<# 
  Reset-Webcam.ps1
  Purpose: Clear false "camera in use" locks by (1) killing likely processes,
           (2) restarting the Camera Frame Server, (3) toggling camera drivers.
  Requirements: Windows 10/11, PowerShell 5+; run as Administrator.
#>
# Self-elevate script if not running as Administrator
if (-not ([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()
).IsInRole([Security.Principal.WindowsBuiltinRole]::Administrator)) {
    Write-Host "Restarting script as Administrator..."
    Start-Process powershell -ArgumentList "-NoProfile -ExecutionPolicy Bypass -File `"$PSCommandPath`"" -Verb RunAs
    exit
}


[CmdletBinding()]
param(
  [switch]$SkipProcessKill,          # Don't kill apps (if you prefer to keep them)
  [switch]$AggressiveKill,           # Also kill browsers (Chrome/Edge/Firefox)
  [switch]$RestartAudio,             # Rarely needed: restarts Windows audio services
  [switch]$NoPause                   # Don’t pause at the end
)

function Ensure-Admin {
  $isAdmin = ([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()
             ).IsInRole([Security.Principal.WindowsBuiltinRole]::Administrator)
  if (-not $isAdmin) {
    Write-Warning "This script must run as Administrator. Relaunching elevated..."
    $argsList = @()
    if ($SkipProcessKill) { $argsList += "-SkipProcessKill" }
    if ($AggressiveKill)  { $argsList += "-AggressiveKill" }
    if ($RestartAudio)    { $argsList += "-RestartAudio" }
    if ($NoPause)         { $argsList += "-NoPause" }
    Start-Process -FilePath "powershell.exe" -Verb RunAs -ArgumentList @("-NoProfile","-ExecutionPolicy","Bypass","-File","`"$PSCommandPath`"") + $argsList
    exit
  }
}

function Start-Logging {
  $global:LogPath = Join-Path $env:TEMP ("Reset-Webcam_{0:yyyyMMdd_HHmmss}.log" -f (Get-Date))
  Start-Transcript -Path $LogPath -ErrorAction SilentlyContinue | Out-Null
  Write-Host "Logging to: $LogPath"
}

function Stop-Logging {
  try { Stop-Transcript | Out-Null } catch {}
}

function Kill-CameraApps {
  param([switch]$Aggressive)
  $softList = @(
    'Teams','ms-teams','CiscoCollabHost','Webex','Zoom','zoom','zoomptch','Skype','SkypeApp',
    'Discord','slack','obs64','ManyCam','SnapCamera','SnapCam','NVIDIA Broadcast','NVBroadcast.Container',
    'Lghub','LogiTune','YouCam','Camera','WindowsCamera'
  )

  # Some vendor services keep handles alive:
  $serviceBackends = @('obs-virtualcam-module','NvContainer','BcastDVRUserService')

  if ($Aggressive) {
    # Browsers use WebRTC; sometimes a stray tab holds the camera.
    $softList += @('chrome','msedge','firefox','brave','opera')
  }

  Write-Host "`n-- Stopping common camera-using apps --"
  foreach ($name in $softList | Select-Object -Unique) {
    Get-Process -Name $name -ErrorAction SilentlyContinue | ForEach-Object {
      try {
        Write-Host ("Stopping {0} (PID {1})..." -f $_.ProcessName,$_.Id)
        $_ | Stop-Process -Force -ErrorAction Stop
      } catch {
        Write-Verbose "Could not stop $name: $($_.Exception.Message)"
      }
    }
  }

