# Copyright (c) 2026, R. W. Rodolico
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# windows_system.ps1
# Boot time, uptime and operating system facts.
# Sensor contract: unix/sensors/Documentation/README.md; keys: Documentation/Spec.md 7.6
# Must stay Windows PowerShell 5.1 compatible and pure ASCII.
#
# Version 1.0.0 20261018 Claude
# Initial version (bug 211, stage W2)

Import-Module ([IO.Path]::Combine($PSScriptRoot, '..', 'lib', 'SysinfoSensor.psm1'))
Test-SysinfoWindows

Invoke-SysinfoSensor {
   if ($null -eq (Get-Command Get-CimInstance -ErrorAction SilentlyContinue)) {
      Exit-SysinfoSensor -Code $SYSINFO_EXIT_NOT_APPLICABLE -Message 'Get-CimInstance not available'
   }
   $os = Get-CimInstance -ClassName Win32_OperatingSystem -ErrorAction Stop | Select-Object -First 1
   if ($null -eq $os) { Exit-SysinfoSensor -Code $SYSINFO_EXIT_NOT_APPLICABLE -Message 'Win32_OperatingSystem returned nothing' }

   # UTC epoch; a DateTime of Kind Unspecified or Local is taken as local time
   $boot = New-Object System.DateTimeOffset ([datetime]$os.LastBootUpTime)
   $lastBoot = $boot.ToUnixTimeSeconds()
   $now = [System.DateTimeOffset]::UtcNow.ToUnixTimeSeconds()

   $ubr = ''
   $release = ''
   $base = [Microsoft.Win32.RegistryKey]::OpenBaseKey([Microsoft.Win32.RegistryHive]::LocalMachine, [Microsoft.Win32.RegistryView]::Registry64)
   try {
      $key = $base.OpenSubKey('SOFTWARE\Microsoft\Windows NT\CurrentVersion')
      if ($null -ne $key) {
         try {
            $ubr = [string]$key.GetValue('UBR', '')
            $release = [string]$key.GetValue('DisplayVersion', '')
            if ($release.Trim() -eq '') { $release = [string]$key.GetValue('ReleaseId', '') }
         } finally { $key.Close() }
      }
   } finally { $base.Close() }

   $version = [string]$os.Version
   $kernel = $version
   if ($ubr -ne '') { $kernel = "$version.$ubr" }

   Write-SysinfoFact -Path @('system', 'last_boot') -Value $lastBoot
   Write-SysinfoFact -Path @('system', 'uptime') -Value ([math]::Max(0, $now - $lastBoot))
   Write-SysinfoFact -Path @('operatingsystem', 'os_name') -Value 'Windows'
   Write-SysinfoFact -Path @('operatingsystem', 'description') -Value $os.Caption
   Write-SysinfoFact -Path @('operatingsystem', 'os_version') -Value $version
   Write-SysinfoFact -Path @('operatingsystem', 'kernel') -Value $kernel
   Write-SysinfoFact -Path @('operatingsystem', 'release') -Value $release
}