# procutil.py - utility for managing processes and executable environment

#

#  Copyright 2005 K. Thananchayan <thananck@yahoo.com>

#  Copyright 2005-2007 Matt Mackall <mpm@selenic.com>

#  Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import contextlib

import imp

import io

import os

import signal

import subprocess

import sys

import time

from ..i18n import _

from .. import (

    encoding,

    error,

    policy,

    pycompat,

)

osutil = policy.importmod(r'osutil')

stderr = pycompat.stderr

stdin = pycompat.stdin

stdout = pycompat.stdout

def isatty(fp):

    try:

        return fp.isatty()

    except AttributeError:

        return False

# glibc determines buffering on first write to stdout - if we replace a TTY

# destined stdout with a pipe destined stdout (e.g. pager), we want line

# buffering (or unbuffered, on Windows)

if isatty(stdout):

    if pycompat.iswindows:

        # Windows doesn't support line buffering

        stdout = os.fdopen(stdout.fileno(), r'wb', 0)

    else:

        stdout = os.fdopen(stdout.fileno(), r'wb', 1)

if pycompat.iswindows:

    from .. import windows as platform

    stdout = platform.winstdout(stdout)

else:

    from .. import posix as platform

findexe = platform.findexe

_gethgcmd = platform.gethgcmd

getuser = platform.getuser

getpid = os.getpid

hidewindow = platform.hidewindow

quotecommand = platform.quotecommand

readpipe = platform.readpipe

setbinary = platform.setbinary

setsignalhandler = platform.setsignalhandler

shellquote = platform.shellquote

shellsplit = platform.shellsplit

spawndetached = platform.spawndetached

sshargs = platform.sshargs

testpid = platform.testpid

try:

    setprocname = osutil.setprocname

except AttributeError:

    pass

try:

    unblocksignal = osutil.unblocksignal

except AttributeError:

    pass

closefds = pycompat.isposix

def explainexit(code):

    """return a message describing a subprocess status

    (codes from kill are negative - not os.system/wait encoding)"""

    if code >= 0:

        return _("exited with status %d") % code

    return _("killed by signal %d") % -code

class _pfile(object):

    """File-like wrapper for a stream opened by subprocess.Popen()"""

    def __init__(self, proc, fp):

        self._proc = proc

        self._fp = fp

    def close(self):

        # unlike os.popen(), this returns an integer in subprocess coding

        self._fp.close()

        return self._proc.wait()

    def __iter__(self):

        return iter(self._fp)

    def __getattr__(self, attr):

        return getattr(self._fp, attr)

    def __enter__(self):

        return self

    def __exit__(self, exc_type, exc_value, exc_tb):

        self.close()

def popen(cmd, mode='rb', bufsize=-1):

    if mode == 'rb':

        return _popenreader(cmd, bufsize)

    elif mode == 'wb':

        return _popenwriter(cmd, bufsize)

    raise error.ProgrammingError('unsupported mode: %r' % mode)

def _popenreader(cmd, bufsize):

    p = subprocess.Popen(quotecommand(cmd), shell=True, bufsize=bufsize,

                         close_fds=closefds,

                         stdout=subprocess.PIPE)

    return _pfile(p, p.stdout)

def _popenwriter(cmd, bufsize):

    p = subprocess.Popen(quotecommand(cmd), shell=True, bufsize=bufsize,

                         close_fds=closefds,

                         stdin=subprocess.PIPE)

    return _pfile(p, p.stdin)

def popen2(cmd, env=None):

