#include "databaselms.h"

#include <QtSql>
#include <QSqlDatabase>
#include <QMessageBox>

DataBaseLMS::DataBaseLMS():
    db(nullptr)
{
    createConnection();
}

DataBaseLMS::~DataBaseLMS()
{
    deleteConnection();
}

bool DataBaseLMS::createConnection()
{
    db = new QSqlDatabase(QSqlDatabase::addDatabase(dbType));
    db->setDatabaseName(dbName);
    db->setUserName(dbUserName);
    db->setPassword(dbPassword);
    if(!db->open())
    {
        QMessageBox::critical(nullptr, dbName, "Connection error: " + db->lastError().text());
        return false;
    }
    else
    {
        QMessageBox::information(nullptr, dbName, "Connection is successful!");
        return true;
    }
}

void DataBaseLMS::deleteConnection()
{
    if(db != nullptr)
    {
        if(db->isOpen())
            db->close();
        delete  db;
    }
}

QList<Instructor> DataBaseLMS::selectAllInstructors()
{
    QList<Instructor> listInstructors;

    QString queryStr = QString("SELECT instructor_id, name, login, password, is_admin, archived "
                                                 "FROM public.instructors "
                                                 "ORDER BY instructor_id ASC");

    QSqlQuery query(*db);
    if(!query.exec(queryStr))
    {
        messageWarningErrorQuery(queryStr);
    }
    else
    {
        while (query.next())
        {//Инструктор
            Instructor instructor;
            instructor.setID(query.value(0).toInt());
            instructor.setName(query.value(1).toString());
            instructor.setLogin(query.value(2).toString());
            instructor.setPassword(query.value(3).toString());
            instructor.setIsAdmin(query.value(4).toBool());
            instructor.setArchived(query.value(5).toBool());
            instructor.setLoggedIn(false);

            listInstructors.append(instructor);
        }
    }

    return listInstructors;
}

QList<Trainee> DataBaseLMS::selectAllTrainees()
{
    QList<Trainee> listTrainees;

    QString queryStr = QString("SELECT trainees.trainee_id, trainees.name, trainees.login, trainees.password, trainees.archived, "
                                                 "groups_of_trainees.name "
                                                 "FROM public.trainees JOIN public.groups_of_trainees ON groups_of_trainees.group_id = trainees.group_trainees "
                                                 "ORDER BY groups_of_trainees.name ASC");

    QSqlQuery query(*db);
    if(!query.exec(queryStr))
    {
        messageWarningErrorQuery(queryStr);
    }
    else
    {
        while (query.next())
        {//Обучаемый
            Trainee trainee;
            trainee.setID(query.value(0).toInt());
            trainee.setName(query.value(1).toString());
            trainee.setLogin(query.value(2).toString());
            trainee.setPassword(query.value(3).toString());
            trainee.setArchived(query.value(4).toBool());
            trainee.setGroup(query.value(5).toString());
            trainee.setWhatItDoes(QStringLiteral(""));
            trainee.setLoggedIn(false);
            trainee.setLearnClass(QStringLiteral(""));
            trainee.setComputer(QStringLiteral(""));

            listTrainees.append(trainee);
        }
    }

    return listTrainees;
}

QList<Group> DataBaseLMS::selectAllGroups()
{
    QList<Group> listGroups;

    QString queryStr = QString("SELECT group_id, name, color "
                                                 "FROM public.groups_of_trainees "
                                                 "ORDER BY group_id ASC");

