1 files changed, 138 insertions, 0 deletions
diff --git a/src/main/kotlin/util/mc/SNbtFormatter.kt b/src/main/kotlin/util/mc/SNbtFormatter.kt
new file mode 100644
index 0000000..e773927
--- /dev/null
+++ b/src/main/kotlin/util/mc/SNbtFormatter.kt
@@ -0,0 +1,138 @@
+package moe.nea.firmament.util.mc
+
+import net.minecraft.nbt.NbtByte
+import net.minecraft.nbt.NbtByteArray
+import net.minecraft.nbt.NbtCompound
+import net.minecraft.nbt.NbtDouble
+import net.minecraft.nbt.NbtElement
+import net.minecraft.nbt.NbtEnd
+import net.minecraft.nbt.NbtFloat
+import net.minecraft.nbt.NbtInt
+import net.minecraft.nbt.NbtIntArray
+import net.minecraft.nbt.NbtList
+import net.minecraft.nbt.NbtLong
+import net.minecraft.nbt.NbtLongArray
+import net.minecraft.nbt.NbtShort
+import net.minecraft.nbt.NbtString
+import net.minecraft.nbt.visitor.NbtElementVisitor
+
+class SNbtFormatter private constructor() : NbtElementVisitor {
+	private val result = StringBuilder()
+	private var indent = 0
+	private fun writeIndent() {
+		result.append("\t".repeat(indent))
+	}
+
+	private fun pushIndent() {
+		indent++
+	}
+
+	private fun popIndent() {
+		indent--
+	}
+
+	fun apply(element: NbtElement): StringBuilder {
+		element.accept(this)
+		return result
+	}
+
+
+	override fun visitString(element: NbtString) {
+		result.append(NbtString.escape(element.asString()))
+	}
+
+	override fun visitByte(element: NbtByte) {
+		result.append(element.numberValue()).append("b")
+	}
+
+	override fun visitShort(element: NbtShort) {
+		result.append(element.shortValue()).append("s")
+	}
+
+	override fun visitInt(element: NbtInt) {
+		result.append(element.intValue())
+	}
+
+	override fun visitLong(element: NbtLong) {
+		result.append(element.longValue()).append("L")
+	}
+
+	override fun visitFloat(element: NbtFloat) {
+		result.append(element.floatValue()).append("f")
+	}
+
+	override fun visitDouble(element: NbtDouble) {
+		result.append(element.doubleValue()).append("d")
+	}
+
+	private fun visitArrayContents(array: List<NbtElement>) {
+		array.forEachIndexed { index, element ->
+			writeIndent()
+			element.accept(this)
+			if (array.size != index + 1) {
+				result.append(",")
+			}
+			result.append("\n")
+		}
+	}
+
+	private fun writeArray(arrayTypeTag: String, array: List<NbtElement>) {
+		result.append("[").append(arrayTypeTag).append("\n")
+		pushIndent()
+		visitArrayContents(array)
+		popIndent()
+		writeIndent()
+		result.append("]")
+
+	}
+
+	override fun visitByteArray(element: NbtByteArray) {
+		writeArray("B;", element)
+	}
+
+	override fun visitIntArray(element: NbtIntArray) {
+		writeArray("I;", element)
+	}
+
+	override fun visitLongArray(element: NbtLongArray) {
+		writeArray("L;", element)
+	}
+
+	override fun visitList(element: NbtList) {
+		writeArray("", element)
+	}
+
+	override fun visitCompound(compound: NbtCompound) {
+		result.append("{\n")
+		pushIndent()
+		val keys = compound.keys.sorted()
+		keys.forEachIndexed { index, key ->
+			writeIndent()
+			val element = compound[key] ?: error("Key '$key' found but not present in compound: $compound")
+			val escapedName = if (key.matches(SIMPLE_NAME)) key else NbtString.escape(key)
+			result.append(escapedName).append(": ")
+			element.accept(this)
+			if (keys.size != index + 1) {
+				result.append(",")
+			}
+			result.append("\n")
+		}
+		popIndent()
+		writeIndent()
+		result.append("}")
+	}
+
+	override fun visitEnd(element: NbtEnd) {
+		result.append("END")
+	}
+
+	companion object {
+		fun prettify(nbt: NbtElement): String {
+			return SNbtFormatter().apply(nbt).toString()
+		}
+
+		fun NbtElement.toPrettyString() = prettify(this)
+
+		private val SIMPLE_NAME = "[A-Za-z0-9._+-]+".toRegex()
+	}
+}