param(
    [string]$ApiBaseUrl = "http://192.168.200.61:18121/api/v1",
    [string]$ClusterID = "cfc0743d-d960-49fb-9de8-96e063d5e4aa",
    [string]$ActorUserID = "f67d943f-5397-4b3a-a229-695fe67ad700",
    [string]$EntryNodeName = "test-1",
    [string]$RelayNodeName = "test-3",
    [string]$ExitNodeName = "test-2",
    [string]$EntryBaseUrl = "http://192.168.200.61:19131",
    [string]$DockerSSH = "test-docker",
    [int]$InitialBatchCount = 12,
    [int]$LearningBatchCount = 24,
    [int]$PostChurnBatchCount = 24,
    [int]$PacketsPerBatch = 8,
    [int]$BatchDelayMilliseconds = 25,
    [string]$ResultPath = "artifacts\c18z14-live-service-channel-active-quality-shift-smoke-result.json"
)

Set-StrictMode -Version Latest
$ErrorActionPreference = "Stop"
Add-Type -AssemblyName System.Net.Http

$repoRoot = (Resolve-Path (Join-Path $PSScriptRoot "..\..")).ProviderPath
$runId = "c18z14-" + (Get-Date -Format "yyyyMMdd-HHmmss")
$resourceId = "vpn-$runId"

function Invoke-Api {
    param([string]$Method, [string]$Path, [object]$Body = $null)
    $uri = "$ApiBaseUrl$Path"
    try {
        if ($null -eq $Body) {
            return Invoke-RestMethod -Method $Method -Uri $uri -TimeoutSec 30
        }
        return Invoke-RestMethod -Method $Method -Uri $uri -ContentType "application/json" -Body ($Body | ConvertTo-Json -Depth 100) -TimeoutSec 30
    } catch {
        $statusCode = $null
        if ($_.Exception.Response) { $statusCode = [int]$_.Exception.Response.StatusCode }
        $details = $_.ErrorDetails.Message
        if (-not $details) { $details = $_.Exception.Message }
        throw "$Method $Path failed with HTTP $statusCode`: $details"
    }
}

function Get-ObjectPropertyValue {
    param([object]$Object, [string]$Name)
    if ($null -eq $Object) { return $null }
    $prop = $Object.PSObject.Properties[$Name]
    if ($null -eq $prop) { return $null }
    return $prop.Value
}

function Get-NodeByName {
    param([string]$Name)
    $nodes = (Invoke-Api -Method GET -Path "/clusters/$ClusterID/nodes?actor_user_id=$ActorUserID").nodes
    $node = @($nodes | Where-Object { $_.name -eq $Name }) | Select-Object -First 1
    if ($null -eq $node) { throw "Node '$Name' was not found in cluster $ClusterID" }
    return $node
}

function Get-MeshPort {
    param([string]$Name)
    switch ($Name) {
        "test-1" { return 19131 }
        "test-2" { return 19132 }
        "test-3" { return 19133 }
        default { return 19131 }
    }
}

function Enable-TestMeshListener {
    param([object]$Node)
    $port = Get-MeshPort -Name $Node.name
    Invoke-Api -Method PUT -Path "/clusters/$ClusterID/nodes/$($Node.id)/workloads/fabric-listener/desired" -Body @{
        actor_user_id = $ActorUserID
        desired_state = "enabled"
        runtime_mode = "container"
        version = "c18z14-live-fsc-active-quality-shift"
        config = @{
            listen_addr = "0.0.0.0:$port"
            listen_port_mode = "manual"
            advertise_endpoint = "http://192.168.200.61:$port"
            advertise_transport = "direct_http"
            connectivity_mode = "private_lan"
            nat_type = "none"
            region = "docker-test"
            production_forwarding = $true
        }
        environment = @{}
    } | Out-Null
}

function Get-SmokeRouteLabel {
    param([object]$RouteIntent)
    if ($null -eq $RouteIntent -or $null -eq $RouteIntent.PSObject.Properties["policy"]) { return "" }
    if ($null -eq $RouteIntent.policy -or $null -eq $RouteIntent.policy.PSObject.Properties["metadata"]) { return "" }
    $metadata = $RouteIntent.policy.metadata
    if ($null -eq $metadata) { return "" }
    $smoke = $metadata.PSObject.Properties["smoke"]
    if ($null -eq $smoke) { return "" }
    return [string]$smoke.Value
}

