param(
    [string]$OutFile = ".\netgescon-tapi-provider-report.json"
)

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

function Get-RegistryValues {
    param([string]$Path)

    if (-not (Test-Path $Path)) {
        return $null
    }

    $item = Get-ItemProperty -Path $Path
    $props = @{}

    foreach ($property in $item.PSObject.Properties) {
        if ($property.Name -in @('PSPath', 'PSParentPath', 'PSChildName', 'PSDrive', 'PSProvider')) {
            continue
        }

        $props[$property.Name] = $property.Value
    }

    return $props
}

function Get-RegistryChildren {
    param([string]$Path)

    if (-not (Test-Path $Path)) {
        return @()
    }

    return @(Get-ChildItem -Path $Path | ForEach-Object {
            [pscustomobject]@{
                Name   = $_.PSChildName
                Path   = $_.PSPath
                Values = Get-RegistryValues -Path $_.PSPath
            }
        })
}

function Get-MapValue {
    param(
        [object]$Map,
        [string]$Key
    )

    if ($null -eq $Map) {
        return $null
    }

    if ($Map -is [System.Collections.IDictionary] -and $Map.Contains($Key)) {
        return $Map[$Key]
    }

    return $null
}

function Get-CollectionCount {
    param([object]$Value)

    if ($null -eq $Value) {
        return 0
    }

    if ($Value -is [string]) {
        return 1
    }

    if ($Value -is [System.Collections.ICollection]) {
        return $Value.Count
    }

    if ($Value -is [System.Array]) {
        return $Value.Length
    }

    return @($Value).Count
}

Write-Host "[1/6] Leggo stato servizio Telefonia..."
$tapiService = Get-Service -Name TapiSrv -ErrorAction Stop

Write-Host "[2/6] Leggo servizi dipendenti..."
$dependentServices = @($tapiService.DependentServices | ForEach-Object {
        [pscustomobject]@{
            Name        = $_.Name
            DisplayName = $_.DisplayName
            Status      = $_.Status.ToString()
        }
    })

Write-Host "[3/6] Leggo chiavi registry Telephony..."
$telephonyRoot = 'HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Telephony'
$telephonyWowRoot = 'HKLM:\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Telephony'

$telephonyValues = Get-RegistryValues -Path $telephonyRoot
$telephonyWowValues = Get-RegistryValues -Path $telephonyWowRoot
$telephonyProviders = Get-RegistryChildren -Path (Join-Path $telephonyRoot 'Providers')
$telephonyWowProviders = Get-RegistryChildren -Path (Join-Path $telephonyWowRoot 'Providers')

Write-Host "[4/6] Cerco riferimenti Panasonic nel registry..."
$panasonicHits = @()
foreach ($root in @(
        'HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Telephony',
        'HKLM:\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Telephony',
        'HKLM:\SOFTWARE\Panasonic',
        'HKLM:\SOFTWARE\WOW6432Node\Panasonic'
    )) {
    if (-not (Test-Path $root)) {
        continue
    }

    $panasonicHits += @(Get-ChildItem -Path $root -Recurse -ErrorAction SilentlyContinue | Where-Object {
            $_.Name -match 'Panasonic|KX|TSP|TAPI'
        } | Select-Object -First 100 | ForEach-Object {
            [pscustomobject]@{
                Path   = $_.PSPath
                Name   = $_.PSChildName
                Values = Get-RegistryValues -Path $_.PSPath
            }
        })
}

Write-Host "[5/6] Leggo provider COM TAPI registrati..."
$clsidHits = @()
foreach ($root in @(
        'HKCR:\CLSID',
        'HKLM:\SOFTWARE\Classes\CLSID'
    )) {
    if (-not (Test-Path $root)) {
        continue
    }

    $clsidHits += @(Get-ChildItem -Path $root -ErrorAction SilentlyContinue | ForEach-Object {
            $values = Get-RegistryValues -Path $_.PSPath
            $defaultValue = Get-MapValue -Map $values -Key '(default)'
            $localizedString = Get-MapValue -Map $values -Key 'LocalizedString'

            if ($null -ne $values -and (($defaultValue -as [string]) -match 'Panasonic|TAPI' -or ($localizedString -as [string]) -match 'Panasonic|TAPI')) {
                [pscustomobject]@{
                    Path   = $_.PSPath
                    Name   = $_.PSChildName
                    Values = $values
                }
            }
        })
}

Write-Host "[6/6] Scrivo report JSON..."
$report = [pscustomobject]@{
    GeneratedAt           = (Get-Date).ToString('o')
    ComputerName          = $env:COMPUTERNAME
    UserName              = $env:USERNAME
    TapiService           = [pscustomobject]@{
        Name        = $tapiService.Name
        DisplayName = $tapiService.DisplayName
        Status      = $tapiService.Status.ToString()
        StartType   = (Get-CimInstance Win32_Service -Filter "Name='TapiSrv'" | Select-Object -ExpandProperty StartMode)
    }
    DependentServices     = $dependentServices
    Telephony             = [pscustomobject]@{
        RootValues    = $telephonyValues
        WowRootValues = $telephonyWowValues
        Providers     = $telephonyProviders
        WowProviders  = $telephonyWowProviders
    }
    PanasonicRegistryHits = $panasonicHits
    TapiClsidHits         = $clsidHits
}

$outDirectory = Split-Path -Path $OutFile -Parent
if (-not [string]::IsNullOrWhiteSpace($outDirectory) -and -not (Test-Path $outDirectory)) {
    New-Item -ItemType Directory -Path $outDirectory -Force | Out-Null
}

$report | ConvertTo-Json -Depth 8 | Set-Content -Path $OutFile -Encoding UTF8

Write-Host ""
Write-Host ("TapiSrv: {0} ({1})" -f $report.TapiService.Status, $report.TapiService.StartType)
Write-Host ("Dependent services: {0}" -f (Get-CollectionCount -Value $report.DependentServices))
Write-Host ("Telephony providers x64: {0}" -f (Get-CollectionCount -Value $report.Telephony.Providers))
Write-Host ("Telephony providers wow64: {0}" -f (Get-CollectionCount -Value $report.Telephony.WowProviders))
Write-Host ("Panasonic registry hits: {0}" -f (Get-CollectionCount -Value $report.PanasonicRegistryHits))
Write-Host ("TAPI CLSID hits: {0}" -f (Get-CollectionCount -Value $report.TapiClsidHits))
Write-Host ("File creato: {0}" -f $OutFile)