package cc.fascinated.service;
import cc.fascinated.common.EndpointStatus;
import cc.fascinated.common.ExpiringSet;
import cc.fascinated.common.WebRequest;
import cc.fascinated.config.Config;
import cc.fascinated.model.cache.CachedEndpointStatus;
import cc.fascinated.model.mojang.MojangProfile;
import cc.fascinated.model.mojang.MojangUsernameToUuid;
import cc.fascinated.repository.EndpointStatusRepository;
import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.collect.Lists;
import com.google.common.hash.Hashing;
import io.micrometer.common.lang.NonNull;
import lombok.Getter;
import lombok.SneakyThrows;
import lombok.extern.log4j.Log4j2;
import net.jodah.expiringmap.ExpirationPolicy;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import java.io.InputStream;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.*;
import java.util.concurrent.TimeUnit;
@Service @Log4j2 @Getter
public class MojangService {
/**
* The splitter and joiner for dots.
*/
private static final Splitter DOT_SPLITTER = Splitter.on('.');
private static final Joiner DOT_JOINER = Joiner.on('.');
/**
* The Mojang API endpoints.
*/
private static final String SESSION_SERVER_ENDPOINT = "https://sessionserver.mojang.com";
private static final String API_ENDPOINT = "https://api.mojang.com";
private static final String FETCH_BLOCKED_SERVERS = SESSION_SERVER_ENDPOINT + "/blockedservers";
/**
* The interval to fetch the blocked servers from Mojang.
*/
private static final long FETCH_BLOCKED_SERVERS_INTERVAL = TimeUnit.HOURS.toMillis(1L);
/**
* Information about the Mojang API endpoints.
*/
private static final String MOJANG_ENDPOINT_STATUS_KEY = "mojang";
private static final List<EndpointStatus> MOJANG_ENDPOINTS = List.of(
new EndpointStatus("https://textures.minecraft.net", List.of(HttpStatus.BAD_REQUEST)),
new EndpointStatus(API_ENDPOINT, List.of(HttpStatus.OK)),
new EndpointStatus(SESSION_SERVER_ENDPOINT, List.of(HttpStatus.FORBIDDEN))
);
@Autowired
private EndpointStatusRepository mojangEndpointStatusRepository;
/**
* A list of banned server hashes provided by Mojang.
* <p>
* This is periodically fetched from Mojang, see
* {@link #fetchBlockedServers()} for more info.
* </p>
*
* @see <a href="https://wiki.vg/Mojang_API#Blocked_Servers">Mojang API</a>
*/
private List<String> bannedServerHashes;
/**
* A cache of blocked server hostnames.
*
* @see #isServerHostnameBlocked(String) for more
*/
private final ExpiringSet<String> blockedServersCache = new ExpiringSet<>(ExpirationPolicy.CREATED, 10L, TimeUnit.MINUTES);
public MojangService() {
new Timer().scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
fetchBlockedServers();
}
}, 0L, FETCH_BLOCKED_SERVERS_INTERVAL);
}
/**
* Fetch a list of blocked servers from Mojang.
*/
@SneakyThrows
private void fetchBlockedServers() {
log.info("Fetching blocked servers from Mojang");
try (
InputStream inputStream = new URL(FETCH_BLOCKED_SERVERS).openStream();
Scanner scanner = new Scanner(inputStream, StandardCharsets.UTF_8).useDelimiter("\n");
) {
List<String> hashes = new ArrayList<>();
while (scanner.hasNext()) {
hashes.add(scanner.next());
}
bannedServerHashes = Collections.synchronizedList(hashes);
log.info("Fetched {} banned server hashes", bannedServerHashes.size());
}
}
/**
* Check if the server with the
* given hostname is blocked by Mojang.
