<#
.SYNOPSIS
    Checks whether a device will accept remote PowerShell, and optionally fixes it.
.DESCRIPTION
    Looks at the pieces remote management actually needs: the WinRM service, a listener,
    the inbound firewall rule, and a local Test-WSMan round trip. It also flags a Public
    network profile, which is the usual reason quick config refuses to run.

    With -Repair it starts WinRM and runs Set-WSManQuickConfig. With -ComplianceOutput it
    returns a single Compliant/NonCompliant string, which is what a ConfigMgr configuration
    item discovery script wants to see.
.PARAMETER Repair
    Fix what's broken. Honors -WhatIf.
.PARAMETER SkipNetworkProfileCheck
    Let the repair run even when a network adapter is on the Public profile.
.PARAMETER ComplianceOutput
    Return only 'Compliant' or 'NonCompliant' instead of the full object.
.EXAMPLE
    .\Test-WinRMReadiness.ps1
.EXAMPLE
    .\Test-WinRMReadiness.ps1 -Repair -WhatIf
#>
[CmdletBinding(SupportsShouldProcess)]
param(
    [switch]$Repair,
    [switch]$SkipNetworkProfileCheck,
    [switch]$ComplianceOutput
)

function Get-WinRMState {
    $issues  = [System.Collections.Generic.List[string]]::new()
    $service = Get-Service -Name WinRM -ErrorAction SilentlyContinue

    if (-not $service) { $issues.Add('WinRM service not found') }
    else {
        if ($service.Status -ne 'Running') { $issues.Add("WinRM service is $($service.Status)") }
        if ("$($service.StartType)" -eq 'Disabled') { $issues.Add('WinRM service is disabled') }
    }

    # Listener and WS-Man checks only work while the service is running.
    $listeners = @()
    $wsman = $false
    if ($service -and $service.Status -eq 'Running') {
        $listeners = @(Get-ChildItem -Path WSMan:\localhost\Listener -ErrorAction SilentlyContinue)
        if ($listeners.Count -eq 0) { $issues.Add('No WinRM listener configured') }
        try { $null = Test-WSMan -ComputerName localhost -ErrorAction Stop; $wsman = $true }
        catch { $issues.Add("Test-WSMan failed: $($_.Exception.Message)") }
    }

    $rules = @(Get-NetFirewallRule -Name 'WINRM-HTTP-In-TCP*' -ErrorAction SilentlyContinue | Where-Object { "$($_.Enabled)" -eq 'True' })
    if ($rules.Count -eq 0) { $issues.Add('No enabled WinRM inbound firewall rule') }

    $public = @(Get-NetConnectionProfile -ErrorAction SilentlyContinue | Where-Object { "$($_.NetworkCategory)" -eq 'Public' })

    [pscustomobject]@{
        ComputerName     = $env:COMPUTERNAME
        Ready            = ($issues.Count -eq 0)
        ServiceStatus    = if ($service) { "$($service.Status)" } else { 'Missing' }
        StartType        = if ($service) { "$($service.StartType)" } else { $null }
        Listeners        = ($listeners | ForEach-Object { $_.Keys -join ' ' }) -join '; '
        FirewallRules    = $rules.Count
        WSManResponds    = $wsman
        PublicNetwork    = ($public.Count -gt 0)
        Issues           = $issues -join '; '
        Action           = 'None'
    }
}

$state = Get-WinRMState

if ($Repair -and -not $state.Ready) {
    if ($state.PublicNetwork -and -not $SkipNetworkProfileCheck) {
        Write-Warning 'A network adapter is on the Public profile. Quick config will refuse to run. Use -SkipNetworkProfileCheck if that is expected.'
        $state.Action = 'Skipped (Public network)'
    }
    elseif ($PSCmdlet.ShouldProcess($env:COMPUTERNAME, 'Enable WinRM (service, listener, firewall rule)')) {
        try {
            if ($state.StartType -eq 'Disabled') { Set-Service -Name WinRM -StartupType Automatic -ErrorAction Stop }
            if ($state.ServiceStatus -ne 'Running') { Start-Service -Name WinRM -ErrorAction Stop }
            Set-WSManQuickConfig -Force -SkipNetworkProfileCheck:$SkipNetworkProfileCheck -ErrorAction Stop
            $state = Get-WinRMState
            $state.Action = 'Repaired'
        }
        catch {
            Write-Error "Repair failed: $($_.Exception.Message)"
            $state.Action = 'Failed'
        }
    }
    else { $state.Action = 'WhatIf' }
}

if ($ComplianceOutput) {
    if ($state.Ready) { 'Compliant' } else { 'NonCompliant' }
}
else {
    $state
}