<#
.SYNOPSIS
    Exports all active Entra ID users and their attributes to a CSV file.

.DESCRIPTION
    Connects to Microsoft Graph, retrieves all users where AccountEnabled is true, 
    and exports every available attribute to a timestamped CSV file in an \Exports subfolder.

.PARAMETER ExportPath
    The subfolder name where the CSV will be saved. Defaults to 'Exports'.

.EXAMPLE
    Export-EntraActiveUsers
#>
function Export-EntraActiveUsers {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory = $false)]
        [string]$ExportPathName = "Exports"
    )

    process {
        Set-StrictMode -Version Latest

        # 1. Setup Paths and Directories
        $BasePath = $PSScriptRoot
        if ([string]::IsNullOrWhiteSpace($BasePath)) {
            $BasePath = Get-Location
        }

        $TargetDirectory = Join-Path -Path $BasePath -ChildPath $ExportPathName
        $Timestamp = Get-Date -Format "yyyyMMdd-HHmm"
        $FileName = "EntraID_ActiveUsers_$Timestamp.csv"
        $FullFilePath = Join-Path -Path $TargetDirectory -ChildPath $FileName

        try {
            Write-Verbose "Ensuring directory exists: $TargetDirectory"
            if (-not (Test-Path -Path $TargetDirectory)) {
                New-Item -Path $TargetDirectory -ItemType Directory -Force | Out-Null
            }

            # 2. Check for Microsoft Graph Connection
            Write-Verbose "Checking Microsoft Graph connection..."
            $CurrentContext = Get-MgContext
            if (-not $CurrentContext) {
                throw "No active Microsoft Graph connection found. Please run 'Connect-MgGraph' first."
            }

            # 3. Retrieve Active Users
            # We filter for AccountEnabled eq true and select all properties (*)
            Write-Verbose "Fetching active users from Entra ID..."
            $UserFilter = "accountEnabled eq true"
            
            # Using -All to ensure we bypass the default page size limits
            $Users = Get-MgUser -All -Filter $UserFilter `
                                -Property Id, UserPrincipalName, GivenName, Surname, DisplayName, Mail, MobilePhone, CompanyName, JobTitle, EmployeeId, FaxNumber, OfficeLocation -ErrorAction Stop | `
                                Select-Object Id, UserPrincipalName, GivenName, Surname, DisplayName, Mail, MobilePhone, CompanyName, JobTitle, EmployeeId, FaxNumber, OfficeLocation

            if ($null -eq $Users -or $Users.Count -eq 0) {
                Write-Warning "No active users found in the tenant."
                return
            }

            Write-Verbose "Found $($Users.Count) users. Exporting to $FullFilePath..."

            # 4. Export to CSV
            $Users | Export-Csv -Path $FullFilePath -NoTypeInformation -Encoding utf8

            Write-Output "Export successfully completed: $FullFilePath"
        }
        catch {
            Write-Error "An error occurred during export: $($_.Exception.Message)"
        }
    }
}