#!/usr/bin/env python3
# SPDX-License-Identifier: BSD-3-Clause OR Apache-2.0
# encoding: utf-8

import argparse
import logging

import cbor2

from ud3tn_utils.aap import AAPTCPClient, AAPUnixClient
from ud3tn_utils.aap.bin.helpers import (
    add_common_parser_arguments,
    initialize_logger,
)
from pyd3tn.bundle7 import (BibeProtocolDataUnit, Bundle,
                            PayloadBlock, PrimaryBlock)


logger = logging.getLogger(__name__)


def build_bpdu(inner_source, inner_dest, payload):
    """Encapsulates a regular bundle with the chosen payload
    in a BIBE Administrative Record, thus forming a BIBE Bundle.

    Args:
        inner_source (str): Source EID of the encapsulated bundle
        inner_dest (str): Destination EID of the encapsulated bundle
        payload (bytes): The payload of the encapsulated bundle

    Returns:
        BPDU (bytes): The bytes making up the BPDU
    """
    inner_bundle = Bundle(
        PrimaryBlock(
            destination=inner_dest,
            source=inner_source,
        ),
        PayloadBlock(payload)
    )
    bibe_ar = BibeProtocolDataUnit(
        bundle=inner_bundle,
        transmission_id=0,
        retransmission_time=0,
        compatibility=False,
    )

    return cbor2.dumps(bibe_ar.record_data)


def main():
    import sys

    parser = argparse.ArgumentParser(
        description="send a bundle via uD3TN's AAP interface",
    )
    add_common_parser_arguments(parser)
    parser.add_argument(
        "dest_eid",
        help="the destination EID of the created bundle",
    )
    parser.add_argument(
        "PAYLOAD",
        default=None,
        nargs="?",
        help="the payload of the created bundle, (default: read from STDIN)",
    )
    parser.add_argument(
        "--bibe-source",
        default=None,
        help=("if set, the payload will be encapsulated twice using BIBE, "
              "with the source of the inner bundle set to the given EID"))
    parser.add_argument(
        "--bibe-destination",
        default=None,
        help=("if set, the payload will be encapsulated twice using BIBE, "
              "with the inner bundle addressed to the given EID"))
    args = parser.parse_args()

    if args.PAYLOAD:
        payload = args.PAYLOAD.encode("utf-8")
    else:
        payload = sys.stdin.buffer.read()
        sys.stdin.buffer.close()

    global logger
    logger = initialize_logger(args.verbosity)

    is_bibe = (
        args.bibe_source is not None or
        args.bibe_destination is not None
    )
    if is_bibe and (args.bibe_source is None or args.bibe_destination is None):
        logger.fatal("--bibe-source and --bibe-destination must both be set")
        sys.exit(1)

    if args.tcp:
        aap_client = AAPTCPClient(address=args.tcp)
    else:
        aap_client = AAPUnixClient(address=args.socket)
    with aap_client:
        aap_client.register(args.agentid)
        if not is_bibe:
            aap_client.send_bundle(args.dest_eid, payload, False)
        else:
            bpdu = build_bpdu(
                args.bibe_source,
                args.bibe_destination,
                payload,
            )
            aap_client.send_bundle(
                args.dest_eid,
                bpdu,
                is_bibe,
            )


if __name__ == "__main__":
    main()