function Clear-SmokeRouteIntents {
    $items = (Invoke-Api -Method GET -Path "/clusters/$ClusterID/mesh/route-intents?actor_user_id=$ActorUserID").route_intents
    foreach ($item in @($items)) {
        if ([string]$item.lifecycle_status -ne "active" -or [string]$item.service_class -ne "vpn_packets") { continue }
        if ((Get-SmokeRouteLabel -RouteIntent $item) -ne "c18z14_live_service_channel_active_quality_shift") { continue }
        Invoke-Api -Method POST -Path "/clusters/$ClusterID/mesh/route-intents/$($item.id)/expire" -Body @{ actor_user_id = $ActorUserID } | Out-Null
    }
}

function New-RouteIntent {
    param([string]$SourceNodeID, [string]$DestinationNodeID, [string[]]$Hops, [int]$Priority, [string]$Label)
    $expiresAt = (Get-Date).ToUniversalTime().AddMinutes(10).ToString("o")
    return Invoke-Api -Method POST -Path "/clusters/$ClusterID/mesh/route-intents" -Body @{
        actor_user_id = $ActorUserID
        source_selector = @{ node_id = $SourceNodeID }
        destination_selector = @{ node_id = $DestinationNodeID }
        service_class = "vpn_packets"
        priority = $Priority
        policy = @{
            synthetic_enabled = $true
            route_version = "$runId-$Label"
            policy_version = "$runId-$Label"
            peer_directory_version = "$runId-$Label"
            hops = @($Hops)
            allowed_channels = @("vpn_packet", "fabric_control")
            max_ttl = 8
            max_hops = 8
            expires_at = $expiresAt
            metadata = @{
                smoke = "c18z14_live_service_channel_active_quality_shift"
                run_id = $runId
                label = $Label
                active_quality_shift_smoke = $true
            }
        }
    }
}

function Get-SyntheticConfig { param([string]$NodeID) return Invoke-Api -Method GET -Path "/clusters/$ClusterID/nodes/$NodeID/mesh/synthetic-config?actor_user_id=$ActorUserID" }
function Get-LatestHeartbeat { param([string]$NodeID) return (Invoke-Api -Method GET -Path "/clusters/$ClusterID/nodes/$NodeID/heartbeats?actor_user_id=$ActorUserID&limit=1").heartbeats[0] }
function Get-LatestRuntimeReport {
    param([string]$NodeID)
    $hb = Get-LatestHeartbeat -NodeID $NodeID
    return @{ heartbeat = $hb; report = $hb.metadata.fabric_service_channel_runtime_report }
}

function Wait-ForRuntimeReady {
    param([string]$NodeID, [int]$MinRoutes, [int]$TimeoutSeconds = 90)
    $deadline = (Get-Date).AddSeconds($TimeoutSeconds)
    do {
        $latest = Get-LatestRuntimeReport -NodeID $NodeID
        if ($null -ne $latest.report -and $latest.report.enabled -eq $true -and $latest.report.production_payload_forwarding -eq $true -and [int]$latest.report.route_candidate_total -ge $MinRoutes) {
            return $latest
        }
        Start-Sleep -Seconds 2
    } while ((Get-Date) -lt $deadline)
    throw "Timed out waiting for production service-channel runtime ready on node $NodeID"
}

function Wait-ForRuntimeConfigVersion {
    param([string]$NodeID, [string]$ConfigVersion, [int]$TimeoutSeconds = 90)
    $deadline = (Get-Date).AddSeconds($TimeoutSeconds)
    do {
        $latest = Get-LatestRuntimeReport -NodeID $NodeID
        if ($null -ne $latest.report -and [string]$latest.report.config_version -ge $ConfigVersion) { return $latest }
        Start-Sleep -Seconds 2
    } while ((Get-Date) -lt $deadline)
    throw "Timed out waiting for node $NodeID to load synthetic config $ConfigVersion"
}

function Wait-ForRouteIntentVisible {
    param([string]$NodeID, [string[]]$RouteIDs, [int]$TimeoutSeconds = 60)
    $deadline = (Get-Date).AddSeconds($TimeoutSeconds)
    do {
        $config = Get-SyntheticConfig -NodeID $NodeID
        $present = @($config.synthetic_mesh_config.routes | Where-Object { $RouteIDs -contains $_.route_id })
        if ($present.Count -ge $RouteIDs.Count) { return $config }
        Start-Sleep -Seconds 2
    } while ((Get-Date) -lt $deadline)
    throw "Timed out waiting for routes '$($RouteIDs -join ",")' in synthetic config for node $NodeID"
}