    # Setting bufsize to -1 lets the system decide the buffer size.

    # The default for bufsize is 0, meaning unbuffered. This leads to

    # poor performance on Mac OS X: http://bugs.python.org/issue4194

    p = subprocess.Popen(cmd, shell=True, bufsize=-1,

                         close_fds=closefds,

                         stdin=subprocess.PIPE, stdout=subprocess.PIPE,

                         env=env)

    return p.stdin, p.stdout

def popen3(cmd, env=None):

    stdin, stdout, stderr, p = popen4(cmd, env)

    return stdin, stdout, stderr

def popen4(cmd, env=None, bufsize=-1):

    p = subprocess.Popen(cmd, shell=True, bufsize=bufsize,

                         close_fds=closefds,

                         stdin=subprocess.PIPE, stdout=subprocess.PIPE,

                         stderr=subprocess.PIPE,

                         env=env)

    return p.stdin, p.stdout, p.stderr, p

def pipefilter(s, cmd):

    '''filter string S through command CMD, returning its output'''

    p = subprocess.Popen(cmd, shell=True, close_fds=closefds,

                         stdin=subprocess.PIPE, stdout=subprocess.PIPE)

    pout, perr = p.communicate(s)

    return pout

def tempfilter(s, cmd):

    '''filter string S through a pair of temporary files with CMD.

    CMD is used as a template to create the real command to be run,

    with the strings INFILE and OUTFILE replaced by the real names of

    the temporary files generated.'''

    inname, outname = None, None

    try:

        infd, inname = pycompat.mkstemp(prefix='hg-filter-in-')

        fp = os.fdopen(infd, r'wb')

        fp.write(s)

        fp.close()

        outfd, outname = pycompat.mkstemp(prefix='hg-filter-out-')

        os.close(outfd)

        cmd = cmd.replace('INFILE', inname)

        cmd = cmd.replace('OUTFILE', outname)

        code = system(cmd)

        if pycompat.sysplatform == 'OpenVMS' and code & 1:

            code = 0

        if code:

            raise error.Abort(_("command '%s' failed: %s") %

                              (cmd, explainexit(code)))

        with open(outname, 'rb') as fp:

            return fp.read()

    finally:

        try:

            if inname:

                os.unlink(inname)

        except OSError:

            pass

        try:

            if outname:

                os.unlink(outname)

        except OSError:

            pass

_filtertable = {

    'tempfile:': tempfilter,

    'pipe:': pipefilter,

}

def filter(s, cmd):

    "filter a string through a command that transforms its input to its output"

    for name, fn in _filtertable.iteritems():

        if cmd.startswith(name):

            return fn(s, cmd[len(name):].lstrip())

    return pipefilter(s, cmd)

def mainfrozen():

    """return True if we are a frozen executable.

    The code supports py2exe (most common, Windows only) and tools/freeze

    (portable, not much used).

    """

    return (pycompat.safehasattr(sys, "frozen") or # new py2exe

            pycompat.safehasattr(sys, "importers") or # old py2exe

            imp.is_frozen(u"__main__")) # tools/freeze

_hgexecutable = None

def hgexecutable():

    """return location of the 'hg' executable.

    Defaults to $HG or 'hg' in the search path.

    """

    if _hgexecutable is None:

        hg = encoding.environ.get('HG')

        mainmod = sys.modules[r'__main__']

        if hg:

            _sethgexecutable(hg)

        elif mainfrozen():

            if getattr(sys, 'frozen', None) == 'macosx_app':

                # Env variable set by py2app

                _sethgexecutable(encoding.environ['EXECUTABLEPATH'])

            else:

                _sethgexecutable(pycompat.sysexecutable)

        elif (os.path.basename(

            pycompat.fsencode(getattr(mainmod, '__file__', ''))) == 'hg'):

            _sethgexecutable(pycompat.fsencode(mainmod.__file__))

        else:

            exe = findexe('hg') or os.path.basename(sys.argv[0])

            _sethgexecutable(exe)

    return _hgexecutable

def _sethgexecutable(path):

    """set location of the 'hg' executable"""

    global _hgexecutable

    _hgexecutable = path

def _testfileno(f, stdf):

    fileno = getattr(f, 'fileno', None)

    try:

        return fileno and fileno() == stdf.fileno()

    except io.UnsupportedOperation:

        return False # fileno() raised UnsupportedOperation

def isstdin(f):

    return _testfileno(f, sys.__stdin__)

def isstdout(f):

    return _testfileno(f, sys.__stdout__)

def protectstdio(uin, uout):

    """Duplicate streams and redirect original if (uin, uout) are stdio

    If uin is stdin, it's redirected to /dev/null. If uout is stdout, it's

    redirected to stderr so the output is still readable.

