finished, also added cobra cli

internal/tree/tree.go

@@ -0,0 +1,76 @@
+package tree
+
+import (
+	"sort"
+	"strings"
+
+	"dirmd/internal/walker"
+)
+
+type Node struct {
+	Name     string
+	IsDir    bool
+	Children map[string]*Node
+}
+
+func Build(entries []walker.Entry) *Node {
+	root := &Node{IsDir: true, Children: make(map[string]*Node)}
+
+	for _, e := range entries {
+		parts := strings.Split(e.RelPath, "/")
+		cur := root
+
+		for i, part := range parts {
+			isLeaf := i == len(parts)-1
+			if _, ok := cur.Children[part]; !ok {
+				cur.Children[part] = &Node{Name: part, IsDir: !isLeaf, Children: make(map[string]*Node)}
+			}
+			cur = cur.Children[part]
+		}
+	}
+
+	return root
+}
+
+func Render(root *Node, rootName string) string {
+	var sb strings.Builder
+	sb.WriteString(rootName)
+	sb.WriteString("/\n")
+	renderNode(&sb, root, "")
+	return sb.String()
+}
+
+func renderNode(sb *strings.Builder, node *Node, prefix string) {
+	keys := make([]string, 0, len(node.Children))
+	for k := range node.Children {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	for i, key := range keys {
+		child := node.Children[key]
+		isLast := i == len(keys)-1
+
+		if isLast {
+			sb.WriteString(prefix + "└── ")
+		} else {
+			sb.WriteString(prefix + "├── ")
+		}
+
+		sb.WriteString(child.Name)
+		if child.IsDir {
+			sb.WriteString("/")
+		}
+		sb.WriteString("\n")
+
+		if child.IsDir {
+			newPrefix := prefix
+			if isLast {
+				newPrefix += "    "
+			} else {
+				newPrefix += "│   "
+			}
+			renderNode(sb, child, newPrefix)
+		}
+	}
+}