# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""Change behavior of obsolescence."""

import os
import pwd

from mercurial import (
    configitems,
    error,
    obsolete,
    pycompat,
    registrar,
)

testedwith = b"4.4 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5 5.9"
minimumhgversion = b"4.4"


configtable = {}
configitem = registrar.configitem(configtable)

configitem(
    b"obshacks", b"obsolescenceexchangeusers", default=configitems.dynamicdefault
)
configitem(b"obshacks", b"userfromenv", default=configitems.dynamicdefault)


def enableevolutionexchange(repo):
    """Enable obsolescence markers exchange if conditions are met."""
    ui = repo.ui

    # Nothing to do if obsolescence isn't enabled at all.
    opts = (obsolete.createmarkersopt, obsolete.allowunstableopt, obsolete.exchangeopt)
    if not any(obsolete.isenabled(repo, opt) for opt in opts):
        return

    features = set(ui.configlist(b"experimental", b"evolution"))
    # Nothing to do if already enabled.
    if b"all" in features or obsolete.exchangeopt in features:
        return

    # Enable exchange if the current user is in the allow list.
    exchangeusers = ui.configlist(b"obshacks", b"obsolescenceexchangeusers", [])
    if not exchangeusers:
        return

    # Some tests can't change the uid, so allow a test mode where the user
    # comes from USER.
    if ui.configbool(b"obshacks", b"userfromenv", False):
        user = ui.environ.get(b"USER")
    else:
        try:
            user = pycompat.bytestr(pwd.getpwuid(os.getuid()).pw_name)
        except KeyError:
            raise error.Abort(b"unable to resolve process user name")

    if user not in exchangeusers:
        return

    ui.setconfig(
        b"experimental",
        b"evolution.%s" % obsolete.exchangeopt,
        True,
        source=b"obshacksext",
    )


def reposetup(ui, repo):
    enableevolutionexchange(repo)