#include "filmsByCategory.h"

FilmsByCategory::FilmsByCategory(QObject *parent)
    : QObject{parent}
{
}

bool FilmsByCategory::openDatabase()
{
    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
    db.setDatabaseName("sakila");
    db.setHostName("localhost");
    db.setUserName("root");
    db.setPassword("12345");
    if(!db.open()){
        qDebug() << "connection failed.";
        return false;
    }
    return true;
}

void FilmsByCategory::getBarSetData()
{
    QSqlQuery query("SELECT cat.name, count(*) as film_count \
                    FROM film_category fc \
                    INNER JOIN category cat USING(category_id) \
                    GROUP BY fc.category_id");

                    if(!query.exec()){
                        qDebug() << query.lastError();
                        return;
                    }
                    while(query.next()){
                        QString catName = query.value(0).toString();
                        int filmCount = query.value(1).toInt();
                        QBarSet* bar = new QBarSet(catName);
                        bar->append(filmCount);
                        m_maxCount = qMax(m_maxCount, filmCount);
                        emit changed(bar);
                    }
                    emit maxCountChanged();
}

QPieSeries* FilmsByCategory::getPieSliceData() {

    QPieSeries* pieSlices = new QPieSeries();

    QSqlQuery query("SELECT cat.name, count(*) as film_count \
                    FROM film_category fc \
                    INNER JOIN category cat USING(category_id) \
                    GROUP BY fc.category_id");

    if (!query.exec()) {
        qWarning() << "Query failed:" << query.lastError();
    }

    double total = 0;
    int maxValue{0};
    int minValue{std::numeric_limits<int>::max()};

    while (query.next()) {
        QString catName = query.value(0).toString();
        int countValue = query.value(1).toInt();
        total += countValue;
        maxValue = qMax(maxValue, countValue);
        minValue = qMin(minValue, countValue);
        QPieSlice* pieSlice = new QPieSlice(catName, countValue);
        pieSlices->append(pieSlice);
    }

    QList<QColor> colors = contrastColors(pieSlices->count());
    int index{0};
    int maxValueIndex{0};
    int minValueIndex{0};

    for(QPieSlice* slice : pieSlices->slices()) {
        slice->setLabel(QString("%1 (%2%)")
                        .arg(slice->label(), QString::number(slice->value()/total*100.0, 'f', 1)));
        slice->setLabelVisible(true);
        slice->setColor(colors[index]);
        slice->setBorderColor(colors[index]);
        if(slice->value()>= maxValue) maxValueIndex = index;
        if(slice->value()<= minValue) minValueIndex = index;
        index++;
    }
    pieSlices -> slices().at(maxValueIndex) -> setExploded(true);
    pieSlices -> slices().at(maxValueIndex) -> setExplodeDistanceFactor(0.1);
    pieSlices -> slices().at(minValueIndex) -> setExploded(true);
    pieSlices -> slices().at(minValueIndex) -> setExplodeDistanceFactor(0.05);
    pieSlices -> setHoleSize(0.5);
    // pieSlices -> setStartAngle(45);
    // pieSlices -> setEndAngle(45+360);

    /* click signal is not available this time */
    // connect(pieSlices, &QPieSeries::clicked, pieSlices , [](QPieSlice* slice){
    //     slice -> setExploded(true);
    //     slice -> setExplodeDistanceFactor(0.15);
    // });

    return pieSlices;
}

int FilmsByCategory::maxCount() const
{
    return m_maxCount;
}

QList<QColor> FilmsByCategory::rainbowColors(int n)
{
    QList<QColor> colors;
    for(int i=0; i<n; i++){
        QColor color = QColor::fromHslF(double(i)/n, 1, 0.5, 0.85);
        colors.append(color);
    }
    return colors;
}

QList<QColor> FilmsByCategory::contrastColors(int n)
{
    QList<QColor> colors;
    for (int i = 0; i < n; ++i) {
        int hue = (i * 350 / n) % 360;
        colors.append(QColor::fromHsl(hue, 255, 127, 220));
    }
    return colors;
}