<?php
declare(strict_types=1);

set_time_limit(0);

$root = dirname(__DIR__, 2);
chdir($root);
require $root . '/config/fileload.php';

$module = 'pi_control';
$pdo = module_fn($module, 'pdo');
module_fn($module, 'ensure_schema');
$table = fn(string $name) => module_fn($module, 'table', $name);
$settingsReloadSec = (int)(getenv('PI_CONTROL_SETTINGS_RELOAD_SEC') !== false ? (int)getenv('PI_CONTROL_SETTINGS_RELOAD_SEC') : 30);
$settingsReloadSec = $settingsReloadSec > 0 ? $settingsReloadSec : 30;

$redis = null;
$queueName = 'pi_control:queue';
$defaultTimeout = 300;
$lastSettingsAt = 0;

$strictHostKey = getenv('PI_CONTROL_STRICT_HOSTKEY') === '1';

$driver = (string)$pdo->getAttribute(PDO::ATTR_DRIVER_NAME);
$nowExpr = $driver === 'pgsql' ? 'NOW()' : "DATETIME('now')";

while (true) {
    if (time() - $lastSettingsAt >= $settingsReloadSec) {
        $settings = modules()->settings($module);
        $queueName = (string)($settings['redis']['queue'] ?? ($settings['redis.queue'] ?? (getenv('PI_CONTROL_REDIS_QUEUE') ?: 'pi_control:queue')));
        $defaultTimeout = (int)($settings['exec_default_timeout'] ?? (getenv('PI_CONTROL_EXEC_DEFAULT_TIMEOUT') !== false ? (int)getenv('PI_CONTROL_EXEC_DEFAULT_TIMEOUT') : 300));
        $defaultTimeout = $defaultTimeout > 0 ? $defaultTimeout : 300;
        $redis = module_fn($module, 'redis');
        $lastSettingsAt = time();
    }

    try {
        $job = $redis->command(['BLPOP', $queueName, 5]);
    } catch (\Throwable $e) {
        fwrite(STDERR, '[worker] Redis error: ' . $e->getMessage() . PHP_EOL);
        $lastSettingsAt = 0;
        sleep(5);
        continue;
    }
    if (!$job || !is_array($job) || count($job) < 2) {
        continue;
    }

    $payload = (string)$job[1];
    $data = json_decode($payload, true);
    if (!is_array($data) || empty($data['run_id'])) {
        continue;
    }
    $runId = (int)$data['run_id'];

    try {
        $runStmt = $pdo->prepare('SELECT * FROM ' . $table('runs') . ' WHERE id = :id LIMIT 1');
        $runStmt->execute(['id' => $runId]);
        $run = $runStmt->fetch(PDO::FETCH_ASSOC);
        if (!$run || ($run['status'] ?? '') !== 'queued') {
            continue;
        }
    } catch (\Throwable $e) {
        fwrite(STDERR, '[worker] DB error: ' . $e->getMessage() . PHP_EOL);
        sleep(2);
        continue;
    }

    $hostId = (int)($run['host_id'] ?? 0);
    if ($hostId <= 0) {
        continue;
    }

    $timeoutSec = (int)($run['timeout_sec'] ?? 0);
    $timeoutSec = $timeoutSec > 0 ? $timeoutSec : $defaultTimeout;
    $lockTtl = max($timeoutSec + 60, 120);

    $lockKey = 'pi_control:lock:host:' . $hostId;
    try {
        $lockOk = $redis->command(['SET', $lockKey, (string)$runId, 'NX', 'EX', (string)$lockTtl]);
    } catch (\Throwable $e) {
        fwrite(STDERR, '[worker] Redis lock error: ' . $e->getMessage() . PHP_EOL);
        $lastSettingsAt = 0;
        sleep(2);
        continue;
    }
    if ($lockOk !== 'OK') {
        try {
            $redis->command(['RPUSH', $queueName, $payload]);
        } catch (\Throwable $e) {
            fwrite(STDERR, '[worker] Redis requeue error: ' . $e->getMessage() . PHP_EOL);
            $lastSettingsAt = 0;
        }
        usleep(250000);
        continue;
    }

