#
# Copyright (C) 2026 GNS3 Technologies Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

"""
Kernel-datapath (NIOBridge) adapter wiring for Docker containers: veth pair
creation, per-link kernel bridge enslavement, carrier semantics, relay
fallback and cleanup.
"""

import os
import uuid
from unittest.mock import MagicMock, call

import pytest
import pytest_asyncio

from tests.utils import AsyncioMagicMock

from gns3server.compute.docker import Docker
from gns3server.compute.docker.docker_vm import DockerVM
from gns3server.compute.docker.docker_error import DockerError
from gns3server.compute.compute_error import ComputeError
from gns3server.compute.nios.nio_udp import NIOUDP
from gns3server.compute.nios.nio_bridge import NIOBridge
from gns3server.compute.ubridge.ubridge_error import UbridgeError


BRIDGE = "gns3a1b2c3d4e5f"


@pytest_asyncio.fixture
async def manager(port_manager):

    m = Docker.instance()
    m.port_manager = port_manager
    return m


@pytest_asyncio.fixture(scope="function")
async def vm(compute_project, manager):

    vm = DockerVM("test", str(uuid.uuid4()), compute_project, manager, "ubuntu:latest", aux_type="none")
    vm._cid = "e90e34656842"
    vm.mac_address = '02:42:3d:b7:93:00'
    vm._start_interface_monitor = AsyncioMagicMock()
    vm._stop_interface_monitor = AsyncioMagicMock()
    return vm


# ---------------------------------------------------------------------------
# NIO factory
# ---------------------------------------------------------------------------

def test_create_nio_bridge(vm):

    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE})
    assert isinstance(nio, NIOBridge)
    assert nio.bridge == BRIDGE
    assert nio.suspend is False


def test_create_nio_bridge_rejects_filters(vm):

    with pytest.raises(ComputeError):
        vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE, "filters": {"loss": [10]}})


def test_create_nio_bridge_accepts_markers(vm):
    """
    Markers ride the kernel NIO (attached to the veth host end via uBridge's
    AF_PACKET marker module); only filters are rejected.
    """

    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE, "markers": {"m": {"bpf": "icmp"}}})
    assert isinstance(nio, NIOBridge)
    assert nio.markers == {"m": {"bpf": "icmp"}}


# ---------------------------------------------------------------------------
# Adapter wiring (start path)
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_add_ubridge_kernel_connection(vm):

    vm._ubridge_hypervisor = MagicMock()
    vm._namespace = 42
    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE})

    await vm._add_ubridge_connection(nio, 0)

    host_ifc, guest_ifc = vm._veth_names(0, 0)
    calls = [
        # stale-pair sweep (no-ops on a clean host)
        call.send(f'docker delete_veth "{host_ifc}"'),
        call.send(f'docker delete_veth "{guest_ifc}"'),
        call.send(f'docker create_veth "{host_ifc}" "{guest_ifc}"'),
        call.send(f'link set "{host_ifc}" down'),
        call.send(f'docker set_mac_addr {guest_ifc} 02:42:3d:b7:93:00'),
        call.send(f'docker move_to_ns {guest_ifc} 42 eth0'),
        # link attach
        call.send(f'brctl create "{BRIDGE}"'),
        call.send(f'link set "{BRIDGE}" up'),
        call.send(f'brctl addif "{BRIDGE}" "{host_ifc}"'),
        call.send(f'link set "{host_ifc}" up'),
    ]
    vm._ubridge_hypervisor.assert_has_calls(calls, any_order=True)
    assert vm._kernel_veths[(0, 0)] == host_ifc
    # no uBridge relay bridge on the kernel datapath
    assert "bridge0" not in vm._bridges


@pytest.mark.asyncio
async def test_add_ubridge_connection_none_nio_stays_on_tap_path(vm):
    """
    Unconnected adapters keep the relay TAP: the veth variant is only created
    for adapters whose NIO is a kernel one at start time.
    """

    vm._ubridge_hypervisor = MagicMock()
    vm._namespace = 42

    await vm._add_ubridge_connection(None, 0)

    vm._ubridge_hypervisor.assert_has_calls([
        call.send("bridge create bridge0"),
        call.send("bridge add_nio_tap bridge0 tap-gns3-e0 off"),
    ], any_order=True)
    assert vm._kernel_veths == {}


@pytest.mark.asyncio
async def test_add_ubridge_kernel_connection_cleans_up_on_failure(vm):

    vm._ubridge_hypervisor = MagicMock()
    vm._namespace = 42

    async def failing_send(command):
        if "create_veth" in command and "delete" not in command:
            raise UbridgeError("could not complete netlink transaction")

    vm._ubridge_send = AsyncioMagicMock(side_effect=failing_send)

    with pytest.raises(UbridgeError):
        await vm._add_ubridge_connection(vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE}), 0)

    host_ifc, _ = vm._veth_names(0, 0)
    vm._ubridge_send.assert_any_call(f'docker delete_veth "{host_ifc}"')
    assert (0, 0) not in vm._kernel_veths