function Wait-ForRouteIntentNotVisible {
    param([string]$NodeID, [string]$RouteID, [int]$TimeoutSeconds = 90)
    $deadline = (Get-Date).AddSeconds($TimeoutSeconds)
    do {
        $config = Get-SyntheticConfig -NodeID $NodeID
        $present = @($config.synthetic_mesh_config.routes | Where-Object { $_.route_id -eq $RouteID })
        if ($present.Count -eq 0) { return $config }
        Start-Sleep -Seconds 2
    } while ((Get-Date) -lt $deadline)
    throw "Timed out waiting for route '$RouteID' to disappear from synthetic config for node $NodeID"
}

function Wait-ForRouteFeedback {
    param([string]$ReporterNodeID, [string]$RouteID, [int]$TimeoutSeconds = 120)
    $deadline = (Get-Date).AddSeconds($TimeoutSeconds)
    do {
        $response = Invoke-Api -Method GET -Path "/clusters/$ClusterID/fabric/service-channels/route-feedback?actor_user_id=$ActorUserID&reporter_node_id=$ReporterNodeID&route_id=$RouteID&service_class=vpn_packets"
        $item = @($response.route_feedback | Where-Object { $_.route_id -eq $RouteID -and $_.feedback_status -eq "healthy" }) | Select-Object -First 1
        if ($null -ne $item) { return $item }
        Start-Sleep -Seconds 2
    } while ((Get-Date) -lt $deadline)
    throw "Timed out waiting for live route feedback for route '$RouteID'"
}

function Wait-ForQualityPreferenceApplied {
    param([string]$NodeID, [int]$TimeoutSeconds = 120)
    $deadline = (Get-Date).AddSeconds($TimeoutSeconds)
    do {
        $latest = Get-LatestRuntimeReport -NodeID $NodeID
        $count = Get-ObjectPropertyValue -Object $latest.report.ingress -Name "route_quality_preference_count"
        if ($null -ne $count -and [int]$count -gt 0) { return $latest }
        Start-Sleep -Seconds 2
    } while ((Get-Date) -lt $deadline)
    throw "Timed out waiting for route quality preferences on node $NodeID"
}

function New-ServiceChannelLease {
    param([string]$EntryNodeID, [string]$ExitNodeID)
    return (Invoke-Api -Method POST -Path "/clusters/$ClusterID/fabric/service-channels/leases" -Body @{
        actor_user_id = $ActorUserID
        organization_id = "org-c18z14-smoke"
        user_id = $ActorUserID
        resource_id = $resourceId
        service_class = "vpn_packets"
        entry_node_ids = @($EntryNodeID)
        exit_node_ids = @($ExitNodeID)
        preferred_entry_node_id = $EntryNodeID
        preferred_exit_node_id = $ExitNodeID
        allowed_channels = @("vpn_packet", "bulk", "control")
        ttl_seconds = 300
        metadata = @{ smoke = "c18z14_live_service_channel_active_quality_shift"; run_id = $runId }
    }).fabric_service_channel_lease
}

function ConvertTo-Base64UrlJson {
    param([object]$Value)
    $json = $Value | ConvertTo-Json -Depth 100 -Compress
    $bytes = [System.Text.Encoding]::UTF8.GetBytes($json)
    return [Convert]::ToBase64String($bytes).TrimEnd("=").Replace("+", "-").Replace("/", "_")
}

function ConvertTo-WebSocketURL {
    param([string]$URL)
    if ($URL.StartsWith("https://")) { return "wss://" + $URL.Substring("https://".Length) }
    if ($URL.StartsWith("http://")) { return "ws://" + $URL.Substring("http://".Length) }
    return $URL
}

