<?php
require __DIR__ . '/../db.php'; // ligação PDO $pdo

header('Content-Type: application/json');

// Ler JSON do POST
$input = json_decode(file_get_contents('php://input'), true);
if (!$input || empty($input['uid']) || empty($input['acks']) || !is_array($input['acks'])) {
    http_response_code(400);
    echo json_encode(['ok'=>false,'err'=>'dados_invalidos']);
    exit;
}

$uid  = $input['uid'];
$acks = $input['acks'];

try {
    $pdo->beginTransaction();

    // Obter ID do device
    $stmt = $pdo->prepare("SELECT id FROM devices WHERE uid=? LIMIT 1 FOR UPDATE");
    $stmt->execute([$uid]);
    $dev = $stmt->fetchColumn();
    if (!$dev) {
        http_response_code(404);
        echo json_encode(['ok'=>false,'err'=>'device']);
        exit;
    }

    // Atualizar status de cada comando
    $stmtDone   = $pdo->prepare("UPDATE commands SET status='done',   ack_ts=NOW() WHERE id=? AND device_id=?");
    $stmtFailed = $pdo->prepare("UPDATE commands SET status='failed', ack_ts=NOW(), error=? WHERE id=? AND device_id=?");

    foreach ($acks as $ack) {
        if (!isset($ack['id'])) continue;
        $cmdId = intval($ack['id']);
        if (!empty($ack['ok'])) {
            $stmtDone->execute([$cmdId, $dev]);
        } else {
            $errMsg = isset($ack['err']) ? substr($ack['err'], 0, 255) : 'erro';
            $stmtFailed->execute([$errMsg, $cmdId, $dev]);
        }
    }

    // Atualizar heartbeat do device
    $pdo->prepare("UPDATE devices SET last_seen=NOW(), status='online' WHERE id=?")->execute([$dev]);

    $pdo->commit();
    echo json_encode(['ok'=>true]);

} catch (Exception $e) {
    $pdo->rollBack();
    http_response_code(500);
    echo json_encode(['ok'=>false,'err'=>$e->getMessage()]);
}