#!/usr/bin/env python3
# vim: set noet sw=4 ts=4:

import pathlib
import subprocess
import sys

def main():
	delete = len(sys.argv) == 2 and sys.argv[1] == '-d'

	remotes = all_remotes()

	to_delete = []
	print('will delete:')
	for local, remote in iter_locals():
		if remote not in remotes:
			to_delete.append(local)
			sys.stdout.buffer.write(b'\t' + local)
	print()

	if delete and len(to_delete) > 0:
		if has_branchless():
			run([b'git', b'hide'] + [b'draft()::' + branch for branch in to_delete])
		else:
			run([b'git', b'branch', b'-D'] + to_delete)

def all_remotes():
	refs = run(['git', 'for-each-ref', '--format=%(refname:short)', 'refs/remotes'], capture_output=True)
	return frozenset(refs.stdout.rstrip(b'\n').split(b'\n'))

def iter_locals():
	refs = run(['git', 'for-each-ref', '--format=%(refname:short) %(upstream)', 'refs/heads'],
			capture_output=True)
	for line in refs.stdout.split(b'\n'):
		if not line:
			continue
		local, remote = line.split(b' ', 1)
		if not remote:
			continue
		assert remote.startswith(b'refs/remotes/')
		remote = remote.removeprefix(b'refs/remotes/')
		yield local, remote

def has_branchless() -> bool:
	repo_root = run(['git', 'rev-parse', '--show-toplevel'], capture_output=True, text=True).stdout.rstrip('\n')
	return pathlib.Path(repo_root, '.git/branchless/config').is_file()

def run(cmd, capture_output=False, text=None):
	return subprocess.run(cmd, capture_output=capture_output, check=True, text=text)

if __name__ == '__main__':
	main()