<#
.SYNOPSIS
    Isolates the OtOpcUa ScriptWorker processes on a Windows node (lmxopcua#780, design §6, owner decisions §14 #5/#6):
    the worker's virtual-account identity, the PeCacheDir ACL, an outbound firewall block on the worker executable and
    a deny on the install folder. Idempotent; -WhatIf prints every change; -Uninstall rolls it back.

.DESCRIPTION
    Only needed when the node runs Scripting:Runner = OutOfProcess or Shadow. It changes, in order:

      1. AnchorService         a DISABLED service '<WorkerServiceName>' whose account is NT SERVICE\<WorkerServiceName>,
                               so that virtual account exists and resolves by name. It is never started: the host launches
                               every worker itself, under a restricted token whose restricting SIDs are that account +
                               Everyone + BUILTIN\Users + RESTRICTED, with every privilege removed
                               (Scripting:Worker:Identity; RestrictedWorkerLauncher.cs). Each access check the worker
                               makes must pass for the host account AND that set.
      2. PeCacheDir            created; ACL replaced: protected, owner Administrators, SYSTEM + Administrators + the host
                               account full control. No Users, no worker access (the HMAC key and launch markers live here).
      3. PeEntriesDir          <PeCacheDir>\pe, the worker identity gets Modify (workers compile and write HMAC'd entries).
      4. WorkerFolderAcl       <InstallRoot>\script-worker, the worker identity gets read + execute.
      5. InstallRootDeny       <InstallRoot>, the worker identity is DENIED ReadData/ListDirectory (inherited), so the
                               worker cannot read appsettings*.json, the logs or the host binaries even where Users can.
      6. FirewallBlockOutbound a Windows Firewall rule blocking all outbound traffic from
                               <InstallRoot>\script-worker\ZB.MOM.WW.OtOpcUa.ScriptWorker.exe (every profile). The
                               self-contained Windows publish starts the worker through that apphost; a framework-dependent
                               worker (dotnet.exe) is NOT covered — the analyzer's System.Net ban is then the only control.
      7. HostServiceEnv        (-ConfigureHostService only) Scripting__Worker__Identity and Scripting__Worker__PeCacheDir
                               in the OtOpcUaHost service environment. Scripting:Runner itself is NOT set here: the
                               runner flip is a separate, per-tier decision (design §12, P2/P3).

    Re-run it after any deploy that REPLACES the install folder (a rename/swap drops the folder ACEs; files copied into
    an existing folder inherit them). The host must be restarted for -ConfigureHostService to take effect.

.PARAMETER InstallRoot
    The host install folder (holds OtOpcUa.Host.exe and script-worker\).

.PARAMETER HostServiceAccount
    The OtOpcUaHost service account: DOMAIN\name, NT SERVICE\name, LocalSystem, or a SID. Gets full control of PeCacheDir.

.PARAMETER PeCacheDir
    The compiled-PE cache (Scripting:Worker:PeCacheDir). Absolute and outside InstallRoot (the host refuses otherwise).
    Default: $env:ProgramData\OtOpcUa\script-pe-cache.

.PARAMETER WorkerServiceName
    The worker identity's virtual account name. Default OtOpcUaScriptWorker (Scripting:Worker:Identity =
    'NT SERVICE\OtOpcUaScriptWorker').

.PARAMETER ConfigureHostService
    Also write the two Scripting__Worker__* entries into the host service's environment (or remove them with -Uninstall).

.PARAMETER Uninstall
    Roll everything back: the firewall rule, every explicit ACE for the worker identity, the anchor service, and (with
    -ConfigureHostService) the env entries. The PE cache is kept unless -RemovePeCache.

.PARAMETER PlanOnly
    Print the plan and return it as objects without touching (or even reading) the machine. Runs on any OS; used by the
    dry-run harness scripts/install/tests/Test-ScriptWorkerIsolation.ps1. -HostServiceAccount must then be a SID.

.EXAMPLE
    .\Install-ScriptWorkerIsolation.ps1 -InstallRoot 'C:\Program Files\OtOpcUa' -HostServiceAccount 'OTOPCUA\svc-otopcua' -WhatIf

.EXAMPLE
    .\Install-ScriptWorkerIsolation.ps1 -InstallRoot 'C:\Program Files\OtOpcUa' -HostServiceAccount 'OTOPCUA\svc-otopcua' -ConfigureHostService

