#!/usr/bin/env python
# Copyright 2019 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License 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 argparse
import sys
import time
from typing import Optional

import nacl.signing
from signedjson.key import encode_verify_key_base64, get_verify_key, read_signing_keys


def exit(status: int = 0, message: Optional[str] = None):
    if message:
        print(message, file=sys.stderr)
    sys.exit(status)


def format_plain(public_key: nacl.signing.VerifyKey):
    print(
        "%s:%s %s"
        % (
            public_key.alg,
            public_key.version,
            encode_verify_key_base64(public_key),
        )
    )


def format_for_config(public_key: nacl.signing.VerifyKey, expiry_ts: int):
    print(
        '  "%s:%s": { key: "%s", expired_ts: %i }'
        % (
            public_key.alg,
            public_key.version,
            encode_verify_key_base64(public_key),
            expiry_ts,
        )
    )


def main():
    parser = argparse.ArgumentParser()

    parser.add_argument(
        "key_file",
        nargs="+",
        type=argparse.FileType("r"),
        help="The key file to read",
    )

    parser.add_argument(
        "-x",
        action="store_true",
        dest="for_config",
        help="format the output for inclusion in the old_signing_keys config setting",
    )

    parser.add_argument(
        "--expiry-ts",
        type=int,
        default=int(time.time() * 1000) + 6 * 3600000,
        help=(
            "The expiry time to use for -x, in milliseconds since 1970. The default "
            "is (now+6h)."
        ),
    )

    args = parser.parse_args()

    formatter = (
        (lambda k: format_for_config(k, args.expiry_ts))
        if args.for_config
        else format_plain
    )

    for file in args.key_file:
        try:
            res = read_signing_keys(file)
        except Exception as e:
            exit(
                status=1,
                message="Error reading key from file %s: %s %s"
                % (file.name, type(e), e),
            )
            res = []
        for key in res:
            formatter(get_verify_key(key))


if __name__ == "__main__":
    main()