# ---------------------------------------------------------------------------
# Link attach / detach
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_connect_nio_kernel_tolerates_bridge_create_race(vm):

    # Both endpoints create the per-link bridge concurrently; the loser must
    # verify (brctl show) instead of failing.
    async def send(command):
        if 'brctl create' in command:
            raise UbridgeError("Could not create bridge: File exists")

    vm._ubridge_send = AsyncioMagicMock(side_effect=send)
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc

    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE})
    await vm._connect_nio(0, nio)

    vm._ubridge_send.assert_any_call(f'brctl show "{BRIDGE}"')
    vm._ubridge_send.assert_any_call(f'brctl addif "{BRIDGE}" "{host_ifc}"')


@pytest.mark.asyncio
async def test_connect_nio_kernel_create_failure_propagates(vm):

    async def send(command):
        if 'brctl create' in command or 'brctl show' in command:
            raise UbridgeError("Could not create bridge: No such device")

    vm._ubridge_send = AsyncioMagicMock(side_effect=send)
    vm._kernel_veths[(0, 0)] = vm._veth_names(0, 0)[0]

    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE})
    with pytest.raises(UbridgeError):
        await vm._connect_nio(0, nio)


@pytest.mark.asyncio
async def test_connect_nio_kernel_without_veth_raises(vm):

    vm._ubridge_send = AsyncioMagicMock()
    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE})
    with pytest.raises(DockerError, match="restart the node"):
        await vm._connect_nio(0, nio)


@pytest.mark.asyncio
async def test_remove_kernel_nio(vm):

    vm._ubridge_hypervisor = MagicMock()
    vm._ubridge_send = AsyncioMagicMock()
    vm.status = "started"
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc
    vm._ethernet_adapters[0].add_nio(0, vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE}))

    await vm.adapter_remove_nio_binding(0)

    vm._ubridge_send.assert_has_calls([
        call(f'link set "{host_ifc}" down'),
        call(f'brctl delif "{BRIDGE}" "{host_ifc}"'),
        call(f'brctl delete "{BRIDGE}"'),
    ], any_order=True)
    assert vm._ethernet_adapters[0].get_nio(0) is None
    # the veth itself stays: it is the adapter interface, not the link
    assert vm._kernel_veths[(0, 0)] == host_ifc


@pytest.mark.asyncio
async def test_remove_kernel_nio_tolerates_peer_winning_bridge_delete(vm):

    # Deleting a bridge that still holds the peer's port fails with EBUSY;
    # a bridge already deleted by the peer fails with ENOENT — both expected.
    vm._ubridge_hypervisor = MagicMock()

    async def send(command):
        if 'brctl delif' in command or 'brctl delete' in command:
            raise UbridgeError("busy")

    vm._ubridge_send = AsyncioMagicMock(side_effect=send)
    vm._kernel_veths[(0, 0)] = vm._veth_names(0, 0)[0]
    vm._ethernet_adapters[0].add_nio(0, vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE}))

    await vm.adapter_remove_nio_binding(0)  # must not raise


# ---------------------------------------------------------------------------
# Carrier / suspend
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_set_adapter_carrier_kernel(vm):

    vm._ubridge_send = AsyncioMagicMock()
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc

    await vm._set_adapter_carrier(0, True)
    await vm._set_adapter_carrier(0, False)

    vm._ubridge_send.assert_has_calls([
        call(f'link set "{host_ifc}" up'),
        call(f'link set "{host_ifc}" down'),
    ])


# ---------------------------------------------------------------------------
# UDP fallback on a veth adapter (kernel link deleted, relay link created
# on a running node)
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_connect_nio_udp_relays_over_veth(vm):

    vm._ubridge_send = AsyncioMagicMock()
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc

    nio = vm.manager.create_nio({"type": "nio_udp", "lport": 4242, "rport": 4343, "rhost": "127.0.0.1"})
    await vm._connect_nio(0, nio)

    vm._ubridge_send.assert_has_calls([
        call("bridge create bridge0"),
        call(f'bridge add_nio_ethernet bridge0 "{host_ifc}"'),
        call("bridge add_nio_udp bridge0 4242 127.0.0.1 4343"),
        call("bridge start bridge0"),
    ], any_order=True)
    assert "bridge0" in vm._bridges


