#include "mainwindow.h"
#include <QImage>
#include <QPixmap>
#include <QImageReader>
#include <QFileDialog>
#include "cmath"
#include "iostream"
#include "algorithm"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent)
{
    draw_widget = new QLabel("", this);

    hlayout = new QHBoxLayout();
    open_button = new QPushButton("Open Image", this);
    hlayout->addWidget(open_button);
    for (int i = 0; i < BUTTONS_COUNT; ++i) {
        buttons[i] = new QPushButton("Button " + QString::number(i + 1), this);
        hlayout->addWidget(buttons[i]);
    }

    vlayout = new QVBoxLayout();
    vlayout->addWidget(draw_widget);
    vlayout->addLayout(hlayout);

    QWidget *central = new QWidget(this);
    central->setLayout(vlayout);
    setCentralWidget(central);

    setFixedSize(800, 600);

    connect(open_button, SIGNAL(clicked(bool)), this, SLOT(open_image()));
    connect(buttons[0], SIGNAL(clicked(bool)), this, SLOT(button0_slot()));
    connect(buttons[1], SIGNAL(clicked(bool)), this, SLOT(button1_slot()));
}

MainWindow::~MainWindow()
{
    delete open_button;
    delete draw_widget;
    for (int i = 0; i < BUTTONS_COUNT; ++i)
        delete buttons[i];
    delete hlayout;
    delete vlayout;
    if (image) delete image;
}

void MainWindow::open_image() {
    QFileDialog dialog(this);
    dialog.setNameFilter(tr("Images (*.png *.bmp *.jpg)"));
    dialog.setViewMode(QFileDialog::Detail);
    QString filename = QFileDialog::getOpenFileName(this, tr("Open File"),
                                                    "C:/",
                                                    tr("Images (*.png *.xpm *.jpg)"));
    if (filename == "") image=nullptr;

    QImageReader reader(filename);
    reader.setAutoTransform(true);
    QImage newImage = reader.read();
    if (newImage.isNull()) image = nullptr;
    image = new QImage(newImage);
    update_image();
}

void MainWindow::update_image() {
    if (!image) return;
    draw_widget->setPixmap(QPixmap::fromImage(*image));
}

void MainWindow::button0_slot() {
    if (!image) return;
    for (int i = 0; i < image->width(); ++i)
        for (int j = 0; j < image->height() / 2; ++j) {
            QRgb x = image->pixel(i, j);
            QRgb y = image->pixel(i, image->height() - 1 - j);

            image->setPixel(i, j, y);
            image->setPixel(i, image->height() - 1 - j, x);
        }
    update_image();
}

bool MainWindow::inImage(int x, int y){
    int n = image->width();
    int m = image->height();
    return 0 <= x && x < n && 0 <= y && y < m;
}

bool inField(int x, int y, QImage* image){
    int n = image->width();
    int m = image->height();
    return 0 <= x && x < n && 0 <= y && y < m;
}


QImage erosionImage(QImage *image, int matrixSizeFix = 3, int color = 0){
    QImage newImage = *image;
    matrixSizeFix /= 2;
    for (int i = 0; i < image->width(); ++i){
        for (int j = 0; j < image->height(); ++j) {
            bool isOkThisColor = 0;
            int toPaint = 0;
            for (int shiftI = -matrixSizeFix; shiftI < matrixSizeFix; shiftI++){
                for (int shiftJ = -matrixSizeFix; shiftJ < matrixSizeFix; shiftJ++){
                    int ni = i + shiftI, nj = j + shiftJ;
                    QRgb x;
                    if (!inField(ni, nj, image)){
                        x = image->pixel(i, j);
                    }
                    else{
                        x = image->pixel(ni, nj);
                    }
                    if (qGray(x) != color){
                        isOkThisColor = 1;
                        toPaint = qGray(x);
                    }
                }
            }
            if (isOkThisColor){
                QColor newPixel(toPaint, toPaint, toPaint);
                newImage.setPixelColor(i, j, newPixel);
            }
            else{
                QColor newPixel(color, color, color);
                newImage.setPixelColor(i, j, newPixel);
            }
        }
    }
    return newImage;
}

int edge(QImage *image){
    int ser = 0, ppl = 0;
    for (int i = 0; i < image->width(); ++i){
        for (int j = 0; j < image->height(); ++j) {
            QRgb x = image->pixel(i, j);
            int sr = qGray(x);
            ser += sr;
            ppl++;
        }
    }
    return ser / ppl;
}

QImage blackAndWhite(QImage *image){

    int edgeImg = edge(image);

    for (int i = 0; i < image->width(); ++i){
        for (int j = 0; j < image->height(); ++j) {
            QRgb x = image->pixel(i, j);
            int sr = qGray(x);
            if (sr <= edgeImg){
                QColor newPixel(0, 0, 0);
                image->setPixelColor(i, j, newPixel);
            }
            else{
                QColor newPixel(255, 255, 255);
                image->setPixelColor(i, j, newPixel);
            }
        }
    }
    return *image;
}

QImage fixImage(QImage *image){
    *image = erosionImage(image, 3, 0);
    return *image;
}

void MainWindow::button1_slot() {
    if (!image) return;

    *image = blackAndWhite(image);

    //*image = fixImage(image);

    update_image();
}