function New-TestIPv4UDPPacket {
    param([int]$SourcePort)
    $payload = [System.Text.Encoding]::ASCII.GetBytes("c18z14-$SourcePort")
    $totalLength = 20 + 8 + $payload.Length
    $packet = New-Object byte[] $totalLength
    $packet[0] = 0x45
    $packet[2] = [byte](($totalLength -shr 8) -band 0xff)
    $packet[3] = [byte]($totalLength -band 0xff)
    $packet[8] = 64
    $packet[9] = 17
    $packet[12] = 10; $packet[13] = 18; $packet[14] = 14; $packet[15] = 10
    $packet[16] = 10; $packet[17] = 18; $packet[18] = 14; $packet[19] = 20
    $udpOffset = 20
    $destPort = 3389
    $udpLength = 8 + $payload.Length
    $packet[$udpOffset] = [byte](($SourcePort -shr 8) -band 0xff)
    $packet[$udpOffset + 1] = [byte]($SourcePort -band 0xff)
    $packet[$udpOffset + 2] = [byte](($destPort -shr 8) -band 0xff)
    $packet[$udpOffset + 3] = [byte]($destPort -band 0xff)
    $packet[$udpOffset + 4] = [byte](($udpLength -shr 8) -band 0xff)
    $packet[$udpOffset + 5] = [byte]($udpLength -band 0xff)
    [Array]::Copy($payload, 0, $packet, 28, $payload.Length)
    return $packet
}

function New-PacketBatchBody {
    param([byte[][]]$Packets)
    $stream = [System.IO.MemoryStream]::new()
    foreach ($packet in $Packets) {
        $length = $packet.Length
        $stream.WriteByte([byte](($length -shr 24) -band 0xff))
        $stream.WriteByte([byte](($length -shr 16) -band 0xff))
        $stream.WriteByte([byte](($length -shr 8) -band 0xff))
        $stream.WriteByte([byte]($length -band 0xff))
        $stream.Write($packet, 0, $packet.Length)
    }
    return $stream.ToArray()
}

function Open-ServiceChannelWebSocket {
    param([object]$Lease)
    $path = $Lease.entry_http.websocket_path_template.Replace("{cluster_id}", $ClusterID).Replace("{channel_id}", $Lease.channel_id).Replace("{resource_id}", $resourceId)
    $url = ConvertTo-WebSocketURL -URL "$EntryBaseUrl$path"
    $socket = [System.Net.WebSockets.ClientWebSocket]::new()
    [void]$socket.Options.SetRequestHeader("X-RAP-Service-Channel-Token", [string]$Lease.token.token)
    [void]$socket.Options.SetRequestHeader("X-RAP-Fabric-Channel-ID", [string]$Lease.channel_id)
    [void]$socket.Options.SetRequestHeader("X-RAP-Service-Class", "vpn_packets")
    [void]$socket.Options.SetRequestHeader("X-RAP-Channel-Class", "vpn_packet")
    [void]$socket.Options.SetRequestHeader("X-RAP-Service-Channel-Authority-Payload", (ConvertTo-Base64UrlJson -Value $Lease.authority_payload))
    [void]$socket.Options.SetRequestHeader("X-RAP-Service-Channel-Authority-Signature", (ConvertTo-Base64UrlJson -Value $Lease.authority_signature))
    $cts = [System.Threading.CancellationTokenSource]::new([TimeSpan]::FromSeconds(30))
    [void]$socket.ConnectAsync([Uri]$url, $cts.Token).GetAwaiter().GetResult()
    $cts.Dispose()
    return @{
        Socket = $socket
        Url = $url
        SentBatches = 0
        SentPackets = 0
    }
}

function Send-ServiceChannelWebSocketBatches {
    param([object]$Session, [int]$Count, [int]$PortBase)
    for ($batch = 0; $batch -lt $Count; $batch++) {
        $packets = @()
        for ($i = 0; $i -lt $PacketsPerBatch; $i++) {
            $packets += ,(New-TestIPv4UDPPacket -SourcePort ($PortBase + ($batch * 100) + $i))
        }
        $body = New-PacketBatchBody -Packets $packets
        $segment = [ArraySegment[byte]]::new($body)
        $cts = [System.Threading.CancellationTokenSource]::new([TimeSpan]::FromSeconds(30))
        [void]$Session.Socket.SendAsync($segment, [System.Net.WebSockets.WebSocketMessageType]::Binary, $true, $cts.Token).GetAwaiter().GetResult()
        $cts.Dispose()
        $Session.SentBatches++
        $Session.SentPackets += $packets.Count
        if ($BatchDelayMilliseconds -gt 0) { Start-Sleep -Milliseconds $BatchDelayMilliseconds }
    }
    Start-Sleep -Milliseconds 500
}

