#
#  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/>.
#

# Pylint doesn't play well with fixtures and dependency injection from pytest
# pylint: disable=redefined-outer-name

from contextlib import contextmanager
import os
import pytest

import grpc

from buildstream.testing import cli  # pylint: disable=unused-import
from tests.testutils import create_artifact_share, assert_shared


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


@contextmanager
def limit_grpc_message_length(limit):
    orig_insecure_channel = grpc.insecure_channel

    def new_insecure_channel(target):
        return orig_insecure_channel(target, options=(("grpc.max_send_message_length", limit),))

    grpc.insecure_channel = new_insecure_channel
    try:
        yield
    finally:
        grpc.insecure_channel = orig_insecure_channel


@pytest.mark.datafiles(DATA_DIR)
def test_large_directory(cli, tmpdir, datafiles):
    project = str(datafiles)

    # Number of files chosen to ensure the complete list of digests exceeds
    # our 1 MB gRPC message limit. I.e., test message splitting.
    MAX_MESSAGE_LENGTH = 1024 * 1024
    NUM_FILES = MAX_MESSAGE_LENGTH // 64 + 1

    large_directory_dir = os.path.join(project, "files", "large-directory")
    os.mkdir(large_directory_dir)
    for i in range(NUM_FILES):
        with open(os.path.join(large_directory_dir, str(i)), "w") as f:
            # The files need to have different content as we want different digests.
            f.write(str(i))

    with create_artifact_share(os.path.join(str(tmpdir), "artifactshare")) as share:
        # Configure bst to push to the artifact share
        cli.configure({"artifacts": {"servers": [{"url": share.repo, "push": True},]}})

        # Enforce 1 MB gRPC message limit
        with limit_grpc_message_length(MAX_MESSAGE_LENGTH):
            # Build and push
            result = cli.run(project=project, args=["build", "import-large-directory.bst"])
            result.assert_success()

        # Assert that we are now cached locally
        assert cli.get_element_state(project, "import-large-directory.bst") == "cached"

        # Assert that the push was successful
        assert_shared(cli, share, project, "import-large-directory.bst")