/*
   Copyright 2014 CoreOS, Inc.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package types

import (
	"strconv"
)

// ID represents a generic identifier which is canonically
// stored as a uint64 but is typically represented as a
// base-16 string for input/output
type ID uint64

func (i ID) String() string {
	return strconv.FormatUint(uint64(i), 16)
}

// IDFromString attempts to create an ID from a base-16 string.
func IDFromString(s string) (ID, error) {
	i, err := strconv.ParseUint(s, 16, 64)
	return ID(i), err
}

// IDSlice implements the sort interface
type IDSlice []ID

func (p IDSlice) Len() int           { return len(p) }
func (p IDSlice) Less(i, j int) bool { return uint64(p[i]) < uint64(p[j]) }
func (p IDSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }