1 files changed, 39 insertions, 0 deletions
diff --git a/src/main/kotlin/moe/nea/ledger/UUIDUtil.kt b/src/main/kotlin/moe/nea/ledger/UUIDUtil.kt
new file mode 100644
index 0000000..ddfb8c2
--- /dev/null
+++ b/src/main/kotlin/moe/nea/ledger/UUIDUtil.kt
@@ -0,0 +1,39 @@
+package moe.nea.ledger
+
+import com.mojang.util.UUIDTypeAdapter
+import io.azam.ulidj.ULID
+import net.minecraft.client.Minecraft
+import java.time.Instant
+import java.util.UUID
+import kotlin.random.Random
+
+object UUIDUtil {
+	@JvmInline
+	value class ULIDWrapper(
+		val wrapped: String
+	) {
+		init {
+			require(ULID.isValid(wrapped))
+		}
+	}
+
+	fun parseDashlessUuid(string: String) = UUIDTypeAdapter.fromString(string)
+	val NIL_UUID = UUID(0L, 0L)
+	fun getPlayerUUID(): UUID {
+		val currentUUID = Minecraft.getMinecraft().thePlayer?.uniqueID
+			?: Minecraft.getMinecraft().session?.playerID?.let(::parseDashlessUuid)
+			?: lastKnownUUID
+		lastKnownUUID = currentUUID
+		return currentUUID
+	}
+
+	fun createULIDAt(timestamp: Instant): ULIDWrapper {
+		return ULIDWrapper(ULID.generate(
+			timestamp.toEpochMilli(),
+			Random.nextBytes(10)
+		))
+	}
+
+	private var lastKnownUUID: UUID = NIL_UUID
+
+}
+\ No newline at end of file