#include <iostream>
#include <string>
#include <stdexcept>
#include <cstdlib>

#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"

struct RGB {
    unsigned char r;
    unsigned char g;
	unsigned char b;
};

RGB getPixelColor(const std::string& filename, int x, int y) {
    int width, height, channels;

    // Load image into memory
    unsigned char* data = stbi_load(filename.c_str(), &width, &height, &channels, 0);
    if (!data) {
        throw std::runtime_error("Failed to load image: " + filename);
    }

    // Validate coordinates
    if (x < 0 || y < 0 || x >= width || y >= height) {
        stbi_image_free(data);
        throw std::out_of_range("Pixel coordinates out of range.");
    }

    // Calculate pixel index
    int index = (y * width + x) * channels;

    RGB color = { 0, 0, 0 };
    if (channels >= 3) { // RGB or RGBA
        color.r = data[index + 0];
        color.g = data[index + 1];
        color.b = data[index + 2];
    }
    else if (channels == 1) {
        color.r = color.g = color.b = data[index];
    }

    // Free image memory
    stbi_image_free(data);
    return color;
}

int main() {
    try {
        std::string filename;
        int x, y;

        std::cout << "Enter image file path: ";
        std::getline(std::cin, filename);

        // Strip surrounding quotes if present
        if (filename.size() >= 2 && filename.front() == '"' && filename.back() == '"') {
            filename = filename.substr(1, filename.size() - 2);
        }

        std::cout << "Lade Bild von: " << filename << "\n";

        std::cout << "Enter pixel coordinates (x y): ";
        if (!(std::cin >> x >> y)) {
            throw std::invalid_argument("Invalid coordinates input.");
        }

        RGB color = getPixelColor(filename, x, y);
        std::cout << "Pixel at (" << x << ", " << y << ") -> "
            << "R: " << static_cast<int>(color.r) << ", "
            << "G: " << static_cast<int>(color.g) << ", "
            << "B: " << static_cast<int>(color.b) << "\n";
    }
    catch (const std::exception& e) {
        std::cerr << "Error: " << e.what() << "\n";
        return EXIT_FAILURE;
    }

    return EXIT_SUCCESS;
}