#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0

"""Regression tests for the SO_TXTIME interface.

Test delivery time in FQ and ETF qdiscs.
"""

import os
import time

from lib.py import ksft_exit, ksft_run, ksft_variants
from lib.py import KsftNamedVariant, KsftSkipEx
from lib.py import NetDrvEpEnv, bkg, cmd, defer, tc
from lib.py import CmdExitFailure


def test_so_txtime(cfg, clockid, ipver, args_tx, args_rx, expect_success):
    """Main function. Run so_txtime as sender and receiver."""
    slow_machine = os.environ.get('KSFT_MACHINE_SLOW')

    if not hasattr(cfg, "bin_remote"):
        cfg.bin_local = cfg.test_dir / "so_txtime"
        cfg.bin_remote = cfg.remote.deploy(cfg.bin_local)

    tstart = time.time_ns() + (2000_000_000 if slow_machine else 200_000_000)

    cmd_addr = f"-S {cfg.addr_v[ipver]} -D {cfg.remote_addr_v[ipver]}"
    cmd_args = f"-{ipver} -c {clockid} -t {tstart} {cmd_addr}"
    cmd_rx = f"{cfg.bin_remote} {cmd_args} {args_rx} -r"
    cmd_tx = f"{cfg.bin_local} -m 100 {cmd_args} {args_tx}"

    expect_fail = not expect_success
    if slow_machine:
        expect_success = False

    with bkg(cmd_rx, host=cfg.remote, fail=expect_success,
             expect_fail=expect_fail, exit_wait=True):
        cmd(cmd_tx)


def _qdisc_setup(ifname, qdisc, optargs=""):
    """Replace root qdisc. Restore the original after the test.

    If the original is mq, children will be of type default_qdisc.
    """
    orig = tc(f"qdisc show dev {ifname} root", json=True)[0].get("kind", None)
    defer(tc, f"qdisc replace dev {ifname} root {orig}")
    try:
        tc(f"qdisc del dev {ifname} root")
    except CmdExitFailure:
        pass
    tc(f"qdisc replace dev {ifname} root handle 1: {qdisc} {optargs}")


def _test_variants_fq():
    for ipver in ["4", "6"]:
        for testcase in [
            ["no_delay", "a,-1", "a,-1"],
            ["zero_delay", "a,0", "a,0"],
            ["one_pkt", "a,10", "a,10"],
            ["in_order", "a,10,b,20", "a,10,b,20"],
            ["reverse_order", "a,20,b,10", "b,10,a,20"],
        ]:
            name = f"v{ipver}_{testcase[0]}"
            yield KsftNamedVariant(name, ipver, testcase[1], testcase[2])


@ksft_variants(_test_variants_fq())
def test_so_txtime_fq_mono(cfg, ipver, args_tx, args_rx):
    """Run all variants of monotonic (fq) tests."""
    cfg.require_ipver(ipver)
    _qdisc_setup(cfg.ifname, "fq")
    test_so_txtime(cfg, "mono", ipver, args_tx, args_rx, True)


@ksft_variants(_test_variants_fq())
def test_so_txtime_fq_tai(cfg, ipver, args_tx, args_rx):
    """Run all variants of fq tests, but pass CLOCK_TAI to test conversion."""
    cfg.require_ipver(ipver)
    _qdisc_setup(cfg.ifname, "fq")
    test_so_txtime(cfg, "tai", ipver, args_tx, args_rx, True)


def _test_variants_etf():
    for ipver in ["4", "6"]:
        for testcase in [
            ["no_delay", "a,-1", "a,-1", False],
            ["zero_delay", "a,0", "a,0", False],
            ["one_pkt", "a,10", "a,10", True],
            ["in_order", "a,10,b,20", "a,10,b,20", True],
            ["reverse_order", "a,20,b,10", "b,10,a,20", True],
        ]:
            name = f"v{ipver}_{testcase[0]}"
            yield KsftNamedVariant(
                name, ipver, testcase[1], testcase[2], testcase[3]
            )


@ksft_variants(_test_variants_etf())
def test_so_txtime_etf(cfg, ipver, args_tx, args_rx, expect_fail):
    """Run all variants of etf tests."""
    cfg.require_ipver(ipver)

    # root qdisc for background traffic (e.g., bkg())
    _qdisc_setup(cfg.ifname, "prio")

    # leaf ETF qdisc only for intended packets
    try:
        etf_args = "clockid CLOCK_TAI delta 400000"
        tc(f"qdisc add dev {cfg.ifname} parent 1:1 handle 10: etf {etf_args}")
    except Exception as e:
        raise KsftSkipEx("tc does not support qdisc etf. skipping") from e

    # redirect mark 100 to leaf
    filter_args = "protocol all handle 100 fw flowid 1:1"
    tc(f"filter add dev {cfg.ifname} parent 1: {filter_args}")

    test_so_txtime(cfg, "tai", ipver, args_tx, args_rx, expect_fail)


def main() -> None:
    """Boilerplate ksft main."""
    with NetDrvEpEnv(__file__) as cfg:
        ksft_run(
            [test_so_txtime_fq_mono, test_so_txtime_fq_tai, test_so_txtime_etf],
            args=(cfg,),
        )
    ksft_exit()


if __name__ == "__main__":
    main()