# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"). You
# may not use this file except in compliance with the License. A copy of
# the License is located at
#
#     http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
# ANY KIND, either express or implied. See the License for the specific
# language governing permissions and limitations under the License.

import os
import tarfile


class Context:
    """
    The context class encapsulates all required functions for
    preparing, managing and removing the docker build context
    """

    def __init__(
            self, artifacts=None, context_path="context.tar.gz", artifact_root="./"
    ):
        """
        The constructor for the Context class

        Args:
            artifacts: array of (source, destination) tuples
            context_path: path for the resulting tar.gz file
            artifact_root: root directory for all artifacts

        Returns:
            None

        """
        self.artifacts = {}
        self.context_path = context_path
        self.artifact_root = artifact_root

        # Check if the context path is just a filename,
        # or includes a directory. If path includes a
        # directory, create directory if it does not exist
        directory = os.path.dirname(context_path)
        if directory != "" and not os.path.isdir(directory):
            os.mkdir(directory)

        if artifacts is not None:
            self.add(artifacts)

    def add(self, artifacts):
        """
        Adds artifacts to the build context

        Args:
            artifacts: array of (source, destination) tuples
        """
        self.artifacts.update(artifacts)

        # TODO: Use glob to expand
        # TODO: Add logic to untar and retar
        with tarfile.open(self.context_path, "w:gz") as tar:
            for artifact_name in artifacts:
                artifact = artifacts[artifact_name]
                if "source" not in artifact or "target" not in artifact:
                    continue
                source = os.path.join(self.artifact_root, artifact["source"])
                target = artifact["target"]
                tar.add(source, arcname=target)

    def remove(self):
        """
        Removes the context tar file

        Args:
            None

        Returns:
            None
        """
        os.remove(self.context_path)