package main

import (
	"crypto/sha256"
	"fmt"
	"io"
	"os"
)

type fileSha struct {
	bytes []byte
	size  int64
}

func sha256File(path string) fileSha {
	h := sha256.New()
	f, err := os.Open(path)
	if err != nil {
		panic(err)
	}
	defer f.Close()
	fi, err := f.Stat()
	if err != nil {
		panic(err)
	}
	io.Copy(h, f)
	return fileSha{
		bytes: h.Sum(nil),
		size:  fi.Size(),
	}
}

func (f fileSha) String() string {
	return fmt.Sprintf("sha256:%x", f.bytes)
}

func (f fileSha) Name() string {
	return fmt.Sprintf("%x", f.bytes)
}

func (f fileSha) Size() int64 {
	return f.size
}