<#
    .SYNOPSIS
    Create Azure Landing Zone (ALZ) for a new customer.
    .DESCRIPTION
    Create Azure Landing Zone (ALZ) for a new customer based on a naming convention.
    .PARAMETER SubscriptionId
    Enter the subscriptionid of the customer.
    .PARAMETER customerAbbreviation
    Enter the abbreviation for the customer.
    .PARAMETER VnetAddressSpace
    Enter the Address space for the VNET, should be atleast /22
    .EXAMPLE
    Deploy-Alz.ps1 -SubscriptionId 1234-5678-9013-4455 -custabbr ucs -VnetAddressSpace 10.232.0.0/22 -vpnGateway $true
#>
param (
    [Parameter(Mandatory)]
    [ValidateNotNullOrEmpty()]
    [string]$SubscriptionId,

    [Parameter(Mandatory)]
    [ValidateNotNullOrEmpty()]
    [string]$customerAbbreviation,

    [Parameter(Mandatory)]
    [ValidateNotNullOrEmpty()]
    [string]$VnetAddressSpace,

    [Parameter()]
    [ValidateNotNullOrEmpty()]
    [string]$vpnGateWay

)

Set-AzContext -SubscriptionId $SubscriptionId

# Create naming standards based on customer abbreviation
$location = 'westeurope'
$VnetResourceGroup = "rg-$($customerAbbreviation)-vnet-01"
$VnetName = "$($customerAbbreviation)-vnet-01"
$DefaultSubnetName = "DefaultSubnet"
$DefaultSubnetNSGName = "nsg-" + $DefaultSubnetName
$AVDSubnetName = "AVDSubnet"
$AVDSubnetNSGName = "nsg-" + $AVDSubnetName
$bit = (($VnetAddressSpace).Split('/'))[0].Split(".")
$GatewaySubnetSpace = $bit[0] + "." + $bit[1]  + "." + $bit[2] + "." + "0" + "/27"
$DefaultSubnetSpace = $bit[0] + "." + $bit[1]  + "." + "1" + "." + "0" + "/24"
$AVDSubnetSpace = $bit[0] + "." + $bit[1]  + "." + "2" + "." + "0" + "/24"
$rsvResourceGroup = "rg-$($customerAbbreviation)-rsv-01"
$rsvNameLRS = "rsv-$($customerAbbreviation)-lrs"
$rsvNameGRS = "rsv-$($customerAbbreviation)-grs"

# Create VNET
New-AzResourceGroup -Name $VnetResourceGroup -Location $Location 
$vnet = New-AzVirtualNetwork -Name $VnetName -Location $location -ResourceGroupName $VnetResourceGroup -AddressPrefix $VnetAddressSpace

# Create NSGs
$DefaultNSG = New-AzNetworkSecurityGroup -Name $DefaultSubnetNSGName -ResourceGroupName $VnetResourceGroup -location $location
$AVDNSG = New-AzNetworkSecurityGroup -Name $AVDSubnetNSGName -ResourceGroupName $VnetResourceGroup -location $location

# Create Subnet Configs
Add-AzVirtualNetworkSubnetConfig -VirtualNetwork $vnet -Name GatewaySubnet -AddressPrefix $GatewaySubnetSpace 
Add-AzVirtualNetworkSubnetConfig -VirtualNetwork $vnet -Name $DefaultSubnetName -AddressPrefix $DefaultSubnetSpace -NetworkSecurityGroup $DefaultNSG
Add-AzVirtualNetworkSubnetConfig -VirtualNetwork $vnet -Name $AVDSubnetName  -AddressPrefix $AVDSubnetSpace -NetworkSecurityGroup $AVDNSG

# Set VNET
Set-AzVirtualNetwork -VirtualNetwork $vnet

# Create Recovery Service Vaults
New-AzResourceGroup -Name $rsvResourceGroup -Location $Location 
$rsvLRS = New-AzRecoveryServicesVault -ResourceGroupName $rsvResourceGroup -Name $rsvNameLRS -Location $location 
Set-AzRecoveryServicesBackupProperty -Vault $rsvLRS -BackupStorageRedundancy LocallyRedundant
$rsvGRS = New-AzRecoveryServicesVault -ResourceGroupName $rsvResourceGroup -Name $rsvNameGRS -Location $location
Set-AzRecoveryServicesBackupProperty -Vault $rsvGRS -BackupStorageRedundancy GeoRedundant

If ($vpnGateWay) {
    Write-Host "Creating VPN Gateway"
    $vnet = Get-AzVirtualNetwork -Name $VnetName -ResourceGroupName $VnetResourceGroup 
    $vnetGWName = "$($customerAbbreviation)-vnetgw-01"
    $vnetGWPIPName = "$($vnetGWName)-pip" 
    $subnet = Get-AzVirtualNetworkSubnetConfig -name 'GatewaySubnet' -VirtualNetwork $vnet
    $ngwpip = New-AzPublicIpAddress -Name $vnetGWPIPName -ResourceGroupName $VnetResourceGroup -Location $location -AllocationMethod Dynamic
    $ngwipconfig = New-AzVirtualNetworkGatewayIpConfig -Name ngwipconfig -SubnetId $subnet.Id -PublicIpAddressId $ngwpip.Id
    New-AzVirtualNetworkGateway -ResourceGroupName $VnetResourceGroup -Name $vnetGWName -Location $location -IpConfigurations $ngwipconfig -GatewayType "Vpn" -VpnType "RouteBased" -GatewaySku "Basic" 
}
else {
    Write-Host "No need to create VPN Gateway." 
}