function Close-ServiceChannelWebSocket {
    param([object]$Session)
    if ($null -eq $Session -or $null -eq $Session.Socket) { return }
    try {
        if ($Session.Socket.State -eq [System.Net.WebSockets.WebSocketState]::Open) {
            $cts = [System.Threading.CancellationTokenSource]::new([TimeSpan]::FromSeconds(10))
            [void]$Session.Socket.CloseOutputAsync([System.Net.WebSockets.WebSocketCloseStatus]::NormalClosure, "c18z14 sent", $cts.Token).GetAwaiter().GetResult()
            $cts.Dispose()
        }
    } finally {
        $Session.Socket.Dispose()
    }
}

function Get-ExitQueueDepth {
    param([string]$NodeID, [string]$VPNConnectionID)
    $latest = Get-LatestRuntimeReport -NodeID $NodeID
    $queueKey = "$VPNConnectionID`:client_to_gateway"
    $depths = $latest.report.inbox.queue_depths
    if ($null -eq $depths) { return 0 }
    $prop = $depths.PSObject.Properties[$queueKey]
    if ($null -eq $prop) { return 0 }
    return [int]$prop.Value
}

function Wait-ForExitQueueDepth {
    param([string]$NodeID, [string]$VPNConnectionID, [int]$MinDepth, [int]$TimeoutSeconds = 90)
    $deadline = (Get-Date).AddSeconds($TimeoutSeconds)
    do {
        $depth = Get-ExitQueueDepth -NodeID $NodeID -VPNConnectionID $VPNConnectionID
        if ($depth -ge $MinDepth) { return $depth }
        Start-Sleep -Seconds 2
    } while ((Get-Date) -lt $deadline)
    throw "Timed out waiting for exit queue depth >= $MinDepth on node $NodeID"
}

function Get-IngressFlowDropped {
    param([string]$NodeID)
    $latest = Get-LatestRuntimeReport -NodeID $NodeID
    $flowScheduler = Get-ObjectPropertyValue -Object $latest.report.ingress -Name "flow_scheduler"
    $dropped = Get-ObjectPropertyValue -Object $flowScheduler -Name "dropped"
    if ($null -eq $dropped) { return 0 }
    return [int]$dropped
}

function Get-BackendClientGatewayDepth {
    param([string]$VPNConnectionID)
    $stats = (Invoke-Api -Method GET -Path "/clusters/$ClusterID/vpn-connections/$VPNConnectionID/tunnel/stats").vpn_packet_stats
    $queue = $stats.client_to_gateway
    if ($null -eq $queue) { return 0 }
    $depth = Get-ObjectPropertyValue -Object $queue -Name "queue_depth"
    if ($null -eq $depth) { return 0 }
    return [int]$depth
}

function Invoke-RemoteDocker {
    param([string]$Command)
    & ssh $DockerSSH $Command
    if ($LASTEXITCODE -ne 0) { throw "ssh $DockerSSH command failed: $Command" }
}

function Stop-TestUpdaters { Invoke-RemoteDocker -Command "docker stop rap_host_agent_updater_test-1 rap_host_agent_updater_test-2 rap_host_agent_updater_test-3 >/dev/null 2>&1 || true" }
function Start-TestUpdaters { Invoke-RemoteDocker -Command "docker start rap_host_agent_updater_test-1 rap_host_agent_updater_test-2 rap_host_agent_updater_test-3 >/dev/null 2>&1 || true" }

$entryNode = Get-NodeByName -Name $EntryNodeName
$relayNode = Get-NodeByName -Name $RelayNodeName
$exitNode = Get-NodeByName -Name $ExitNodeName
$slowInitialRouteID = ""
$fastRouteID = ""
$slowCandidateRouteID = ""
$session = $null
$updatersStopped = $false
$result = $null

try {
    Stop-TestUpdaters
    $updatersStopped = $true
    Enable-TestMeshListener -Node $entryNode
    Enable-TestMeshListener -Node $relayNode
    Enable-TestMeshListener -Node $exitNode
    Clear-SmokeRouteIntents

    $slowInitial = New-RouteIntent -SourceNodeID $entryNode.id -DestinationNodeID $exitNode.id -Hops @($entryNode.id, $relayNode.id, $exitNode.id) -Priority 1999999960 -Label "slow-initial"
    $fast = New-RouteIntent -SourceNodeID $entryNode.id -DestinationNodeID $exitNode.id -Hops @($entryNode.id, $exitNode.id) -Priority 1999999950 -Label "fast-live"
    $slowInitialRouteID = $slowInitial.route_intent.id
    $fastRouteID = $fast.route_intent.id

