feat: Add Minecraft Account linking endpoints.

.editorconfig

@@ -13,4 +13,7 @@ trim_trailing_whitespace = true # Gets rid of unnecessary indentation, and IJ ig
 # Note: Turn on Smart Tabs!
 ij_java_continuation_indent_size = 8 # Should be twice the tab width (8 for 4 columns, 16 for 8)
 ij_json_continuation_indent_size = 4 # Should be the tab size
-ij_toml_continuation_indent_size = 4 # Should be the tab size
+ij_toml_continuation_indent_size = 4 # Should be the tab size
+
+[*.key]
+insert_final_newline = false # Don't do this for any publickeys.

src/main/java/net/modgarden/backend/ModGardenBackend.java

@@ -35,6 +35,7 @@
 import java.io.InputStreamReader;
 import java.lang.reflect.Type;
 import java.net.http.HttpClient;
+import java.security.NoSuchAlgorithmException;
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.PreparedStatement;
@@ -108,6 +109,7 @@ public static void main(String[] args) {
         app.error(422, BackendError::handleError);
         app.error(500, BackendError::handleError);
 		app.start(7070);
+
 		LOG.info("Mod Garden Backend Started!");
     }
 
@@ -138,6 +140,7 @@ public static void v1(Javalin app) {
 
 		get(app, 1, "discord/oauth/modrinth", DiscordBotOAuthHandler::authModrinthAccount);
 		get(app, 1, "discord/oauth/minecraft", DiscordBotOAuthHandler::authMinecraftAccount);
+		get(app, 1, "discord/oauth/minecraft/challenge", DiscordBotOAuthHandler::getMicrosoftCodeChallenge);
 
 		post(app, 1, "discord/submission/create/modrinth", DiscordBotSubmissionHandler::submitModrinth);
 		post(app, 1, "discord/submission/delete", DiscordBotSubmissionHandler::unsubmit);

src/main/java/net/modgarden/backend/handler/v1/discord/DiscordBotLinkHandler.java

@@ -1,22 +1,16 @@
 package net.modgarden.backend.handler.v1.discord;
 
 import com.mojang.serialization.Codec;
-import com.mojang.serialization.JsonOps;
 import com.mojang.serialization.codecs.RecordCodecBuilder;
 import io.javalin.http.Context;
 import net.modgarden.backend.ModGardenBackend;
 import net.modgarden.backend.data.LinkCode;
 import net.modgarden.backend.data.profile.User;
-import net.modgarden.backend.util.ExtraCodecs;
 
-import java.math.BigInteger;
 import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.SQLException;
-import java.util.ArrayList;
-import java.util.List;
 import java.util.Locale;
-import java.util.UUID;
 
 public class DiscordBotLinkHandler {
     public static void link(Context ctx) {
@@ -49,19 +43,20 @@ public static void link(Context ctx) {
             deleteStatement.execute();
             if (accountId == null) {
                 ctx.result("Invalid link code for " + capitalisedService + ".");
-                ctx.status(422);
+                ctx.status(400);
                 return;
             }
 
             if (body.service.equals(LinkCode.Service.MODRINTH.serializedName())) {
-				handleModrinth(ctx, connection, body.discordId, accountId, capitalisedService);
+				handleModrinth(ctx, connection, body.discordId, accountId);
 				return;
 			} else if (body.service.equals(LinkCode.Service.MINECRAFT.serializedName())) {
-				handleMinecraft(ctx, connection, body.discordId, accountId, capitalisedService);
+				handleMinecraft(ctx, connection, body.discordId, accountId);
+				DiscordBotOAuthHandler.invalidateFromUuid(body.linkCode);
 				return;
 			}
 			ctx.result("Invalid link code service '" + capitalisedService + "'.");
-			ctx.status(422);
+			ctx.status(400);
         } catch (SQLException ex) {
             ModGardenBackend.LOG.error("Exception in SQL query.", ex);
             ctx.result("Internal Error.");
@@ -72,78 +67,66 @@ public static void link(Context ctx) {
 	private static void handleModrinth(Context ctx,
 									   Connection connection,
 									   String discordId,
-									   String accountId,
-									   String capitalisedService) throws SQLException {
+									   String accountId) throws SQLException {
 		try (var accountCheckStatement = connection.prepareStatement("SELECT 1 FROM users WHERE modrinth_id = ?");
 			 var userCheckStatement = connection.prepareStatement("SELECT 1 FROM users WHERE discord_id = ? AND modrinth_id IS NOT NULL");
 			 var insertStatement = connection.prepareStatement("UPDATE users SET modrinth_id = ? WHERE discord_id = ?")) {
 			accountCheckStatement.setString(1, accountId);
 			ResultSet accountCheckResult = accountCheckStatement.executeQuery();
 			if (accountCheckResult.isBeforeFirst() && accountCheckResult.getBoolean(1)) {
-				ctx.result("The specified " + capitalisedService + " account has already been linked to a Mod Garden account.");
-				ctx.status(422);
+				ctx.result("The specified Modrinth account has already been linked to a Mod Garden account.");
+				ctx.status(400);
 				return;
 			}
 
