From 2112a604f1002f9150debafca214a0bf26ede92a Mon Sep 17 00:00:00 2001
From: Tnze <cjd001113@outlook.com>
Date: Mon, 5 Jul 2021 01:28:07 +0800
Subject: [PATCH] nbt.StringifiedNBT as nbt.NBTEncoder

---
 nbt/snbt.go             | 58 +++++++++++++++++++++++++++++++++++++----
 nbt/snbt_decode_test.go | 19 ++++++++++++++
 2 files changed, 72 insertions(+), 5 deletions(-)

diff --git a/nbt/snbt.go b/nbt/snbt.go
index 7f40fe2..5ce6871 100644
--- a/nbt/snbt.go
+++ b/nbt/snbt.go
@@ -1,10 +1,58 @@
 package nbt
 
-type StringifiedNBT struct {
-	Name    string
-	Content string
+import "io"
+
+type StringifiedNBT string
+
+func (n StringifiedNBT) TagType() (tagType byte) {
+	d := decodeState{data: []byte(n)}
+	d.scan.reset()
+	d.scanWhile(scanSkipSpace)
+	switch d.opcode {
+	case scanBeginLiteral:
+		start := d.readIndex()
+		if d.scanWhile(scanContinue); d.opcode == scanError {
+			return
+		}
+		literal := d.data[start:d.readIndex()]
+		tagType, _ = parseLiteral(literal)
+
+	case scanBeginCompound:
+		tagType = TagCompound
+
+	case scanBeginList:
+		d.scanWhile(scanSkipSpace)
+		if d.opcode == scanBeginLiteral {
+			start := d.readIndex()
+			if d.scanWhile(scanContinue); d.opcode == scanError {
+				return
+			}
+			literal := d.data[start:d.readIndex()]
+			if d.opcode == scanSkipSpace {
+				d.scanWhile(scanSkipSpace)
+			}
+			if d.opcode == scanListType {
+				switch literal[0] {
+				case 'B':
+					tagType = TagByteArray
+				case 'I':
+					tagType = TagIntArray
+				case 'L':
+					tagType = TagLongArray
+				}
+			}
+		} else {
+			tagType = TagList
+		}
+	}
+	return
 }
 
-func (n *StringifiedNBT) Decode(tagType byte, tagName string, r DecoderReader) error {
-	panic("unimplemented")
+func (n StringifiedNBT) Encode(w io.Writer) error {
+	d := decodeState{data: []byte(n)}
+	d.scan.reset()
+	return writeValue(NewEncoder(w), &d, "")
 }
+
+//func (n *StringifiedNBT) Decode(tagType byte, r DecoderReader) error {
+//}
diff --git a/nbt/snbt_decode_test.go b/nbt/snbt_decode_test.go
index a683d18..74af6e4 100644
--- a/nbt/snbt_decode_test.go
+++ b/nbt/snbt_decode_test.go
@@ -109,3 +109,22 @@ func Test_WriteSNBT_nestingList(t *testing.T) {
 		t.Error("Exceeded the maximum depth of support, but no error was reported")
 	}
 }
+
+func TestStringifiedNBT_TagType(t *testing.T) {
+	for _, v := range []struct {
+		snbt string
+		Type byte
+	}{
+		{`123B`, TagByte},
+		{`123`, TagInt},
+		{`[]`, TagList},
+		{`[B;]`, TagByteArray},
+		{`[I;]`, TagIntArray},
+		{`[L;]`, TagLongArray},
+		{`{abc:123B}`, TagCompound},
+	} {
+		if T := StringifiedNBT(v.snbt).TagType(); T != v.Type {
+			t.Errorf("Parse SNBT TagType error: %s is %d, not %d", v.snbt, v.Type, T)
+		}
+	}
+}