Add files via upload

skillpackage/io.go

@@ -0,0 +1,200 @@
+package skillpackage
+
+import (
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const (
+	maxPackageFiles = 4000
+	maxPackageDepth = 24
+	maxScriptsDepth = 24
+	defaultMaxRead  = 10 << 20
+)
+
+// SafeRelPath resolves rel inside root (no ..).
+func SafeRelPath(root, rel string) (string, error) {
+	rel = strings.TrimSpace(rel)
+	rel = filepath.ToSlash(rel)
+	rel = strings.TrimPrefix(rel, "/")
+	if rel == "" || rel == "." {
+		return "", fmt.Errorf("empty resource path")
+	}
+	if strings.Contains(rel, "..") {
+		return "", fmt.Errorf("invalid path %q", rel)
+	}
+	abs := filepath.Join(root, filepath.FromSlash(rel))
+	cleanRoot := filepath.Clean(root)
+	cleanAbs := filepath.Clean(abs)
+	relOut, err := filepath.Rel(cleanRoot, cleanAbs)
+	if err != nil || relOut == ".." || strings.HasPrefix(relOut, ".."+string(filepath.Separator)) {
+		return "", fmt.Errorf("path escapes skill directory: %q", rel)
+	}
+	return cleanAbs, nil
+}
+
+// ListPackageFiles lists files under a skill directory.
+func ListPackageFiles(skillsRoot, skillID string) ([]PackageFileInfo, error) {
+	root := SkillDir(skillsRoot, skillID)
+	if _, err := ResolveSKILLPath(root); err != nil {
+		return nil, fmt.Errorf("skill %q: %w", skillID, err)
+	}
+	var out []PackageFileInfo
+	err := filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		rel, e := filepath.Rel(root, path)
+		if e != nil {
+			return e
+		}
+		if rel == "." {
+			return nil
+		}
+		depth := strings.Count(rel, string(os.PathSeparator))
+		if depth > maxPackageDepth {
+			if d.IsDir() {
+				return filepath.SkipDir
+			}
+			return nil
+		}
+		if strings.HasPrefix(d.Name(), ".") {
+			if d.IsDir() {
+				return filepath.SkipDir
+			}
+			return nil
+		}
+		if len(out) >= maxPackageFiles {
+			return fmt.Errorf("skill package exceeds %d files", maxPackageFiles)
+		}
+		fi, err := d.Info()
+		if err != nil {
+			return err
+		}
+		out = append(out, PackageFileInfo{
+			Path:  filepath.ToSlash(rel),
+			Size:  fi.Size(),
+			IsDir: d.IsDir(),
+		})
+		return nil
+	})
+	return out, err
+}
+
+// ReadPackageFile reads a file relative to the skill package.
+func ReadPackageFile(skillsRoot, skillID, relPath string, maxBytes int64) ([]byte, error) {
+	if maxBytes <= 0 {
+		maxBytes = defaultMaxRead
+	}
+	root := SkillDir(skillsRoot, skillID)
+	abs, err := SafeRelPath(root, relPath)
+	if err != nil {
+		return nil, err
+	}
+	fi, err := os.Stat(abs)
+	if err != nil {
+		return nil, err
+	}
+	if fi.IsDir() {
+		return nil, fmt.Errorf("path is a directory")
+	}
+	if fi.Size() > maxBytes {
+		return readFileHead(abs, maxBytes)
+	}
+	return os.ReadFile(abs)
+}
+
+// WritePackageFile writes a file inside the skill package.
+func WritePackageFile(skillsRoot, skillID, relPath string, content []byte) error {
+	root := SkillDir(skillsRoot, skillID)
+	if _, err := ResolveSKILLPath(root); err != nil {
+		return fmt.Errorf("skill %q: %w", skillID, err)
+	}
+	abs, err := SafeRelPath(root, relPath)
+	if err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Dir(abs), 0755); err != nil {
+		return err
+	}
+	return os.WriteFile(abs, content, 0644)
+}
+
+func readFileHead(path string, max int64) ([]byte, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	buf := make([]byte, max)
+	n, err := f.Read(buf)
+	if err != nil && n == 0 {
+		return nil, err
+	}
+	return buf[:n], nil
+}
+
+func listScripts(skillsRoot, skillID string) ([]SkillScriptInfo, error) {
+	root := filepath.Join(SkillDir(skillsRoot, skillID), "scripts")
+	st, err := os.Stat(root)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, nil
+		}
+		return nil, err
+	}
+	if !st.IsDir() {
+		return nil, nil
+	}
+	var out []SkillScriptInfo
+	err = filepath.WalkDir(root, func(path string, d os.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		rel, e := filepath.Rel(root, path)
+		if e != nil {
+			return e
+		}
+		if rel == "." {
+			return nil
+		}
+		if d.IsDir() {
+			if strings.HasPrefix(d.Name(), ".") {
+				return filepath.SkipDir
+			}
+			if strings.Count(rel, string(os.PathSeparator)) >= maxScriptsDepth {
+				return filepath.SkipDir
+			}
+			return nil
+		}
+		if strings.HasPrefix(d.Name(), ".") {
+			return nil
+		}
+		relSkill := filepath.Join("scripts", rel)
+		full := filepath.Join(root, rel)
+		fi, err := os.Stat(full)
+		if err != nil || fi.IsDir() {
+			return nil
+		}
+		out = append(out, SkillScriptInfo{
+			Name:    filepath.Base(rel),
+			RelPath: filepath.ToSlash(relSkill),
+			Size:    fi.Size(),
+		})
+		return nil
+	})
+	return out, err
+}
+
+func countNonDirFiles(files []PackageFileInfo) int {
+	n := 0
+	for _, f := range files {
+		if !f.IsDir && f.Path != "SKILL.md" {
+			n++
+		}
+	}
+	return n
+}