// Copyright (C) 2019 Marius Schellenberger

package main

import (
	"flag"
	"fmt"
	"git.giftfish.de/ston1th/gocrypt/pkg/crypto"
	"git.giftfish.de/ston1th/godrop/v2"
	"io"
	"io/ioutil"
	"os"
)

var (
	encMode bool
	decMode bool
	input   string
	output  string
)

func fatal(err error) {
	if err != nil {
		fatals(err.Error())
	}
}

func fatals(s string) {
	stderr("error: " + s + "\n")
	os.Exit(1)
}

func stderr(s string) {
	fmt.Fprintf(os.Stderr, s)
}

func init() {
	fatal(godrop.PledgePromises("stdio rpath wpath cpath tty unveil"))
	fatal(godrop.Unveil("/", ""))
	flag.BoolVar(&encMode, "enc", false, "encryption mode - password is read from stdin")
	flag.BoolVar(&decMode, "dec", false, "decryption mode - password is read from stdin")
	flag.StringVar(&input, "f", "", "input file")
	flag.StringVar(&output, "o", "-", "output file (default stdout)")
	flag.Parse()
}

func main() {
	var (
		in  []byte
		out io.WriteCloser
		err error
	)
	if input == "" {
		fatals("input file is empty")
	} else {
		fatal(godrop.Unveil(input, "r"))
		in, err = ioutil.ReadFile(input)
		fatal(err)
	}
	if output == "" {
		fatals("output file is empty")
	} else if output == "-" {
		out = os.Stdout
	} else {
		fatal(godrop.Unveil(output, "wc"))
		out, err = os.OpenFile(output, os.O_WRONLY|os.O_CREATE, 0640)
		fatal(err)
	}
	fatal(godrop.PledgePromises("stdio tty"))
	stderr("Enter password: ")
	pass, err := crypto.Password()
	stderr("\n")
	fatal(err)
	fatal(godrop.PledgePromises("stdio"))
	switch {
	case encMode == true:
		err = crypto.Encrypt(pass, in, out)
		fatal(err)
	case decMode == true:
		err = crypto.Decrypt(pass, in, out)
		fatal(err)
	}
	fatal(out.Close())
}