<?php

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

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

    /**
     * Call Domestic Prices v3 API
     * Endpoint: /base-rates/search
     */
    public function getDomesticRate($payload)
    {
        return $this->post('/base-rates/search', $payload);
    }

    /**
     * Call International Prices v3 API
     * Endpoint: /base-rates/search (Under International Base path)
     * Note: The spec shows a different base URL for International
     */
    public function getInternationalRate($payload)
    {
        // International uses a different base URL structure in the 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);
    }

    private function post($endpoint, $payload, $overrideUrl = null)
    {
        $url = ($overrideUrl ? $overrideUrl : $this->baseUrl) . $endpoint;

        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            'Authorization: Bearer ' . $this->token,
            'Content-Type: application/json',
            'Accept: application/json'
        ]);

        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

        if (curl_errno($ch)) {
            $error = curl_error($ch);

            return ['error' => 'CURL Error: ' . $error];
        }


        $data = json_decode($response, true);

        // Check for HTTP errors (400, 401, 403, etc)
        if ($httpCode >= 400) {
            $msg = isset($data['error']['message']) ? $data['error']['message'] : 'Unknown Error';
            if (isset($data['error']['errors'][0]['detail'])) {
                $msg .= ' - ' . $data['error']['errors'][0]['detail'];
            }
            return ['error' => "HTTP $httpCode: $msg"];
        }

        return $data;
    }
}