<?php
/**
 * Startpunt voor Microsoft 365 OAuth 2.0 Flow
 */

require_once __DIR__ . '/../includes/auth.php';
require_once __DIR__ . '/../includes/integrations/microsoft.php';

$user = require_auth();
$db = get_db_connection();

// Haal eventueel opgeslagen client_id en tenant_id op uit database
$stmt = $db->prepare("SELECT settings FROM integrations WHERE user_id = ? AND provider = 'OUTLOOK'");
$stmt->execute([$user['id']]);
$row = $stmt->fetch();
$savedSettings = json_decode($row['settings'] ?? '{}', true) ?: [];

$clientId = !empty($_GET['client_id']) 
    ? trim($_GET['client_id']) 
    : (!empty($savedSettings['client_id']) ? $savedSettings['client_id'] : fociz_env('MICROSOFT_CLIENT_ID', ''));

$tenantId = !empty($_GET['tenant_id']) 
    ? trim($_GET['tenant_id']) 
    : (!empty($savedSettings['tenant_id']) ? $savedSettings['tenant_id'] : fociz_env('MICROSOFT_TENANT_ID', 'common'));

if (empty($clientId)) {
    header('Location: /integrations.php?error=' . urlencode('Vul eerst de Application (Client) ID en het Client Secret in bij de Outlook instellingen om te koppelen met Microsoft 365.'));
    exit;
}

// Bepaal de dynamische of geconfigureerde redirect URI
$redirectUri = rtrim(APP_URL, '/') . '/auth/callback_microsoft.php';

// Genereer unieke CSRF state
$state = bin2hex(random_bytes(16));
$_SESSION['ms_oauth_state'] = $state;
$_SESSION['ms_oauth_user_id'] = $user['id'];

// Stuur gebruiker door naar Microsoft login
$authUrl = microsoft_get_auth_url($clientId, $redirectUri, $tenantId, $state);
header("Location: {$authUrl}");
exit;