 			userCheckStatement.setString(1, discordId);
 			ResultSet userCheckResult = userCheckStatement.executeQuery();
 			if (userCheckResult.isBeforeFirst() && userCheckResult.getBoolean(1)) {
-				ctx.result("The specified Mod Garden account is already linked with " + capitalisedService + ".");
-				ctx.status(422);
+				ctx.result("The specified Mod Garden account is already linked with Modrinth.");
+				ctx.status(400);
 				return;
 			}
 
 			insertStatement.setString(1, accountId);
 			insertStatement.setString(2, discordId);
 			insertStatement.execute();
 
-			ctx.result("Successfully linked " + capitalisedService + " account to Mod Garden account associated with Discord ID '" + discordId + "'.");
+			ctx.result("Successfully linked Modrinth account to Mod Garden account associated with Discord ID '" + discordId + "'.");
 			ctx.status(201);
 		}
 	}
 
 	private static void handleMinecraft(Context ctx,
-									   Connection connection,
-									   String discordId,
-									   String uuid,
-									   String capitalisedService) throws SQLException {
-		try (var accountCheckStatement = connection.prepareStatement("SELECT 1 FROM users WHERE instr(minecraft_accounts, ?) > 0");
-			 var insertStatement = connection.prepareStatement("UPDATE users SET minecraft_accounts = ? WHERE discord_id = ?")) {
-			accountCheckStatement.setString(1, uuid);
-			ResultSet accountCheckResult = accountCheckStatement.executeQuery();
-			if (accountCheckResult.isBeforeFirst() && accountCheckResult.getBoolean(1)) {
-				ctx.result("The specified " + capitalisedService + " account has already been linked to a Mod Garden account.");
-				ctx.status(422);
-				return;
-			}
-
+										Connection connection,
+										String discordId,
+										String uuid) throws SQLException {
+		try (var accountCheckStatement = connection.prepareStatement("SELECT user_id FROM minecraft_accounts WHERE uuid = ?");
+			 var insertStatement = connection.prepareStatement("INSERT INTO minecraft_accounts (uuid, user_id) VALUES (?, ?)")) {
 			User user = User.query(discordId, "discord");
 			if (user == null) {
 				ctx.result("Could not find user from Discord ID '" + discordId + "'.");
-				ctx.status(422);
+				ctx.status(400);
 				return;
 			}
 
-			List<UUID> uuids = new ArrayList<>(user.minecraftAccounts());
-			uuids.add(new UUID(
-					new BigInteger(uuid.substring(0, 16), 16).longValue(),
-					new BigInteger(uuid.substring(16), 16).longValue()
-			));
-
-			var dataResult = ExtraCodecs.UUID_CODEC.listOf().encodeStart(JsonOps.INSTANCE, uuids);
-
-			if (!dataResult.hasResultOrPartial()) {
-				ModGardenBackend.LOG.error("Failed to create Minecraft account data. {}", dataResult.error().orElseThrow().message());
-				ctx.result("Failed to create Minecraft account data.");
-				ctx.status(500);
+			accountCheckStatement.setString(1, uuid);
+			ResultSet accountCheckResult = accountCheckStatement.executeQuery();
+			if (accountCheckResult.isBeforeFirst() && accountCheckResult.getString(1) != null) {
+				if (accountCheckResult.getString(1).equals(user.id())) {
+					ctx.result("Your Minecraft account is already linked to your Mod Garden account.");
+					ctx.status(200);
+					return;
+				}
+				ctx.result("The specified Minecraft account has already been linked to a Mod Garden account.");
+				ctx.status(400);
 				return;
 			}
 
-			accountCheckStatement.setString(1, dataResult.getOrThrow().toString());
-			accountCheckStatement.setString(2, discordId);
+			insertStatement.setString(1, uuid);
+			insertStatement.setString(2, user.id());
 			insertStatement.execute();
 
-			ctx.result("Successfully linked " + capitalisedService + " account to Mod Garden account associated with Discord ID '" + discordId + "'.");
+			ctx.result("Successfully linked Minecraft account to Mod Garden account associated with Discord ID '" + discordId + "'.");
 			ctx.status(201);
 		}
 	}