@pytest.mark.asyncio
async def test_connect_nio_udp_on_veth_is_idempotent(vm):

    vm._ubridge_send = AsyncioMagicMock()
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc
    vm._bridges.add("bridge0")  # relay already exists from a previous link

    nio = vm.manager.create_nio({"type": "nio_udp", "lport": 4242, "rport": 4343, "rhost": "127.0.0.1"})
    await vm._connect_nio(0, nio)

    for c in vm._ubridge_send.call_args_list:
        command = c.args[0]
        assert "bridge create" not in command
        assert "add_nio_ethernet" not in command


# ---------------------------------------------------------------------------
# Guards and cleanup
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_update_nio_kernel_rejects_filters(vm):

    vm._ubridge_hypervisor = MagicMock()
    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE})
    vm._ethernet_adapters[0].add_nio(0, nio)
    nio.filters = {"loss": [50]}

    with pytest.raises(DockerError, match="kernel-datapath"):
        await vm.adapter_update_nio_binding(0, nio)


@pytest.mark.asyncio
async def test_update_nio_kernel_suspend_toggles_carrier(vm):

    vm._ubridge_hypervisor = MagicMock()
    vm._ubridge_send = AsyncioMagicMock()
    vm.status = "started"
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc
    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE})
    vm._ethernet_adapters[0].add_nio(0, nio)

    nio.suspend = True
    await vm.adapter_update_nio_binding(0, nio)
    vm._ubridge_send.assert_any_call(f'link set "{host_ifc}" down')


@pytest.mark.asyncio
async def test_start_capture_kernel_uses_af_packet(vm):

    vm._ubridge_hypervisor = MagicMock()
    vm._ubridge_send = AsyncioMagicMock()
    vm.status = "started"
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc
    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE})
    vm._ethernet_adapters[0].add_nio(0, nio)

    await vm.start_capture(0, "/tmp/capture.pcap")

    assert nio.capturing is True
    vm._ubridge_send.assert_any_call(f'capture start_kernel {host_ifc} "/tmp/capture.pcap"')


@pytest.mark.asyncio
async def test_stop_capture_kernel(vm):

    vm._ubridge_hypervisor = MagicMock()
    vm._ubridge_send = AsyncioMagicMock()
    vm.status = "started"
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc
    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE})
    vm._ethernet_adapters[0].add_nio(0, nio)
    await vm.start_capture(0, "/tmp/capture.pcap")

    await vm.stop_capture(0)

    assert nio.capturing is False
    vm._ubridge_send.assert_any_call("capture stop_kernel")


@pytest.mark.asyncio
async def test_start_capture_second_concurrent_fails(vm):
    """
    uBridge's kernel capture is a singleton per process: a second concurrent
    capture returns EALREADY and must surface to the caller.
    """

    async def send(command):
        if "capture start_kernel" in command:
            raise UbridgeError("Could not start kernel capture: Operation already in progress")

    vm._ubridge_hypervisor = MagicMock()
    vm._ubridge_send = AsyncioMagicMock(side_effect=send)
    vm.status = "started"
    vm._kernel_veths[(0, 0)] = vm._veth_names(0, 0)[0]
    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE})
    vm._ethernet_adapters[0].add_nio(0, nio)

    with pytest.raises(UbridgeError, match="already in progress"):
        await vm.start_capture(0, "/tmp/capture.pcap")


@pytest.mark.asyncio
async def test_connect_nio_kernel_restarts_capture(vm):

    vm._ubridge_send = AsyncioMagicMock()
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc

    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE})
    nio.start_packet_capture("/tmp/capture.pcap")
    await vm._connect_nio(0, nio)

    vm._ubridge_send.assert_any_call(f'capture start_kernel {host_ifc} "/tmp/capture.pcap"')


# ---------------------------------------------------------------------------
# Markers (AF_PACKET taps on the veth host end)
# ---------------------------------------------------------------------------

def _marker_spec(bpf="icmp", tag=1, enabled=True, direction=None, link_id="l1"):
    return {"bpf": bpf, "tag": tag, "enabled": enabled, "direction": direction,
            "data_link_type": "DLT_EN10MB", "link_id": link_id}


@pytest.mark.asyncio
async def test_connect_nio_kernel_applies_markers(vm):

    vm._ubridge_send = AsyncioMagicMock()
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc

    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE, "markers": {"icmp-m": _marker_spec()}})
    await vm._connect_nio(0, nio)

    pcap = os.path.join(vm.project.markers_working_directory(), f"{vm.id}_l1_icmp-m.pcap")
    vm._ubridge_send.assert_any_call(f'marker add_kernel icmp-m {host_ifc} "icmp" tag 1 link l1 pcap "{pcap}"')
    assert vm._marker_filter_bridges[("icmp-m", "l1")] == host_ifc


