#
#  Copyright (C) 2019 Bloomberg Finance LP
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU Lesser General Public
#  License as published by the Free Software Foundation; either
#  version 2 of the License, or (at your option) any later version.
#
#  This library is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
#  Lesser General Public License for more details.
#
#  You should have received a copy of the GNU Lesser General Public
#  License along with this library. If not, see <http://www.gnu.org/licenses/>.
#
#  Authors:
#        Raoul Hidalgo Charman <raoul.hidalgocharman@codethink.co.uk>
#
# Pylint doesn't play well with fixtures and dependency injection from pytest
# pylint: disable=redefined-outer-name
from contextlib import contextmanager
import os
import shutil
import pytest

from buildstream._exceptions import ErrorDomain
from buildstream._project import Project
from buildstream import _yaml
from buildstream.testing import cli  # pylint: disable=unused-import
from buildstream.testing import create_repo

from tests.testutils import create_artifact_share, dummy_context

DATA_DIR = os.path.join(os.path.dirname(os.path.realpath(__file__)), "project")


def move_local_cas_to_remote_source_share(local, remote):
    shutil.rmtree(os.path.join(remote, 'repo', 'cas'))
    shutil.move(os.path.join(local, 'source_protos'), os.path.join(remote, 'repo'))
    shutil.move(os.path.join(local, 'cas'), os.path.join(remote, 'repo'))
    shutil.rmtree(os.path.join(local, 'sources'))
    shutil.rmtree(os.path.join(local, 'artifacts'))


def create_test_element(tmpdir, project_dir):
    repo = create_repo('git', str(tmpdir))
    ref = repo.create(os.path.join(project_dir, 'files'))
    element_path = os.path.join(project_dir, 'elements')
    element_name = 'fetch.bst'
    element = {
        'kind': 'import',
        'sources': [repo.source_config(ref=ref)]
    }
    _yaml.roundtrip_dump(element, os.path.join(element_path, element_name))

    return element_name, repo, ref


@contextmanager
def context_with_source_cache(cli, cache, share, tmpdir):
    user_config_file = str(tmpdir.join('buildstream.conf'))
    user_config = {
        'scheduler': {
            'pushers': 1
        },
        'source-caches': {
            'url': share.repo,
        },
        'cachedir': cache,
    }
    _yaml.roundtrip_dump(user_config, file=user_config_file)
    cli.configure(user_config)

    with dummy_context(config=user_config_file) as context:
        yield context


@pytest.mark.datafiles(DATA_DIR)
def test_source_fetch(cli, tmpdir, datafiles):
    project_dir = str(datafiles)
    element_name, _repo, _ref = create_test_element(tmpdir, project_dir)
    cache_dir = os.path.join(str(tmpdir), 'cache')

    # use artifact cache for sources for now, they should work the same
    with create_artifact_share(os.path.join(str(tmpdir), 'sourceshare')) as share:
        with context_with_source_cache(cli, cache_dir, share, tmpdir) as context:
            project = Project(project_dir, context)
            project.ensure_fully_loaded()

            element = project.load_elements([element_name])[0]
            assert not element._source_cached()
            source = list(element.sources())[0]

            cas = context.get_cascache()
            assert not cas.contains(source._get_source_name())

            # Just check that we sensibly fetch and build the element
            res = cli.run(project=project_dir, args=['build', element_name])
            res.assert_success()

            assert os.listdir(os.path.join(str(tmpdir), 'cache', 'sources', 'git')) != []

            # get root digest of source
            sourcecache = context.sourcecache
            digest = sourcecache.export(source)._get_digest()

            move_local_cas_to_remote_source_share(str(cache_dir), share.directory)

            # check the share has the object
            assert share.has_object(digest)

            state = cli.get_element_state(project_dir, element_name)
            assert state == 'fetch needed'

            # Now fetch the source and check
            res = cli.run(project=project_dir, args=['source', 'fetch', element_name])
            res.assert_success()
            assert "Pulled source" in res.stderr

            # check that we have the source in the cas now and it's not fetched
            assert element._source_cached()
            assert os.listdir(os.path.join(str(tmpdir), 'cache', 'sources', 'git')) == []


