Initial DDC release

internal/files/tree.go

@@ -0,0 +1,85 @@
+package files
+
+import (
+	"os"
+	"path"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"ddc/internal/extract"
+)
+
+const (
+	maxTreeEntries = 20000
+	maxTreeDepth   = 32
+)
+
+type Node struct {
+	Name      string `json:"name"`
+	Path      string `json:"path"`
+	IsDir     bool   `json:"isDir"`
+	IsArchive bool   `json:"isArchive"`
+	Size      int64  `json:"size"`
+	Children  []Node `json:"children,omitempty"`
+}
+
+func BuildTree(root string) ([]Node, error) {
+	entryCount := 0
+	return readLevel(root, "", 0, &entryCount)
+}
+
+func readLevel(root, relative string, depth int, entryCount *int) ([]Node, error) {
+	entries, err := os.ReadDir(filepath.Join(root, relative))
+	if err != nil {
+		return nil, err
+	}
+
+	nodes := make([]Node, 0, len(entries))
+	for _, entry := range entries {
+		if *entryCount >= maxTreeEntries {
+			break
+		}
+		entryType := entry.Type()
+		if entry.Name() == PartFileName || (!entryType.IsDir() && !entryType.IsRegular()) {
+			continue
+		}
+		*entryCount++
+
+		node := Node{
+			Name:  entry.Name(),
+			Path:  path.Join(filepath.ToSlash(relative), entry.Name()),
+			IsDir: entry.IsDir(),
+		}
+
+		if node.IsDir {
+			if depth < maxTreeDepth {
+				children, err := readLevel(root, filepath.Join(relative, entry.Name()), depth+1, entryCount)
+				if err != nil {
+					return nil, err
+				}
+				node.Children = children
+				for _, child := range children {
+					node.Size += child.Size
+				}
+			}
+		} else {
+			info, err := entry.Info()
+			if err != nil {
+				continue
+			}
+			node.Size = info.Size()
+			node.IsArchive = extract.IsArchive(entry.Name())
+		}
+
+		nodes = append(nodes, node)
+	}
+
+	sort.SliceStable(nodes, func(first, second int) bool {
+		if nodes[first].IsDir != nodes[second].IsDir {
+			return nodes[first].IsDir
+		}
+		return strings.ToLower(nodes[first].Name) < strings.ToLower(nodes[second].Name)
+	})
+	return nodes, nil
+}