<?php

use Symfony\Component\HttpClient\HttpClient;
use Symfony\Contracts\HttpClient\Exception\TransportExceptionInterface;
use Symfony\Contracts\HttpClient\Exception\ClientExceptionInterface;
use Symfony\Contracts\HttpClient\Exception\ServerExceptionInterface;

class UspsV3Client
{
    private $token;
    private $isLive;
    private $baseUrl;

    public function __construct($token, $isLive = false)
    {
        $this->token = $token;
        $this->isLive = $isLive;
        // Base URLs per OpenAPI Spec
        $this->baseUrl = $this->isLive 
            ? 'https://apis.usps.com/prices/v3' 
            : 'https://apis-tem.usps.com/prices/v3';
    }

    /**
     * Get Domestic Rate (Rates v3)
     */
    public function getDomesticRate($payload)
    {
        return $this->post('/base-rates/search', $payload);
    }

    /**
     * Get International Rate (Rates v3)
     */
    public function getInternationalRate($payload)
    {
        // International endpoint uses a different base structure per spec
        $intlBaseUrl = $this->isLive 
            ? 'https://apis.usps.com/international-prices/v3' 
            : 'https://apis-tem.usps.com/international-prices/v3';

        return $this->post('/base-rates/search', $payload, $intlBaseUrl);
    }

    /**
     * Internal POST logic using Symfony HTTP Client
     */
    private function post($endpoint, $payload, $overrideUrl = null)
    {
        $url = ($overrideUrl ? $overrideUrl : $this->baseUrl) . $endpoint;

        $client = HttpClient::create([
            'timeout' => 15,
            'verify_peer' => false,
            'verify_host' => false,
        ]);

        try {
            $response = $client->request('POST', $url, [
                'headers' => [
                    'Authorization' => 'Bearer ' . $this->token,
                    'Content-Type' => 'application/json',
                    'Accept' => 'application/json'
                ],
                'json' => $payload
            ]);

            // toArray(false) prevents exception on 4xx/5xx responses so we can parse the error body
            $data = $response->toArray(false);
            $statusCode = $response->getStatusCode();

            // Handle API Errors (400 Bad Request, 401 Unauthorized, etc)
            if ($statusCode >= 400) {
                $msg = isset($data['error']['message']) ? $data['error']['message'] : 'Unknown Error';
                
                // Try to extract deeper error detail (e.g., from 'errors' array)
                if (isset($data['error']['errors'][0]['detail'])) {
                    $msg .= ' - ' . $data['error']['errors'][0]['detail'];
                } elseif (isset($data['error']['code'])) {
                    $msg .= ' (' . $data['error']['code'] . ')';
                }

                return ['error' => "API HTTP $statusCode: $msg"];
            }

            return $data;

        } catch (TransportExceptionInterface $e) {
            return ['error' => 'Network/Transport Error: ' . $e->getMessage()];
        } catch (\Exception $e) {
            return ['error' => 'Client Error: ' . $e->getMessage()];
        }
    }
}