package ls
import(
	"os"
	"fmt"
	"flag"
	"strings"
)

func IsDir(p string) (bool, error) {
	finfo, e := os.Stat(p)
	if e != nil {
		return false, e
	}
	return finfo.IsDir(), e
}

func ReadDir(p string) ([]os.FileInfo, error) {
	f, e := os.Open(p)
	if e != nil {
		return nil, e
	}
	l, e := f.Readdir(-1)
	if e != nil {
			return nil, e
	}
	f.Close()

	return l, nil
}

func Stat(p string) (os.FileInfo, error) {
	f, e := os.Open(p)
	if e != nil {
		return nil, e
	}
	s, e := f.Stat()
	f.Close()
	return s, nil
}

func ls(p string, fold int) error {
	if fold == 0 {
		return nil
	}
	isDir, e := IsDir(p)
	if e != nil {
		return e
	}

	pp := strings.TrimRight(p, "/")
	if isDir {
		l, e := ReadDir(p)

		if e != nil {
			return e
		}
		for _, f := range l {
			s := pp+"/"+f.Name()
			fmt.Println(s)
			ls(s, fold-1)
		}
	} else {
		f, e := Stat(p)	
		if e != nil {
			return e
		}
		fmt.Println(f.Name())
	}
	return nil
}

func Run(args []string) int {
	var(
		foldLvl int
	)
	status := 0
	arg0 := args[0]
	args = args[1:]
	flagSet := flag.NewFlagSet(arg0, flag.ExitOnError)
	flagSet.IntVar(&foldLvl, "r", 1, "List recursively with choosing deepness.")
	flagSet.Usage = func() {
		fmt.Fprintf(os.Stderr, "Usage of %s: %s [files]\n", arg0, arg0)
		flagSet.PrintDefaults()
	}
	flagSet.Parse(args)
	args = flagSet.Args()
	if len(args) == 0 {
		l, e := ReadDir(".")
		if e != nil {
			status = 1
			fmt.Fprintf(os.Stderr, "%s: %s.\n", arg0, e)
		} else {
			for _, f := range l {
				fmt.Println(f.Name())
			}
		}
	} else {
		for _, p := range args {
			e := ls(p, foldLvl)
			if e != nil {
				status = 1
				fmt.Fprintf(os.Stderr, "%s: %s.\n", arg0, e)
			}
			
		}
	}
	return status
}