    $pdo->exec('UPDATE ' . $table('runs') . ' SET status = \'running\', started_at = ' . $nowExpr . ' WHERE id = ' . (int)$runId);

    $hostStmt = $pdo->prepare('SELECT * FROM ' . $table('hosts') . ' WHERE id = :id LIMIT 1');
    $hostStmt->execute(['id' => $hostId]);
    $host = $hostStmt->fetch(PDO::FETCH_ASSOC);

    if (!$host) {
        $pdo->exec('UPDATE ' . $table('runs') . ' SET status = \'failed\', error = \'Host not found\', finished_at = ' . $nowExpr . ' WHERE id = ' . (int)$runId);
        try {
            $redis->command(['DEL', $lockKey]);
        } catch (\Throwable $e) {
            fwrite(STDERR, '[worker] Redis unlock error: ' . $e->getMessage() . PHP_EOL);
            $lastSettingsAt = 0;
        }
        continue;
    }

    $commandText = (string)($run['command_text'] ?? '');
    [$status, $exitCode, $output, $error] = executeSsh($host, $commandText, $timeoutSec, $strictHostKey);

    $output = truncateText($output, 20000);
    $error = truncateText($error, 20000);

    $stmt = $pdo->prepare(
        'UPDATE ' . $table('runs') . ' SET status = :status, output = :output, error = :error, exit_code = :exit_code, finished_at = ' . $nowExpr . ' WHERE id = :id'
    );
    $stmt->execute([
        'status' => $status,
        'output' => $output !== '' ? $output : null,
        'error' => $error !== '' ? $error : null,
        'exit_code' => $exitCode,
        'id' => $runId,
    ]);

    try {
        $redis->command(['DEL', $lockKey]);
    } catch (\Throwable $e) {
        fwrite(STDERR, '[worker] Redis unlock error: ' . $e->getMessage() . PHP_EOL);
        $lastSettingsAt = 0;
    }
}

function executeSsh(array $host, string $command, int $timeoutSec, bool $strictHostKey): array
{
    $hostAddr = (string)($host['host'] ?? '');
    $user = (string)($host['username'] ?? '');
    $port = (int)($host['port'] ?? 22);
    $authType = (string)($host['auth_type'] ?? 'key');
    $keyPath = (string)($host['key_path'] ?? '');
    $password = (string)($host['password'] ?? '');

    $opts = $strictHostKey
        ? '-o StrictHostKeyChecking=accept-new -o UserKnownHostsFile=/root/.ssh/known_hosts'
        : '-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null';

    $target = escapeshellarg($user . '@' . $hostAddr);
    $remoteCmd = escapeshellarg($command);

    $cmd = 'ssh ' . $opts . ' -p ' . (int)$port . ' ';
    if ($authType === 'key' && $keyPath !== '') {
        $cmd .= '-i ' . escapeshellarg($keyPath) . ' ';
    }
    $cmd .= $target . ' -- ' . $remoteCmd;

    if ($authType === 'pass' && $password !== '') {
        $cmd = 'sshpass -p ' . escapeshellarg($password) . ' ' . $cmd;
    }

    $descriptors = [
        1 => ['pipe', 'w'],
        2 => ['pipe', 'w'],
    ];
    $process = proc_open($cmd, $descriptors, $pipes);
    if (!is_resource($process)) {
        return ['failed', 255, '', 'proc_open failed'];
    }

    stream_set_blocking($pipes[1], false);
    stream_set_blocking($pipes[2], false);

    $output = '';
    $error = '';
    $start = time();

    while (true) {
        $status = proc_get_status($process);
        $output .= stream_get_contents($pipes[1]);
        $error .= stream_get_contents($pipes[2]);

        if (!$status['running']) {
            $exitCode = (int)$status['exitcode'];
            proc_close($process);
            $finalStatus = $exitCode === 0 ? 'success' : 'failed';
            return [$finalStatus, $exitCode, $output, $error];
        }

        if (time() - $start > $timeoutSec) {
            proc_terminate($process, 9);
            proc_close($process);
            return ['timeout', 124, $output, $error];
        }

        usleep(100000);
    }
}

function truncateText(string $text, int $limit): string
{
    if (strlen($text) <= $limit) {
        return $text;
    }
    return substr($text, 0, $limit) . "\n...truncated...";
}