#Requires -Modules ActiveDirectory
<#
.SYNOPSIS
    Zarządza członkostwem w grupach AD — przegląd, porównanie, raport.

.DESCRIPTION
    Umożliwia:
    - Listowanie członków grupy (z zagnieżdżonymi)
    - Listowanie grup użytkownika
    - Porównanie członkostwa dwóch grup
    - Eksport do CSV

.PARAMETER GroupName
    Nazwa grupy AD do sprawdzenia.

.PARAMETER UserName
    SamAccountName użytkownika — wyświetla grupy do których należy.

.PARAMETER Recursive
    Rozwiń zagnieżdżone grupy (domyślnie: $true).

.PARAMETER CompareGroup
    Porównaj członków dwóch grup — podaj nazwę drugiej grupy.

.PARAMETER ExportCSV
    Ścieżka do pliku CSV.

.EXAMPLE
    .\Get-ADGroupMembership.ps1 -GroupName "IT-Admins"
    .\Get-ADGroupMembership.ps1 -UserName jkowalski
    .\Get-ADGroupMembership.ps1 -GroupName "Group-A" -CompareGroup "Group-B"
#>

param(
    [string]$GroupName,
    [string]$UserName,
    [bool]$Recursive = $true,
    [string]$CompareGroup,
    [string]$ExportCSV
)

Import-Module ActiveDirectory -ErrorAction Stop

# --- Tryb: grupy użytkownika ---
if ($UserName) {
    $user = Get-ADUser -Identity $UserName -Properties MemberOf, DisplayName -ErrorAction Stop
    Write-Host "`nGrupy użytkownika: $($user.DisplayName) [$($user.SamAccountName)]`n" -ForegroundColor Cyan

    if ($Recursive) {
        $groups = Get-ADPrincipalGroupMembership -Identity $UserName | Sort-Object Name
    } else {
        $groups = $user.MemberOf | ForEach-Object { Get-ADGroup -Identity $_ } | Sort-Object Name
    }

    $groups | Select-Object Name, GroupCategory, GroupScope,
        @{N='Description'; E={ (Get-ADGroup $_.DistinguishedName -Properties Description).Description }} |
        Format-Table -AutoSize

    Write-Host "Łącznie grup: $($groups.Count)"

    if ($ExportCSV) {
        $groups | Select-Object Name, GroupCategory, GroupScope | Export-Csv $ExportCSV -NoTypeInformation -Encoding UTF8
        Write-Host "Wyeksportowano do: $ExportCSV" -ForegroundColor Green
    }
    return
}

# --- Tryb: członkowie grupy ---
if ($GroupName) {
    $group = Get-ADGroup -Identity $GroupName -Properties Description, Members -ErrorAction Stop
    Write-Host "`nGrupa: $($group.Name)" -ForegroundColor Cyan
    Write-Host "Opis : $($group.Description)"
    Write-Host "Typ  : $($group.GroupCategory) / $($group.GroupScope)`n"

    if ($Recursive) {
        $members = Get-ADGroupMember -Identity $GroupName -Recursive | Sort-Object ObjectClass, Name
    } else {
        $members = Get-ADGroupMember -Identity $GroupName | Sort-Object ObjectClass, Name
    }

    $label = if ($Recursive) { "rekurencyjnie" } else { "bezpośrednio" }
    Write-Host "Członkowie ($label): $($members.Count)" -ForegroundColor Yellow

    $details = $members | ForEach-Object {
        if ($_.objectClass -eq 'user') {
            $u = Get-ADUser -Identity $_.SamAccountName -Properties Department, Enabled, LastLogonDate
            [PSCustomObject]@{
                Type       = 'Użytkownik'
                Name       = $u.DisplayName
                Login      = $u.SamAccountName
                Department = $u.Department
                Enabled    = $u.Enabled
                LastLogon  = $u.LastLogonDate?.ToString("yyyy-MM-dd")
            }
        } elseif ($_.objectClass -eq 'group') {
            [PSCustomObject]@{
                Type       = 'GRUPA (zagn.)'
                Name       = $_.Name
                Login      = $_.SamAccountName
                Department = "-"
                Enabled    = "-"
                LastLogon  = "-"
            }
        } else {
            [PSCustomObject]@{
                Type       = $_.objectClass
                Name       = $_.Name
                Login      = $_.SamAccountName
                Department = "-"
                Enabled    = "-"
                LastLogon  = "-"
            }
        }
    }

    $details | Format-Table -AutoSize

    # Porównanie grup
    if ($CompareGroup) {
        $groupB = Get-ADGroupMember -Identity $CompareGroup -Recursive | Select-Object -Expand SamAccountName
        $groupA = $members | Select-Object -Expand SamAccountName

        $onlyInA = $groupA | Where-Object { $_ -notin $groupB }
        $onlyInB = $groupB | Where-Object { $_ -notin $groupA }
        $inBoth  = $groupA | Where-Object { $_ -in $groupB }

        Write-Host "`n--- PORÓWNANIE: $GroupName vs $CompareGroup ---" -ForegroundColor Cyan
        Write-Host "Wspólni ($($inBoth.Count)):   $($inBoth -join ', ')"
        Write-Host "Tylko w $GroupName ($($onlyInA.Count)): $($onlyInA -join ', ')"
        Write-Host "Tylko w $CompareGroup ($($onlyInB.Count)): $($onlyInB -join ', ')"
    }

    if ($ExportCSV) {
        $details | Export-Csv $ExportCSV -NoTypeInformation -Encoding UTF8
        Write-Host "`nWyeksportowano do: $ExportCSV" -ForegroundColor Green
    }
    return
}

Write-Host "Podaj -GroupName lub -UserName." -ForegroundColor Red