#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <gtk/gtk.h>

GtkWidget* entry;
GtkWidget* result_label;

void show_price(GtkWidget *widget, gpointer data){
	const char *input;
	int menu_number;
	
	input = gtk_editable_get_text(GTK_EDITABLE(entry));
	menu_number = atoi(input);
	
	switch(menu_number){
		case 1:
			gtk_label_set_text(GTK_LABEL(result_label), "price : 8$");
			break;
		
		case 2:
			gtk_label_set_text(GTK_LABEL(result_label), "price : 7$");
			break;
			
		case 3:
			gtk_label_set_text(GTK_LABEL(result_label), "price : 4$");
			break;
	}
}

static void activate(GtkApplication *app, gpointer user_data){
	GtkWidget *window;
	GtkWidget *box;
	GtkWidget *menu_label;
	GtkWidget *input_box;
	GtkWidget *button;
	GtkWidget *input_label;
	
	window = gtk_application_window_new(app);
	
	gtk_window_set_title(
		GTK_WINDOW(window), 
		"Today's Menu"
	);
	
	gtk_window_set_default_size(
		GTK_WINDOW(window),
		600,
		350
	);
	
	box = gtk_box_new(
		GTK_ORIENTATION_VERTICAL,
		15
	);
	
	gtk_widget_set_margin_top(box, 30);
	gtk_widget_set_margin_bottom(box, 30);
	gtk_widget_set_margin_start(box, 30);
	gtk_widget_set_margin_end(box, 30);
	
	gtk_window_set_child(
		GTK_WINDOW(window),
		box
	);
	
	menu_label = gtk_label_new(
		"Today's Menu\n\n"
		"1. Premium Water    8$\n"
		"2. Premium Dust    7$\n"
		"3. Premium Air    4$\n"
	);
	
	gtk_box_append(
		GTK_BOX(box), 
		menu_label
	);
	
	input_box = gtk_box_new(
		GTK_ORIENTATION_HORIZONTAL, 
		10
	);
	
	input_label = gtk_label_new("Order Number:");
	
	gtk_box_append(
		GTK_BOX(input_box), 
		input_label
	);
	
	entry = gtk_entry_new();
	
	gtk_entry_set_placeholder_text(
		GTK_ENTRY(entry), 
		"enter 1~3"
	);
	
	gtk_box_append(
		GTK_BOX(input_box),
		entry
	);
	
	button = gtk_button_new_with_label("Confirmed");
	
	gtk_box_append(
		GTK_BOX(input_box),
		button
	);
	
	gtk_box_append(
		GTK_BOX(box),
		input_box
	);
	
	result_label = gtk_label_new(
		"The price is displayed here."
	);
	
	gtk_box_append(
		GTK_BOX(box),
		result_label
	);
	
	g_signal_connect(
		button, 
		"clicked",
		G_CALLBACK(show_price),
		NULL
	);
	
	gtk_window_present(
		GTK_WINDOW(window)
	);
}

int main(int argc, char **argv) {
	GtkApplication *app;
	int status;
	
	app = gtk_application_new(
		"com.example.menu",
		G_APPLICATION_DEFAULT_FLAGS
	);
	
	g_signal_connect(
		app, 
		"activate",
		G_CALLBACK(activate),
		NULL
	);
	
	status = g_application_run(
		G_APPLICATION(app), 
		argc,
		argv
	);
	
	g_object_unref(app);
	
	return status;
}