param(
    [string]$Extensions = "201,205,206",
    [string]$LogFile = ".\netgescon-tapi-poll.log",
    [int]$IntervalSeconds = 2
)

$TapiMediaTypeAudio = 8
$TapiEventFilterCallNotification = 4
$TapiEventFilterCallState = 8
$TapiEventFilterCallMedia = 16
$TapiEventFilterCallHub = 32
$TapiEventFilterCallInfoChange = 64
$TapiEventFilterPrivate = 128

Set-StrictMode -Version Latest
$ErrorActionPreference = "Stop"

function Get-SafeProperty {
    param(
        [Parameter(Mandatory = $true)] $Object,
        [Parameter(Mandatory = $true)] [string]$Name
    )

    try {
        return $Object.$Name
    }
    catch {
        return $null
    }
}

function Get-SafeCallInfoString {
    param(
        [Parameter(Mandatory = $true)] $Call,
        [Parameter(Mandatory = $true)] [int]$Id
    )

    try {
        return [string]$Call.CallInfoString($Id)
    }
    catch {
        return ""
    }
}

function Get-SafeMethodResult {
    param(
        [Parameter(Mandatory = $true)] $Object,
        [Parameter(Mandatory = $true)] [string]$MethodName,
        [object[]]$Arguments = @()
    )

    try {
        return $Object.GetType().InvokeMember($MethodName, [System.Reflection.BindingFlags]::InvokeMethod, $null, $Object, $Arguments)
    }
    catch {
        return $null
    }
}

function Try-RegisterCallNotifications {
    param(
        [Parameter(Mandatory = $true)] $Tapi,
        [Parameter(Mandatory = $true)] $Address,
        [Parameter(Mandatory = $true)] [bool]$Monitor,
        [Parameter(Mandatory = $true)] [bool]$Owner
    )

    try {
        $cookie = $Tapi.RegisterCallNotifications($Address, $Monitor, $Owner, $TapiMediaTypeAudio, 0)
        return [pscustomobject]@{
            Ok = $true
            Cookie = $cookie
            Error = ''
        }
    }
    catch {
        return [pscustomobject]@{
            Ok = $false
            Cookie = $null
            Error = $_.Exception.Message
        }
    }
}

function Convert-ComCollectionToArray {
    param($Collection)

    $items = @()
    if ($null -eq $Collection) {
        return $items
    }

    try {
        foreach ($item in $Collection) {
            $items += $item
        }
    }
    catch {
    }

    return ,$items
}

function Normalize-ExtensionToken {
    param([string]$Value)

    if ($null -eq $Value) {
        $trimmed = ''
    }
    else {
        $trimmed = [string]$Value
    }
    $trimmed = $trimmed.Trim()
    if ($trimmed -eq '') {
        return ''
    }

    if ($trimmed -match '(\d+)$') {
        return $matches[1].TrimStart('0')
    }

    return $trimmed
}

function Should-WatchAddress {
    param(
        [Parameter(Mandatory = $true)] $Address,
        [Parameter(Mandatory = $true)] [string[]]$WatchList
    )

    $dial = [string](Get-SafeProperty -Object $Address -Name 'DialableAddress')
    $name = [string](Get-SafeProperty -Object $Address -Name 'AddressName')

    $dialToken = Normalize-ExtensionToken -Value $dial
    $nameToken = Normalize-ExtensionToken -Value $name

    foreach ($watch in $WatchList) {
        $watchToken = Normalize-ExtensionToken -Value $watch
        if ($watchToken -eq '') {
            continue
        }

        if ($dialToken -eq $watchToken -or $nameToken -eq $watchToken) {
            return $true
        }
    }

    return $false
}

function Write-LogLine {
    param([string]$Text)

    $line = "{0} | {1}" -f (Get-Date).ToString('yyyy-MM-dd HH:mm:ss'), $Text
    Add-Content -Path $script:LogFilePath -Value $line -Encoding UTF8
    Write-Host $line
}

function Get-CallHubSnapshot {
    param([Parameter(Mandatory = $true)] $Tapi)

    $snapshots = @()
    $hubs = Convert-ComCollectionToArray -Collection (Get-SafeProperty -Object $Tapi -Name 'CallHubs')
    foreach ($hub in @($hubs)) {
        $calls = Convert-ComCollectionToArray -Collection (Get-SafeProperty -Object $hub -Name 'Calls')
        $snapshots += [pscustomobject]@{
            HubType = $hub.GetType().FullName
            CallCount = @($calls).Count
        }
    }

    return @($snapshots)
}

$watchList = @($Extensions.Split(',') | ForEach-Object { $_.Trim() } | Where-Object { $_ -ne '' })
$script:LogFilePath = $LogFile

