<?php
declare(strict_types=1);

namespace PpPhp\Core\Platform\Event\Dispatcher\Runtime;

use PpPhp\Core\Platform\Event\Dispatcher\DelayedDispatcher;

final class DispatcherRuntimeStore
{
    public const CACHE_DIR = 'storage/cache/events/runtime';
    public const STATE_FILE = 'dispatcher-runtime.json';

    public function __construct(
        private readonly string $basePath,
        private readonly DispatcherSnapshotSerializer $serializer = new DispatcherSnapshotSerializer()
    ) {}

    public function stateFile(): string
    {
        return rtrim($this->basePath, DIRECTORY_SEPARATOR) . '/' . self::CACHE_DIR . '/' . self::STATE_FILE;
    }

    public function save(DelayedDispatcher $dispatcher): DispatcherRuntimeState
    {
        $state = new DispatcherRuntimeState(
            $dispatcher->statistics()->toArray(),
            $dispatcher->snapshot()->toArray(),
            date('c')
        );

        $file = $this->stateFile();
        if (!is_dir(dirname($file))) {
            mkdir(dirname($file), 0775, true);
        }

        file_put_contents($file, $this->serializer->encode($state));

        return $state;
    }

    public function load(): DispatcherRuntimeState
    {
        $file = $this->stateFile();

        if (!is_file($file)) {
            return new DispatcherRuntimeState();
        }

        return $this->serializer->decode((string) file_get_contents($file));
    }

    public function reset(): void
    {
        $file = $this->stateFile();
        if (is_file($file)) {
            unlink($file);
        }
    }

    public function exists(): bool
    {
        return is_file($this->stateFile());
    }
}