  # Try friendly stop of some services if present
  foreach ($svc in $serviceBackends | Select-Object -Unique) {
    $s = Get-Service -Name $svc -ErrorAction SilentlyContinue
    if ($s -and $s.Status -eq 'Running') {
      Write-Host "Stopping service $($s.Name)..."
      try { Stop-Service -Name $s.Name -Force -ErrorAction Stop } catch {}
    }
  }
}

function Restart-CameraFrameServer {
  $svcName = 'FrameServer'    # Windows Camera Frame Server
  Write-Host "`n-- Restarting Camera Frame Server service ($svcName) --"
  $svc = Get-Service -Name $svcName -ErrorAction SilentlyContinue
  if (-not $svc) {
    Write-Warning "Service $svcName not found (older builds may differ). Skipping."
    return
  }
  try {
    if ($svc.Status -eq 'Running') { Restart-Service -Name $svcName -Force -ErrorAction Stop }
    else { Start-Service -Name $svcName -ErrorAction Stop }
    Start-Sleep -Seconds 2
    Write-Host "Camera Frame Server status: $((Get-Service $svcName).Status)"
  } catch {
    Write-Warning "Failed to restart $svcName: $($_.Exception.Message)"
  }
}

function Get-CameraDevices {
  # Prefer PnPDevice if available (Win10+)
  $devices = @()
  try {
    $devices = @(
      Get-PnpDevice -Class Camera -ErrorAction SilentlyContinue
    )
    # Some cameras show up under 'Image' class on older drivers
    $devices += Get-PnpDevice -Class Image -ErrorAction SilentlyContinue
  } catch {}

  if (-not $devices -or $devices.Count -eq 0) {
    # Fallback via WMI
    $devices = Get-CimInstance Win32_PnPEntity |
      Where-Object { $_.PNPClass -in @('Camera','Image') }
  }
  $devices | Sort-Object -Property Status, FriendlyName -Unique
}

function Reset-CameraDrivers {
  Write-Host "`n-- Resetting camera drivers (disable/enable) --"
  $cams = Get-CameraDevices
  if (-not $cams -or $cams.Count -eq 0) {
    Write-Warning "No camera-class devices found."
    return
  }

  foreach ($cam in $cams) {
    $name = $cam.FriendlyName
    $id   = $cam.InstanceId
    if (-not $id) { $id = $cam.PNPDeviceID } # WMI fallback

    Write-Host "Toggling: $name"
    try {
      # Try PnP cmdlets first
      if (Get-Command Disable-PnpDevice -ErrorAction SilentlyContinue) {
        Disable-PnpDevice -InstanceId $id -Confirm:$false -ErrorAction Stop
        Start-Sleep -Seconds 2
        Enable-PnpDevice  -InstanceId $id -Confirm:$false -ErrorAction Stop
      } else {
        # Fallback: WMI (less reliable for toggling); advise user if missing PnP cmdlets
        Write-Warning "PnP cmdlets not available; please run in Windows PowerShell 5+ on Win10/11."
      }
      Start-Sleep -Seconds 2
    } catch {
      Write-Warning "Failed to toggle $name ($id): $($_.Exception.Message)"
    }
  }
}

function Restart-AudioStack {
  Write-Host "`n-- Restarting Windows audio services (optional) --"
  $audioSvcs = @('Audiosrv','AudioEndpointBuilder')
  foreach ($svc in $audioSvcs) {
    try {
      $s = Get-Service -Name $svc -ErrorAction Stop
      if ($s.Status -eq 'Running') {
        Restart-Service -Name $svc -Force -ErrorAction Stop
      } else {
        Start-Service -Name $svc -ErrorAction Stop
      }
    } catch {
      Write-Warning "Audio service $svc restart failed: $($_.Exception.Message)"
    }
  }
}

# ------------ MAIN ------------
Ensure-Admin
Start-Logging
try {
  Write-Host "=== Webcam Reset Routine ==="

  if (-not $SkipProcessKill) {
    Kill-CameraApps -Aggressive:$AggressiveKill
  } else {
    Write-Host "-- Skipping process kill step (per -SkipProcessKill) --"
  }

  Restart-CameraFrameServer
  Reset-CameraDrivers

  if ($RestartAudio) {
    Restart-AudioStack
  }

  Write-Host "`nDone. Try your camera again."
  Write-Host "If the problem persists, unplug/replug external webcams or reboot as a last resort."
  Write-Host "Full log: $LogPath"
}
finally {
  Stop-Logging
  if (-not $NoPause) {
    Write-Host "`nPress Enter to close..."
    [void][System.Console]::ReadLine()
  }
}