@pytest.mark.asyncio
async def test_connect_nio_kernel_marker_disabled_at_apply(vm):
    """
    A disabled marker is installed but silenced (marker enable_kernel off) so
    the UI can flip it back on instantly — same contract as the relay path.
    """

    vm._ubridge_send = AsyncioMagicMock()
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc

    nio = vm.manager.create_nio(
        {"type": "nio_bridge", "bridge": BRIDGE, "markers": {"icmp-m": _marker_spec(enabled=False)}}
    )
    await vm._connect_nio(0, nio)

    vm._ubridge_send.assert_any_call(f"marker enable_kernel {host_ifc} icmp-m off")


@pytest.mark.asyncio
async def test_update_nio_kernel_applies_markers(vm):

    vm._ubridge_hypervisor = MagicMock()
    vm._ubridge_send = AsyncioMagicMock()
    vm.status = "started"
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc
    nio = vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE})
    vm._ethernet_adapters[0].add_nio(0, nio)

    nio.markers = {"tcp-m": _marker_spec(bpf="tcp", tag=2, link_id="l2")}
    await vm.adapter_update_nio_binding(0, nio)

    pcap = os.path.join(vm.project.markers_working_directory(), f"{vm.id}_l2_tcp-m.pcap")
    vm._ubridge_send.assert_any_call(f'marker add_kernel tcp-m {host_ifc} "tcp" tag 2 link l2 pcap "{pcap}"')


@pytest.mark.asyncio
async def test_marker_toggle_kernel_uses_enable_kernel(vm):

    vm._ubridge_send = AsyncioMagicMock()
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc
    vm._marker_filter_bridges[("icmp-m", "l1")] = host_ifc

    await vm._ubridge_set_marker_filter_state("icmp-m", False)
    vm._ubridge_send.assert_any_call(f"marker enable_kernel {host_ifc} icmp-m off")
    await vm._ubridge_set_marker_filter_state("icmp-m", True)
    vm._ubridge_send.assert_any_call(f"marker enable_kernel {host_ifc} icmp-m on")


@pytest.mark.asyncio
async def test_remove_kernel_nio_deletes_markers(vm):
    """
    The veth survives link deletion (it is the adapter interface), so kernel
    markers must be torn down explicitly — otherwise a deleted link's markers
    would keep sniffing and signaling.
    """

    vm._ubridge_hypervisor = MagicMock()
    vm._ubridge_send = AsyncioMagicMock()
    vm.status = "started"
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc
    vm._marker_filter_bridges[("icmp-m", "l1")] = host_ifc
    vm._marker_specs[("icmp-m", "l1")] = _marker_spec()
    vm._ethernet_adapters[0].add_nio(0, vm.manager.create_nio({"type": "nio_bridge", "bridge": BRIDGE}))

    await vm.adapter_remove_nio_binding(0)

    vm._ubridge_send.assert_any_call(f"marker delete_kernel {host_ifc} icmp-m")
    assert ("icmp-m", "l1") not in vm._marker_filter_bridges
    assert ("icmp-m", "l1") not in vm._marker_specs


@pytest.mark.asyncio
async def test_rebuild_marker_filter_kernel(vm):
    """
    The fine-grained rebuild path (bpf/tag/direction change) goes through the
    overridden primitives: delete_kernel + add_kernel with the new expression.
    """

    vm._ubridge_hypervisor = MagicMock()
    vm._ubridge_send = AsyncioMagicMock()
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc
    vm._marker_filter_bridges[("icmp-m", "l1")] = host_ifc

    await vm.rebuild_marker_filter("icmp-m", "l1", "tcp", tag=9)

    pcap = os.path.join(vm.project.markers_working_directory(), f"{vm.id}_l1_icmp-m.pcap")
    vm._ubridge_send.assert_any_call(f"marker delete_kernel {host_ifc} icmp-m")
    vm._ubridge_send.assert_any_call(f'marker add_kernel icmp-m {host_ifc} "tcp" tag 9 link l1 pcap "{pcap}"')


@pytest.mark.asyncio
async def test_remove_kernel_veths(vm):

    vm._ubridge_hypervisor = MagicMock()
    vm._ubridge_send = AsyncioMagicMock()
    host_ifc, _ = vm._veth_names(0, 0)
    vm._kernel_veths[(0, 0)] = host_ifc

    await vm._remove_kernel_veths()

    vm._ubridge_send.assert_called_once_with(f'docker delete_veth "{host_ifc}"')
    assert vm._kernel_veths == {}


def test_veth_names_deterministic_and_bounded(vm):

    host_ifc, guest_ifc = vm._veth_names(3, 2)
    assert host_ifc == f"gv{vm.id.replace('-', '')[:8]}e3p2"
    assert guest_ifc == f"gc{vm.id.replace('-', '')[:8]}e3p2"
    assert host_ifc != guest_ifc
    # multi-port adapters can reach two-digit adapter/port numbers
    long_host, long_guest = vm._veth_names(12, 8)
    assert len(long_host) <= 15 and len(long_guest) <= 15