<?php
require_once 'includes/oauth_microsoft.php';

if (!isMicrosoftOAuthConfigured()) {
    http_response_code(503);
    exit('Logowanie Microsoft nie jest skonfigurowane.');
}

$expectedState = $_SESSION['microsoft_oauth_state'] ?? null;
$state = $_GET['state'] ?? '';
$code = $_GET['code'] ?? '';
$error = $_GET['error'] ?? '';

unset($_SESSION['microsoft_oauth_state']);

if ($error !== '') {
    header('Location: login.php?oauth_error=' . urlencode('Logowanie Microsoft zostalo anulowane lub odrzucone.'));
    exit();
}

if (!$expectedState || !hash_equals($expectedState, (string)$state) || $code === '') {
    header('Location: login.php?oauth_error=' . urlencode('Nieprawidlowy stan logowania Microsoft.'));
    exit();
}

try {
    $tokens = exchangeMicrosoftCodeForTokens($code);
    $identity = extractMicrosoftIdentity($tokens);
    $user = findOrProvisionMicrosoftUser($pdo, $identity);
    loginUserIntoSession($user);
    header('Location: index.php');
    exit();
} catch (Throwable $e) {
    error_log($e->getMessage());
    header('Location: login.php?oauth_error=' . urlencode('Nie udalo sie zalogowac przez Microsoft 365.'));
    exit();
}
?>