Fix 'show-applicable-for-history' with /warns + initialize H2

* The 'show-applicable-for-history' option was turning /history
  into /warns. Extend the option to similarly infuse /warns with
  applicability, but don't take over the command.
* Initialize the H2 database driver if possible. Use data sources
  and direct instantiation to avoid registering the Driver if
  possible.

bans-core/src/main/java/space/arim/libertybans/core/commands/ListCommands.java

@@ -23,6 +23,7 @@
 import jakarta.inject.Singleton;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.ComponentLike;
+import org.checkerframework.checker.nullness.qual.NonNull;
 import space.arim.api.jsonchat.adventure.util.ComponentText;
 import space.arim.libertybans.api.CompositeVictim;
 import space.arim.libertybans.api.PunishmentType;
@@ -47,6 +48,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 import java.util.function.UnaryOperator;
 import java.util.stream.Stream;
 
@@ -121,34 +123,25 @@ public ReactionStage<Void> execute() {
 				target = command().next();
 
 				if (config().commands().showApplicableForHistory()) {
-					yield argumentParser().parsePlayer(sender(), target).thenCompose((uuidAndAddress) -> {
-						if (uuidAndAddress == null) {
-							return completedFuture(null);
-						}
-						return parsePageThenExecute(
-								selector.selectionByApplicabilityBuilder(
-										uuidAndAddress.uuid(), uuidAndAddress.address()
-								).selectAll()
-						);
-					});
-				}
-				SelectionOrderBuilder selectionOrderBuilder = selector.selectionBuilder();
-				if (listType == ListType.HISTORY) {
-					selectionOrderBuilder.selectAll();
+					yield historyOrWarns(
+							argumentParser().parsePlayer(sender(), target),
+							(uuidAndAddress) -> selector.selectionByApplicabilityBuilder(
+									uuidAndAddress.uuid(), uuidAndAddress.address()
+							)
+					);
 				} else {
-					selectionOrderBuilder.type(PunishmentType.WARN);
+					yield historyOrWarns(
+							argumentParser().parseVictim(
+									sender(), target, ParseVictim.ofPreferredType(Victim.VictimType.PLAYER)
+							),
+							(victim) -> {
+								// Select punishments made against this user OR against the composite user
+								CompositeVictim compositeWildcard = new AsCompositeWildcard().apply(victim);
+								SelectionPredicate<Victim> victimSelection = matchingAnyOf(victim, compositeWildcard);
+								return selector.selectionBuilder().victims(victimSelection);
+							}
+					);
 				}
-				yield argumentParser().parseVictim(
-						sender(), target, ParseVictim.ofPreferredType(Victim.VictimType.PLAYER)
-				).thenCompose((victim) -> {
-					if (victim == null) {
-						return completedFuture(null);
-					}
-					// Select punishments made against this user OR against the composite user
-					CompositeVictim compositeWildcard = new AsCompositeWildcard().apply(victim);
-					SelectionPredicate<Victim> victimSelection = matchingAnyOf(victim, compositeWildcard);
-					return parsePageThenExecute(selectionOrderBuilder.victims(victimSelection));
-				});
 			}
 			case BLAME -> {
 				if (!command().hasNext()) {
@@ -171,6 +164,23 @@ yield argumentParser().parseOperator(
 			};
 		}
 
+		private <V> ReactionStage<Void> historyOrWarns(CentralisedFuture<V> parseVictim,
+													   Function<@NonNull V, SelectionBuilderBase<?, ?>> createSelection) {
+			return parseVictim.thenCompose((victim) -> {
+				if (victim == null) {
+					return completedFuture(null);
+				}
+				SelectionBuilderBase<?, ?> selectionBuilder = createSelection.apply(victim);
+				if (listType == ListType.HISTORY) {
+					selectionBuilder.selectAll();
+				} else {
+					assert listType == ListType.WARNS;
+					selectionBuilder.type(PunishmentType.WARN);
+				}
+				return parsePageThenExecute(selectionBuilder);
+			});
+		}
+
 		private ReactionStage<Void> parsePageThenExecute(SelectionBuilderBase<?, ?> selectionBuilder) {
 			int selectedPage = parsePage();
 			if (selectedPage <= 0) {

bans-core/src/main/java/space/arim/libertybans/core/config/MainConfig.java

@@ -138,8 +138,8 @@ interface Commands {
 
 		@ConfKey("show-applicable-for-history")
 		@ConfComments({
-				"By default, /history shows all active punishments for the player requested.",
-				"Enabling this option will make /history scan all punishments which would apply to the player",
+				"By default, /history and /warns show punishments specifically for the player requested.",
+				"Enabling this option will make /history and /warn scan punishments which would apply to the player",
 				"",
 				"For example, an IP ban may apply to a player, but it will not be in the player's /history unless this is enabled"
 		})

bans-core/src/main/java/space/arim/libertybans/core/database/JdbcDriver.java

@@ -1,6 +1,6 @@
 /*
  * LibertyBans
- * Copyright © 2021 Anand Beh
+ * Copyright © 2023 Anand Beh
  *
  * LibertyBans is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -24,40 +24,47 @@
 import java.util.Map;
 
