#!/usr/bin/env python3

from __future__ import print_function

import os

import subprocess

import sys

import threading

import time

# we cannot use mercurial.testing as long as python2 is not dropped as the test will only install the mercurial module for python2 in python2 run

DEBUG_FILE = os.environ.get('SIGPIPE_REMOTE_DEBUG_FILE')

if DEBUG_FILE is None:

    debug_stream = sys.stderr.buffer

else:

    debug_stream = open(DEBUG_FILE, 'bw', buffering=0)

SYNCFILE1 = os.environ.get('SYNCFILE1')

SYNCFILE2 = os.environ.get('SYNCFILE2')

if SYNCFILE1 is None:

    print('SIGPIPE-HELPER: missing variable $SYNCFILE1', file=sys.stderr)

    sys.exit(255)

if SYNCFILE2 is None:

    print('SIGPIPE-HELPER: missing variable $SYNCFILE2', file=sys.stderr)

    sys.exit(255)

def _timeout_factor():

    """return the current modification to timeout"""

    default = int(os.environ.get('HGTEST_TIMEOUT_DEFAULT', 360))

    current = int(os.environ.get('HGTEST_TIMEOUT', default))

    if current == 0:

        return 1

    return current / float(default)

def wait_file(path, timeout=10):

    timeout *= _timeout_factor()

    start = time.time()

    while not os.path.exists(path):

        if (time.time() - start) > timeout:

            raise RuntimeError(b"timed out waiting for file: %s" % path)

        time.sleep(0.01)

def write_file(path, content=b''):

    with open(path, 'wb') as f:

        f.write(content)

# end of mercurial.testing content

if sys.version_info[0] < 3:

    print('SIGPIPE-HELPER: script should run with Python 3', file=sys.stderr)

    sys.exit(255)

def sysbytes(s):

    return s.encode('utf-8')

def sysstr(s):

    return s.decode('latin-1')

piped_stdout = os.pipe2(os.O_NONBLOCK | os.O_CLOEXEC)

piped_stderr = os.pipe2(os.O_NONBLOCK | os.O_CLOEXEC)

stdout_writer = os.fdopen(piped_stdout[1], "rb")

stdout_reader = os.fdopen(piped_stdout[0], "rb")

stderr_writer = os.fdopen(piped_stderr[1], "rb")

stderr_reader = os.fdopen(piped_stderr[0], "rb")

debug_stream.write(b'SIGPIPE-HELPER: Starting\n')

TESTLIB_DIR = os.path.dirname(sys.argv[0])

WAIT_SCRIPT = os.path.join(TESTLIB_DIR, 'wait-on-file')

hooks_cmd = '%s 10 %s %s'

hooks_cmd %= (

    WAIT_SCRIPT,

    SYNCFILE2,

    SYNCFILE1,

)

cmd = ['hg']

cmd += sys.argv[1:]

sub = subprocess.Popen(

    cmd,

    bufsize=0,

    close_fds=True,

    stdin=sys.stdin,

    stdout=stdout_writer,

    stderr=stderr_writer,

)

debug_stream.write(b'SIGPIPE-HELPER: Mercurial started\n')

shut_down = threading.Event()

close_lock = threading.Lock()

def _read(stream):

    try:

        return stream.read()

    except ValueError:

        # read on closed file

        return None

def forward_stdout():

    while not shut_down.is_set():

        c = _read(stdout_reader)

        while c is not None:

            sys.stdout.buffer.write(c)

            c = _read(stdout_reader)

        time.sleep(0.001)

    with close_lock:

        if not stdout_reader.closed:

            stdout_reader.close()

            debug_stream.write(b'SIGPIPE-HELPER: stdout closed\n')

def forward_stderr():

    while not shut_down.is_set():

        c = _read(stderr_reader)

        if c is not None:

            sys.stderr.buffer.write(c)

            c = _read(stderr_reader)

        time.sleep(0.001)

    with close_lock:

        if not stderr_reader.closed:

            stderr_reader.close()

            debug_stream.write(b'SIGPIPE-HELPER: stderr closed\n')

stdout_thread = threading.Thread(target=forward_stdout, daemon=True)

stderr_thread = threading.Thread(target=forward_stderr, daemon=True)

try:

    stdout_thread.start()

    stderr_thread.start()

    debug_stream.write(b'SIGPIPE-HELPER: Redirection in place\n')

    try:

        wait_file(sysbytes(SYNCFILE1))

    except RuntimeError as exc:

        msg = sysbytes(str(exc))

        debug_stream.write(b'SIGPIPE-HELPER: wait failed: %s\n' % msg)

    else:

        debug_stream.write(b'SIGPIPE-HELPER: SYNCFILE1 detected\n')

    with close_lock:

        if not stdout_reader.closed:

            stdout_reader.close()

        if not stderr_reader.closed:

            stderr_reader.close()

        sys.stdin.close()

        debug_stream.write(b'SIGPIPE-HELPER: pipes closed\n')

    debug_stream.write(b'SIGPIPE-HELPER: creating SYNCFILE2\n')

    write_file(sysbytes(SYNCFILE2))

finally:

    debug_stream.write(b'SIGPIPE-HELPER: Shutting down\n')

    shut_down.set()

    if not sys.stdin.closed:

        sys.stdin.close()

    try:

        sub.wait(timeout=30)

    except subprocess.TimeoutExpired:

        msg = b'SIGPIPE-HELPER: Server process failed to terminate\n'

        debug_stream.write(msg)

    else:

        debug_stream.write(b'SIGPIPE-HELPER: Server process terminated\n')

    debug_stream.write(b'SIGPIPE-HELPER: Shut down\n')