    QSqlQuery query(*db);
    if(!query.exec(queryStr))
    {
        messageWarningErrorQuery(queryStr);
    }
    else
    {
        while (query.next())
        {//Группа
            Group group;
            group.setID(query.value(0).toInt());
            group.setName(query.value(1).toString());
            group.setColor((Group::ColorGroup)query.value(2).toInt());

            listGroups.append(group);
        }
    }

    return listGroups;
}

bool DataBaseLMS::insertInstructor(Instructor instructor)
{
    QString queryStr = QString("INSERT INTO public.instructors (name, login, password, is_admin, archived) "
                                                 "VALUES ('%1', '%2', '%3', %4, %5)").arg(
                                                        instructor.getName(),
                                                        instructor.getLogin(),
                                                        instructor.getPassword(),
                                                        instructor.getIsAdmin() ? "true" : "false",
                                                        instructor.getArchived() ? "true" : "false");

    return queryExec(queryStr);
}

bool DataBaseLMS::deleteInstructor(int instructor_id)
{
    QString queryStr = QString("DELETE FROM public.instructors WHERE instructor_id = %1").arg(QString::number(instructor_id));

    return queryExec(queryStr);
}

bool DataBaseLMS::updateInstructor(Instructor instructor)
{
    QString queryStr = QString("UPDATE public.instructors "
                                                 "SET name = '%1', login = '%2', password = '%3', is_admin = %4, archived = %5 "
                                                 "WHERE instructor_id = %6").arg(
                                                        instructor.getName(),
                                                        instructor.getLogin(),
                                                        instructor.getPassword(),
                                                        instructor.getIsAdmin() ? "true" : "false",
                                                        instructor.getArchived() ? "true" : "false",
                                                        QString::number(instructor.getID()) );

    return queryExec(queryStr);
}

bool DataBaseLMS::insertGroup(Group group)
{
    QString queryStr = QString("INSERT INTO public.groups_of_trainees (name, color) "
                                                 "VALUES ('%1', %2)").arg(
                                                        group.getName(),
                                                        QString::number((int)group.getColor()));

    return queryExec(queryStr);
}

bool DataBaseLMS::deleteGroup(int group_id)
{
    QString queryStr = QString("DELETE FROM public.groups_of_trainees WHERE group_id = %1").arg(QString::number(group_id));

    return queryExec(queryStr);
}

bool DataBaseLMS::updateGroup(Group group)
{
    QString queryStr = QString("UPDATE public.groups_of_trainees SET name = '%1', color = %2 WHERE group_id = %3").arg(
                                                        group.getName(),
                                                        QString::number((int)group.getColor()),
                                                        QString::number(group.getID()) );

    return queryExec(queryStr);
}

bool DataBaseLMS::insertTrainee(Trainee trainee)
{
    QString queryStr = QString("INSERT INTO public.trainees (name, login, password, archived, group_trainees) "
                                                 "VALUES ('%1', '%2', '%3', %4, "
                                                 "(SELECT group_id FROM public.groups_of_trainees WHERE name = '%5') "
                                                 ")").arg(
                                                        trainee.getName(),
                                                        trainee.getLogin(),
                                                        trainee.getPassword(),
                                                        trainee.getArchived() ? "true" : "false",
                                                        trainee.getGroup());

    return queryExec(queryStr);
}

bool DataBaseLMS::deleteTrainee(int trainee_id)
{
    QString queryStr = QString("DELETE FROM public.trainees WHERE trainee_id = %1").arg(QString::number(trainee_id));

    return queryExec(queryStr);
}

bool DataBaseLMS::updateTrainee(Trainee trainee)
{
    QString queryStr = QString("UPDATE public.trainees "
                                                 "SET name = '%1', login = '%2', password = '%3', archived = %4, group_trainees = "
                                                 "(SELECT group_id FROM public.groups_of_trainees WHERE name = '%5') "
                                                 "WHERE trainee_id = %6").arg(
                                                        trainee.getName(),
                                                        trainee.getLogin(),
                                                        trainee.getPassword(),
                                                        trainee.getArchived() ? "true" : "false",
                                                        trainee.getGroup(),
                                                        QString::number(trainee.getID()) );

    return queryExec(queryStr);
}

bool DataBaseLMS::queryExec(QString queryStr)
{
    QSqlQuery query(*db);
    if(!query.exec(queryStr))
    {
        messageWarningErrorQuery(queryStr);
        return false;
    }
    else
        return true;
}

void DataBaseLMS::messageWarningErrorQuery(QString queryStr)
{
    QMessageBox::warning(nullptr, dbName, "Error query: " + queryStr + "\n" + db->lastError().text());
}