    $visibleConfig = Wait-ForRouteIntentVisible -NodeID $entryNode.id -RouteIDs @($slowInitialRouteID, $fastRouteID)
    $exitVisibleConfig = Wait-ForRouteIntentVisible -NodeID $exitNode.id -RouteIDs @($slowInitialRouteID, $fastRouteID)
    $readyBefore = Wait-ForRuntimeReady -NodeID $entryNode.id -MinRoutes 2
    $exitReadyBefore = Wait-ForRuntimeReady -NodeID $exitNode.id -MinRoutes 0
    $loadedConfig = Wait-ForRuntimeConfigVersion -NodeID $entryNode.id -ConfigVersion $visibleConfig.synthetic_mesh_config.config_version
    $exitLoadedConfig = Wait-ForRuntimeConfigVersion -NodeID $exitNode.id -ConfigVersion $exitVisibleConfig.synthetic_mesh_config.config_version

    $lease = New-ServiceChannelLease -EntryNodeID $entryNode.id -ExitNodeID $exitNode.id
    if ($lease.status -ne "ready" -or [string]$lease.primary_route.route_id -ne $slowInitialRouteID) {
        throw "Initial lease should select slow route '$slowInitialRouteID': status=$($lease.status) route=$($lease.primary_route.route_id)"
    }

    $baselineExitDepth = Get-ExitQueueDepth -NodeID $exitNode.id -VPNConnectionID $resourceId
    $baselineBackendDepth = Get-BackendClientGatewayDepth -VPNConnectionID $resourceId
    $baselineDropped = Get-IngressFlowDropped -NodeID $entryNode.id
    $session = Open-ServiceChannelWebSocket -Lease $lease

    Send-ServiceChannelWebSocketBatches -Session $session -Count $InitialBatchCount -PortBase 62000
    $initialPackets = $InitialBatchCount * $PacketsPerBatch
    $initialExitDepth = Wait-ForExitQueueDepth -NodeID $exitNode.id -VPNConnectionID $resourceId -MinDepth ($baselineExitDepth + $initialPackets)
    $initialRuntime = Get-LatestRuntimeReport -NodeID $entryNode.id
    if ([string]$initialRuntime.report.ingress.last_selected_route_id -ne $slowInitialRouteID) {
        throw "Initial active websocket route was '$($initialRuntime.report.ingress.last_selected_route_id)', want slow route '$slowInitialRouteID'"
    }

    $expiredSlowInitial = Invoke-Api -Method POST -Path "/clusters/$ClusterID/mesh/route-intents/$slowInitialRouteID/expire" -Body @{ actor_user_id = $ActorUserID }
    $notVisibleConfig = Wait-ForRouteIntentNotVisible -NodeID $entryNode.id -RouteID $slowInitialRouteID
    $fastOnlyRuntime = Wait-ForRuntimeConfigVersion -NodeID $entryNode.id -ConfigVersion $notVisibleConfig.synthetic_mesh_config.config_version

    Send-ServiceChannelWebSocketBatches -Session $session -Count $LearningBatchCount -PortBase 64000
    $learningPackets = $LearningBatchCount * $PacketsPerBatch
    $learnedExitDepth = Wait-ForExitQueueDepth -NodeID $exitNode.id -VPNConnectionID $resourceId -MinDepth ($baselineExitDepth + $initialPackets + $learningPackets) -TimeoutSeconds 120
    $fastFeedback = Wait-ForRouteFeedback -ReporterNodeID $entryNode.id -RouteID $fastRouteID -TimeoutSeconds 120

    $slowCandidate = New-RouteIntent -SourceNodeID $entryNode.id -DestinationNodeID $exitNode.id -Hops @($entryNode.id, $relayNode.id, $exitNode.id) -Priority 1999999960 -Label "slow-candidate"
    $slowCandidateRouteID = $slowCandidate.route_intent.id
    $candidateVisibleConfig = Wait-ForRouteIntentVisible -NodeID $entryNode.id -RouteIDs @($slowCandidateRouteID, $fastRouteID)
    $candidateLoadedConfig = Wait-ForRuntimeConfigVersion -NodeID $entryNode.id -ConfigVersion $candidateVisibleConfig.synthetic_mesh_config.config_version
    $qualityRuntime = Wait-ForQualityPreferenceApplied -NodeID $entryNode.id -TimeoutSeconds 120

