<?php

/**
 * CLI Task Scheduler
 *
 * Scans scheduler-tasks/ directory for PHP files with pattern: task-name.interval.php
 * Each task is executed as a separate CLI process at the specified interval (in seconds)
 * Handles graceful shutdown on SIGTERM/SIGINT signals
 */

declare(strict_types=1);

require_once __DIR__ . '/../vendor/autoload.php';

use Psr\Log\LoggerInterface;
use AutoStore\DiContainer;

class Scheduler
{
    private string $tasksDirectory;
    private LoggerInterface $logger;
    private array $tasks = [];
    private bool $running = true;

    public function __construct(string $tasksDirectory, LoggerInterface $logger)
    {
        $this->tasksDirectory = $tasksDirectory;
        $this->logger = $logger;
        $this->loadTasks();
    }

    private function loadTasks(): void
    {
        if (!is_dir($this->tasksDirectory)) {
            $this->logger->error("Tasks directory not found: {$this->tasksDirectory}");
            return;
        }

        $files = scandir($this->tasksDirectory);
        foreach ($files as $file) {
            if ($file === '.' || $file === '..') {
                continue;
            }

            $filePath = $this->tasksDirectory . '/' . $file;
            if (!is_file($filePath)) {
                continue;
            }

            // Parse interval from filename (e.g., "task.60.php" -> 60 seconds)
            if (preg_match('/^(.+)\.(\d+)\.php$/', $file, $matches)) {
                $taskName = $matches[1];
                $interval = (int) $matches[2];

                $this->tasks[] = [
                    'name' => $taskName,
                    'file' => $filePath,
                    'interval' => $interval,
                    'last_run' => null,
                ];

                $this->logger->info("Loaded task: {$taskName} with interval {$interval} seconds");
            }
        }
    }

    public function run(): void
    {
        $this->logger->info('Scheduler started');

        // Install signal handlers for graceful shutdown
        pcntl_async_signals(true);
        pcntl_signal(SIGTERM, [$this, 'handleSignal']);
        pcntl_signal(SIGINT, [$this, 'handleSignal']);

        while ($this->running) {
            $this->executeDueTasks();
            sleep(1); // Check every second
        }

        $this->logger->info('Scheduler stopped');
    }

    private function executeDueTasks(): void
    {
        $currentTime = time();

        foreach ($this->tasks as &$task) {
            if ($task['last_run'] === null || ($currentTime - $task['last_run']) >= $task['interval']) {
                $this->executeTask($task);
                $task['last_run'] = $currentTime;
            }
        }
    }

    private function executeTask(array $task): void
    {
        $this->logger->info("Executing task: {$task['name']}");

        $command = sprintf('php %s > /dev/null 2>&1 &', escapeshellarg($task['file']));
        exec($command, $output, $exitCode);

        if ($exitCode === 0) {
            $this->logger->info("Task {$task['name']} executed successfully");
        } else {
            $this->logger->error("Task {$task['name']} failed with exit code: {$exitCode}");
        }
    }

    public function handleSignal(int $signal): void
    {
        $this->logger->info("Received signal: {$signal}. Shutting down gracefully...");
        $this->running = false;
    }
}

// Main execution
try {
    echo "Scheduler started\n";
    $diContainer = new DiContainer();
    $logger = $diContainer->get(LoggerInterface::class);
    $tasksDirectory = __DIR__ . '/scheduler-tasks';

    $scheduler = new Scheduler($tasksDirectory, $logger);
    $scheduler->run();

    exit(0);
} catch (\Exception $e) {
    $logger = $logger ?? new \Monolog\Logger('scheduler');
    $logger->error('Scheduler failed: ' . $e->getMessage());
    exit(1);
}