#!/usr/bin/env python3

from github import Github, GithubException
import argparse
import os

GH_TOKEN_ENV_VAR_NAME = "GH_TOKEN"
GH_REPO_SLUG = os.environ["CI_REPO_SLUG"]


class UploadReleaseAssetError(Exception):
    pass


def upload_asset_to_github_release(
    asset_path: str, release_tag: str, github_token: str, asset_name: str = None
):
    """
    Upload an asset to a release
    :param asset_path: the file path
    :param release_tag: the release tag as identified on Github
    :param github_token: a token to allow editing the release
    :param asset_name: an optional name to give to the asset
    """
    repo = Github(github_token).get_repo(GH_REPO_SLUG)
    try:
        print("Getting release on {}".format(GH_REPO_SLUG))
        gh_release = repo.get_release(id=release_tag)
        print(gh_release, gh_release.tag_name, gh_release.upload_url)
    except GithubException as e:
        raise UploadReleaseAssetError("Release {} not found".format(release_tag))
    try:
        assert os.path.exists(asset_path)
        if asset_name:
            print("Uploading asset: {} as {}".format(asset_path, asset_name))
            gh_release.upload_asset(path=asset_path, label=asset_name, name=asset_name)
        else:
            print("Uploading asset: {}".format(asset_path))
            gh_release.upload_asset(asset_path)
        print("OK")
    except GithubException as e:
        print(e)
        raise UploadReleaseAssetError(
            "Could not upload asset for release {}.".format(release_tag)
        )


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("release_asset", help="The file to be uploaded")
    parser.add_argument("release_tag", help="The version tag")
    parser.add_argument(
        "--github-token",
        default=os.environ.get(GH_TOKEN_ENV_VAR_NAME),
        help="The Github API token. If not specified, it will"
        " be taken from ${}.".format(GH_TOKEN_ENV_VAR_NAME),
    )
    parser.add_argument(
        "--asset-name", default=None, help="An optional name for the release asset"
    )
    args = parser.parse_args()

    upload_asset_to_github_release(
        args.release_asset, args.release_tag, args.github_token, args.asset_name
    )

    return 0


if __name__ == "__main__":
    exit(main())