    Send-ServiceChannelWebSocketBatches -Session $session -Count $PostChurnBatchCount -PortBase 67000
    $postChurnPackets = $PostChurnBatchCount * $PacketsPerBatch
    $finalExitDepth = Wait-ForExitQueueDepth -NodeID $exitNode.id -VPNConnectionID $resourceId -MinDepth ($baselineExitDepth + $initialPackets + $learningPackets + $postChurnPackets) -TimeoutSeconds 120
    $finalRuntime = Get-LatestRuntimeReport -NodeID $entryNode.id
    if ([string]$finalRuntime.report.ingress.last_selected_route_id -ne $fastRouteID) {
        throw "Post-churn active websocket route was '$($finalRuntime.report.ingress.last_selected_route_id)', want learned fast route '$fastRouteID'"
    }

    $sessionURL = $session.Url
    $sessionSentBatches = $session.SentBatches
    $sessionSentPackets = $session.SentPackets
    Close-ServiceChannelWebSocket -Session $session
    $session = $null

    $finalDropped = Get-IngressFlowDropped -NodeID $entryNode.id
    $finalBackendDepth = Get-BackendClientGatewayDepth -VPNConnectionID $resourceId
    $expiredFastFeedback = Invoke-Api -Method POST -Path "/clusters/$ClusterID/fabric/service-channels/route-feedback/expire" -Body @{
        actor_user_id = $ActorUserID
        reporter_node_id = $entryNode.id
        route_id = $fastRouteID
        service_class = "vpn_packets"
        reason = "c18z14 active quality shift smoke cleanup"
    }
    $expiredSlowCandidate = Invoke-Api -Method POST -Path "/clusters/$ClusterID/mesh/route-intents/$slowCandidateRouteID/expire" -Body @{ actor_user_id = $ActorUserID }
    $expiredFast = Invoke-Api -Method POST -Path "/clusters/$ClusterID/mesh/route-intents/$fastRouteID/expire" -Body @{ actor_user_id = $ActorUserID }

