Rudimentary support for IPv6 in server socket creation

I haven't completely implemented it yet, but I did come up with a basic algorithm
to convert the IPv6 address into a 'code' form. I still have to write the code to
actually create the socket, though.

check_input.cpp

@@ -30,7 +30,7 @@ GameType check_server(char* ip_text, char* port_text) {
 	std::string code = connect_code::encode(addr, std::to_string(port));
 
 	/* Create server socket and wait for client to connect */
-	Server* server = new Server(4, ES_UDP, addr.data(), port);
+	Server* server = new Server(check_ip_ver(addr.data()), ES_UDP, addr.data(), port);
 	server->create_socket();
 	display_text_centered("Your code is " + code + "\nWaiting for connection...");
 	std::string response = "";

connect_code.cpp

@@ -1,3 +1,4 @@
+#include <iostream>
 #include <string>
 #include <vector>
 #include <iomanip>
@@ -5,6 +6,15 @@
 #include <cstdint>
 #include "includes/connect_code.hpp"
 #include "includes/numeric_base.hpp"
+#include "includes/easysock.h"
+
+#if defined(_WIN32)
+	#include <In6addr.h>
+	#include <Ws2tcpip.h>
+#else
+	#include <sys/socket.h>
+	#include <arpa/inet.h>
+#endif
 
 namespace connect_code {
 
@@ -44,13 +54,67 @@ namespace connect_code {
 		uint32_t addr_val = (std::stoul(octets[0]) << 24) + (std::stoul(octets[1]) << 16) + (std::stoul(octets[2]) << 8) + (std::stoul(octets[3]));
 		return std::to_string(addr_val);
 	}
+	
+	/* Expand an IPv6 address (expand '::' into ':0000:', for example).
+	This is done by first converting the address into a binary representation,
+	and then printing every character of the binary representation into a string. */
+	std::string expand_ip6_addr(std::string addr) {
+		char ip6_string[40]; // 32 characters + 7 colons
+		struct in6_addr* ip6_s_ptr = (struct in6_addr *)malloc(sizeof(in6_addr)); // Struct pointer, to store the binary representation of the address
+		inet_pton(AF_INET6, addr.data(), ip6_s_ptr); // Convert the string representation into a binary form
+		
+		/* This abomination, converts the binary representation into a string.
+		It uses sprintf to print every byte in the binary representation into a string. 
+		The bytes are formatted as 2-character hexadecimal values. */
+		sprintf(ip6_string,
+			"%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x", 
+			ip6_s_ptr->s6_addr[0], ip6_s_ptr->s6_addr[1],
+			ip6_s_ptr->s6_addr[2], ip6_s_ptr->s6_addr[3],
+			ip6_s_ptr->s6_addr[4], ip6_s_ptr->s6_addr[5],
+			ip6_s_ptr->s6_addr[6], ip6_s_ptr->s6_addr[7],
+			ip6_s_ptr->s6_addr[8], ip6_s_ptr->s6_addr[9],
+			ip6_s_ptr->s6_addr[10], ip6_s_ptr->s6_addr[11],
+			ip6_s_ptr->s6_addr[12], ip6_s_ptr->s6_addr[13],
+			ip6_s_ptr->s6_addr[14], ip6_s_ptr->s6_addr[15]);
+			
+		return std::string(ip6_string);
+	}
 
 
 	std::string encode(std::string address, std::string port) {
+		std::string addr_coded;
 		/* Convert the address to decimal, and convert that to hex */
-		std::string addr_coded = dotted_dec_to_dec(address);
-		addr_coded = base_convert(addr_coded, 10, 32);
-
+		if (check_ip_ver(address.data()) == 4) {
+			/* I don't really have a reason to use my own function (dotted_dec_to_dec() 
+			and dec_to_dotted_dec()), to convert the IP address from text to binary.
+			The inet_pton() and inet_ntop() functions can do this just fine, and also
+			take care of edge cases. Maybe someday, I might change this code. I could probably
+			repurpose the functions for something else, though. */
+			
+			/* First, convert the address into a 32-bit integer (the integer is stored as a string).
+			Then, convert the address into base-32. */
+			addr_coded = dotted_dec_to_dec(address);
+			addr_coded = base_convert(addr_coded, 10, 32);
+		}
+		if (check_ip_ver(address.data()) == 6) {
+			/* First, expand the address into the full 39-character format (32 hex values + 7 colons).
+			Then, tokenize the string, using colons as the delimiters.
+			Finally, take each token in the string, and convert it from base-16 to base-32, appending a '-' as a delimiter. */
+			std::string addr_expanded = expand_ip6_addr(address);
+			std::string addr_coded = "";
+			std::vector<std::string> addr_tokenized = tokenize_str(addr_expanded, ":");
+			for (int i = 0; i < addr_tokenized.size(); i++ ) {
+				addr_coded += base_convert(addr_tokenized[i], 16, 32);
+				addr_coded += "-";
+			}
+			/* TODO - Check if the IP address is actually converted properly, and test if the server socket is created correctly.
+			 Also do the same for client side, and check client-server connection. */
+						
+			std::cout << addr_coded << std::endl;
+			abort();
+			
+		}
+		
 		/* Convert the port to hex */
 		std::string port_coded = base_convert(port, 10, 32);
 		std::string ret_val = addr_coded + "_" + port_coded;