# This Source Code Form is subject to the terms of the Mozilla Public

# License, v. 2.0. If a copy of the MPL was not distributed with this

# file, You can obtain one at http://mozilla.org/MPL/2.0/.

"""

Support for optimizing tasks based on the set of files that have changed.

"""

from __future__ import absolute_import, print_function, unicode_literals

import logging

import requests

from redo import retry

from mozpack.path import match as mozpackmatch, join as join_path

from mozversioncontrol import get_repository_object, InvalidRepoPath

from subprocess import CalledProcessError

from mozbuild.util import memoize

logger = logging.getLogger(__name__)

@memoize

def get_changed_files(repository, revision):

    """

    Get the set of files changed in the push headed by the given revision.

    Responses are cached, so multiple calls with the same arguments are OK.

    """

    url = '%s/json-automationrelevance/%s' % (repository.rstrip('/'), revision)

    logger.debug("Querying version control for metadata: %s", url)

    def get_automationrelevance():

        response = requests.get(url, timeout=30)

        return response.json()

    contents = retry(get_automationrelevance, attempts=10, sleeptime=10)

    logger.debug('{} commits influencing task scheduling:'

                 .format(len(contents['changesets'])))

    changed_files = set()

    for c in contents['changesets']:

        desc = ""  # Support empty desc

        if c['desc']:

            desc = c['desc'].splitlines()[0].encode('ascii', 'ignore')

        logger.debug(" {cset} {desc}".format(

            cset=c['node'][0:12],

            desc=desc))

        changed_files |= set(c['files'])

    return changed_files

def check(params, file_patterns):

    """Determine whether any of the files changed in the indicated push to

    https://hg.mozilla.org match any of the given file patterns."""

    repository = params.get('head_repository')

    revision = params.get('head_rev')

    if not repository or not revision:

        logger.warning("Missing `head_repository` or `head_rev` parameters; "

                       "assuming all files have changed")

        return True

    changed_files = get_changed_files(repository, revision)

    if 'comm_head_repository' in params:

        repository = params.get('comm_head_repository')

        revision = params.get('comm_head_rev')

        if not revision:

            logger.warning("Missing `comm_head_rev` parameters; "

                           "assuming all files have changed")

            return True

        changed_files |= {

            join_path("comm", file) for file in

            get_changed_files(repository, revision)

        }

    for pattern in file_patterns:

        for path in changed_files:

            if mozpackmatch(path, pattern):

                return True

    return False

@memoize

def get_locally_changed_files(repo):

    try:

        vcs = get_repository_object(repo)

        return set(vcs.get_outgoing_files('AM'))

    except (InvalidRepoPath, CalledProcessError):

        return set()