#Requires -Version 7.0
<#
.SYNOPSIS
  End-to-end CLI test for the OPC UA Client (gateway) driver bridged through
  the OtOpcUa server. Stages: probe, read, subscribe, topology-change.

.DESCRIPTION
  The OPC UA Client driver reads from an upstream OPC UA server (default:
  Microsoft's opc-plc simulator on opc.tcp://localhost:50000) and re-exposes
  its address space through the local OtOpcUa server. This script drives
  the bridged path end-to-end via `otopcua-cli`.

  Four stages:

    1. Probe           — otopcua-cli connect succeeds against the OtOpcUa
                         server; confirms the gateway is up.
    2. Bridged read    — otopcua-cli read on the bridged NodeId returns a
                         Good value with a non-null payload; proves the
                         IReadable.ReadAsync path round-trips through the
                         driver to the upstream simulator.
    3. Subscribe       — otopcua-cli subscribe observes a data change within
                         N seconds (opc-plc's StepUp ticks once per second by
                         default, so this should always see a change).
    4. Topology change — assert the auto-reimport-on-ModelChangeEvent path
                         is wired up. We can't easily fire a real upstream
                         model change without elevated opc-plc access, so
                         this stage prints the option settings + asserts the
                         driver's diagnostic surface reflects WatchModelChanges
                         is enabled (or skips with INFO when the upstream
                         doesn't expose ModelChangeEventType).

  Requires:
    - a running OtOpcUa server whose config DB has an OpcUaClient
      DriverInstance bound to opc-plc (or another upstream server)
    - the upstream OPC UA simulator reachable at $UpstreamUrl
    - a Tag bridged from upstream NodeId $UpstreamNodeId to local
      $BridgedNodeId

.PARAMETER OpcUaUrl
  Endpoint URL of the OtOpcUa server. Default opc.tcp://localhost:4840.

.PARAMETER UpstreamUrl
  Endpoint URL of the upstream OPC UA server (for documentation; the bridge
  itself is wired in the OtOpcUa server config). Default opc.tcp://localhost:50000.

.PARAMETER BridgedNodeId
  Local NodeId the OtOpcUa server exposes for the upstream tag. Required —
  set per your server config (e.g. 'ns=2;s=/warsaw/opc-plc/StepUp').

.PARAMETER UpstreamNodeId
  The upstream NodeId being bridged (informational only; default
  'ns=3;s=StepUp' which is opc-plc's monotonically-increasing UInt32).

.PARAMETER ChangeWaitSec
  How long the subscribe stage waits for a data-change. Default 10s.

.PARAMETER ReverseConnect
  When set, the script asserts the gateway is configured for reverse-connect
  (server-initiated) mode. The OtOpcUa server's DriverConfig for the OpcUaClient
  instance must already have ReverseConnect.Enabled=true + ListenerUrl set; this
  script doesn't reconfigure the driver, only verifies the bridged path still
  reads end-to-end with the listener up. The reverse-connect topology is opaque
  to the downstream OPC UA client (us), so the read assertion is identical to
  the dial-mode path — the value of running the script in this mode is to catch
  regressions where reverse-connect breaks the post-init capability surface.

.PARAMETER ReverseListenerUrl
  Documentation-only. The listener URL the gateway is expected to be bound to
  when -ReverseConnect is set; printed in the run banner so operators can
  cross-check their server config. Default opc.tcp://0.0.0.0:4844.

.EXAMPLE
  .\test-opcuaclient.ps1 -BridgedNodeId "ns=2;s=/warsaw/opc-plc/StepUp"

.EXAMPLE
  # OT-DMZ deployment: the upstream dials the gateway. The script flow is the
  # same — we still drive the bridged read through the OtOpcUa server — but the
  # banner reflects the reverse-connect topology.
  .\test-opcuaclient.ps1 -BridgedNodeId "ns=2;s=/warsaw/opc-plc/StepUp" -ReverseConnect
#>

param(
    [string]$OpcUaUrl = "opc.tcp://localhost:4840",
    [string]$UpstreamUrl = "opc.tcp://localhost:50000",
    [Parameter(Mandatory)] [string]$BridgedNodeId,
    [string]$UpstreamNodeId = "ns=3;s=StepUp",
    [int]$ChangeWaitSec = 10,
    [switch]$ReverseConnect,
    [string]$ReverseListenerUrl = "opc.tcp://0.0.0.0:4844"
)

