fix: Fixed reversed offsets for unity files

storage/unity_file.go

@@ -39,6 +39,23 @@ func CreateUnityFile(fileName string) (UnityFile, error) {
 	return u, nil
 }
 
+func OpenUnityFile(fileName, metadataName string) (UnityFile, error) {
+	var u UnityFile
+
+	// Read the file
+	f, err := os.Open(fileName)
+	if err != nil {
+		return u, err
+	}
+	u.fd = f
+
+	if err := u.ReadMetadataFile(metadataName); err != nil {
+		return u, err
+	}
+
+	return u, nil
+}
+
 func (u UnityFile) Size() int {
 	return u.fileSize
 }
@@ -54,7 +71,7 @@ func (u *UnityFile) WriteChunk(data world.ChunkData) error {
 	encodedSize := encoded.Len()
 
 	// Go to the end of the file
-	u.fd.Seek(0, u.fileSize)
+	u.fd.Seek(int64(u.fileSize), io.SeekStart)
 	// Write the encoded contents to the file
 	if _, err := u.fd.Write(encoded.Bytes()); err != nil {
 		return err
@@ -100,7 +117,7 @@ func (u *UnityFile) ReadMetadataFile(fileName string) error {
 func (u UnityFile) ReadChunk(pos world.ChunkPos) (world.ChunkData, error) {
 	m := u.metadata[pos]
 
-	u.fd.Seek(0, m.StartOffset)
+	u.fd.Seek(int64(m.StartOffset), io.SeekStart)
 
 	fileReader := io.LimitReader(u.fd, int64(m.FileSize))
 
@@ -112,6 +129,20 @@ func (u UnityFile) ReadChunk(pos world.ChunkPos) (world.ChunkData, error) {
 	return data, nil
 }
 
+func (u UnityFile) ReadAllChunks() ([]world.ChunkData, error) {
+	chunks := []world.ChunkData{}
+
+	for pos := range u.metadata {
+		chunk, err := u.ReadChunk(pos)
+		if err != nil {
+			return nil, err
+		}
+		chunks = append(chunks, chunk)
+	}
+
+	return chunks, nil
+}
+
 func (u *UnityFile) Close() error {
 	return u.fd.Close()
 }

storage/unity_file_test.go

@@ -1,6 +1,7 @@
 package storage
 
 import (
+	"fmt"
 	"os"
 	"path"
 	"reflect"
@@ -69,6 +70,7 @@ func TestWriteMultipleFiles(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Error creating temporary directory: %v", err)
 	}
+	fmt.Println(tempDir)
 	defer os.RemoveAll(tempDir)
 
 	u, err := CreateUnityFile(path.Join(tempDir, "test-unity"))
@@ -119,3 +121,60 @@ func TestWriteMultipleFiles(t *testing.T) {
 		}
 	}
 }
+
+func TestReadAllChunks(t *testing.T) {
+	tempDir, err := os.MkdirTemp("", "unity")
+	if err != nil {
+		t.Fatalf("Error creating temporary directory: %v", err)
+	}
+	fmt.Println(tempDir)
+	defer os.RemoveAll(tempDir)
+
+	u, err := CreateUnityFile(path.Join(tempDir, "test-unity"))
+	if err != nil {
+		t.Fatalf("Error creating unity file: %v", err)
+	}
+
+	var (
+		chunk1 world.ChunkData
+		chunk2 world.ChunkData
+		chunk3 world.ChunkData
+	)
+	chunk1.Pos = world.ChunkPos{
+		X: 0,
+		Z: 0,
+	}
+	chunk1.Sections[0].BlockStates[0] = 2
+	chunk2.Sections[0].BlockStates[0] = 3
+	chunk2.Pos = world.ChunkPos{
+		X: 1,
+		Z: 0,
+	}
+	chunk3.Sections[0].BlockStates[0] = 4
+	chunk3.Pos = world.ChunkPos{
+		X: 2,
+		Z: 0,
+	}
+
+	chunks := []world.ChunkData{chunk1, chunk2, chunk3}
+
+	// Write all chunks
+	for _, data := range chunks {
+		if err := u.WriteChunk(data); err != nil {
+			t.Fatalf("Error writing chunk: %v", err)
+		}
+	}
+
+	t.Log(chunks)
+
+	readChunks, err := u.ReadAllChunks()
+	if err != nil {
+		t.Fatalf("Error reading chunks: %v", err)
+	}
+
+	for index, chunk := range readChunks {
+		if !reflect.DeepEqual(chunk, chunks[index]) {
+			t.Fatalf("Chunks were not equal")
+		}
+	}
+}