add nip34/git-natural-api, using the same approach as https://jsr.io/@fiatjaf/git-natural-api.

nip34/gitnaturalapi/tree.go

@@ -0,0 +1,101 @@
+package gitnaturalapi
+
+import "encoding/hex"
+
+type TreeEntry struct {
+	Path  string
+	Mode  string
+	IsDir bool
+	Hash  string
+}
+
+type TreeFile struct {
+	Name    string
+	Hash    string
+	Content []byte
+}
+
+type TreeDirectory struct {
+	Name    string
+	Hash    string
+	Content *Tree
+}
+
+type Tree struct {
+	Directories []TreeDirectory
+	Files       []TreeFile
+}
+
+func LoadTree(obj *ParsedObject, objects map[string]*ParsedObject, depth *int) *Tree {
+	directories := make([]TreeDirectory, 0)
+	files := make([]TreeFile, 0)
+	entries := ParseTree(obj.Data)
+
+	for _, entry := range entries {
+		child := objects[entry.Hash]
+
+		if entry.IsDir {
+			var content *Tree
+			if child != nil && (depth == nil || *depth > 0) {
+				var newDepth *int
+				if depth != nil {
+					d := *depth - 1
+					newDepth = &d
+				}
+				content = LoadTree(child, objects, newDepth)
+			}
+			directories = append(directories, TreeDirectory{
+				Name:    entry.Path,
+				Hash:    entry.Hash,
+				Content: content,
+			})
+		} else {
+			var content []byte
+			if child != nil {
+				content = child.Data
+			}
+			files = append(files, TreeFile{
+				Name:    entry.Path,
+				Hash:    entry.Hash,
+				Content: content,
+			})
+		}
+	}
+
+	return &Tree{Directories: directories, Files: files}
+}
+
+func ParseTree(treeData []byte) []TreeEntry {
+	entries := make([]TreeEntry, 0)
+	offset := 0
+
+	for offset < len(treeData) {
+		modeEnd := offset
+		for treeData[modeEnd] != 0x20 {
+			modeEnd++
+		}
+		mode := string(treeData[offset:modeEnd])
+		offset = modeEnd + 1
+
+		filenameEnd := offset
+		for treeData[filenameEnd] != 0x00 {
+			filenameEnd++
+		}
+		path := string(treeData[offset:filenameEnd])
+		offset = filenameEnd + 1
+
+		hash := hex.EncodeToString(treeData[offset : offset+20])
+		offset += 20
+
+		isDir := mode == "40000" || mode == "040000"
+
+		entries = append(entries, TreeEntry{
+			Mode:  mode,
+			Path:  path,
+			Hash:  hash,
+			IsDir: isDir,
+		})
+	}
+
+	return entries
+}