<?php

namespace App\Temporal\WebhookDelivery;

use Carbon\CarbonInterval;
use Temporal\Activity\ActivityOptions;
use Temporal\Common\RetryOptions;
use Temporal\Workflow;

class WebhookDeliveryWorkflow implements WebhookDeliveryWorkflowInterface
{
    private array $endpointStatuses = [];
    private int $totalDelivered = 0;
    private int $totalFailed = 0;
    private int $totalDeadLettered = 0;
    private int $retryCount = 0;

    /** @var WebhookDeliveryActivityInterface */
    private $deliveryStub;

    /** @var WebhookDeliveryActivityInterface */
    private $deadLetterStub;

    public function __construct()
    {
        $this->deliveryStub = Workflow::newActivityStub(
            WebhookDeliveryActivityInterface::class,
            ActivityOptions::new()
                ->withStartToCloseTimeout(CarbonInterval::seconds(30))
                ->withRetryOptions(
                    RetryOptions::new()
                        ->withMaximumAttempts(3)
                        ->withInitialInterval(CarbonInterval::seconds(1))
                        ->withBackoffCoefficient(3.0)
                )
        );

        $this->deadLetterStub = Workflow::newActivityStub(
            WebhookDeliveryActivityInterface::class,
            ActivityOptions::new()
                ->withStartToCloseTimeout(CarbonInterval::seconds(10))
                ->withRetryOptions(
                    RetryOptions::new()->withMaximumAttempts(1)
                )
        );
    }

    public function deliver(array $payload, array $endpoints, array $simulationConfig = []): \Generator
    {
        // Initialize endpoint statuses
        foreach ($endpoints as $endpoint) {
            $this->endpointStatuses[$endpoint] = [
                'status' => 'pending',
                'attempt' => 0,
                'responseTime' => 0,
            ];
        }

        // Fan-out: deliver to all endpoints in parallel
        $promises = [];
        foreach ($endpoints as $endpoint) {
            $this->endpointStatuses[$endpoint]['status'] = 'delivering';

            $promises[$endpoint] = Workflow::async(function () use ($endpoint, $payload, $simulationConfig) {
                try {
                    $result = yield $this->deliveryStub->deliverToEndpoint($endpoint, $payload, $simulationConfig);
                    return ['endpoint' => $endpoint, 'success' => true, 'result' => (array) $result];
                } catch (\Throwable $e) {
                    return ['endpoint' => $endpoint, 'success' => false, 'error' => $e->getMessage()];
                }
            });
        }

        // Collect results from all parallel activities
        foreach ($promises as $endpoint => $promise) {
            $outcome = (array) (yield $promise);

            if ($outcome['success']) {
                $result = $outcome['result'];
                $this->endpointStatuses[$endpoint] = [
                    'status' => 'delivered',
                    'attempt' => $result['attempt'] ?? 1,
                    'responseTime' => $result['responseTime'] ?? 0,
                ];
                $this->totalDelivered++;

                $attempt = $result['attempt'] ?? 1;
                if ($attempt > 1) {
                    $this->retryCount += ($attempt - 1);
                }
            } else {
                $this->endpointStatuses[$endpoint]['status'] = 'failed';
                $this->totalFailed++;

                // Dead-letter failed deliveries
                yield $this->deadLetterStub->deadLetter($endpoint, $payload, $outcome['error'] ?? 'Unknown error');
                $this->endpointStatuses[$endpoint]['status'] = 'dead_lettered';
                $this->totalDeadLettered++;
            }
        }

        return [
            'status' => 'completed',
            'totalDelivered' => $this->totalDelivered,
            'totalFailed' => $this->totalFailed,
            'totalDeadLettered' => $this->totalDeadLettered,
            'retryCount' => $this->retryCount,
            'endpoints' => $this->endpointStatuses,
        ];
    }

    public function getDeliveryStatus(): array
    {
        return [
            'totalDelivered' => $this->totalDelivered,
            'totalFailed' => $this->totalFailed,
            'totalDeadLettered' => $this->totalDeadLettered,
            'retryCount' => $this->retryCount,
            'endpoints' => $this->endpointStatuses,
        ];
    }
}