#include <X11/Xlib.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>

#define WIDTH  800   // Width of the window
#define HEIGHT 600   // Height of the window
#define SCALE_X 50   // Scale factor for x-axis
#define SCALE_Y 100  // Scale factor for y-axis
#define OFFSET_X 100 // Horizontal offset
#define OFFSET_Y 300 // Vertical offset (middle of the window)
#define GRID_SPACING_X 50  // Grid spacing for x-axis
#define GRID_SPACING_Y 50  // Grid spacing for y-axis

void draw_grid(Display *display, Window window, GC gc) {
    int x, y;

    // Set color for grid lines (light gray)
    XSetForeground(display, gc, 0xcccccc);

    // Draw vertical grid lines
    for (x = OFFSET_X; x < WIDTH; x += GRID_SPACING_X) {
        XDrawLine(display, window, gc, x, 0, x, HEIGHT);
    }

    // Draw horizontal grid lines
    for (y = 0; y < HEIGHT; y += GRID_SPACING_Y) {
        XDrawLine(display, window, gc, OFFSET_X, y, WIDTH, y);
    }
}

void draw_sine_wave(Display *display, Window window, GC gc) {
    double x;
    int prev_x = OFFSET_X;
    int prev_y = OFFSET_Y;

    // Set color for sine wave (black)
    XSetForeground(display, gc, BlackPixel(display, DefaultScreen(display)));

    for (x = 0; x < 2 * M_PI * 4; x += 0.01) {
        // Compute screen coordinates for the sine wave
        int screen_x = OFFSET_X + (int)(x * SCALE_X);
        int screen_y = OFFSET_Y - (int)(sin(x) * SCALE_Y);

        // Draw a line from the previous point to the current point
        XDrawLine(display, window, gc, prev_x, prev_y, screen_x, screen_y);

        // Update previous coordinates
        prev_x = screen_x;
        prev_y = screen_y;
    }
}

int main(void) {
    Display *display;
    Window window;
    int screen;
    GC gc;

    // Open connection to X server
    display = XOpenDisplay(NULL);
    if (display == NULL) {
        fprintf(stderr, "Unable to open X display\n");
        exit(1);
    }

    screen = DefaultScreen(display);

    // Create a simple window
    window = XCreateSimpleWindow(display, RootWindow(display, screen), 10, 10, WIDTH, HEIGHT, 1,
                                 BlackPixel(display, screen), WhitePixel(display, screen));

    // Set window properties and show it
    XSelectInput(display, window, ExposureMask | KeyPressMask);
    XMapWindow(display, window);

    // Create graphics context
    gc = XCreateGC(display, window, 0, NULL);

    // Event loop
    XEvent event;
    while (1) {
        XNextEvent(display, &event);

        if (event.type == Expose) {
            // When the window is exposed, first draw the grid, then the sine wave
            draw_grid(display, window, gc);
            draw_sine_wave(display, window, gc);
        }

        if (event.type == KeyPress)
            break;  // Exit the loop on any keypress
    }

    // Clean up
    XFreeGC(display, gc);
    XDestroyWindow(display, window);
    XCloseDisplay(display);

    return 0;
}