<?php

namespace App\Services\Checkout;

use App\Models\CheckoutSession;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Log;

class CheckoutWebhookService
{
    public function __construct(
        private readonly CheckoutSessionService $sessions,
        private readonly CheckoutAssignmentService $assignment,
    ) {
    }

    public function handleStripeEvent(array $event): bool
    {
        $eventType = $event['type'] ?? null;
        $intent = $event['data']['object'] ?? null;

        if (! $eventType || ! is_array($intent)) {
            return false;
        }

        if (! str_starts_with($eventType, 'payment_intent.')) {
            return false;
        }

        $intentId = $intent['id'] ?? null;

        if (! $intentId) {
            return false;
        }

        $session = $this->locateStripeSession($intent);

        if (! $session) {
            return false;
        }

        $lock = Cache::lock("checkout:webhook:stripe:{$intentId}", 30);

        if (! $lock->get()) {
            Log::info('[CheckoutWebhook] Stripe intent lock busy', [
                'intent_id' => $intentId,
                'session_id' => $session->id,
            ]);

            return true;
        }

        try {
            $session->forceFill([
                'stripe_payment_intent_id' => $session->stripe_payment_intent_id ?: $intentId,
                'provider' => CheckoutSession::PROVIDER_STRIPE,
            ])->save();

            $metadata = [
                'stripe_last_event' => $eventType,
                'stripe_last_event_id' => $event['id'] ?? null,
                'stripe_intent_status' => $intent['status'] ?? null,
                'stripe_last_update_at' => now()->toIso8601String(),
            ];

            $this->mergeProviderMetadata($session, $metadata);

            return $this->applyStripeIntent($session, $eventType, $intent);
        } finally {
            $lock->release();
        }
    }

    public function handlePayPalEvent(array $event): bool
    {
        $eventType = $event['event_type'] ?? null;
        $resource = $event['resource'] ?? [];

        if (! $eventType || ! is_array($resource)) {
            return false;
        }

        $orderId = $resource['order_id'] ?? $resource['id'] ?? null;

        $session = $this->locatePayPalSession($resource, $orderId);

        if (! $session) {
            return false;
        }

        $lockKey = "checkout:webhook:paypal:".($orderId ?: $session->id);
        $lock = Cache::lock($lockKey, 30);

        if (! $lock->get()) {
            Log::info('[CheckoutWebhook] PayPal lock busy', [
                'order_id' => $orderId,
                'session_id' => $session->id,
            ]);

            return true;
        }

        try {
            $session->forceFill([
                'paypal_order_id' => $orderId ?: $session->paypal_order_id,
                'provider' => CheckoutSession::PROVIDER_PAYPAL,
            ])->save();

            $metadata = [
                'paypal_last_event' => $eventType,
                'paypal_last_event_id' => $event['id'] ?? null,
                'paypal_last_update_at' => now()->toIso8601String(),
                'paypal_order_id' => $orderId,
                'paypal_capture_id' => $resource['id'] ?? null,
            ];

            $this->mergeProviderMetadata($session, $metadata);

            return $this->applyPayPalEvent($session, $eventType, $resource);
        } finally {
            $lock->release();
        }
    }

    protected function applyStripeIntent(CheckoutSession $session, string $eventType, array $intent): bool
    {
        switch ($eventType) {
            case 'payment_intent.processing':
            case 'payment_intent.amount_capturable_updated':
                $this->sessions->markProcessing($session, [
                    'stripe_intent_status' => $intent['status'] ?? null,
                ]);
                return true;

            case 'payment_intent.requires_action':
                $reason = $intent['next_action']['type'] ?? 'requires_action';
                $this->sessions->markRequiresCustomerAction($session, $reason);
                return true;

            case 'payment_intent.payment_failed':
                $failure = $intent['last_payment_error']['message'] ?? 'payment_failed';
                $this->sessions->markFailed($session, $failure);
                return true;

            case 'payment_intent.succeeded':
                if ($session->status !== CheckoutSession::STATUS_COMPLETED) {
                    $this->sessions->markProcessing($session, [
                        'stripe_intent_status' => $intent['status'] ?? null,
                    ]);

                    $this->assignment->finalise($session, [
                        'source' => 'stripe_webhook',
                        'stripe_payment_intent_id' => $intent['id'] ?? null,
                        'stripe_charge_id' => $this->extractStripeChargeId($intent),
                    ]);

                    $this->sessions->markCompleted($session, now());
                }

                return true;

            default:
                return false;
        }
    }

    protected function applyPayPalEvent(CheckoutSession $session, string $eventType, array $resource): bool
    {
        switch ($eventType) {
            case 'CHECKOUT.ORDER.APPROVED':
                $this->sessions->markProcessing($session, [
                    'paypal_order_status' => $resource['status'] ?? null,
                ]);
                return true;

            case 'PAYMENT.CAPTURE.COMPLETED':
                if ($session->status !== CheckoutSession::STATUS_COMPLETED) {
                    $this->sessions->markProcessing($session, [
                        'paypal_order_status' => $resource['status'] ?? null,
                    ]);

                    $this->assignment->finalise($session, [
                        'source' => 'paypal_webhook',
                        'paypal_order_id' => $resource['order_id'] ?? null,
                        'paypal_capture_id' => $resource['id'] ?? null,
                    ]);

                    $this->sessions->markCompleted($session, now());
                }

                return true;

            case 'PAYMENT.CAPTURE.DENIED':
                $this->sessions->markFailed($session, 'paypal_capture_denied');
                return true;

            default:
                return false;
        }
    }

    protected function mergeProviderMetadata(CheckoutSession $session, array $data): void
    {
        $session->provider_metadata = array_merge($session->provider_metadata ?? [], $data);
        $session->save();
    }

    protected function locateStripeSession(array $intent): ?CheckoutSession
    {
        $intentId = $intent['id'] ?? null;

        if ($intentId) {
            $session = CheckoutSession::query()
                ->where('stripe_payment_intent_id', $intentId)
                ->first();

            if ($session) {
                return $session;
            }
        }

        $metadata = $intent['metadata'] ?? [];
        $sessionId = $metadata['checkout_session_id'] ?? null;

        if ($sessionId) {
            return CheckoutSession::find($sessionId);
        }

        return null;
    }

    protected function locatePayPalSession(array $resource, ?string $orderId): ?CheckoutSession
    {
        if ($orderId) {
            $session = CheckoutSession::query()
                ->where('paypal_order_id', $orderId)
                ->first();

            if ($session) {
                return $session;
            }
        }

        $metadata = $this->extractPayPalMetadata($resource);
        $sessionId = $metadata['checkout_session_id'] ?? null;

        if ($sessionId) {
            return CheckoutSession::find($sessionId);
        }

        return null;
    }

    protected function extractPayPalMetadata(array $resource): array
    {
        $customId = $resource['custom_id'] ?? ($resource['purchase_units'][0]['custom_id'] ?? null);
        if ($customId) {
            $decoded = json_decode($customId, true);
            if (is_array($decoded)) {
                return $decoded;
            }
        }

        $meta = Arr::get($resource, 'supplementary_data.related_ids', []);
        return is_array($meta) ? $meta : [];
    }

    protected function extractStripeChargeId(array $intent): ?string
    {
        $charges = $intent['charges']['data'] ?? null;
        if (is_array($charges) && count($charges) > 0) {
            return $charges[0]['id'] ?? null;
        }

        return null;
    }
}