From e5231dfdb6c7e972ebb9f0799e4f9edcc7f3811b Mon Sep 17 00:00:00 2001
From: adman <adman.else@gmail.com>
Date: Mon, 4 May 2026 00:27:00 +0200
Subject: [PATCH] improve chunk palette handling and logging; fix biome format
 and storage comparison logic

---
 level/anvil/chunk.go      |  2 +-
 level/anvil/level_test.go | 25 +++++++++++++++++++++++++
 level/section.go          | 15 +++++++++++++--
 level/storage.go          |  4 ++--
 4 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/level/anvil/chunk.go b/level/anvil/chunk.go
index 6c171a3..d958fbe 100644
--- a/level/anvil/chunk.go
+++ b/level/anvil/chunk.go
@@ -50,7 +50,7 @@ func (c Chunk) ToStorage(version string) (toChunk *level.Chunk, err error) {
 			toChunk.Sections[i].BlockCount = int16(f.Len)
 		}
 	}
-
+	f = level.MakeBiomeFormat(version)
 	for i, s := range c.Sections {
 		pallete := make([]int32, len(s.Biomes.Palette))
 		for j, p := range s.Biomes.Palette {
diff --git a/level/anvil/level_test.go b/level/anvil/level_test.go
index dbed822..08244d0 100644
--- a/level/anvil/level_test.go
+++ b/level/anvil/level_test.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"log/slog"
 	"os"
 	"testing"
 
@@ -48,7 +49,14 @@ func TestRegionFile(t *testing.T) {
 	fmt.Println("Chunk loaded successfully")
 }
 
+func loadPacketToChunk(b []byte) (chunk *level.Chunk, err error) {
+	buffer := bytes.NewBuffer(b)
+	chunk, err = level.ReadChunkFromChunkPacketData(buffer, "1.21.11", 384)
+	return
+}
+
 func TestConverToPacket(t *testing.T) {
+	slog.SetLogLoggerLevel(slog.LevelDebug)
 	f, err := os.Open("./testdata/r.0.0.mca")
 	if err != nil {
 		t.Errorf("Failed to open file: %v", err)
@@ -90,4 +98,21 @@ func TestConverToPacket(t *testing.T) {
 		t.Errorf("Chunk data is different: %v", cmp.Diff(a, b))
 	}
 
+	aChunk, err := loadPacketToChunk(a)
+	if err != nil {
+		t.Errorf("Failed to load chunk from packet: %v", err)
+		return
+	}
+
+	bChunk, err := loadPacketToChunk(b)
+	if err != nil {
+		t.Errorf("Failed to load chunk from file: %v", err)
+		return
+	}
+	if !aChunk.Equals(packetChunk) {
+		t.Errorf("Chunk is different: %v", cmp.Diff(aChunk, packetChunk))
+	}
+	if !bChunk.Equals(aChunk) {
+		t.Errorf("Chunk is different: %v", cmp.Diff(bChunk, aChunk))
+	}
 }
diff --git a/level/section.go b/level/section.go
index d4a12aa..097a66c 100644
--- a/level/section.go
+++ b/level/section.go
@@ -4,6 +4,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"io"
+	"log/slog"
 	"math"
 
 	"github.com/admin-else/strom/data"
@@ -43,7 +44,7 @@ func MakeBlockFormat(version string) StorageFormat {
 	return StorageFormat{
 		AvailableBpes: []uint8{0, 4, 5, 6, 7, 8, directBpe},
 		BiggestDirect: true,
-		Len:           BiomesPerChunkSection,
+		Len:           BlocksPerChunkSection,
 	}
 }
 
@@ -69,7 +70,7 @@ func ReadSectionStorage(r io.Reader, format StorageFormat) (s *Storage, err erro
 		if err != nil {
 			return
 		}
-		if paletteLen <= 0 {
+		if paletteLen < 0 {
 			err = BadPaletteLenErr
 			return
 		}
@@ -79,6 +80,16 @@ func ReadSectionStorage(r io.Reader, format StorageFormat) (s *Storage, err erro
 			if err != nil {
 				return
 			}
+			if slog.Default().Enabled(nil, slog.LevelDebug) {
+				b, _ := data.LookupBlockByStateId("1.21.11", v)
+				if b == nil {
+					slog.Debug("unknown palette block in chunk packet", "id", v)
+				} else {
+					slog.Debug("palette block in chunk packet", "id", v, "name", b.Name)
+				}
+
+			}
+
 			pallette = append(pallette, v)
 		}
 	}
diff --git a/level/storage.go b/level/storage.go
index a522e43..cf05b3f 100644
--- a/level/storage.go
+++ b/level/storage.go
@@ -36,8 +36,8 @@ func (r StorageFormat) Import(data []uint64, bpe uint8, palette []int32) (s *Sto
 	if !slices.Contains(r.AvailableBpes, bpe) {
 		var newBpe uint8
 		for _, newBpe = range r.AvailableBpes {
-			if bpe < newBpe {
-				continue
+			if bpe <= newBpe {
+				break
 			}
 		}
 		var tmps *Storage