$tapi = New-Object -ComObject TAPI.TAPI
$tapi.Initialize()
$tapi.EventFilter = $TapiEventFilterCallNotification + $TapiEventFilterCallState + $TapiEventFilterCallMedia + $TapiEventFilterCallHub + $TapiEventFilterCallInfoChange + $TapiEventFilterPrivate

$allAddresses = @(Convert-ComCollectionToArray -Collection $tapi.Addresses)
$addresses = @($allAddresses | Where-Object {
    Should-WatchAddress -Address $_ -WatchList $watchList
})

if ($addresses.Count -eq 0) {
    throw "Nessun indirizzo TAPI trovato per le estensioni: $Extensions"
}

Write-LogLine "=== AVVIO POLL TAPI ==="
Write-LogLine "Watch list: $Extensions"
Write-LogLine "Provider addresses totali: $($allAddresses.Count)"
Write-LogLine "Provider addresses filtrati: $($addresses.Count)"
$registrationCookies = @()
foreach ($address in $addresses) {
    $addressName = [string](Get-SafeProperty -Object $address -Name 'AddressName')
    $dial = [string](Get-SafeProperty -Object $address -Name 'DialableAddress')
    $provider = [string](Get-SafeProperty -Object $address -Name 'ServiceProviderName')
    Write-LogLine ("ADDRESS READY name={0} dial={1} provider={2}" -f $addressName, $dial, $provider)

    $registration = Try-RegisterCallNotifications -Tapi $tapi -Address $address -Monitor $true -Owner $true
    if ($registration.Ok) {
        $registrationCookies += $registration.Cookie
        Write-LogLine ("REGISTER OK mode=monitor+owner cookie={0} address={1} dial={2}" -f $registration.Cookie, $addressName, $dial)
    }
    else {
        Write-LogLine ("REGISTER KO address={0} dial={1} error={2}" -f $addressName, $dial, $registration.Error)
    }
}

$lastSnapshot = @{}
$lastHubSignature = "__UNSET__"

while ($true) {
    $hubSnapshot = Get-CallHubSnapshot -Tapi $tapi
    $hubSignature = (($hubSnapshot | ForEach-Object { "{0}:{1}" -f $_.HubType, $_.CallCount }) -join '|')
    if ($hubSignature -ne $lastHubSignature) {
        $hubText = $hubSignature
        if ($hubText -eq '') {
            $hubText = 'none'
        }
        Write-LogLine ("CALLHUBS {0}" -f $hubText)
        $lastHubSignature = $hubSignature
    }

    foreach ($address in $addresses) {
        $addressName = [string](Get-SafeProperty -Object $address -Name 'AddressName')
        $dial = [string](Get-SafeProperty -Object $address -Name 'DialableAddress')
        $calls = @(Convert-ComCollectionToArray -Collection (Get-SafeProperty -Object $address -Name 'Calls'))

        if ($calls.Count -eq 0) {
            $key = "$addressName|$dial"
            if (-not $lastSnapshot.ContainsKey($key) -or $lastSnapshot[$key] -ne 'IDLE') {
                Write-LogLine ("IDLE address={0} dial={1}" -f $addressName, $dial)
                $lastSnapshot[$key] = 'IDLE'
            }
            continue
        }

        $index = 0
        foreach ($call in $calls) {
            $index++
            $state = Get-SafeProperty -Object $call -Name 'State'
            if ($null -eq $state) {
                $state = Get-SafeProperty -Object $call -Name 'CallState'
            }

            $caller = Get-SafeCallInfoString -Call $call -Id 14
            $called = Get-SafeCallInfoString -Call $call -Id 15
            $connected = Get-SafeCallInfoString -Call $call -Id 16

            $signature = "state=$state;caller=$caller;called=$called;connected=$connected"
            $key = "$addressName|$dial|$index"

            if (-not $lastSnapshot.ContainsKey($key) -or $lastSnapshot[$key] -ne $signature) {
                Write-LogLine ("CALL address={0} dial={1} idx={2} state={3} caller={4} called={5} connected={6}" -f $addressName, $dial, $index, $state, $caller, $called, $connected)
                $lastSnapshot[$key] = $signature
            }
        }
    }

    Start-Sleep -Seconds $IntervalSeconds
}