#!/usr/bin/env python3

import argparse
import sys
import subprocess

from contextlib import redirect_stderr, redirect_stdout


def test(script):
    with open('out.log', 'w') as out, open('err.log', 'w') as err:
        with redirect_stdout(out), redirect_stderr(err):
            cmd = [script, '-o']
            # These 2 should be equivalents since stdout=None and
            # stderr=None will make the child process to inherit the
            # fds from the parent (?)
            ret = subprocess.run(cmd) # Doesn't use the redirected stdout/stderr
            ret = subprocess.run(cmd, stdout=None, stderr=None) # Doesn't use the redirected stdout/stderr
            ret = subprocess.run(cmd, stdout=sys.stdout, stderr=sys.stderr)


def nested(script):
    with open('nestedout.log', 'w') as out, open('nestederr.log', 'w') as err:
        cmd = [script]
        ret = subprocess.run(cmd, stdout=out, stderr=err)


def output():
    print("This is stdout")
    print("This is stderr", file=sys.stderr)


def entrypoint():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        '-o', '--output',
        action='store_true',
        help=('Whether to print to stdout and stderr or run the actual test'))
    parser.add_argument(
        '-n', '--nested',
        action='store_true',
        help=('Whether to run this script nested'))

    args = parser.parse_args()

    if args.output:
        output()
    elif args.nested:
        nested(sys.argv[0])
    else:
        test(sys.argv[0])


if __name__ == '__main__':
    entrypoint()