// Package files finds and displays files on disk
package files

import (
	"cmp"
	"strings"
	"time"
)

const string_format = "%s %s %s %d %t"

type File interface {
	Name() string
	Path() string
	Date() time.Time
	Filesize() int64
	IsDir() bool
	String() string
}

type Files []File

func SortByModified(a, b File) int {
	if a.Date().Before(b.Date()) {
		return 1
	} else if a.Date().After(b.Date()) {
		return -1
	} else {
		return 0
	}
}

func SortByModifiedReverse(a, b File) int {
	if a.Date().After(b.Date()) {
		return 1
	} else if a.Date().Before(b.Date()) {
		return -1
	} else {
		return 0
	}
}

func SortBySize(a, b File) int {
	return cmp.Compare(b.Filesize(), a.Filesize())
}

func SortBySizeReverse(a, b File) int {
	return cmp.Compare(a.Filesize(), b.Filesize())
}

func SortByName(a, b File) int {
	return cmp.Compare(a.Name(), b.Name())
}

func SortByNameReverse(a, b File) int {
	return cmp.Compare(b.Name(), a.Name())
}

func SortByPath(a, b File) int {
	return cmp.Compare(a.Path(), b.Path())
}

func SortByPathReverse(a, b File) int {
	return cmp.Compare(b.Path(), a.Path())
}

func SortByExtension(a, b File) int {
	aext, bext := getExts(a, b)
	return cmp.Compare(aext, bext)
}

func SortByExtensionReverse(a, b File) int {
	aext, bext := getExts(a, b)
	return cmp.Compare(bext, aext)
}

func SortDirectoriesFirst(a, b File) int {
	if !a.IsDir() && b.IsDir() {
		return 1
	} else if a.IsDir() && !b.IsDir() {
		return -1
	} else {
		return 0
	}
}

func SortDirectoriesLast(a, b File) int {
	if a.IsDir() && !b.IsDir() {
		return 1
	} else if !a.IsDir() && b.IsDir() {
		return -1
	} else {
		return 0
	}
}

func getExts(a, b File) (string, string) {
	var aext, bext string
	as := strings.Split(a.Name(), ".")
	bs := strings.Split(b.Name(), ".")
	if len(as) <= 1 {
		aext = ""
	} else {
		aext = as[len(as)-1]
	}
	if len(bs) <= 1 {
		aext = ""
	} else {
		bext = bs[len(bs)-1]
	}
	return aext, bext
}