[CmdletBinding()]
param (
    [Parameter(Mandatory=$true)]
    [String]
    $InstallerUrl
)

<#
.SYNOPSIS
    Silently installs the ActivTrak agent.
.DESCRIPTION
    This script silently downloads and installs the ActivTrak agent from a given URL.
    Installer URLs expire after 72 hours. Generate a new installer URL using the instructions on this page:
    https://support.activtrak.com/hc/en-us/articles/360052228952-Deploy-Via-PowerShell-Script
.PARAMETER InstallerUrl
    The URL from which to download the ActivTrak installer
.LINK
    https://support.activtrak.com/hc/en-us/articles/360052228952-Deploy-Via-PowerShell-Script
#>
process {
  # Download
  
  Write-Host "Downloading application..."
  ## Create a WebRequest to read only headers
  [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls -bor [Net.SecurityProtocolType]::Tls11 -bor [Net.SecurityProtocolType]::Tls12
  $Request = [System.Net.HttpWebRequest]::Create($InstallerUrl)
  $Request.Method = "HEAD"
  
  try {
      $Response = $Request.GetResponse()
      $ContentDisposition = $Response.Headers["Content-Disposition"]
      $Response.Close()
  } catch {
      throw "Failed to retrieve response headers. $_"
  }
  
  if ($ContentDisposition) {
      $InstallerName = [System.Net.WebUtility]::UrlDecode(($ContentDisposition -replace '.*filename=([^;]+).*', '$1'))
      $InstallerPath = Join-Path -Path $env:TEMP -ChildPath $InstallerName
  
      ## Download file to the full path
      try {
          # Invoke-WebRequest -Uri $InstallerUrl -OutFile $InstallerPath
  
          # Use Legacy WebClient for compatibility
          (New-Object Net.WebClient).DownloadFile($InstallerUrl, $InstallerPath)
      } catch {
          throw "Download failed. $_"
      }
  
      # Install
      try {
          Write-Host "Installing application..."
          $ExitCode = (Start-Process -FilePath "msiexec.exe" -ArgumentList "/i `"$($InstallerPath)`" /qn /l*v `"$($InstallerPath).log`"" -Wait -PassThru).ExitCode
      } catch {
          throw "Failed installing application. $_"
      }
  } else {
      Write-Host "Content-Disposition header not found. Please contact ActivTrak Support at Support@ActivTrak.com if problem persists."
  }
}

end {
    # Clean up

    Write-Host "Removing package download from '$InstallerPath'"
    Remove-Item -Path $InstallerPath -Force

    switch ($ExitCode) {
        0 { Write-Host "Installation succeeded."; break }
        3010 { Write-Host "A reboot is required to complete installation."; break }
        default {
            Write-Error "Installation failed with exit code $ExitCode. For help see https://learn.microsoft.com/en-us/windows/win32/msi/error-codes"
        }
    }
}