# SetupVodiaTeamsDirectRouting.ps1
# Vodia Teams Direct Routing Setup

$ErrorActionPreference = "Stop"

$script:GraphConnected = $false

function Press-Continue {
    while ($true) {
        $r = (Read-Host "Press C to continue or Q to quit").ToUpper()

        switch ($r) {
            "C" { return }
            "Q" { exit }
        }
    }
}

function Ensure-NuGet {
    if (-not (Get-PackageProvider NuGet -ErrorAction SilentlyContinue)) {
        Write-Host "Installing NuGet provider..." -ForegroundColor Yellow
        Install-PackageProvider -Name NuGet -Force
    }
}

function Ensure-Module {
    param(
        [string]$Name
    )

    if (-not (Get-Module -ListAvailable -Name $Name)) {

        Write-Host ""
        Write-Host "Installing module $Name..." -ForegroundColor Yellow

        Install-Module `
            -Name $Name `
            -Scope CurrentUser `
            -Force `
            -AllowClobber

        Write-Host "$Name installed." -ForegroundColor Green
    }
}

function Connect-TeamsServices {

    Ensure-NuGet

    try {
        Set-PSRepository `
            -Name PSGallery `
            -InstallationPolicy Trusted `
            -ErrorAction SilentlyContinue
    }
    catch {}

    Ensure-Module MicrosoftTeams

    Import-Module MicrosoftTeams

    Write-Host ""
    Write-Host "Connecting to Microsoft Teams..."
    Write-Host "Complete MFA if prompted."

    Connect-MicrosoftTeams

    $tenant = Get-CsTenant

    Write-Host ""
    Write-Host "Connected to Teams." -ForegroundColor Green

    if ($tenant.DisplayName) {
        Write-Host "Tenant: $($tenant.DisplayName)"
    }
}

function Connect-GraphIfNeeded {

    if ($script:GraphConnected) {
        return
    }

    Ensure-Module Microsoft.Graph.Users
    Ensure-Module Microsoft.Graph.Identity.DirectoryManagement

    Import-Module Microsoft.Graph.Users
    Import-Module Microsoft.Graph.Identity.DirectoryManagement

    Write-Host ""
    Write-Host "Connecting to Microsoft Graph..."
    Write-Host "Complete MFA if prompted."

    Connect-MgGraph `
        -Scopes `
        "User.ReadWrite.All", `
        "Directory.ReadWrite.All", `
        "Organization.Read.All"

    $script:GraphConnected = $true

    Write-Host "Microsoft Graph connected." -ForegroundColor Green
}

function Get-GatewayName {

    while ($true) {

        Write-Host ""
        Write-Host "The DNS name must resolve."
        Write-Host "The resolved address should point to the Vodia PBX."

        $fqdn = Read-Host "Enter PSTN Gateway DNS Name"

        try {

            $dns = Resolve-DnsName `
                -Name $fqdn `
                -Type A `
                -ErrorAction Stop

            Write-Host ""
            Write-Host "DNS Resolution Successful" -ForegroundColor Green

            foreach ($ip in $dns.IPAddress) {
                Write-Host "IP: $ip"
            }

            Press-Continue

            return $fqdn
        }
        catch {

            Write-Host ""
            Write-Host "DNS resolution failed." -ForegroundColor Red

            Press-Continue
        }
    }
}

function Ensure-Gateway {

    param(
        [string]$GatewayFqdn
    )

    $existing = Get-CsOnlinePSTNGateway `
        -Identity $GatewayFqdn `
        -ErrorAction SilentlyContinue

    if ($existing) {

        Write-Host ""
        Write-Host "Gateway already exists." -ForegroundColor Yellow
        Write-Host "No changes will be made."

        return
    }

    try {

        Write-Host ""
        Write-Host "Creating PSTN Gateway..."

        New-CsOnlinePSTNGateway `
            -Fqdn $GatewayFqdn `
            -SipSignalingPort 5061 `
            -Enabled $true `
            -MediaBypass $false

        Write-Host "Gateway created." -ForegroundColor Green
    }
    catch {

        Write-Host ""
        Write-Host "Gateway creation failed." -ForegroundColor Red
        Write-Host $_.Exception.Message

        Press-Continue
    }
}

function Ensure-Usage {

    param(
        [string]$UsageName
    )

    $usage = Get-CsOnlinePstnUsage

    if ($usage.Usage -contains $UsageName) {

        Write-Host "$UsageName already exists." -ForegroundColor Yellow
        return
    }

    Set-CsOnlinePstnUsage `
        -Identity Global `
        -Usage @{ Add = $UsageName }

    Write-Host "$UsageName created." -ForegroundColor Green
}

function Ensure-Route {

    param(
        [string]$RouteName,
        [string]$UsageName,
        [string]$GatewayFqdn
    )

    $route = Get-CsOnlineVoiceRoute `
        -Identity $RouteName `
        -ErrorAction SilentlyContinue

    if ($route) {

        Write-Host "$RouteName already exists." -ForegroundColor Yellow
        Write-Host "No changes will be made."

