#!/bin/bash
#
#  Copyright (c) 2025, The OpenThread Authors.
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#
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#  modification, are permitted provided that the following conditions are met:
#  1. Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer.
#  2. Redistributions in binary form must reproduce the above copyright
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#     documentation and/or other materials provided with the distribution.
#  3. Neither the name of the copyright holder nor the
#     names of its contributors may be used to endorse or promote products
#     derived from this software without specific prior written permission.
#
#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
#  POSSIBILITY OF SUCH DAMAGE.
#

set -euxo pipefail

die()
{
    echo " *** ERROR: " "$*"
    exit 1
}

at_exit()
{
    EXIT_CODE=$?

    sudo killall ot-daemon || true

    sudo ip link del veth-a || true
    sudo ip link del veth-b || true

    exit $EXIT_CODE
}

wait_for()
{
    local command="$1"
    local expect="$2"

    local count=15
    while [ ${count} -ne 0 ]; do
        count=$((count - 1))
        eval sudo "${OT_CTL_PATH}" "${command}" | grep -q "${expect}" && return 0
        sleep 1
    done

    return 1
}

wait_for_onlinkprefix()
{
    local count=30

    while [ "$count" -gt 0 ]; do
        onlinkprefix=$(sudo "${OT_CTL_PATH}" br onlinkprefix favored)
        onlinkprefix_addr=${onlinkprefix%%::*}
        if [ -n "$onlinkprefix_addr" ]; then
            if sudo ip addr show dev veth-a | grep -q "${onlinkprefix_addr}"; then
                return 0
            fi
        fi
        sleep 1
        count=$((count - 1))
    done

    echo "Timed out waiting for onlink prefix on veth-a"
    return 1
}

setup_veth()
{
    sudo ip link add veth-a type veth peer name veth-b
    sudo ip link set veth-a up
    sudo ip link set veth-b up
    sudo sysctl -w net.ipv6.conf.veth-a.accept_ra=2
    sudo sysctl -w net.ipv6.conf.veth-a.accept_ra_rt_info_max_plen=128
}

do_build()
{
    ./script/cmake-build simulation
    ./script/cmake-build posix -DOT_BORDER_ROUTING=ON -DOT_PLATFORM_NETIF=1 -DOT_PLATFORM_UDP=1 -DOT_UDP_FORWARD=0 -DOT_POSIX_MAX_POWER_TABLE=1 -DOT_DAEMON=ON
}

do_check()
{
    trap at_exit INT TERM EXIT

    export OT_CTL_PATH="$PWD/build/posix/src/posix/ot-ctl"

    # Setup virtual ethernet pair
    sudo ip link del veth-a || true
    sudo ip link del veth-b || true

    setup_veth

    RADIO_NCP_PATH="$PWD/build/simulation/examples/apps/ncp/ot-rcp"
    RADIO_URL="spinel+hdlc+forkpty://${RADIO_NCP_PATH}?forkpty-arg=2"

    sudo -E "$PWD/build/posix/src/posix/ot-daemon" -d7 -v -I wpan0 -B veth-a "${RADIO_URL}" &
    wait_for "state" "Done" || die "failed to start daemon"

    # verify this reset and factoryreset end immediately
    sudo "${OT_CTL_PATH}" reset
    wait_for "state" "disabled" || die "daemon did not enter disabled state after reset"

    sudo "${OT_CTL_PATH}" factoryreset
    wait_for "state" "disabled" || die "daemon did not enter disabled state after factoryreset"

    # Bring up Thread network
    sudo "${OT_CTL_PATH}" dataset init new || die "failed to init new dataset"
    sudo "${OT_CTL_PATH}" dataset commit active || die "failed to commit active dataset"
    sudo "${OT_CTL_PATH}" ifconfig up || die "failed to bring ifconfig up"
    sudo "${OT_CTL_PATH}" thread start || die "failed to start thread"

    wait_for "state" "leader" || die "did not become leader"
    wait_for "br state" "running" || die "failed to start br"

    # Simulate infra interface index change
    sudo ip link del veth-a
    wait_for "br state" "stopped" || die "failed to stop br"

    setup_veth

    # Verify border routing is still functional by checking for a published prefix
    # The border router should re-detect the interface and re-establish routing.
    # A key indicator of this is the successful publication of the onlink prefix.
    wait_for_onlinkprefix

    echo "Test passed: OTBR correctly handled infra interface index change."
}

main()
{
    if [[ $# == 0 ]]; then
        do_build
        do_check
        return 0
    fi

    while [[ $# != 0 ]]; do
        case $1 in
            build)
                do_build
                ;;
            check)
                do_check
                ;;
            *)
                echo "Unknown action: $1"
                return 1
                ;;
        esac
        shift
    done
}

main "$@"