<?php

use function Amp\call;
use Amp\Mysql\CommandResult;
use Amp\Mysql\ConnectionException;
use Amp\Mysql\InitializationException;
use Amp\Mysql\QueryError;
use Amp\Mysql\ResultSet;
use Amp\Promise;
use Amp\Socket\ConnectException;

function query(\Amp\Mysql\Pool $pool, string $query): Promise
{
    return call(function () use ($query, $pool) {
        $tryAgain = true;
        while (true) {
            echo "Try\n";
            /**
             * @var \Sensphere\DB\MySql\Connection $connection
             */
            try {
                /**
                 * @var ResultSet $result
                 */
                $result = yield $pool->query($query);

                if ($result instanceof CommandResult) {
                    return new \Sensphere\DB\Async\Result(
                        null,
                        $result->affectedRows()
                    );
                }

                echo "Got response\n";

                /**
                 * @var ResultSet $result
                 */
                $rows = [];
                while (yield $result->advance()) {
                    $rows[] = $result->getCurrent();
                }

                echo "Resolve\n";
                return $rows;
            } catch (ConnectException | InitializationException | ConnectionException $e) {
                // Always retry if server went away. It maybe necessary to retry multiple times if there are multiple idle connections in the pool
                if (strpos($e->getMessage(), 'went away') !== false) {
                    echo "MySQL went away on query $query\n";
                    $tryAgain = true;
                }

                // Retry once on connect errors
                if ($tryAgain) {
                    $tryAgain = false;
                    continue;
                }

                throw new Exception($e->getMessage(), $e->getCode(), $e);
            } catch (QueryError $e) {
                throw new Exception('query error ("' . $message . '"), query "' . $e->getQuery() . '", ' . $this->schema, $code);
            }
        }
    });
}

\Amp\Loop::run(function () {
    $pool = \Amp\Mysql\pool("user=...;host=...;pass=...;db=...", null, 10);
    yield query($pool, "SET wait_timeout = 1");
    yield new \Amp\Delayed(2000);
    $sql = "SELECT ...";
    yield query($pool, $sql);
    echo "DONE\n";
});