*
* @param hostname the server hostname to check
* @return whether the hostname is blocked
*/
public boolean isServerBlocked(@NonNull String hostname) {
// Remove trailing dots
while (hostname.charAt(hostname.length() - 1) == '.') {
hostname = hostname.substring(0, hostname.length() - 1);
}
// Is the hostname banned?
if (isServerHostnameBlocked(hostname)) {
return true;
}
List<String> splitDots = Lists.newArrayList(DOT_SPLITTER.split(hostname)); // Split the hostname by dots
boolean isIp = splitDots.size() == 4; // Is it an IP address?
if (isIp) {
for (String element : splitDots) {
try {
int part = Integer.parseInt(element);
if (part >= 0 && part <= 255) { // Ensure the part is within the valid range
continue;
}
} catch (NumberFormatException ignored) {
// Safely ignore, not a number
}
isIp = false;
break;
}
}
// Check if the hostname is blocked
if (!isIp && isServerHostnameBlocked("*." + hostname)) {
return true;
}
// Additional checks for the hostname
while (splitDots.size() > 1) {
splitDots.remove(isIp ? splitDots.size() - 1 : 0);
String starredPart = isIp ? DOT_JOINER.join(splitDots) + ".*" : "*." + DOT_JOINER.join(splitDots);
if (isServerHostnameBlocked(starredPart)) {
return true;
}
}
return false;
}
/**
* Check if the hash for the given
* hostname is in the blocked server list.
*
* @param hostname the hostname to check
* @return whether the hostname is blocked
*/
private boolean isServerHostnameBlocked(@NonNull String hostname) {
// Check the cache first for the hostname
if (blockedServersCache.contains(hostname)) {
return true;
}
String hashed = Hashing.sha1().hashBytes(hostname.toLowerCase().getBytes(StandardCharsets.ISO_8859_1)).toString();
boolean blocked = bannedServerHashes.contains(hashed); // Is the hostname blocked?
if (blocked) { // Cache the blocked hostname
blockedServersCache.add(hostname);
}
return blocked;
}
/**
* Gets the status of the Mojang API.
*
* @return the status of the Mojang API
*/
public CachedEndpointStatus getMojangApiStatus() {
log.info("Getting Mojang API status");
Optional<CachedEndpointStatus> endpointStatus = mojangEndpointStatusRepository.findById(MOJANG_ENDPOINT_STATUS_KEY);
if (endpointStatus.isPresent() && Config.INSTANCE.isProduction()) {
log.info("Got cached Mojang API status");
return endpointStatus.get();
}
// Fetch the status of the Mojang APIs
Map<String, Boolean> endpoints = new HashMap<>();
for (EndpointStatus endpoint : MOJANG_ENDPOINTS) {
boolean online = false;
ResponseEntity<?> response = WebRequest.get(endpoint.getEndpoint(), String.class);
if (endpoint.getAllowedStatuses().contains(response.getStatusCode())) {
online = true;
}
endpoints.put(endpoint.getEndpoint(), online);
}
log.info("Fetched Mojang API status for {} endpoints", endpoints.size());
CachedEndpointStatus status = new CachedEndpointStatus(
MOJANG_ENDPOINT_STATUS_KEY,
endpoints,
System.currentTimeMillis()
);
mojangEndpointStatusRepository.save(status);
status.setCached(-1L); // Indicate that the status is not cached
return status;
}
/**
* Gets the Session Server profile of the
* player with the given UUID.
*
* @param id the uuid or name of the player
* @return the profile
*/
public MojangProfile getProfile(String id) {
return WebRequest.getAsEntity(SESSION_SERVER_ENDPOINT + "/session/minecraft/profile/" + id, MojangProfile.class);
}
/**
* Gets the UUID of the player using
* the name of the player.
*
* @param id the name of the player
* @return the profile
*/
public MojangUsernameToUuid getUuidFromUsername(String id) {
return WebRequest.getAsEntity(API_ENDPOINT + "/users/profiles/minecraft/" + id, MojangUsernameToUuid.class);
}
}