.EXAMPLE
    .\Install-ScriptWorkerIsolation.ps1 -InstallRoot 'C:\Program Files\OtOpcUa' -HostServiceAccount 'OTOPCUA\svc-otopcua' -ConfigureHostService -Uninstall
#>
[CmdletBinding(SupportsShouldProcess, ConfirmImpact = 'Medium')]
param(
    [Parameter(Mandatory)] [string]$InstallRoot,
    [Parameter(Mandatory)] [string]$HostServiceAccount,
    [string]$PeCacheDir,
    [ValidatePattern('^[A-Za-z0-9_.\-]{1,80}$')] [string]$WorkerServiceName = 'OtOpcUaScriptWorker',
    [string]$HostServiceName = 'OtOpcUaHost',
    [switch]$ConfigureHostService,
    [switch]$Uninstall,
    [switch]$RemovePeCache,
    [switch]$PlanOnly
)

Set-StrictMode -Version Latest
$ErrorActionPreference = 'Stop'
Import-Module (Join-Path $PSScriptRoot 'ScriptWorkerIsolation.psm1') -Force

if (-not $PeCacheDir) {
    $programData = if ($env:ProgramData) { $env:ProgramData } else { 'C:\ProgramData' }
    $PeCacheDir = "$($programData.TrimEnd('\'))\OtOpcUa\script-pe-cache"
}

function Resolve-HostSid([string]$Account) {
    if ($Account -match '^[Ss]-1-\d+(-\d+)+$') { return $Account.ToUpperInvariant() }
    if ($PlanOnly) { throw "-PlanOnly needs -HostServiceAccount as a SID (no account lookup without the OS)" }
    if ($Account -in 'LocalSystem', '.\LocalSystem', 'NT AUTHORITY\SYSTEM') { return 'S-1-5-18' }
    if ($Account -match '^NT SERVICE\\(.+)$') { return (Get-OtOpcUaServiceSid -Name $Matches[1]) }
    $name = $Account -replace '^\.\\', "$env:COMPUTERNAME\"
    ([System.Security.Principal.NTAccount]::new($name)).Translate([System.Security.Principal.SecurityIdentifier]).Value
}

$hostSid = Resolve-HostSid $HostServiceAccount
$plan = Get-ScriptWorkerIsolationPlan -InstallRoot $InstallRoot -HostSid $hostSid -PeCacheDir $PeCacheDir `
    -WorkerServiceName $WorkerServiceName -HostServiceName $HostServiceName `
    -ConfigureHostService:$ConfigureHostService -Uninstall:$Uninstall -RemovePeCache:$RemovePeCache

$workerSid = Get-OtOpcUaServiceSid -Name $WorkerServiceName
Write-Host ("ScriptWorker isolation {0}: worker identity NT SERVICE\{1} ({2}), host account {3} ({4})" -f `
    $(if ($Uninstall) { 'ROLLBACK' } else { 'install' }), $WorkerServiceName, $workerSid, $HostServiceAccount, $hostSid)

if ($PlanOnly) {
    foreach ($step in $plan) { Write-Host ("  [plan] {0,-22} {1}" -f $step.Id, $step.Change) }
    return $plan
}

if ($PSVersionTable.PSEdition -eq 'Core' -and -not $IsWindows) { throw 'Install-ScriptWorkerIsolation.ps1 applies changes on Windows only (use -PlanOnly elsewhere)' }
if (-not $Uninstall -and -not (Test-Path -LiteralPath (Join-Path $InstallRoot 'script-worker'))) {
    throw "$InstallRoot\script-worker not found - publish the Host (it carries script-worker\) before isolating it"
}
$principal = [Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()
if (-not $WhatIfPreference -and -not $principal.IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)) {
    throw 'run elevated (services, firewall rules and folder ACLs need an administrator)'
}

$results = foreach ($step in $plan) {
    if ($PSCmdlet.ShouldProcess($step.Target, "$($step.Id): $($step.Change)")) {
        $outcome = Invoke-ScriptWorkerIsolationStep -Step $step
        Write-Host ("  [{0,-9}] {1,-22} {2}" -f $outcome, $step.Id, $step.Target)
        [pscustomobject]@{ Id = $step.Id; Target = $step.Target; Outcome = $outcome }
    }
}

if (-not $WhatIfPreference) {
    Write-Host ''
    if ($Uninstall) {
        Write-Host 'Rolled back. If the host still sets Scripting:Worker:Identity (appsettings or env), unset it and restart the host.'
    }
    else {
        Write-Host 'Done. Host configuration for this node:'
        Write-Host "  Scripting:Worker:Identity   = NT SERVICE\$WorkerServiceName"
        Write-Host "  Scripting:Worker:PeCacheDir = $PeCacheDir"
        if (-not $ConfigureHostService) { Write-Host '  (not written: re-run with -ConfigureHostService, or set them in appsettings)' }
        Write-Host '  Restart OtOpcUaHost for a configuration change to take effect.'
    }
}
$results