#!/usr/bin/env python3
from __future__ import annotations

import os
import pathlib
import platform
import subprocess

import httpx

CURRENT_DIR = pathlib.Path(__file__).parent

def main():
	delta()

def delta():
	if platform.system() == 'Darwin':
		print('$ brew install git-delta')
		subprocess.run(['brew', 'install', 'git-delta'], check=True)
		return

	client = httpx.Client()
	r = client.get('https://api.github.com/repos/dandavison/delta/releases/latest',
			headers={'Accept': 'application/vnd.github+json', 'X-GitHub-Api-Version': '2022-11-28'})
	r.raise_for_status()
	latest = r.json()

	if platform.system() == 'Linux':
		version = latest['name']
		arch = get_output(['dpkg', '--print-architecture'])
		filename = f'git-delta_{version}_{arch}.deb'

	(asset,) = (asset for asset in latest['assets'] if asset['name'] == filename)
	deb_path = CURRENT_DIR / 'git-delta.deb'
	download(client, asset['browser_download_url'], deb_path)

	try:
		subprocess.run(['sudo', 'dpkg', '-i', deb_path], check=True)
	finally:
		os.unlink(deb_path)

def get_output(argv: list[str]) -> str:
	proc = subprocess.run(argv, check=True, capture_output=True, encoding='ascii')
	return proc.stdout.rstrip('\n')

def download(client: httpx.Client, url: str, path: pathlib.Path) -> None:
	print('downloading', url, 'to', path)
	with client.stream('GET', url, follow_redirects=True) as r:
		r.raise_for_status()
		with path.open('wb') as f:
			for chunk in r.iter_bytes():
				f.write(chunk)

if __name__ == '__main__':
	main()