    Returns (fin, fout) which point to the original (uin, uout) fds, but

    may be copy of (uin, uout). The returned streams can be considered

    "owned" in that print(), exec(), etc. never reach to them.

    """

    uout.flush()

    fin, fout = uin, uout

    if uin is stdin:

        newfd = os.dup(uin.fileno())

        nullfd = os.open(os.devnull, os.O_RDONLY)

        os.dup2(nullfd, uin.fileno())

        os.close(nullfd)

        fin = os.fdopen(newfd, r'rb')

    if uout is stdout:

        newfd = os.dup(uout.fileno())

        os.dup2(stderr.fileno(), uout.fileno())

        fout = os.fdopen(newfd, r'wb')

    return fin, fout

def restorestdio(uin, uout, fin, fout):

    """Restore (uin, uout) streams from possibly duplicated (fin, fout)"""

    uout.flush()

    for f, uif in [(fin, uin), (fout, uout)]:

        if f is not uif:

            os.dup2(f.fileno(), uif.fileno())

            f.close()

@contextlib.contextmanager

def protectedstdio(uin, uout):

    """Run code block with protected standard streams"""

    fin, fout = protectstdio(uin, uout)

    try:

        yield fin, fout

    finally:

        restorestdio(uin, uout, fin, fout)

def shellenviron(environ=None):

    """return environ with optional override, useful for shelling out"""

    def py2shell(val):

        'convert python object into string that is useful to shell'

        if val is None or val is False:

            return '0'

        if val is True:

            return '1'

        return pycompat.bytestr(val)

    env = dict(encoding.environ)

    if environ:

        env.update((k, py2shell(v)) for k, v in environ.iteritems())

    env['HG'] = hgexecutable()

    return env

if pycompat.iswindows:

    def shelltonative(cmd, env):

        return platform.shelltocmdexe(cmd, shellenviron(env))

else:

    def shelltonative(cmd, env):

        return cmd

def system(cmd, environ=None, cwd=None, out=None):

    '''enhanced shell command execution.

    run with environment maybe modified, maybe in different dir.

    if out is specified, it is assumed to be a file-like object that has a

    write() method. stdout and stderr will be redirected to out.'''

    try:

        stdout.flush()

    except Exception:

        pass

    cmd = quotecommand(cmd)

    env = shellenviron(environ)

    if out is None or isstdout(out):

        rc = subprocess.call(cmd, shell=True, close_fds=closefds,

                             env=env, cwd=cwd)

    else:

        proc = subprocess.Popen(cmd, shell=True, close_fds=closefds,

                                env=env, cwd=cwd, stdout=subprocess.PIPE,

                                stderr=subprocess.STDOUT)

        for line in iter(proc.stdout.readline, ''):

            out.write(line)

        proc.wait()

        rc = proc.returncode

    if pycompat.sysplatform == 'OpenVMS' and rc & 1:

        rc = 0

    return rc

def gui():

    '''Are we running in a GUI?'''

    if pycompat.isdarwin:

        if 'SSH_CONNECTION' in encoding.environ:

            # handle SSH access to a box where the user is logged in

            return False

        elif getattr(osutil, 'isgui', None):

            # check if a CoreGraphics session is available

            return osutil.isgui()

        else:

            # pure build; use a safe default

            return True

    else:

        return pycompat.iswindows or encoding.environ.get("DISPLAY")

def hgcmd():

    """Return the command used to execute current hg

    This is different from hgexecutable() because on Windows we want

    to avoid things opening new shell windows like batch files, so we

    get either the python call or current executable.

    """