 public enum JdbcDriver {
-	HSQLDB("org.hsqldb.jdbc.JDBCDriver", "org.hsqldb.jdbc.JDBCDataSource", ';', ';'),
-	MARIADB_CONNECTOR("org.mariadb.jdbc.Driver", "org.mariadb.jdbc.MariaDbDataSource", '?', '&'),
-	PG_JDBC("org.postgresql.Driver", "org.postgresql.ds.PGSimpleDataSource", '?', '&'),
+	H2("org.h2.Driver", "org.h2.jdbcx.JdbcDataSource", "h2", ';', ';'),
+	HSQLDB("org.hsqldb.jdbc.JDBCDriver", "org.hsqldb.jdbc.JDBCDataSource", "hsqldb", ';', ';'),
+	MARIADB_CONNECTOR("org.mariadb.jdbc.Driver", "org.mariadb.jdbc.MariaDbDataSource", "mariadb", '?', '&'),
+	PG_JDBC("org.postgresql.Driver", "org.postgresql.ds.PGSimpleDataSource", "postgresql", '?', '&'),
 	;
 
 	private final String driverClassName;
 	private final String dataSourceClassName;
 
+	private final String urlPrefix;
 	private final char urlPropertyPrefix;
 	private final char urlPropertySeparator;
 
-	private JdbcDriver(String driverClassName, String dataSourceClassName,
-					   char urlPropertyPrefix, char urlPropertySeparator) {
+	JdbcDriver(String driverClassName, String dataSourceClassName,
+			   String urlPrefix, char urlPropertyPrefix, char urlPropertySeparator) {
+		this.urlPrefix = urlPrefix;
 		this.driverClassName = driverClassName;
 		this.dataSourceClassName = dataSourceClassName;
 
 		this.urlPropertyPrefix = urlPropertyPrefix;
 		this.urlPropertySeparator = urlPropertySeparator;
 	}
 
-	public String driverClassName() {
+	String driverClassName() {
 		return driverClassName;
 	}
 
-	String dataSourceClassName() {
+	public String dataSourceClassName() {
 		return dataSourceClassName;
 	}
 
+	public boolean ownsUrl(String jdbcUrl) {
+		return jdbcUrl.startsWith("jdbc:" + urlPrefix);
+	}
+
 	String formatConnectionProperties(Map<String, Object> properties) {
 		if (properties.isEmpty()) {
 			return "";
 		}
 		List<String> connectProps = new ArrayList<>(properties.size());
-		properties.forEach((key, value) -> connectProps.add(key + "=" + value));
+		properties.forEach((key, value) -> connectProps.add(key + '=' + value));
 
 		return urlPropertyPrefix + String.join(Character.toString(urlPropertySeparator), connectProps);
 	}

bans-core/src/main/java/space/arim/libertybans/core/importing/JdbcDetails.java

@@ -1,6 +1,6 @@
 /*
  * LibertyBans
- * Copyright © 2020 Anand Beh
+ * Copyright © 2023 Anand Beh
  *
  * LibertyBans is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -21,6 +21,7 @@
 
 import space.arim.libertybans.core.database.JdbcDriver;
 
+import javax.sql.DataSource;
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.SQLException;
@@ -40,25 +41,35 @@ public JdbcDetails(String jdbcUrl, String username, String password) {
 
 	@Override
 	public Connection openConnection() throws SQLException {
-		// Workaround DriverManager not supporting drivers not loaded through system ClassLoader
-		if (jdbcUrl.startsWith("jdbc:hsqldb")) {
-			initDriver(JdbcDriver.HSQLDB);
-		}
-		if (jdbcUrl.startsWith("jdbc:mariadb")) {
-			initDriver(JdbcDriver.MARIADB_CONNECTOR);
-		}
-		if (jdbcUrl.startsWith("jdbc:postgresql")) {
-			initDriver(JdbcDriver.PG_JDBC);
+		// Connect manually if possible, for two reasons
+		// 1. Workaround DriverManager not supporting drivers not loaded through system ClassLoader
+		// 2. Avoid polluting the driver registry if we don't have to. Helps the ecosystem
+		for (JdbcDriver driver : JdbcDriver.values()) {
+			if (driver.ownsUrl(jdbcUrl)) {
+				try {
+					return manualConnect(driver);
+				} catch (ReflectiveOperationException ex) {
+					throw new ImportException("Failed to initialize JDBC data source for " + driver, ex);
+				}
+			}
 		}
+		// Scan the global driver registry. This is potentially susceptible to classloading chaos,
+		// however, this url was requested for importing purposes, so we must serve the request
 		return DriverManager.getConnection(jdbcUrl, username, password);
 	}
 
-	private void initDriver(JdbcDriver driver) {
-		try {
-			Class.forName(driver.driverClassName());
-		} catch (ClassNotFoundException ex) {
-			throw new ImportException("Failed to initialize JDBC driver " + driver, ex);
-		}
+	private Connection manualConnect(JdbcDriver driver) throws SQLException, ReflectiveOperationException {
+		// Instantiate data source
+		DataSource dataSource = Class.forName(driver.dataSourceClassName())
+				.asSubclass(DataSource.class)
+				.getDeclaredConstructor()
+				.newInstance();
+		// Set url. All implementations have this method
+		dataSource.getClass()
+				.getMethod("setUrl", String.class)
+				.invoke(dataSource, jdbcUrl);
+		// Retrieve connection
+		return dataSource.getConnection(username, password);
 	}
 
 	@Override