# ADGroup.ps1
# Security group management.
# No dependencies on other AD modules.

function Ensure-ADSecurityGroup {
    <#
    .SYNOPSIS
        Idempotently creates a security group and syncs membership.
    #>
    param(
        [Parameter(Mandatory)]
        [string]$Name,

        [Parameter(Mandatory)]
        [string]$Path,

        [string]$Description = '',

        [ValidateSet('Global', 'DomainLocal', 'Universal')]
        [string]$Scope = 'Global',

        [string[]]$Members = @()
    )

    $created = $false

    try {
        $group = Get-ADGroup -Identity $Name -ErrorAction Stop
        Write-Host "  [OK] Group exists: $Name" -ForegroundColor Green
    } catch {
        New-ADGroup -Name $Name -Path $Path -GroupScope $Scope -GroupCategory Security `
            -Description $Description -ProtectedFromAccidentalDeletion $true
        Write-Host "  [CREATED] Group: $Name" -ForegroundColor Yellow
        $created = $true
    }

    # Ensure protected from accidental deletion
    $group = Get-ADGroup -Identity $Name -Properties ProtectedFromAccidentalDeletion
    if (-not $group.ProtectedFromAccidentalDeletion) {
        Set-ADObject -Identity $group.DistinguishedName -ProtectedFromAccidentalDeletion $true
        Write-Host "  [UPDATED] $Name ProtectedFromAccidentalDeletion=True" -ForegroundColor Yellow
    }

    # Sync membership
    if ($Members.Count -gt 0) {
        $currentMembers = @(Get-ADGroupMember -Identity $Name -ErrorAction SilentlyContinue | Select-Object -ExpandProperty SamAccountName)

        foreach ($member in $Members) {
            if ($member -notin $currentMembers) {
                Add-ADGroupMember -Identity $Name -Members $member
                Write-Host "  [ADDED] $member -> $Name" -ForegroundColor Yellow
            }
        }

        # Remove members not in desired list
        foreach ($current in $currentMembers) {
            if ($current -notin $Members) {
                Remove-ADGroupMember -Identity $Name -Members $current -Confirm:$false
                Write-Host "  [REMOVED] $current from $Name" -ForegroundColor Red
            }
        }
    }

    return $created
}

function Compare-ADSecurityGroup {
    <#
    .SYNOPSIS
        Compares desired group state against AD. Returns diffs.
    #>
    param(
        [Parameter(Mandatory)]
        [string]$Name,

        [string[]]$Members = @()
    )

    $diffs = @()

    try {
        $group = Get-ADGroup -Identity $Name -Properties ProtectedFromAccidentalDeletion -ErrorAction Stop
        Write-Host "  [OK] Group exists: $Name" -ForegroundColor Green

        # Check protection
        if (-not $group.ProtectedFromAccidentalDeletion) {
            Write-Host "  [DRIFT] $Name not protected from accidental deletion" -ForegroundColor Red
            $diffs += [PSCustomObject]@{ Type = 'GroupProtection'; Group = $Name; Status = 'Unprotected' }
        }

        # Check membership
        $currentMembers = @(Get-ADGroupMember -Identity $Name -ErrorAction SilentlyContinue | Select-Object -ExpandProperty SamAccountName)

        foreach ($member in $Members) {
            if ($member -notin $currentMembers) {
                Write-Host "  [DRIFT] $member not in group $Name" -ForegroundColor Red
                $diffs += [PSCustomObject]@{ Type = 'GroupMember'; Group = $Name; Member = $member; Status = 'Missing' }
            }
        }

        foreach ($current in $currentMembers) {
            if ($current -notin $Members) {
                Write-Host "  [DRIFT] $current in group $Name but not in desired state" -ForegroundColor Red
                $diffs += [PSCustomObject]@{ Type = 'GroupMember'; Group = $Name; Member = $current; Status = 'Extra' }
            }
        }
    } catch {
        Write-Host "  [MISSING] Group: $Name" -ForegroundColor Red
        $diffs += [PSCustomObject]@{ Type = 'Group'; Name = $Name; Status = 'Missing' }
    }

    return $diffs
}