manageBDD.cpp

#include "manageBDD.h"
// DEBUG
#include <QDebug>


/*!
 * \class ManageBDD
 * \code
 * #include <manageBDD.h>
 * \endcode
 * \brief The ManageBDD class, offers the ability to execute queries on
 * the SQLite database.
 *
 * The Service should hava a single instance of this class and preferably living in
 * a thread so that a single database connection can be used throughout the entire
 * time the application is used.
 *
 * \inmodule Tepee3D
 */


/*!
 * Constructs a new ManageBDD instance, opens a database connection
 * and fill it for the first use if necessary.
 */
ManageBDD::ManageBDD() : QObject()
{
    this->dataBase = new QSqlDatabase(QSqlDatabase::addDatabase("QSQLITE"));
    qDebug() << "DB CONNECTION VALID ? " << this->dataBase->isValid();
    this->applicationPath = QCoreApplication::applicationDirPath();
    this->localDBName = "";
    this->databasePath = "";
    this->previousDbName = "";
}

/*!
 * Destroys a ManageBDD instance, close the database connection if opened.
 */
ManageBDD::~ManageBDD()
{
    if (this->dataBase->isOpen())
        this->dataBase->close();
    QString connectionName = this->dataBase->connectionName();
//    delete &this->dataBase;
    delete this->dataBase;
    QSqlDatabase::removeDatabase(connectionName);
}

/*!
 * Opens a database connection to the database specified by \a dbName.
 * If the connection is successfully opened, returns true, false otherwise.
 */
bool ManageBDD::openDatabase(const QString& dbName)
{
    // GET DB PATH FROM HASH OF SAVED DB PATHS
    this->localDBName = this->nameToPathHash[dbName];

    // IF DATABASE HAS NOT BEEN OPENED YET
    if (this->localDBName.isNull() || this->localDBName.isEmpty())
    {
#ifdef Q_OS_QNX
        // ON QNX, DATABASE HAVE TO BE COPIED TO THE data DIRECTORY
        // IN ORDER TO BE USED
        this->copyDatabaseToWritableDirectory(dbName);
#endif

#if defined Q_OS_WIN32 || defined Q_OS_WIN64
        // ON WINDOWS THE SQL DATABASES MUST BE IN THE APPDATA DIRECTORY
        // OTHERWISE THE PROGRAM AS TO BE RUN AS ADMINISTRATOR TO SAVE IN THE BDD
        this->copyDatabaseToWritableDirectory(dbName);
#endif

#ifdef Q_OS_LINUX
        // ON LINUX DATABASES CAN BE READ DIRECTLY FROM THE databases DIRECTORY
        // OF THE APPLICATION
        if (this->databasePath.isEmpty())
            this->databasePath = QDir::currentPath() + "/databases/";
        this->nameToPathHash[dbName] = this->databasePath + dbName;
        this->localDBName =  this->nameToPathHash[dbName];
#endif
    }

    qDebug() << localDBName;
    this->dataBase->setHostName("localhost");
    this->dataBase->setDatabaseName(localDBName);

    // THE DATABASE IS NOW CONTAINED IN THE TEPEE3DENGINE
    // THIS ALLOWS US TO PROVIDE A DATABASE SCHEMA WITHOUT HAVING TO
    // CREATE IT ON THE FIRST BOOT
    qDebug() << "Trying to open db";
    bool value = this->dataBase->open();
    qDebug() << "Database open " << value;
    return value;
}

void ManageBDD::copyDatabaseToWritableDirectory(const QString &dbName)
{
    if (this->databasePath.isEmpty())
    {
        QDir dbDir(QStandardPaths::writableLocation(QStandardPaths::DataLocation));
        this->databasePath = dbDir.absolutePath();
        qDebug() << this->databasePath;
        if (!dbDir.exists())
            dbDir.mkpath(dbDir.absolutePath());
        qDebug() << "Data dir exists : " << dbDir.exists();
    }
    QFile dbFile(this->databasePath + "/" + dbName);
    qDebug() << dbFile.fileName();
    if (!dbFile.exists())
    {
        qDebug() << "File doesn't exist";
        QFile dbTemplate(this->applicationPath + "/databases/" + dbName);
        qDebug() << "Trying to copy " << dbTemplate.fileName();
        if (dbTemplate.exists())
            dbTemplate.copy(dbFile.fileName());

    }
    else
        qDebug() << "File already exists";
    dbFile.setPermissions(QFile::ReadOwner|QFile::WriteOwner);
    // OPENED DB PATH IS SAVED IN HASH
    this->nameToPathHash[dbName] = dbFile.fileName();
    this->localDBName = this->nameToPathHash[dbName];
}

/*!
 * Executes \a query on the database. The result will be transmitted to \a sender
 * along with the given \a id and \a data parameters.
 */
//execute a query in database and send the result by a signal
void ManageBDD::executeSQLQuery(const QString& query, QPointer<QObject> sender, int id, const QString &dbName, QPointer<QObject> data)
{
    QList<QSqlRecord> results;
    if (dbName != this->previousDbName)
    {
        this->dataBase->close();
        this->openDatabase(dbName);
        this->previousDbName = dbName;
        QSqlQuery sqlQuery(*this->dataBase);
        sqlQuery.exec("PRAGMA synchronous=OFF;");
    }
    if (this->dataBase->isOpen())
    {
//        qDebug() << "Received query : {" << query << "}";
        QSqlQuery sqlQuery(*this->dataBase);
        sqlQuery.prepare(query);
        if (!sqlQuery.exec())
            qDebug() << "YOU SHOULD CHECK YOUR SQL QUERY FOR REQUEST id : " << id << " request : " << query ;
        results.push_back(sqlQuery.record());
        while (sqlQuery.next())
            results.push_back(sqlQuery.record());
    }
    emit resultFromSQLQuery(results, sender, id, data);
}