feat: application registration

1 files changed, 27 insertions, 6 deletions

diff --git a/src/main/java/moe/nea/prickly/config/ConfigCompat.java b/src/main/java/moe/nea/prickly/config/ConfigCompat.java
index d574759..6c94947 100644
--- a/src/main/java/moe/nea/prickly/config/ConfigCompat.java
+++ b/src/main/java/moe/nea/prickly/config/ConfigCompat.java
@@ -5,8 +5,8 @@ import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.util.Map;
-import java.util.Properties;
+import java.util.*;
+import java.util.stream.Collectors;
 import lombok.extern.slf4j.Slf4j;
 import org.jspecify.annotations.Nullable;
 
@@ -30,11 +30,32 @@ public class ConfigCompat {
 		return (Map) properties;
 	}
 
-	public static Map<String, String> DOTENV_FALLBACK = loadDotenv();
+	public static Map<String, String> DOTENV_FALLBACK = Collections.unmodifiableMap(loadDotenv());
+	public static NavigableMap<String, String> ENV;
+
+	static {
+		var env = new TreeMap<String, String>();
+		env.putAll(DOTENV_FALLBACK);
+		env.putAll(System.getenv());
+		ENV = Collections.unmodifiableNavigableMap(env);
+	}
 
 	public static @Nullable String getEnv(String key) {
-		var value = System.getenv(key);
-		if (value != null) return value;
-		return DOTENV_FALLBACK.get(key);
+		return ENV.get(key);
+	}
+
+	public static Map<String, String> getAllEnvStartingWith(String prefix) {
+		return ENV.subMap(prefix + "_", prefix + (char) ((int) '_' + 1));
+	}
+
+	public static Set<String> getAllDirectChildren(String prefix) {
+		int start = prefix.length() + 1;
+		return getAllEnvStartingWith(prefix).keySet().stream()
+				.map(it -> {
+					int nextUnderscore = it.indexOf('_', start);
+					if (nextUnderscore < 0) return it.substring(start);
+					else return it.substring(start, nextUnderscore);
+				})
+				.collect(Collectors.toSet());
 	}
 }