# logtoprocess.py - send ui.log() data to a subprocess

#

# Copyright 2016 Facebook, Inc.

#

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

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

"""send ui.log() data to a subprocess (EXPERIMENTAL)

This extension lets you specify a shell command per ui.log() event,

sending all remaining arguments to as environment variables to that command.

Scripts are configured in the `[logtoprocess]` section, each key an event name.

For example::

  [logtoprocess]

would log the warning message and traceback of any failed command dispatch.

Scripts are run asynchronously as detached daemon processes; mercurial will

not ensure that they exit cleanly.

"""

from __future__ import absolute_import

import os

from mercurial import (

    pycompat,

)

from mercurial.utils import (

    procutil,

)

# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for

# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should

# be specifying the version(s) of Mercurial they are tested with, or

# leave the attribute unspecified.

testedwith = 'ships-with-hg-core'

def uisetup(ui):

    class logtoprocessui(ui.__class__):

        def log(self, event, *msg, **opts):

            """Map log events to external commands

            Arguments are passed on as environment variables.

            """

            script = self.config('logtoprocess', event)

            if script:

                env = {

                    b'EVENT': event,

                    b'HGPID': os.getpid(),

                }

                # keyword arguments get prefixed with OPT_ and uppercased

                env.update((b'OPT_%s' % key.upper(), value)

                           for key, value in pycompat.byteskwargs(opts).items())

                fullenv = procutil.shellenviron(env)

                procutil.runbgcommand(script, fullenv, shell=True)

            return super(logtoprocessui, self).log(event, *msg, **opts)

    # Replace the class for this instance and all clones created from it:

    ui.__class__ = logtoprocessui