# ============================================================
#  Hotspot IPv6 readiness test   (pure ASCII -- safe to copy/paste)
#
#  Purpose:
#    1) After connecting this laptop to a PHONE HOTSPOT,
#       check whether the laptop receives a global IPv6 address.
#    2) Check whether the HOME host can be reached directly over IPv6.
#
#  Output: Desktop\hotspot-ipv6-result.txt
# ============================================================

# --- change these two lines if the home IPv6 address changes ---
$HOME_V6   = '240e:338:263:3600:29f1:e63f:d476:597e'
$HOME_PORT = 38443
# ---------------------------------------------------------------

$desk = [Environment]::GetFolderPath('Desktop')
if (-not $desk) { $desk = $env:TEMP }
$o = Join-Path $desk 'hotspot-ipv6-result.txt'
$L = New-Object System.Collections.Generic.List[string]
function A($s) { $L.Add([string]$s) }
function Flush() { $L -join "`r`n" | Set-Content -Path $o -Encoding UTF8 }

$okOut  = $false
$okHome = $false

A ('TIME ' + (Get-Date -Format 'yyyy-MM-dd HH:mm:ss'))
A ('HOST ' + [System.Net.Dns]::GetHostName())
A ('RESULT FILE: ' + $o)
A ''

A '[1] Global IPv6 addresses on this machine'
$ga = @(Get-NetIPAddress -AddressFamily IPv6 -ErrorAction SilentlyContinue |
        Where-Object { $_.IPAddress -notlike 'fe80*' -and $_.IPAddress -ne '::1' })
if ($ga.Count -eq 0) {
  A '  NONE  <-- this network gives NO global IPv6'
} else {
  foreach ($a in $ga) {
    A ("  {0} :: {1}/{2} :: Pref={3} Suffix={4} State={5}" -f `
      $a.InterfaceAlias, $a.IPAddress, $a.PrefixLength, `
      $a.PrefixOrigin, $a.SuffixOrigin, $a.AddressState)
  }
}
Flush

A ''
A '[2] IPv6 default route'
$r = @(Get-NetRoute -AddressFamily IPv6 -DestinationPrefix '::/0' -ErrorAction SilentlyContinue)
if ($r.Count -eq 0) { A '  NONE' } else {
  foreach ($x in $r) { A ("  {0} -> {1}" -f $x.InterfaceAlias, $x.NextHop) }
}
Flush

function Tcp6([string]$h, [int]$port, [int]$ms) {
  try {
    $a = @([System.Net.Dns]::GetHostAddresses($h) |
           Where-Object { $_.AddressFamily -eq [System.Net.Sockets.AddressFamily]::InterNetworkV6 })
    if ($a.Count -eq 0) { return 'NO-AAAA' }
    $ad = $a[0]
    $c = New-Object System.Net.Sockets.TcpClient($ad.AddressFamily)
    $iar = $c.BeginConnect($ad, $port, $null, $null)
    if (-not $iar.AsyncWaitHandle.WaitOne($ms, $false)) { $c.Close(); return 'TIMEOUT' }
    try { $c.EndConnect($iar); $c.Close(); return ('OK ' + $ad.IPAddressToString) }
    catch { $c.Close(); return ('FAIL ' + $_.Exception.Message) }
  } catch { return ('ERR ' + $_.Exception.Message) }
}

A ''
A '[3] Outbound IPv6 test (decisive for the whole route)'
foreach ($h in @('ipv6.icanhazip.com', 'www.taobao.com')) {
  $res = Tcp6 $h 443 4000
  A ("  {0}:443 -> {1}" -f $h, $res)
  if ($res -like 'OK*') { $okOut = $true }
}
Flush

A ''
A '[4] Direct reach to HOME host over IPv6 (the real goal)'
$u = 'http://[' + $HOME_V6 + ']:' + $HOME_PORT + '/'
A ('  target = ' + $u)
try {
  $r2 = Invoke-WebRequest -Uri $u -UseBasicParsing -TimeoutSec 6
  A ('  HTTP status = ' + $r2.StatusCode)
  A ('  body line 1 = ' + (($r2.Content -split '\r?\n')[0]))
  if ($r2.StatusCode -eq 200) { $okHome = $true }
} catch {
  A ('  FAILED: ' + $_.Exception.Message)
}
Flush

A ''
A '===== SUMMARY ====='
if ($okOut -and $okHome) {
  A '  PASS: hotspot gives IPv6 AND home host is reachable.'
  A '  -> The IPv6 direct route is viable from this laptop.'
} elseif ($okOut -and -not $okHome) {
  A '  PARTIAL: IPv6 outbound OK, but home host unreachable.'
  A '  -> Most likely the home gateway blocks inbound IPv6,'
  A '     or the home IPv6 address/prefix has changed.'
} else {
  A '  FAIL: no usable IPv6 outbound on this network.'
  A '  -> The hotspot handed out no IPv6 (IPv6 sharing may be off).'
}
Flush