#include "BlackBorderDetector.h"
#include <QDebug>

BlackBorderDetector::BlackBorderDetector(double threshold)
{
    _blackThreshold = static_cast<uint8_t>(255.0 * threshold);
}

bool BlackBorderDetector::isBlack(const QColor &color) const
{
    return color.red() < _blackThreshold && color.green() < _blackThreshold && color.blue() < _blackThreshold;
}

BlackBorder BlackBorderDetector::process(const QImage &image)
{
    BlackBorder border;
    if (image.isNull()) {
        return border;
    }

    int width = image.width();
    int height = image.height();

    int width33 = width / 3;
    int height33 = height / 3;
    int width66 = width33 * 2;
    int height66 = height33 * 2;
    int xCenter = width / 2;
    int yCenter = height / 2;

    int firstNonBlackX = -1;
    int firstNonBlackY = -1;

    // Find the first non-black pixel from the left edge
    for (int x = 0; x < width33; ++x) {
        if (!isBlack(image.pixelColor(x, height33)) ||
            !isBlack(image.pixelColor(x, height66)) ||
            !isBlack(image.pixelColor(width - 1 - x, yCenter))) {
            firstNonBlackX = x;
            break;
        }
    }

    // Find the first non-black pixel from the top edge
    for (int y = 0; y < height33; ++y) {
        if (!isBlack(image.pixelColor(width33, y)) ||
            !isBlack(image.pixelColor(width66, y)) ||
            !isBlack(image.pixelColor(xCenter, height - 1 - y))) {
            firstNonBlackY = y;
            break;
        }
    }

    if (firstNonBlackX != -1 && firstNonBlackY != -1) {
        border.unknown = false;
        border.verticalSize = firstNonBlackX;
        border.horizontalSize = firstNonBlackY;
    }

    return border;
}