<?php
namespace JVBase\managers\queue;
if (!defined('ABSPATH')) {
	exit;
}

final class Processor
{
	public function __construct(
		private Storage $storage,
		private Executor $defaultExecutor,
		private TypeRegistry $registry,
		private Locker $locker
	) {}

	public function run(): void
	{
		$this->locker->withLock(function () {
			$ops = $this->storage->fetchRunnable(10);

			foreach ($ops as $op) {
				if (!$this->storage->markProcessing($op->id)) {
					continue;
				}

				$this->processOne($op);
			}

			$this->storage->invalidateQueueCache();
		});
	}

	private function processOne(Operation $op): void
	{
		$progress = new Progress($op);
		$executor = $this->registry->getExecutor($op->type) ?? $this->defaultExecutor;

		try {
			$result = $executor->execute($op, $progress);

			$op->state = 'completed';
			$op->outcome = $result->outcome;
			$op->result = $result->result;
			$op->completedAt = current_time('mysql');

		} catch (\Throwable $e) {
			$this->handleFailure($op, $e);
		}

		$this->storage->save($op);
	}

	private function handleFailure(Operation $op, \Throwable $e): void
	{
		$hash = md5($e->getMessage());

		if ($op->lastErrorHash === $hash) {
			// Same error twice → permanent failure
			$op->state = 'completed';
			$op->outcome = 'failed_permanent';
			$op->completedAt = current_time('mysql');
		} else {
			// New error → schedule retry
			$op->retries++;
			$op->lastErrorHash = $hash;
			$op->state = 'scheduled';
			$op->scheduledAt = $this->calculateBackoff($op->retries);
		}

		$op->errorMessage = $e->getMessage();

		JVB()->error()->log(
			'[Queue]:processOne',
			$e->getMessage(),
			[
				'operation_id' => $op->id,
				'type'         => $op->type,
				'user_id'      => $op->userId,
				'retries'      => $op->retries,
			],
			$op->outcome === 'failed_permanent' ? 'critical' : 'warning'
		);
	}

	private function calculateBackoff(int $attempt): string
	{
		$delay = min(30 * pow(2, $attempt - 1), 3600);
		$jitter = rand(0, (int)($delay * 0.1));
		return date('Y-m-d H:i:s', time() + $delay + $jitter);
	}
}