM %1 WHERE t%1name = :name").arg(mTable);
	mDeleteQuery = new QSqlQuery(deleteQuery);
	QString idQuery = QString("SELECT i%1id FROM %1 WHERE t%1name = :name").arg(mTable);
	mIdQuery = new QSqlQuery(idQuery);
	populate();
}

ListModel::~ListModel(){
	qDeleteAll(mItems);
}

QModelIndex ListModel::index(int row, int column, const QModelIndex &) const{
	if(column != 0){
		return QModelIndex();
	}
	if(row > mItems.size()){
		return QModelIndex();
	}
	return createIndex(row, 0);
}

int ListModel::rowCount(const QModelIndex &) const{
	return mItems.size();
}

QVariant ListModel::data(const QModelIndex &index, int role) const{
	if(!index.isValid()){
		return QVariant();
	}
	if(index.column() > 0){
		return QVariant();
	}
	if(index.row() > mItems.size()){
		return QVariant();
	}
	ListItem *item = static_cast<ListItem*>(index.internalPointer());
	Q_ASSERT(item != 0);
	switch (role){
		case Qt::DisplayRole:
			return item->name();
			break;
		case IdRole:
			return item->id();
	}
	return QVariant();
}

bool ListModel::insertRows(int row, int count, const QModelIndex &){
	beginInsertRows(QModelIndex(), row, row + count - 1);
	for(int i = row; i < (row + count); ++i){
		ListItem *newItem = new ListItem(QString(), -1);
		mItems.insert(i, newItem);
	}
	endInsertRows();
	return true;
}

bool ListModel::removeRows(int row, int count, const QModelIndex&){
	if(row > mItems.size()){
		return false;
	}
	if((row - count - mItems.size()) < 0){
		return false;
	}
	beginRemoveRows(QModelIndex(), row, row + (count - 1));
	for(int i = row; i < (row + count); ++i){
		ListItem *delItem = mItems.at(i);
		delete delItem;
		mItems.removeAt(i);
	}
	endRemoveRows();
	return true;
}

bool ListModel::setData(const QModelIndex &idx, const QVariant &data, int role){
	if((!idx.isValid()) || (role != Qt::EditRole) || (idx.column() != 0)){
		return false;
	}
	ListItem *item = static_cast<ListItem*>(idx.internalPointer());
	Q_ASSERT(item != 0);
	int id = item->id();
	bool success = false;
	if(id == -1){
		//this is an update
		mUpdateQuery->bindValue(":id", id);
		success = mUpdateQuery->exec();
	}else{
		//this is an insert
		mInsertQuery->bindValue(":name", data);
		success = mInsertQuery->exec();
		if(success){
			mIdQuery->bindValue(":name", data);
			success = mIdQuery->exec();
			int count = 0;
			while(mIdQuery->next()){
				id = mIdQuery->value(0).toInt();
				++count;
			}
			Q_ASSERT(count == 1);
			item->setName(data.toString());
			item->setId(id);
		}
	}
	if(success){
		qSort(mItems.begin(), mItems.end(), sortListItems);
		dataChanged(index(0, 0), index((mItems.size() - 1), 0));
	}
	return success;
}

bool ListModel::addItem(const QVariant &item){
	bool success = false;
	if(insertRows(0, 1, QModelIndex())){
		QModelIndex idx = index(0, 0);
		if(idx.isValid()){
			success = setData(idx, item);
		}
	}
	return success;
}

bool ListModel::removeItem(const QVariant &item){
	QString text = item.toString();
	int rowToDelete = -1;
	for(int row = 0; row < rowCount(); ++row){
		QString data = index(row, 0).data().toString();
		if(data == text){
			rowToDelete = row;
			break;
		}
	}
	if(rowToDelete == -1){
		return false;
	}
	bool success = removeRows(rowToDelete, 1, QModelIndex());
	if(success){
		mDeleteQuery->bindValue(":name", item.toString());
		success = mDeleteQuery->exec();
	}
	return success;
}

bool ListModel::renameItem(const QVariant &oldName, const QVariant &newName){
	QModelIndex idx = QModelIndex();
	bool success = false;
	for(int i = 0; i < rowCount(); ++i){
		idx = index(i, 0);
		if(idx.data().toString() == oldName.toString()){
			success = setData(idx, newName);
		}
	}
	return success;
}

void ListModel::populate(){
	QString query = QString("SELECT i%1id, t%1name FROM %1 ORDER BY t%1name").arg(mTable);
	QSqlQuery q(query);
	q.exec();
	while(q.next()){
		ListItem *newItem = new ListItem(q.value(1).toString(), q.value(0).toInt());
		mItems << newItem;
	}
}

bool sortListItems(const ListItem *lhs, const ListItem *rhs){
	return lhs->name().toLower() < rhs->name().toLower();
}