<?php

namespace App\Services\PayPal;

use App\Services\PayPal\Exceptions\PayPalException;
use Illuminate\Http\Client\Factory as HttpFactory;
use Illuminate\Http\Client\PendingRequest;
use Illuminate\Http\Client\RequestException;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Str;

class PayPalClient
{
    public function __construct(
        private readonly HttpFactory $http,
    ) {}

    public function get(string $endpoint, array $query = [], array $headers = []): array
    {
        return $this->send('GET', $endpoint, [
            'query' => $query,
            'headers' => $headers,
        ]);
    }

    public function post(string $endpoint, array|object $payload = [], array $headers = []): array
    {
        return $this->send('POST', $endpoint, [
            'json' => $payload,
            'headers' => $headers,
        ]);
    }

    protected function send(string $method, string $endpoint, array $options = []): array
    {
        $request = $this->preparedRequest();

        try {
            $response = $request->send(strtoupper($method), ltrim($endpoint, '/'), $options);
        } catch (RequestException $exception) {
            throw new PayPalException(
                $exception->getMessage(),
                $exception->response?->status(),
                $exception->response?->json() ?? []
            );
        }

        if ($response->failed()) {
            $body = $response->json() ?? [];
            $message = Arr::get($body, 'message')
                ?? Arr::get($body, 'details.0.description')
                ?? sprintf('PayPal request failed with status %s', $response->status());

            throw new PayPalException($message, $response->status(), $body);
        }

        return $response->json() ?? [];
    }

    protected function preparedRequest(): PendingRequest
    {
        $baseUrl = $this->baseUrl();
        $token = $this->accessToken();

        return $this->http
            ->baseUrl($baseUrl)
            ->withHeaders([
                'Accept' => 'application/json',
                'Content-Type' => 'application/json',
                'User-Agent' => sprintf('FotospielApp/%s PayPalClient', app()->version()),
            ])
            ->withToken($token)
            ->acceptJson()
            ->asJson();
    }

    protected function accessToken(): string
    {
        $cacheKey = 'paypal:access_token';
        $cached = Cache::get($cacheKey);

        if (is_string($cached) && $cached !== '') {
            return $cached;
        }

        $tokenResponse = $this->requestAccessToken();
        $accessToken = Arr::get($tokenResponse, 'access_token');

        if (! is_string($accessToken) || $accessToken === '') {
            throw new PayPalException('PayPal access token missing from response.', null, $tokenResponse);
        }

        $expiresIn = (int) Arr::get($tokenResponse, 'expires_in', 0);
        if ($expiresIn > 60) {
            Cache::put($cacheKey, $accessToken, now()->addSeconds($expiresIn - 60));
        }

        return $accessToken;
    }

    protected function requestAccessToken(): array
    {
        $clientId = config('services.paypal.client_id');
        $secret = config('services.paypal.secret');

        if (! $clientId || ! $secret) {
            throw new PayPalException('PayPal client credentials are not configured.');
        }

        $response = $this->http
            ->baseUrl($this->baseUrl())
            ->withBasicAuth($clientId, $secret)
            ->asForm()
            ->acceptJson()
            ->post('/v1/oauth2/token', [
                'grant_type' => 'client_credentials',
            ]);

        if ($response->failed()) {
            $body = $response->json() ?? [];
            $message = Arr::get($body, 'error_description')
                ?? Arr::get($body, 'message')
                ?? sprintf('PayPal OAuth failed with status %s', $response->status());

            throw new PayPalException($message, $response->status(), $body);
        }

        return $response->json() ?? [];
    }

    protected function baseUrl(): string
    {
        $sandbox = (bool) config('services.paypal.sandbox', true);
        $baseUrl = $sandbox ? 'https://api-m.sandbox.paypal.com' : 'https://api-m.paypal.com';

        $baseUrl = trim($baseUrl);

        if (! Str::startsWith($baseUrl, ['http://', 'https://'])) {
            $baseUrl = 'https://'.ltrim($baseUrl, '/');
        }

        return rtrim($baseUrl, '/');
    }
}