        return
    }

    New-CsOnlineVoiceRoute `
        -Identity $RouteName `
        -NumberPattern ".*" `
        -OnlinePstnUsages $UsageName `
        -OnlinePstnGatewayList $GatewayFqdn

    Write-Host "$RouteName created." -ForegroundColor Green
}

function Ensure-Policy {

    param(
        [string]$PolicyName,
        [string]$UsageName
    )

    $policy = Get-CsOnlineVoiceRoutingPolicy `
        -Identity $PolicyName `
        -ErrorAction SilentlyContinue

    if ($policy) {

        Write-Host "$PolicyName already exists." -ForegroundColor Yellow
        Write-Host "No changes will be made."

        return
    }

    New-CsOnlineVoiceRoutingPolicy `
        -Identity $PolicyName `
        -OnlinePstnUsages $UsageName

    Write-Host "$PolicyName created." -ForegroundColor Green
}

function Show-Users {

    Connect-GraphIfNeeded

    Get-MgUser -All |
        Select-Object DisplayName,UserPrincipalName |
        Sort-Object DisplayName |
        Format-Table -AutoSize
}

function Show-Licenses {

    Connect-GraphIfNeeded

    Get-MgSubscribedSku |
        Select-Object `
            SkuPartNumber,
            ConsumedUnits,
            @{Name="Available";Expression={$_.PrepaidUnits.Enabled - $_.ConsumedUnits}},
            SkuId |
        Format-Table -AutoSize
}

function Assign-License {

    Connect-GraphIfNeeded

    $upn = Read-Host "Enter User UPN"

    $licenses = Get-MgSubscribedSku

    $licenses |
        Select-Object SkuPartNumber,SkuId |
        Format-Table -AutoSize

    $skuName = Read-Host "Enter SkuPartNumber"

    $sku = $licenses | Where-Object {
        $_.SkuPartNumber -eq $skuName
    }

    if (-not $sku) {

        Write-Host "SKU not found." -ForegroundColor Red
        return
    }

    Set-MgUserLicense `
        -UserId $upn `
        -AddLicenses @(
            @{
                SkuId = $sku.SkuId
            }
        ) `
        -RemoveLicenses @()

    Write-Host "License assigned." -ForegroundColor Green
}

function Assign-Policy {

    param(
        [string]$PolicyName
    )

    $upn = Read-Host "Enter User UPN"

    Grant-CsOnlineVoiceRoutingPolicy `
        -Identity $upn `
        -PolicyName $PolicyName

    Write-Host "$PolicyName assigned." -ForegroundColor Green
}

# =====================================================
# MAIN
# =====================================================

try {

    Write-Host ""
    Write-Host "Vodia Teams Direct Routing Setup"
    Write-Host ""

    Connect-TeamsServices

    $GatewayFqdn = Get-GatewayName

    $Prefix = $GatewayFqdn.Split(".")[0]

    $RouteName = "Route-$Prefix"
    $UsageName = "Usage-$Prefix"
    $PolicyName = "Policy-$Prefix"

    Write-Host ""
    Write-Host "Configuration Names"
    Write-Host "-------------------"
    Write-Host "Gateway : $GatewayFqdn"
    Write-Host "Route   : $RouteName"
    Write-Host "Usage   : $UsageName"
    Write-Host "Policy  : $PolicyName"

    Ensure-Gateway `
        -GatewayFqdn $GatewayFqdn

    Ensure-Usage `
        -UsageName $UsageName

    Ensure-Route `
        -RouteName $RouteName `
        -UsageName $UsageName `
        -GatewayFqdn $GatewayFqdn

    Ensure-Policy `
        -PolicyName $PolicyName `
        -UsageName $UsageName

    while ($true) {

        Write-Host ""
        Write-Host "===================================="
        Write-Host "1 - List Users"
        Write-Host "2 - List Licenses"
        Write-Host "3 - Assign License"
        Write-Host "4 - Assign Routing Policy"
        Write-Host "5 - Assign License and Policy"
        Write-Host "Q - Quit"
        Write-Host "===================================="
        Write-Host ""
        Write-Host "You may also assign licenses and routing"
        Write-Host "policies through the Teams Admin Center"
        Write-Host "or Microsoft 365 Admin Center."
        Write-Host ""

        $selection = (Read-Host "Selection").ToUpper()

        switch ($selection) {

            "1" {
                Show-Users
            }

            "2" {
                Show-Licenses
            }

            "3" {
                Assign-License
            }

            "4" {
                Assign-Policy -PolicyName $PolicyName
            }

            "5" {
                Assign-License
                Assign-Policy -PolicyName $PolicyName
            }

            "Q" {
                break
            }

            default {
                Write-Host "Invalid selection."
            }
        }
    }
}
finally {

    try {
        Disconnect-MicrosoftTeams
    }
    catch {}

    try {
        Disconnect-MgGraph
    }
    catch {}
}