# upgrade.py - functions for automatic upgrade of Mercurial repository

#

# Copyright (c) 2022-present, Pierre-Yves David

#

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

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

from ..i18n import _

from .. import (

    error,

    requirements as requirementsmod,

    scmutil,

)

def get_share_safe_action(repo):

    """return an automatic-upgrade action for `share-safe` if applicable

    If no action is needed, return None, otherwise return a callback to upgrade

    or downgrade the repository according the configuration and repository

    format.

    """

    ui = repo.ui

    requirements = repo.requirements

    auto_upgrade_share_source = ui.configbool(

        b'format',

        b'use-share-safe.automatic-upgrade-of-mismatching-repositories',

    )

    action = None

    if (

        auto_upgrade_share_source

        and requirementsmod.SHARED_REQUIREMENT not in requirements

    ):

        sf_config = ui.configbool(b'format', b'use-share-safe')

        sf_local = requirementsmod.SHARESAFE_REQUIREMENT in requirements

        if sf_config and not sf_local:

            msg = _(

                b"automatically upgrading repository to the `share-safe`"

                b" feature\n"

            )

            hint = b"(see `hg help config.format.use-share-safe` for details)\n"

            def action():

                if not ui.quiet:

                    ui.write_err(msg)

                    ui.write_err(hint)

                requirements.add(requirementsmod.SHARESAFE_REQUIREMENT)

                scmutil.writereporequirements(repo, requirements)

        elif sf_local and not sf_config:

            msg = _(

                b"automatically downgrading repository from the `share-safe`"

                b" feature\n"

            )

            hint = b"(see `hg help config.format.use-share-safe` for details)\n"

            def action():

                if not ui.quiet:

                    ui.write_err(msg)

                    ui.write_err(hint)

                requirements.discard(requirementsmod.SHARESAFE_REQUIREMENT)

                scmutil.writereporequirements(repo, requirements)

    return action

AUTO_UPGRADE_ACTIONS = [

    get_share_safe_action,

]

def may_auto_upgrade(repo, maker_func):

    """potentially perform auto-upgrade and return the final repository to use

    Auto-upgrade are "quick" repository upgrade that might automatically be run

    by "any" repository access. See `hg help config.format` for automatic

    upgrade documentation.

    note: each relevant upgrades are done one after the other for simplicity.

    This avoid having repository is partially inconsistent state while

    upgrading.

    repo: the current repository instance

    maker_func: a factory function that can recreate a repository after an upgrade

    """

    clear = False

    loop = 0

    while not clear:

        loop += 1

        if loop > 100:

            # XXX basic protection against infinite loop, make it better.

            raise error.ProgrammingError("Too many auto upgrade loops")

        clear = True

        for get_action in AUTO_UPGRADE_ACTIONS:

            action = get_action(repo)

            if action is not None:

                clear = False

                with repo.wlock(wait=False), repo.lock(wait=False):

                    action = get_action(repo)

                    if action is not None:

                        action()

                    repo = maker_func()

    return repo