# Copyright (c) 2018, Oracle and/or its affiliates.
# The Universal Permissive License (UPL), Version 1.0
#
# Oracle OCI Virtual Cloud Networks IP configuration script
#
# 2018-05-11 initial release

param (
    [Parameter(Mandatory=$false)][string]$vnicOcid
)

function PromptYesNo()
{
    param(
        [parameter(Mandatory=$true)][String]$title,
        [parameter(Mandatory=$true)][String]$message,
        [parameter(Mandatory=$true)][String]$yesHelp,
        [parameter(Mandatory=$true)][String]$noHelp
    )

    $yesOption = New-Object System.Management.Automation.Host.ChoiceDescription "&Yes", $yesHelp
    $noOption = New-Object System.Management.Automation.Host.ChoiceDescription "&No", $noHelp
    $options = [System.Management.Automation.Host.ChoiceDescription[]]($yesOption, $noOption)
    $choice = $Host.UI.PromptForChoice($title, $message, $options, 1)

    if ($choice -eq 1)
    {
        Exit 0
    }
}

#
# Constants
#
$metadataServiceVnicsUrl = "http://169.254.169.254/opc/v1/vnics/"
$dnsIPAddress = "169.254.169.254"

#
# Query Metadata Service
#
$wc = New-Object system.Net.WebClient -ErrorAction Stop;
$allVnicsMetadata = ($wc.downloadString($metadataServiceVnicsUrl) | ConvertFrom-Json -ErrorAction Stop);

#
# List available Secondary VNICs if OCID was not provided
#
if (!$vnicOcid)
{
    if ($allVnicsMetadata.Length -le 1)
    {
        Write-Error "Couldn't find any secondary VNICs attached to this instance."
        Exit 1
    }

    while ($true)
    {
        for ($vnicCounter = 1; $vnicCounter -lt $allVnicsMetadata.Length; $vnicCounter++)
        {
            Write-Host $vnicCounter ") Private IP:" $vnic.privateIp "Subnet:" $vnic.subnetCidrBlock "MAC:" $vnic.macAddr "VLAN Tag:" $vnic.vlanTag;
        }

        Write-Host "0 ) Exit"

        try
        {
            [int16]$vnicIndex = Read-Host -Prompt "VNIC to be configured"

            if ($vnicIndex -eq 0)
            {
                Exit 0
            }

            if ($vnicIndex -le 0 -or $vnicIndex -ge $allVnicsMetadata.Length)
            {
                throw [System.Exception] "Invalid VNIC index."
            }

            $vnicOcid = $allVnicsMetadata[$vnicIndex].vnicId
            break
        }
        catch
        {
            Write-Error "INVALID VNIC! Please enter a valid number." 
        }
    }
}

Write-Host "+ Specified VNIC: $vnicOcid"

#
# Obtain the metadata for the specified VNIC
#
$secondaryVnicMetadata = ($allVnicsMetadata | Where-Object {$_.vnicId -eq $vnicOcid});
if (!$secondaryVnicMetadata)
{
    Write-Error "Couldn't find a VNIC attahced to this instance with the specified OCID."
    Exit 1
}

$subnetPrefix = ([int]($secondaryVnicMetadata.subnetCidrBlock.split("/")[1]));

Write-Host "+ Found VNIC Settings: " (ConvertTo-Json $secondaryVnicMetadata)

#
# Find the network adapter to be configured 
#
$secondaryVnicAdapter = (Get-NetAdapter -ErrorAction Stop | Where-Object {$_.MacAddress -eq $secondaryVnicMetadata.macAddr.Replace(":", "-")})
if( @($secondaryVnicAdapter).Count -ne 1)
{
    $secondaryVnicAdapter = (Get-NetAdapter -ErrorAction Stop | Where-Object {$_.Vlanid -eq $secondaryVnicMetadata.vlanTag -and $_.InterfaceDescription -like "Microsoft Network Adapter Multiplexor Driver #*"})
}

if (!$secondaryVnicAdapter)
{
    Write-Error "Couldn't find a Network Interface for the specified VNIC."
    Exit 1
} 

Write-Host "+ Found Network Interface: " $secondaryVnicAdapter.Name

#
# Configure the Network Interface
#
$mac = Get-NetAdapter -Name $secondaryVnicAdapter.Name | select -expand MacAddress
if ($mac -ne $secondaryVnicMetadata.macAddr.Replace(":", "-")) 
{
    PromptYesNo -title "WARNING!" -message "The Network Interface for the specified VNIC already has a different MAC Address. The current settings will be overwritten. Proceed?" -yesHelp "Overwrite current settings." -noHelp "Do not change existing settings and exit."
    Set-NetAdapter -Name $secondaryVnicAdapter.Name -MacAddress $secondaryVnicMetadata.macAddr.Replace(":", "-")
}

$secondaryVnicAdapterIPConfig = (Get-NetIPAddress -InterfaceAlias $secondaryVnicAdapter.InterfaceAlias -AddressFamily IPv4 -ErrorAction SilentlyContinue);
if ($secondaryVnicAdapterIPConfig)
{
    PromptYesNo -title "WARNING!" -message "The Network Interface for the specified VNIC already has an IP Address. The current settings will be overwritten. Proceed?" -yesHelp "Overwrite current settings." -noHelp "Do not change existing settings and exit."
    Remove-NetIPAddress -InterfaceAlias $secondaryVnicAdapter.InterfaceAlias -AddressFamily IPv4
}

New-NetIPAddress -InterfaceAlias $secondaryVnicAdapter.InterfaceAlias -AddressFamily IPv4 -IPAddress $secondaryVnicMetadata.privateIp -PrefixLength $subnetPrefix -ErrorAction Stop
Write-Host "Assigned a static IP Address to the Network Interface." -ForegroundColor Green

Set-DnsClientServerAddress -InterfaceAlias $secondaryVnicAdapter.InterfaceAlias -ServerAddresses $dnsIPAddress -ErrorAction Stop
Write-Host "Set the DNS server IP Address." -ForegroundColor Green

$secondaryVnicAdapterDefaultRoute = (Get-NetRoute -InterfaceAlias $secondaryVnicAdapter.InterfaceAlias -DestinationPrefix 0.0.0.0/0 -ErrorAction SilentlyContinue);
if ($secondaryVnicAdapterDefaultRoute)
{
    PromptYesNo -title "WARNING!" -message "The Network Interface for the specified VNIC already has default gateway. The current settings will be overwritten. Proceed?" -yesHelp "Overwrite current settings." -noHelp "Do not change existing settings and exit."
    Remove-NetRoute -InterfaceAlias $secondaryVnicAdapter.InterfaceAlias -DestinationPrefix 0.0.0.0/0 -ErrorAction Stop
}

New-NetRoute -InterfaceAlias $secondaryVnicAdapter.InterfaceAlias -DestinationPrefix 0.0.0.0/0 -NextHop $secondaryVnicMetadata.virtualRouterIp -ErrorAction Stop | Out-Null
Write-Host "Created a default route for the Network Interface." -ForegroundColor Green
Write-Host "The Network Interface was successfully configured." -ForegroundColor Green