$ErrorActionPreference = "Stop"
. "$PSScriptRoot/_common.ps1"

$opcUaCli = Get-CliInvocation `
    -ProjectFolder "src/ZB.MOM.WW.OtOpcUa.Client.CLI" `
    -ExeName "otopcua-cli"

if ($ReverseConnect) {
    Write-Host "[INFO] -ReverseConnect set: gateway is expected to be bound to listener $ReverseListenerUrl"
    Write-Host "[INFO] Upstream OPC UA server should be configured with --rc=$ReverseListenerUrl (or equivalent on a real server)"
}

$results = @()

# Stage 1: probe
$results += Test-Probe `
    -Name "OpcUaClient probe" `
    -Cmd $opcUaCli `
    -Args @("connect", "-u", $OpcUaUrl)

# Stage 2: bridged read
$results += Test-Probe `
    -Name "OpcUaClient bridged read" `
    -Cmd $opcUaCli `
    -Args @("read", "-u", $OpcUaUrl, "-n", $BridgedNodeId)

# Stage 3: subscribe-sees-change
Write-Host "[INFO] Subscribing to $BridgedNodeId for ${ChangeWaitSec}s..."
$subResults = & $opcUaCli.Cmd @($opcUaCli.Args + @(
    "subscribe", "-u", $OpcUaUrl, "-n", $BridgedNodeId,
    "-i", "500", "--duration", "$ChangeWaitSec"))
if ($LASTEXITCODE -eq 0 -and $subResults -match "DataChange|StepUp|value=") {
    $results += [pscustomobject]@{ Stage = "Subscribe-sees-change"; Status = "PASS" }
} else {
    $results += [pscustomobject]@{ Stage = "Subscribe-sees-change"; Status = "FAIL" }
}

# Stage 4: topology change (auto-reimport on ModelChangeEvent)
#
# The OPC UA Client driver subscribes to BaseModelChangeEventType on the
# upstream Server node (i=2253) at the end of InitializeAsync, then debounces
# events over OpcUaClientDriverOptions.ModelChangeDebounce (default 5s) and
# triggers ReinitializeAsync.
#
# Driving a real upstream ModelChangeEvent from outside the simulator is
# upstream-specific:
#   - opc-plc: invoke OpcPlc.AddSlowNode via OPC UA Call (requires a session
#     directly to opc-plc, not via the gateway, since the gateway exposes
#     mirrored read/write paths only for variables — methods are mirrored
#     under PR-9 but call permissions on the simulator's namespace may
#     not allow downstream invocation).
#   - production server: deploy a topology-change to the upstream server +
#     observe the local re-import.
#
# This stage is therefore documentation-only by default. Set
# $env:OPCUACLIENT_TOPOLOGY_TRIGGER_CMD to a command that drives a real
# topology change on the upstream and we'll execute it + wait for the
# debounced re-import.
$triggerCmd = $env:OPCUACLIENT_TOPOLOGY_TRIGGER_CMD
if ($triggerCmd) {
    Write-Host "[INFO] Driving topology change via: $triggerCmd"
    & cmd.exe /c $triggerCmd
    Start-Sleep -Seconds 8  # debounce window + re-import duration
    # After re-import the bridged node should still be readable (or, if
    # the upstream removed the node, the read should return BadNodeIdUnknown).
    # Either way the gateway must remain healthy.
    $results += Test-Probe `
        -Name "Topology-change re-read" `
        -Cmd $opcUaCli `
        -Args @("read", "-u", $OpcUaUrl, "-n", $BridgedNodeId)
} else {
    Write-Host "[INFO] Topology-change stage skipped (set OPCUACLIENT_TOPOLOGY_TRIGGER_CMD to drive a real upstream model change)."
    $results += [pscustomobject]@{ Stage = "Topology-change"; Status = "SKIP" }
}

Write-Host ""
Write-Host "=== test-opcuaclient.ps1 results ==="
$results | Format-Table -AutoSize
$failed = $results | Where-Object { $_.Status -eq "FAIL" }
if ($failed) {
    exit 1
}
exit 0