#!/usr/bin/env python3

import subprocess
import tempfile
import argparse
import hashlib
import tarfile
import json
import os

parser = argparse.ArgumentParser()
parser.add_argument("tarfile", type = argparse.FileType("wb"),  help = "tarball to create")
parser.add_argument("firmware", nargs = "+",                    help = "firmware files to stuff into tarball")
args = parser.parse_args()

tar     = tarfile.TarFile.open(fileobj = args.tarfile, mode = "w|gz")
head    = subprocess.check_output(("git", "rev-parse", "HEAD")).strip()
time    = subprocess.check_output(("git", "show", "-s", "--format=%ct", "HEAD")).strip()
commits = dict((path, hash) for hash, path, branch in
               (line.split() for line in subprocess.check_output(("git", "submodule", "status")).splitlines()))
sha256  = {}

for fn in args.firmware:
    with open(fn, "rb") as f:
        sha256[os.path.basename(fn)] = hashlib.sha256(f.read()).hexdigest()
    tar.add(fn, os.path.basename(fn))

with tempfile.NamedTemporaryFile() as f:
    os.fchmod(f.fileno(), 0644)
    use_gpg = os.path.isdir(os.getenv("GNUPGHOME", ""))
    if use_gpg:
        gpg = subprocess.Popen(("gpg", "--clearsign", "--personal-digest-preferences", "SHA256", "--no-permission-warning"),
                               stdin = subprocess.PIPE, stdout = f)
        jf = gpg.stdin
    else:
        jf = f
    json.dump(dict(head = head, time = time, commits = commits, sha256  = sha256), jf, indent = 2)
    if use_gpg:
        gpg.stdin.close()
        if gpg.wait():
            raise subprocess.CalledProcessError(gpg.returncode, "gpg")
    f.seek(0)
    tar.add(f.name, "MANIFEST")

tar.close()
args.tarfile.close()