#!/usr/bin/env python3
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import sys
import os

# Add the current directory to sys.path to find verify_utils
CUR_DIR = os.path.dirname(os.path.abspath(__file__))
sys.path.append(CUR_DIR)

import verify_utils
from pktverify import consts


def verify(pv):
    pkts = pv.pkts
    pv.summary.show()

    LEADER = pv.vars['LEADER']
    ROUTER_1 = pv.vars['ROUTER_1']
    ROUTER_24 = pv.vars['ROUTER_24']

    # 5.2.6 Router Downgrade Threshold - REED
    #
    # 5.2.6.1 Topology
    # - Build a topology with 23 active routers, including the Leader, with no communication constraints and links of
    #   highest quality (quality=3)
    # - Set Router Downgrade Threshold and Router Upgrade Threshold on all test bed routers and Leader to 32
    #
    # 5.2.6.2 Purpose & Description
    # The purpose of this test case is to verify that the DUT will downgrade to a REED when the network becomes too
    #   dense and the Router Downgrade Threshold conditions are met.
    #
    # Spec Reference        | V1.1 Section | V1.3.0 Section
    # ----------------------|--------------|---------------
    # Router ID Management  | 5.9.9        | 5.9.9
    print("5.2.6 Router Downgrade Threshold - REED")

    # Step 1: All
    # - Description: Ensure topology is formed correctly without Router_24,
    # - Pass Criteria: N/A
    print("Step 1: All - Ensure topology is formed correctly without Router_24")

    # Step 2: Router_24
    # - Description: Harness causes Router_24 to attach to the network and ensures it has a link of quality 2 or better
    #   to Router_1 and Router_2
    # - Pass Criteria: N/A
    print("Step 2: Router_24 - Harness causes Router_24 to attach to the network")
    pkts.filter_wpan_src64(ROUTER_24).\
        filter_mle_cmd(consts.MLE_PARENT_REQUEST).\
        must_next()

    # Step 3: Router_1 (DUT)
    # - Description: Allow enough time for the DUT to get Network Data Updates and resign its Router ID.
    # - Pass Criteria:
    #   - The DUT MUST first reconnect to the network as a Child by sending properly formatted Parent Request and
    #     Child ID Request messages.
    #   - Once the DUT attaches as a Child, it MUST send an Address Release Message to the Leader:
    #     - CoAP Request URI: coap://[<leader address>]:MM/a/ar
    #     - CoAP Payload:
    #       - MAC Extended Address TLV
    #       - RLOC16 TLV,
    print(
        "Step 3: Router_1 (DUT) - Allow enough time for the DUT to get Network Data Updates and resign its Router ID.")

    # Verify DUT sends Parent Request
    pkts.filter_wpan_src64(ROUTER_1).\
        filter_mle_cmd(consts.MLE_PARENT_REQUEST).\
        must_next()

    # Verify DUT sends Child ID Request
    pkts.filter_wpan_src64(ROUTER_1).\
        filter_mle_cmd(consts.MLE_CHILD_ID_REQUEST).\
        must_next()

    # Verify DUT sends Address Release with required TLVs
    pkts.filter_wpan_src64(ROUTER_1).\
        filter_coap_request(consts.ADDR_REL_URI).\
        filter(lambda p: {
            consts.NL_MAC_EXTENDED_ADDRESS_TLV,
            consts.NL_RLOC16_TLV
        } <= {int(t, 16) if isinstance(t, str) else t for t in p.coap.tlv.type}).\
        must_next()

    # Step 4: Leader
    # - Description: Receives Address Release message and automatically sends a 2.04 Changed CoAP response.
    # - Pass Criteria: N/A
    print("Step 4: Leader - Receives Address Release message and automatically sends a 2.04 Changed CoAP response.")
    pkts.filter_wpan_src64(LEADER).\
        filter_coap_ack(consts.ADDR_REL_URI).\
        must_next()

    # Step 5: Leader
    # - Description: Harness verifies connectivity by instructing the device to send an ICMPv6 Echo Request to the DUT
    # - Pass Criteria: The DUT MUST respond with an ICMPv6 Echo Reply
    print("Step 5: Leader - Harness verifies connectivity by instructing the device to send an ICMPv6 Echo Request")
    _pkt = pkts.filter_ping_request().\
        filter_wpan_src64(LEADER).\
        must_next()
    pkts.filter_ping_reply(identifier=_pkt.icmpv6.echo.identifier).\
        must_next()


if __name__ == '__main__':
    verify_utils.run_main(verify)