package main

import (
	"encoding/base64"
	"log"
	"net/http"
	"os"
	"strings"
)

func MethodNotAllowed(w http.ResponseWriter, allowedMethods ...string) {
	for _, method := range allowedMethods {
		w.Header().Add("Allow", strings.ToUpper(method))
	}
	w.WriteHeader(http.StatusMethodNotAllowed)
}

func InternalServerError(w http.ResponseWriter, err error) {
	log.Println(err)
	w.WriteHeader(http.StatusInternalServerError)
}

func And[T any](f1, f2 func(T) bool) func(T) bool {
	return func(v T) bool {
		return f1(v) && f2(v)
	}
}

func Or[T any](f1, f2 func(T) bool) func(T) bool {
	return func(v T) bool {
		return f1(v) || f2(v)
	}
}

func Not[T any](f func(T) bool) func(T) bool {
	return func(v T) bool {
		return !f(v)
	}
}

func IsSymlink(entry os.DirEntry) bool {
	return entry.Type()&os.ModeSymlink == os.ModeSymlink
}

func IsRegular(entry os.DirEntry) bool {
	return entry.Type().IsRegular()
}

func IsDir(entry os.DirEntry) bool {
	return entry.IsDir()
}

func IsHidden(entry os.DirEntry) bool {
	return strings.HasPrefix(entry.Name(), ".")
}

func FsEntry2Name(entry os.DirEntry) string {
	return entry.Name()
}

func DecodeBase64String(str string) (string, error) {
	data, err := base64.URLEncoding.DecodeString(str)
	return string(data), err
}

func EncodeBase64String(str string) string {
	return base64.URLEncoding.EncodeToString([]byte(str))
}