#Requires -Version 5.1
<#
.SYNOPSIS
    Destroys ephemeral build VMs that were not cleaned up (e.g. after host power loss).

.DESCRIPTION
    Scans F:\CI\BuildVMs\ for clone directories older than -MaxAgeHours.
    For each stale directory, stops the VM (hard), deletes via vmrun deleteVM,
    then removes the directory.

    Run as a daily scheduled task or on host startup to prevent disk accumulation.
    Safe to run while CI jobs are active — only touches VMs older than MaxAgeHours.

.PARAMETER CloneBaseDir
    Directory containing ephemeral VM clones. Default: F:\CI\BuildVMs

.PARAMETER MaxAgeHours
    Age threshold in hours. Directories with LastWriteTime older than this are
    treated as orphaned. Must exceed the longest expected build duration.
    Default: 4 (runner.timeout is 2h — 4h gives double margin)

.PARAMETER VmrunPath
    Path to vmrun.exe.
    Default: C:\Program Files (x86)\VMware\VMware Workstation\vmrun.exe

.PARAMETER WhatIf
    List orphaned VMs without destroying them.

.EXAMPLE
    # Dry run
    .\Cleanup-OrphanedBuildVMs.ps1 -WhatIf

    # Live cleanup (run elevated)
    .\Cleanup-OrphanedBuildVMs.ps1
#>
[CmdletBinding(SupportsShouldProcess)]
param(
    [string] $CloneBaseDir = 'F:\CI\BuildVMs',

    [ValidateRange(1, 168)]
    [int] $MaxAgeHours = 4,

    [string] $VmrunPath = 'C:\Program Files (x86)\VMware\VMware Workstation\vmrun.exe'
)

Set-StrictMode -Version Latest
$ErrorActionPreference = 'Continue'   # Don't abort on individual VM errors

if (-not (Test-Path $CloneBaseDir)) {
    Write-Host "[Cleanup] Clone base dir not found: $CloneBaseDir — nothing to do."
    exit 0
}

if (-not (Test-Path $VmrunPath -PathType Leaf)) {
    Write-Warning "[Cleanup] vmrun.exe not found at: $VmrunPath"
    Write-Warning "          Skipping vmrun stop/delete — will attempt directory removal only."
}

$cutoff    = (Get-Date).AddHours(-$MaxAgeHours)
$orphans   = @(Get-ChildItem -Path $CloneBaseDir -Directory -ErrorAction SilentlyContinue |
                 Where-Object { $_.LastWriteTime -lt $cutoff })

if (-not $orphans) {
    Write-Host "[Cleanup] No orphaned VMs found (threshold: $MaxAgeHours h)."
    exit 0
}

Write-Host "[Cleanup] Found $($orphans.Count) orphaned VM director$(if ($orphans.Count -eq 1) {'y'} else {'ies'}) older than $MaxAgeHours h."

foreach ($dir in $orphans) {
    $vmx = Get-ChildItem -Path $dir.FullName -Filter '*.vmx' -ErrorAction SilentlyContinue |
               Select-Object -First 1

    if ($PSCmdlet.ShouldProcess($dir.FullName, "Destroy orphaned VM")) {
        Write-Host "[Cleanup] Processing: $($dir.FullName)"

        if ($vmx -and (Test-Path $VmrunPath -PathType Leaf)) {
            # Hard stop — don't wait for graceful shutdown on an orphan
            & $VmrunPath -T ws stop $vmx.FullName hard 2>&1 | Out-Null
            Start-Sleep -Seconds 2
            $deleteOut = & $VmrunPath -T ws deleteVM $vmx.FullName 2>&1
            if ($LASTEXITCODE -ne 0) {
                Write-Warning "[Cleanup] vmrun deleteVM failed (exit $LASTEXITCODE): $deleteOut"
                Write-Warning "          Falling back to directory removal."
            }
        }
        elseif (-not $vmx) {
            Write-Warning "[Cleanup] No .vmx found in $($dir.FullName) — removing directory only."
        }

        Remove-Item $dir.FullName -Recurse -Force -ErrorAction SilentlyContinue
        if (Test-Path $dir.FullName) {
            Write-Warning "[Cleanup] Could not fully remove: $($dir.FullName) — manual cleanup needed."
        }
        else {
            Write-Host "[Cleanup] Removed: $($dir.FullName)"
        }
    }
    else {
        Write-Host "[Cleanup] WhatIf: would destroy $($dir.FullName) (age: $([int]((Get-Date) - $dir.LastWriteTime).TotalHours) h)"
    }
}

Write-Host "[Cleanup] Done."