@pytest.mark.datafiles(DATA_DIR)
def test_fetch_fallback(cli, tmpdir, datafiles):
    project_dir = str(datafiles)
    element_name, repo, ref = create_test_element(tmpdir, project_dir)
    cache_dir = os.path.join(str(tmpdir), 'cache')

    # use artifact cache for sources for now, they should work the same
    with create_artifact_share(os.path.join(str(tmpdir), 'sourceshare')) as share:
        with context_with_source_cache(cli, cache_dir, share, tmpdir) as context:
            project = Project(project_dir, context)
            project.ensure_fully_loaded()

            element = project.load_elements([element_name])[0]
            assert not element._source_cached()
            source = list(element.sources())[0]

            cas = context.get_cascache()
            assert not cas.contains(source._get_source_name())
            assert not os.path.exists(os.path.join(cache_dir, 'sources'))

            # Now check if it falls back to the source fetch method.
            res = cli.run(project=project_dir, args=['source', 'fetch', element_name])
            res.assert_success()
            brief_key = source._get_brief_display_key()
            assert ("Remote source service ({}) does not have source {} cached"
                    .format(share.repo, brief_key)) in res.stderr
            assert ("SUCCESS Fetching from {}"
                    .format(repo.source_config(ref=ref)['url'])) in res.stderr

            # Check that the source in both in the source dir and the local CAS
            assert element._source_cached()


@pytest.mark.datafiles(DATA_DIR)
def test_pull_fail(cli, tmpdir, datafiles):
    project_dir = str(datafiles)
    element_name, repo, _ref = create_test_element(tmpdir, project_dir)
    cache_dir = os.path.join(str(tmpdir), 'cache')

    with create_artifact_share(os.path.join(str(tmpdir), 'sourceshare')) as share:
        with context_with_source_cache(cli, cache_dir, share, tmpdir) as context:
            project = Project(project_dir, context)
            project.ensure_fully_loaded()

            element = project.load_elements([element_name])[0]
            assert not element._source_cached()
            source = list(element.sources())[0]

            # remove files and check that it doesn't build
            shutil.rmtree(repo.repo)

            # Should fail in stream, with a plugin task causing the error
            res = cli.run(project=project_dir, args=['build', element_name])
            res.assert_main_error(ErrorDomain.STREAM, None)
            res.assert_task_error(ErrorDomain.PLUGIN, None)
            assert "Remote source service ({}) does not have source {} cached".format(
                share.repo, source._get_brief_display_key()) in res.stderr


@pytest.mark.datafiles(DATA_DIR)
def test_source_pull_partial_fallback_fetch(cli, tmpdir, datafiles):
    project_dir = str(datafiles)
    element_name, repo, ref = create_test_element(tmpdir, project_dir)
    cache_dir = os.path.join(str(tmpdir), 'cache')

    # use artifact cache for sources for now, they should work the same
    with create_artifact_share(os.path.join(str(tmpdir), 'sourceshare')) as share:
        with context_with_source_cache(cli, cache_dir, share, tmpdir) as context:
            project = Project(project_dir, context)
            project.ensure_fully_loaded()

            element = project.load_elements([element_name])[0]
            assert not element._source_cached()
            source = list(element.sources())[0]

            cas = context.get_cascache()
            assert not cas.contains(source._get_source_name())

            # Just check that we sensibly fetch and build the element
            res = cli.run(project=project_dir, args=['build', element_name])
            res.assert_success()

            assert os.listdir(os.path.join(str(tmpdir), 'cache', 'sources', 'git')) != []

            # get root digest of source
            sourcecache = context.sourcecache
            digest = sourcecache.export(source)._get_digest()

            move_local_cas_to_remote_source_share(str(cache_dir), share.directory)

            # Remove the cas content, only keep the proto and such around
            shutil.rmtree(os.path.join(str(tmpdir), "sourceshare", "repo", "cas", "objects"))
            # check the share doesn't have the object
            assert not share.has_object(digest)

            state = cli.get_element_state(project_dir, element_name)
            assert state == 'fetch needed'

            # Now fetch the source and check
            res = cli.run(project=project_dir, args=['source', 'fetch', element_name])
            res.assert_success()

            assert ("SUCCESS Fetching from {}"
                    .format(repo.source_config(ref=ref)['url'])) in res.stderr