Auto-detect package by target

main.go

@@ -235,12 +235,33 @@ func addCmd(args []string) error {
 	}
 
 	reader := bufio.NewReader(os.Stdin)
-	pkgName := promptWithDefault(reader, "Package name", defaultPkg)
+	var pkgName string
+
+	matchedPkg, err := findPackageByTarget(repo, defaultTarget)
+	if err != nil {
+		return err
+	}
+	if matchedPkg != "" {
+		ok, err := promptYesNo(fmt.Sprintf("Merge into existing package %q?", matchedPkg), true)
+		if err != nil {
+			return err
+		}
+		if ok {
+			pkgName = matchedPkg
+		}
+	}
+
+	if pkgName == "" {
+		pkgName = promptWithDefault(reader, "Package name", defaultPkg)
 		if pkgName == "" {
 			return errors.New("package name cannot be empty")
 		}
+	}
 
-	targetRootInput := promptWithDefault(reader, "Target path", defaultTarget)
+	targetRootInput := defaultTarget
+	if pkgName != matchedPkg || matchedPkg == "" {
+		targetRootInput = promptWithDefault(reader, "Target path", defaultTarget)
+	}
 	targetRoot, err := filepath.Abs(expandHome(targetRootInput))
 	if err != nil {
 		return err
@@ -749,6 +770,44 @@ func findStaleLinks(filesDir, targetRoot string) ([]string, error) {
 	return stale, nil
 }
 
+func findPackageByTarget(repo, targetRoot string) (string, error) {
+	repoEntries, err := os.ReadDir(repo)
+	if err != nil {
+		return "", err
+	}
+
+	absTarget, err := filepath.Abs(expandHome(targetRoot))
+	if err != nil {
+		return "", err
+	}
+
+	for _, entry := range repoEntries {
+		if !entry.IsDir() || strings.HasPrefix(entry.Name(), ".") {
+			continue
+		}
+
+		pkgDir := filepath.Join(repo, entry.Name())
+		configPath := filepath.Join(pkgDir, configFileName)
+		cfg, err := loadConfig(configPath)
+		if err != nil {
+			continue
+		}
+		target, err := selectTarget(cfg.targets)
+		if err != nil {
+			continue
+		}
+		absPkgTarget, err := filepath.Abs(expandHome(target))
+		if err != nil {
+			continue
+		}
+		if absPkgTarget == absTarget {
+			return entry.Name(), nil
+		}
+	}
+
+	return "", nil
+}
+
 func removeLinks(paths []string, dryRun bool) error {
 	for _, path := range paths {
 		if dryRun {