package utio

import (
	"os"
	"path/filepath"
	"regexp"
	"strings"
)

// Files gives back all the files in the specified directory
func Files(root string) ([]string, error) {
	var files []string
	if err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return nil
		}
		if info.IsDir() {
			return nil
		}
		files = append(files, path)
		return nil
	}); err != nil {
		return nil, err
	}
	return files, nil
}

// Files gives back all the files in the specified directory that match the specified glob pattern.
func FilesFilter(dir, glob string) ([]string, error) {
	files, err := Files(dir)
	if err != nil {
		return nil, err
	}
	var filtered []string
	globRE := globToRE(glob)
	for _, f := range files {
		if globRE.MatchString(f) {
			filtered = append(filtered, f)
		}
	}
	return filtered, nil
}

// Home gives back the home directory for the current user.
func Home() (string, error) {
	return os.UserHomeDir()
}

// PathExists tests if the supplied path exists.
func PathExists(path string) bool {
	var _, err = os.Stat(path)
	return err == nil
}

// PathDoesNotExist tests if the supplied does not exist.
func PathDoesNotExist(path string) bool {
	var _, err = os.Stat(path)
	return os.IsNotExist(err)
}

func globToRE(glob string) *regexp.Regexp {
	pattern := glob
	pattern = strings.ReplaceAll(pattern, "\\", "\\\\")
	pattern = strings.ReplaceAll(pattern, ".", "\\.")
	pattern = strings.ReplaceAll(pattern, "*", ".*")
	pattern = strings.ReplaceAll(pattern, "?", ".")
	return regexp.MustCompile(pattern)
}