<?php

namespace App\Http\Controllers\Api;

use App\Models\Configuration;
use App\Models\PayPalPayment;
use Illuminate\Support\Facades\Http;
use Symfony\Component\HttpFoundation\Response;

class PaypalWebhook extends BaseApiController
{
    protected Configuration $config;
    protected PayPalPayment $payment;

    public function __construct()
    {
        parent::__construct();
        $this->config  = model(Configuration::class);
        $this->payment = model(PayPalPayment::class);
    }

    public function handle()
    {
        $config = $this->loadConfig();
        if (!$config) {
            return $this->respondError('PayPal configuration incomplete', Response::HTTP_INTERNAL_SERVER_ERROR);
        }

        $payload = $this->payloadData();
        if (empty($payload)) {
            return $this->respondError('Invalid JSON payload', Response::HTTP_BAD_REQUEST);
        }

        $requiredHeaders = [
            'paypal-transmission-id',
            'paypal-transmission-time',
            'paypal-cert-url',
            'paypal-auth-algo',
            'paypal-transmission-sig',
        ];

        foreach ($requiredHeaders as $header) {
            if (!$this->laravelRequest->headers->has($header)) {
                return $this->respondError("Missing required header: {$header}", Response::HTTP_BAD_REQUEST);
            }
        }

        $accessToken = $this->getAccessToken($config['client_id'], $config['secret'], $config['token_url']);
        if (!$accessToken) {
            return $this->respondError('Failed to get access token', Response::HTTP_INTERNAL_SERVER_ERROR);
        }

        $verificationData = [
            'auth_algo'         => $this->laravelRequest->headers->get('paypal-auth-algo'),
            'cert_url'          => $this->laravelRequest->headers->get('paypal-cert-url'),
            'transmission_id'   => $this->laravelRequest->headers->get('paypal-transmission-id'),
            'transmission_sig'  => $this->laravelRequest->headers->get('paypal-transmission-sig'),
            'transmission_time' => $this->laravelRequest->headers->get('paypal-transmission-time'),
            'webhook_id'        => $config['webhook_id'],
            'webhook_event'     => $payload,
        ];

        if (!$this->verifyWebhookSignature($config['verify_url'], $accessToken, $verificationData)) {
            return $this->respondError('Webhook verification failed', Response::HTTP_UNAUTHORIZED);
        }

        try {
            $this->processPayment($payload);
            return $this->success(['status' => 'success'], 'Webhook processed successfully');
        } catch (\Throwable $e) {
            log_message('error', 'Payment processing error: ' . $e->getMessage());
            return $this->respondError('Payment processing error', Response::HTTP_INTERNAL_SERVER_ERROR);
        }
    }

    protected function loadConfig(): ?array
    {
        $mode = (string) ($this->config->getConfig('paypal_mode') ?? '');

        $configs = [
            'sandbox' => [
                'webhook_id' => $this->config->getConfig('sandbox_webhookid_paypal'),
                'client_id'  => $this->config->getConfig('sandbox_clientid_paypal'),
                'secret'     => $this->config->getConfig('sandbox_secret_paypal'),
                'verify_url' => $this->config->getConfig('sandbox_verifylink_paypal'),
                'token_url'  => $this->config->getConfig('sandbox_tokenurl_paypal'),
            ],
            'production' => [
                'webhook_id' => $this->config->getConfig('production_webhookid_paypal'),
                'client_id'  => $this->config->getConfig('production_clientid_paypal'),
                'secret'     => $this->config->getConfig('production_secret_paypal'),
                'verify_url' => $this->config->getConfig('production_verifylink_paypal'),
                'token_url'  => $this->config->getConfig('production_tokenurl_paypal'),
            ],
        ];

        if (!isset($configs[$mode])) {
            return null;
        }

        $cfg = $configs[$mode];
        if (in_array(null, $cfg, true) || in_array('', $cfg, true)) {
            return null;
        }

        return $cfg + ['mode' => $mode];
    }

    protected function getAccessToken(string $clientId, string $secret, string $urlToken): ?string
    {
        try {
            $response = Http::asForm()
                ->withBasicAuth($clientId, $secret)
                ->acceptJson()
                ->post($urlToken, ['grant_type' => 'client_credentials']);

            if (!$response->successful()) {
                log_message('error', 'Access token fetch failed: HTTP ' . $response->status());
                return null;
            }

            return $response->json('access_token');
        } catch (\Throwable $e) {
            log_message('error', 'Access token fetch failed: ' . $e->getMessage());
            return null;
        }
    }

    protected function verifyWebhookSignature(string $verifyUrl, string $accessToken, array $verificationData): bool
    {
        try {
            $response = Http::withToken($accessToken)
                ->acceptJson()
                ->post($verifyUrl, $verificationData);

            if (!$response->successful()) {
                log_message('error', 'Webhook verification failed: HTTP ' . $response->status());
                return false;
            }

            return ($response->json('verification_status') ?? '') === 'SUCCESS';
        } catch (\Throwable $e) {
            log_message('error', 'Webhook verification failed: ' . $e->getMessage());
            return false;
        }
    }

    protected function processPayment(array $eventData): void
    {
        $resource = $eventData['resource'] ?? [];

        $this->payment->create([
            'webhook_id'      => $eventData['id'] ?? null,
            'transaction_id'  => $resource['id'] ?? null,
            'status'          => $resource['status'] ?? null,
            'amount'          => $resource['amount']['value'] ?? null,
            'currency'        => $resource['amount']['currency_code'] ?? null,
            'payer_email'     => $resource['payer']['email_address'] ?? null,
            'raw_payload'     => json_encode($eventData),
        ]);
    }
}