# List-ComputerGroups.ps1 — robust fallback + HTTP 400 handling + introspection

param(
  [string]$Url,
  [string]$Token,
  [switch]$SkipCertCheck,
  [int]$PageSize = 200,
  [string]$NameLike,
  [switch]$Raw,
  [switch]$Grid,
  [string]$ExportCsv,
  [switch]$Introspect
)

$ErrorActionPreference = 'Stop'
try { [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12 } catch {}

function Get-GatewayUri {
  param([Parameter(Mandatory)][string]$HostLike)
  $h = $HostLike.Trim()
  if ($h -match '^https?://') { $h = $h -replace '^https?://','' }
  $h = $h.TrimEnd('/')
  if ([string]::IsNullOrWhiteSpace($h)) { throw 'TaniumUrl empty after normalization.' }
  "https://$h/plugin/products/gateway/graphql"
}

# TLS bypass for Windows PowerShell 5.1
$script:__oldCb = $null
function Enter-InsecureTls { param([switch]$Enable)
  if (-not $Enable) { return }
  $script:__oldCb = [System.Net.ServicePointManager]::ServerCertificateValidationCallback
  $cb = [System.Net.Security.RemoteCertificateValidationCallback]{ param($s,$c,$ch,$e) $true }
  [System.Net.ServicePointManager]::ServerCertificateValidationCallback = $cb
}
function Exit-InsecureTls {
  if ($script:__oldCb -ne $null) {
    [System.Net.ServicePointManager]::ServerCertificateValidationCallback = $script:__oldCb
    $script:__oldCb = $null
  }
}

# Load config if needed
$BaseDir = if ($PSScriptRoot) { $PSScriptRoot } else { $pwd.Path }
$configPath = Join-Path $BaseDir 'config.json'
if (-not $Url -or -not $Token) {
  if (-not (Test-Path $configPath)) { throw "Missing -Url/-Token and config.json not found: $configPath" }
  $cfg = Get-Content -Path $configPath -Raw | ConvertFrom-Json
  if (-not $Url)   { $Url   = [string]$cfg.TaniumUrl }
  if (-not $Token) { $Token = [string]$cfg.TaniumApiToken }
  if (-not $PSBoundParameters.ContainsKey('SkipCertCheck')) { $SkipCertCheck = [bool]$cfg.SkipCertificateCheck }
}

$gateway = Get-GatewayUri -HostLike $Url
$headers = @{ 'Content-Type' = 'application/json'; session = $Token }

# ---- Introspection (optional)
if ($Introspect) {
$IntrospectQuery = @'
query {
  __type(name: "ComputerGroup") {
    name
    fields { name type { kind name ofType { kind name } } }
  }
}
'@
  $body = @{ query = $IntrospectQuery } | ConvertTo-Json -Depth 6
  $resp = $null
  $ps7 = ($PSVersionTable.PSVersion.Major -ge 7)
  if ($ps7 -and $SkipCertCheck) {
    $resp = Invoke-RestMethod -SkipCertificateCheck -Method Post -Uri $gateway -Headers $headers -Body $body
  } else {
    try { Enter-InsecureTls -Enable:$SkipCertCheck; $resp = Invoke-RestMethod -Method Post -Uri $gateway -Headers $headers -Body $body }
    finally { Exit-InsecureTls }
  }
  if ($resp.errors) { Write-Error (($resp.errors | ForEach-Object message) -join '; '); return }
  $resp.data.__type.fields | Select-Object name,@{n='type';e={$_.type.name ?? $_.type.ofType.name}} | Format-Table -AutoSize
  return
}

# ---- Queries (order = safest → richer)
$Q_Basic = @'
query listComputerGroups($first: Int, $after: Cursor) {
  computerGroups(first: $first, after: $after) {
    edges { node { id name managementRightsEnabled } }
    pageInfo { hasNextPage endCursor }
  }
}
'@

$Q_ContentSet   = @'
query listComputerGroups($first: Int, $after: Cursor) {
  computerGroups(first: $first, after: $after) {
    edges { node { id name managementRightsEnabled contentSet { name } } }
    pageInfo { hasNextPage endCursor }
  }
}
'@

$Q_ContentSetV2 = @'
query listComputerGroups($first: Int, $after: Cursor) {
  computerGroups(first: $first, after: $after) {
    edges { node { id name managementRightsEnabled contentSetV2 { name } } }
    pageInfo { hasNextPage endCursor }
  }
}
'@

$Q_Filter = @'
query listComputerGroups($first: Int, $after: Cursor) {
  computerGroups(first: $first, after: $after) {
    edges { node {
      id name managementRightsEnabled
      filter { memberOf { name } sensor { name } op value }
    } }
    pageInfo { hasNextPage endCursor }
  }
}
'@