    $result = [ordered]@{
        schema_version = "c18z14.live_service_channel_active_quality_shift_smoke.v1"
        run_id = $runId
        base_url = $ApiBaseUrl
        entry_base_url = $EntryBaseUrl
        cluster_id = $ClusterID
        entry_node = @{ name = $entryNode.name; id = $entryNode.id }
        relay_node = @{ name = $relayNode.name; id = $relayNode.id }
        exit_node = @{ name = $exitNode.name; id = $exitNode.id }
        resource_id = $resourceId
        route_intents = @{
            slow_initial_route_id = $slowInitialRouteID
            fast_route_id = $fastRouteID
            slow_candidate_route_id = $slowCandidateRouteID
            slow_initial_status = $expiredSlowInitial.route_intent.lifecycle_status
            slow_candidate_status = $expiredSlowCandidate.route_intent.lifecycle_status
            fast_status = $expiredFast.route_intent.lifecycle_status
        }
        lease = @{
            status = $lease.status
            channel_id = $lease.channel_id
            primary_route_id = $lease.primary_route.route_id
        }
        active_websocket = @{
            url = $sessionURL
            initial_batches = $InitialBatchCount
            learning_batches = $LearningBatchCount
            post_churn_batches = $PostChurnBatchCount
            packets_per_batch = $PacketsPerBatch
            sent_batches = $sessionSentBatches
            sent_packets = $sessionSentPackets
            initial_route_id = $initialRuntime.report.ingress.last_selected_route_id
            final_route_id = $finalRuntime.report.ingress.last_selected_route_id
        }
        live_feedback = @{
            route_id = $fastFeedback.route_id
            feedback_status = $fastFeedback.feedback_status
            score_adjustment = $fastFeedback.score_adjustment
            reasons = $fastFeedback.reasons
            last_send_duration_ms = $fastFeedback.last_send_duration_ms
            expire_result = $expiredFastFeedback.route_feedback_expire
        }
        exit_queue = @{
            baseline_depth = $baselineExitDepth
            initial_depth = $initialExitDepth
            learned_depth = $learnedExitDepth
            final_depth = $finalExitDepth
        }
        degraded_route_queue = @{ baseline_depth = $baselineBackendDepth; depth = $finalBackendDepth }
        flow_drops = @{ baseline = $baselineDropped; final = $finalDropped; delta = ($finalDropped - $baselineDropped) }
        passed = $true
        checks = [ordered]@{
            production_forwarding_ready = ($readyBefore.report.production_payload_forwarding -eq $true)
            exit_production_forwarding_ready = ($exitReadyBefore.report.production_payload_forwarding -eq $true)
            entry_runtime_loaded_visible_config = ([string]$loadedConfig.report.config_version -ge [string]$visibleConfig.synthetic_mesh_config.config_version)
            exit_runtime_loaded_visible_config = ([string]$exitLoadedConfig.report.config_version -ge [string]$exitVisibleConfig.synthetic_mesh_config.config_version)
            initial_lease_selected_slow_route = ([string]$lease.primary_route.route_id -eq $slowInitialRouteID)
            active_websocket_started_on_slow_route = ([string]$initialRuntime.report.ingress.last_selected_route_id -eq $slowInitialRouteID)
            fast_only_runtime_loaded_after_slow_expire = ([string]$fastOnlyRuntime.report.config_version -ge [string]$notVisibleConfig.synthetic_mesh_config.config_version)
            backend_persisted_live_fast_feedback = ([string]$fastFeedback.route_id -eq $fastRouteID -and [string]$fastFeedback.feedback_status -eq "healthy")
            candidate_runtime_loaded = ([string]$candidateLoadedConfig.report.config_version -ge [string]$candidateVisibleConfig.synthetic_mesh_config.config_version)
            node_applied_quality_preference = ([int]$qualityRuntime.report.ingress.route_quality_preference_count -gt 0)
            active_websocket_stayed_on_learned_fast_route_after_churn = ([string]$finalRuntime.report.ingress.last_selected_route_id -eq $fastRouteID)
            all_packets_reached_exit = ($finalExitDepth -ge ($baselineExitDepth + $initialPackets + $learningPackets + $postChurnPackets))
            no_degraded_route_used = ($finalBackendDepth -eq $baselineBackendDepth)
            no_flow_drops = (($finalDropped - $baselineDropped) -eq 0)
            route_intents_expired = ($expiredFast.route_intent.lifecycle_status -eq "expired" -and $expiredSlowCandidate.route_intent.lifecycle_status -eq "expired")
        }
        telemetry = @{
            initial_entry_ingress = $initialRuntime.report.ingress
            quality_entry_ingress = $qualityRuntime.report.ingress
            final_entry_ingress = $finalRuntime.report.ingress
        }
    }
    $failedChecks = @($result.checks.GetEnumerator() | Where-Object { $_.Value -ne $true })
    if ($failedChecks.Count -gt 0) { throw "C18Z14 failed checks: $($failedChecks.Name -join ', ')" }
}
finally {
    if ($session) { try { Close-ServiceChannelWebSocket -Session $session } catch {} }
    if ($slowInitialRouteID) { try { Invoke-Api -Method POST -Path "/clusters/$ClusterID/mesh/route-intents/$slowInitialRouteID/expire" -Body @{ actor_user_id = $ActorUserID } | Out-Null } catch {} }
    if ($slowCandidateRouteID) { try { Invoke-Api -Method POST -Path "/clusters/$ClusterID/mesh/route-intents/$slowCandidateRouteID/expire" -Body @{ actor_user_id = $ActorUserID } | Out-Null } catch {} }
    if ($fastRouteID) {
        try { Invoke-Api -Method POST -Path "/clusters/$ClusterID/mesh/route-intents/$fastRouteID/expire" -Body @{ actor_user_id = $ActorUserID } | Out-Null } catch {}
        try {
            Invoke-Api -Method POST -Path "/clusters/$ClusterID/fabric/service-channels/route-feedback/expire" -Body @{
                actor_user_id = $ActorUserID
                reporter_node_id = $entryNode.id
                route_id = $fastRouteID
                service_class = "vpn_packets"
                reason = "c18z14 active quality shift smoke cleanup"
            } | Out-Null
        } catch {}
    }
    if ($updatersStopped) { try { Start-TestUpdaters } catch { Write-Warning "Could not restart test updaters: $($_.Exception.Message)" } }
}

$resultFullPath = Join-Path $repoRoot $ResultPath
$resultDir = Split-Path -Parent $resultFullPath
if (-not (Test-Path $resultDir)) { New-Item -ItemType Directory -Path $resultDir | Out-Null }
$result | ConvertTo-Json -Depth 100 | Set-Content -Path $resultFullPath -Encoding UTF8
Write-Host "C18Z14 live service-channel active quality shift smoke passed. Result: $resultFullPath"
$result