package library

import (
	"path"
	"strings"
	"unicode/utf8"

	"pipu/api/internal/platform/apperr"
)

// normalizeExcludedDirs accepts literal paths relative to the storage root, not globs.
func normalizeExcludedDirs(dirs []string) ([]string, error) {
	invalid := func() ([]string, error) {
		return nil, apperr.Validation("excluded_dirs", "validation.excluded_dirs_invalid", "use up to 100 relative folder paths without .., one per entry", nil)
	}
	if len(dirs) > 100 {
		return invalid()
	}
	out := []string{}
	seen := map[string]bool{}
	for _, dir := range dirs {
		dir = strings.ReplaceAll(strings.TrimSpace(dir), "\\", "/")
		if dir == "" || strings.HasPrefix(dir, "/") || strings.ContainsAny(dir, "\x00\r\n") || utf8.RuneCountInString(dir) > 1000 || (len(dir) > 1 && dir[1] == ':') {
			return invalid()
		}
		for _, part := range strings.Split(dir, "/") {
			if part == ".." {
				return invalid()
			}
		}
		dir = path.Clean(dir)
		if dir == "." {
			return invalid()
		}
		if !seen[dir] {
			out = append(out, dir)
			seen[dir] = true
		}
	}
	return out, nil
}

func pathExcluded(rel string, dirs []string) bool {
	for _, dir := range dirs {
		if rel == dir || strings.HasPrefix(rel, dir+"/") {
			return true
		}
	}
	return false
}