# Copyright 2021 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import subprocess
import logging
import psutil
import os
import signal


def TerminateProcess(process: subprocess.Popen):
    """Terminates `process` and ensures it's cleaned up before returning.

    Raises:
      RuntimeError: When failed to terminate the process after a timeout.
    """

    logging.debug(f"Terminating PID:{process.pid}")

    try:
        process.terminate()
        process.wait(2.0)
    except (psutil.TimeoutExpired, psutil.AccessDenied, PermissionError) as e:
        logging.info(f"Terminate failed, moving on to kill.")
    except psutil.NoSuchProcess:
        return
    else:
        return

    try:
        process.kill()
        process.wait(2.0)
    except (psutil.TimeoutExpired, psutil.AccessDenied, PermissionError) as e:
        raise RuntimeError(f"Could not clean up PID:{process.pid}.") from e
    else:
        return


def SendSignalToRootProcess(process: subprocess.Popen, signal: signal.Signals):
    os.system(f"sudo kill -{signal.value} {process.pid}")


def TerminateRootProcess(process: subprocess.Popen):
    """Kills elevated `process` and ensures it's cleaned up before returning.

    Raises:
      RuntimeError: When failed to terminate the process after a timeout.
    """

    logging.debug(f"Terminating PID:{process.pid}")

    try:
        SendSignalToRootProcess(process, signal.SIGTERM)
        process.wait(2.0)
    except (psutil.TimeoutExpired, psutil.AccessDenied, PermissionError) as e:
        raise RuntimeError(f"Could not clean up PID:{process.pid}.") from e
    except psutil.NoSuchProcess:
        return
    else:
        return


def FindProcess(process_name: str) -> psutil.Process:
    """Looks for the process associated with |browser|.

    Args:
      process_name: Name of the process to return.

    Returns:
      A psutil.process representation of the process matching `process_name`.

    Raises:
      RuntimeError: When no process is found for the browser.
    """

    processes = filter(
        lambda p: p.name() == process_name, psutil.process_iter()
    )
    returned_process = None
    for process in processes:
        if not returned_process:
            returned_process = process
        else:
            raise RuntimeError(
                "Too many copies of the process running, this is wrong."
            )

    return returned_process


def FindChromiumSrcDir(path: os.PathLike) -> os.PathLike:
    path = os.path.abspath(path)
    while path:
        (head, tail) = os.path.split(path)
        if tail == "src":
            return path
        path = head