# DeployCenter - Network detection
# Compatible with Windows PowerShell 5.1

function Get-DeployNetworkIPv4 {
    [CmdletBinding()]
    param()

    # Prefer an interface with a default gateway; exclude loopback,
    # APIPA, and non-routable IPv4 addresses that are generally useless in WinPE.
    $candidates = @()
    try {
        foreach ($interface in [System.Net.NetworkInformation.NetworkInterface]::GetAllNetworkInterfaces()) {
            if ($interface.NetworkInterfaceType -eq [System.Net.NetworkInformation.NetworkInterfaceType]::Loopback) { continue }

            $properties = $interface.GetIPProperties()
            $ipv4Properties = $properties.GetIPv4Properties()
            if ($null -eq $ipv4Properties) { continue }

            $hasGateway = @(
                $properties.GatewayAddresses | Where-Object {
                    $_.Address.AddressFamily -eq [System.Net.Sockets.AddressFamily]::InterNetwork -and
                    $_.Address.ToString() -ne '0.0.0.0'
                }
            ).Count -gt 0

            foreach ($unicast in $properties.UnicastAddresses) {
                $address = $unicast.Address
                if ($address.AddressFamily -ne [System.Net.Sockets.AddressFamily]::InterNetwork) { continue }
                $addressText = $address.ToString()
                if ($addressText -eq '127.0.0.1' -or $addressText -like '169.254.*' -or $addressText -eq '0.0.0.0') { continue }
                $candidates += [pscustomobject]@{
                    Address    = $addressText
                    HasGateway = $hasGateway
                    Index      = [int]$ipv4Properties.Index
                }
            }
        }
    } catch {
        # Network detection must not prevent DeployCenter from starting.
        if (Get-Command Write-Log -ErrorAction SilentlyContinue) {
            Write-Log (ConvertTo-DeployCenterLocalizedLogMessage -Message "Network detection: $($_.Exception.Message)") 'WARNING'
        }
    }

    $chosen = $candidates | Sort-Object @{Expression='HasGateway';Descending=$true}, Index | Select-Object -First 1
    if ($chosen) { return [string]$chosen.Address }
    return $null
}