import structio
import subprocess
import shlex

# In the interest of compatibility, structio.parallel
# tries to be compatible with the subprocess module. You
# can even pass the constants such as DEVNULL, PIPE, etc.
# to it and it'll work


# TODO: Implement a higher-level multiprocessing module that does not expose the
#  internal Process object directly so that there's no chance of leaving dangling
#  processes running in the background (unless explicitly desired, of course)

async def main(data: str):
    cmd = shlex.split("python -c 'print(input())'")
    to_send = data.encode(errors="ignore")
    # This will print data to stdout
    await structio.parallel.run(cmd, input=to_send)
    # Other option
    out = await structio.parallel.check_output(cmd, input=to_send)
    # Thanks to Linux, Mac OS X and Windows all using different
    # line endings, we have to do this abomination
    out = out.decode().rstrip("\r").rstrip("\r\n").rstrip("\n")
    assert out == data
    # Other, other option :D
    process = structio.parallel.Process(
        cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE
    )
    # Note that the process is spawned only after we run start()!
    await process.start()
    out, _ = await process.communicate(to_send)
    out = out.decode().rstrip("\r").rstrip("\r\n").rstrip("\n")
    assert out == data
    # We can also use process pools to spawn multiple processes
    # at the same time while limiting resource usage
    pool = structio.AsyncProcessPool(4)    # Max. 4 processes at a time
    for i in range(0, (4 * 5) + 1):   # We iterate 21 instead of 20 times: this is important to the test!
        # This will stop every 4 iterations
        await pool.submit(shlex.split(f"""python -c 'print({i}); __import__("time").sleep(1)'"""))
    # Since we're exiting the program right after the last iteration, we need
    # to wait for the pool to complete.
    await pool.close()
    await pool.wait()


structio.run(main, "owo")