# Define a helper function to extract the domain part of an email address
function Get-Domain {
    param([string]$email)
    return $email.Split("@")[1]
}

# Define the base path for JoinInfo and TenantInfo
$joinInfoBasePath = "Registry::HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\CloudDomainJoin\JoinInfo"
$tenantInfoBasePath = "Registry::HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\CloudDomainJoin\TenantInfo"

# Get all GUID-based subkeys under JoinInfo
if (Test-Path $joinInfoBasePath) {
    $joinInfoGuids = Get-ChildItem -Path $joinInfoBasePath

    foreach ($joinInfoGuid in $joinInfoGuids) {
        $joinInfoPath = "$joinInfoBasePath\$($joinInfoGuid.PSChildName)"
        $joinInfoValues = Get-ItemProperty -Path $joinInfoPath

        # Check if the UserEmail key exists in JoinInfo
        if ($joinInfoValues.PSObject.Properties['UserEmail']) {
            $userEmail = $joinInfoValues.UserEmail
            $joinDomain = Get-Domain -email $userEmail
            Write-Host "Found UserEmail: $userEmail in JoinInfo GUID: $($joinInfoGuid.PSChildName)"

            # Now check the TenantInfo path for matching TenantId
            if (Test-Path $tenantInfoBasePath) {
                $tenantInfoGuids = Get-ChildItem -Path $tenantInfoBasePath

                foreach ($tenantInfoGuid in $tenantInfoGuids) {
                    $tenantInfoPath = "$tenantInfoBasePath\$($tenantInfoGuid.PSChildName)"
                    $tenantInfoValues = Get-ItemProperty -Path $tenantInfoPath

                    # Check if the TenantId key exists in TenantInfo and matches the TenantId from JoinInfo
                    if ($tenantInfoValues.TenantId -eq $joinInfoValues.TenantId) {
                        Write-Host "Match found for TenantId in TenantInfo GUID: $($tenantInfoGuid.PSChildName)"
                        Write-Host "Processing additional checks if required..."
                        
                        # Add additional checks or processing here if needed
                    } else {
                        Write-Host "No matching TenantId found for JoinInfo GUID: $($joinInfoGuid.PSChildName) in TenantInfo GUID: $($tenantInfoGuid.PSChildName)"
                    }
                }
            } else {
                Write-Host "TenantInfo path does not exist."
            }
        } else {
            Write-Host "No UserEmail found in JoinInfo GUID: $($joinInfoGuid.PSChildName)"
        }
    }
}

# If no mismatching domains are found, exit with success (0)
Write-Host "Script completed."
exit 0