$queries = @($Q_Basic, $Q_ContentSet, $Q_ContentSetV2, $Q_Filter)

function Invoke-Gql {
  param([string]$Query, [hashtable]$Vars, [string]$OpName)
  $body = @{ query = $Query; variables = $Vars; operationName = $OpName } | ConvertTo-Json -Depth 10
  $ps7 = ($PSVersionTable.PSVersion.Major -ge 7)
  try {
    if ($ps7 -and $SkipCertCheck) {
      return Invoke-RestMethod -SkipCertificateCheck -Method Post -Uri $gateway -Headers $headers -ContentType 'application/json' -Body $body
    } else {
      Enter-InsecureTls -Enable:$SkipCertCheck
      return Invoke-RestMethod -Method Post -Uri $gateway -Headers $headers -ContentType 'application/json' -Body $body
    }
  }
  catch {
    # If server returned HTTP 400 with a JSON GraphQL error, parse it and return so we can fallback.
    $we = $_.Exception
    if ($we.Response) {
      try {
        $sr = New-Object IO.StreamReader($we.Response.GetResponseStream())
        $txt = $sr.ReadToEnd()
        if ($txt) { return ($txt | ConvertFrom-Json) }
      } catch { }
    }
    throw  # non-GraphQL error -> bubble up
  }
  finally { Exit-InsecureTls }
}

# ---- Fetch with fallback chain
$allEdges = New-Object System.Collections.Generic.List[object]
$cursor   = $null
$qIndex   = 0
$opName   = 'listComputerGroups'

while ($true) {
  $vars = @{ first = $PageSize; after = $cursor }
  $resp = Invoke-Gql -Query $queries[$qIndex] -Vars $vars -OpName $opName

  if ($resp.errors) {
    if ($qIndex -lt ($queries.Count - 1)) {
      # restart from page 1 with next query
      $qIndex++; $cursor = $null; $allEdges.Clear()
      continue
    } else {
      throw ("GraphQL errors: " + (($resp.errors | ForEach-Object { $_.message }) -join '; '))
    }
  }

  $edges = $resp.data.computerGroups.edges
  if ($edges) { $allEdges.AddRange($edges) }

  $pi = $resp.data.computerGroups.pageInfo
  if (-not $pi -or -not $pi.hasNextPage) { break }
  $cursor = $pi.endCursor
}

if ($Raw) { [pscustomobject]@{ total = $allEdges.Count; edges = $allEdges } | ConvertTo-Json -Depth 14; return }
if ($allEdges.Count -eq 0) { Write-Output 'No computer groups returned.'; return }

function Get-ContentSetName($n) {
  if ($n.PSObject.Properties.Match('contentSet').Count -gt 0 -and $n.contentSet) { return $n.contentSet.name }
  if ($n.PSObject.Properties.Match('contentSetV2').Count -gt 0 -and $n.contentSetV2) { return $n.contentSetV2.name }
  return ''
}
function Get-FilterSummary($n) {
  if (-not $n.PSObject.Properties.Match('filter')) { return '' }
  $f = $n.filter; if ($null -eq $f) { return '' }
  if ($f.memberOf -and $f.memberOf.name) { return ("memberOf: " + $f.memberOf.name) }
  if ($f.sensor -and $f.sensor.name)     { return ("sensor '" + $f.sensor.name + "' " + $f.op + " '" + $f.value + "'") }
  return ''
}

$rows = foreach ($edge in $allEdges) {
  $n = $edge.node
  if ($NameLike -and -not ($n.name -match $NameLike)) { continue }
  [pscustomobject]@{
    Id               = $n.id
    Name             = $n.name
    ManagementRights = $n.managementRightsEnabled
    ContentSet       = (Get-ContentSetName $n)
    Filter           = (Get-FilterSummary  $n)
  }
}

if (-not $rows) { Write-Output 'No matching groups.'; return }
$rowsSorted = $rows | Sort-Object Name

if ($ExportCsv) {
  try { $rowsSorted | Export-Csv -NoTypeInformation -Encoding UTF8 -Path $ExportCsv; Write-Host "Exported to: $ExportCsv" -ForegroundColor Green }
  catch { Write-Warning "CSV export failed: $($_.Exception.Message)" }
}

if ($Grid) {
  $title = "Computer Groups — {0} item(s)" -f ($rowsSorted.Count)
  if (Get-Command Out-GridView -ErrorAction SilentlyContinue) { $rowsSorted | Out-GridView -Title $title; return }
  else { Write-Warning "Out-GridView not available. On PS7+: Install-Module Microsoft.PowerShell.GraphicalTools" }
}

$rowsSorted | Format-Table -AutoSize