<?php
class ReverbApi {

    const BASE_URL    = 'https://api.reverb.com/api';
    const API_VERSION = '3.0';

    private $token;

    public function __construct($token) {
        $this->token = $token;
    }

    // -------------------------------------------------------------------------
    // Listings
    // -------------------------------------------------------------------------

    public function getListings($page = 1, $per_page = 50) {
        return $this->request('GET', '/my/listings', [
            'page'     => $page,
            'per_page' => $per_page,
        ]);
    }

    public function createListing(array $data) {
        return $this->request('POST', '/listings', [], $data);
    }

    public function updateListing($listing_id, array $data) {
        return $this->request('PUT', '/listings/' . urlencode($listing_id), [], $data);
    }

    public function endListing($listing_id) {
        return $this->request('PUT', '/listings/' . urlencode($listing_id) . '/end');
    }

    public function uploadPhoto($listing_id, $image_url) {
        return $this->request('POST', '/my/listings/' . urlencode($listing_id) . '/photos', [], [
            'image_url' => $image_url,
        ]);
    }

    // -------------------------------------------------------------------------
    // Orders
    // -------------------------------------------------------------------------

    public function getOrders($page = 1, $per_page = 50) {
        return $this->request('GET', '/my/orders', [
            'page'     => $page,
            'per_page' => $per_page,
        ]);
    }

    public function getOrder($order_number) {
        return $this->request('GET', '/my/orders/' . urlencode($order_number));
    }

    // -------------------------------------------------------------------------
    // Metadata
    // -------------------------------------------------------------------------

    public function getCategories() {
        return $this->request('GET', '/categories/flat');
    }

    public function getListingConditions() {
        return $this->request('GET', '/listing_conditions');
    }

    // -------------------------------------------------------------------------
    // Webhooks
    // -------------------------------------------------------------------------

    public function registerWebhook($url, $event) {
        return $this->request('POST', '/webhooks', [], [
            'url'   => $url,
            'event' => $event,
        ]);
    }

    public function getWebhooks() {
        return $this->request('GET', '/webhooks');
    }

    public function deleteWebhook($webhook_id) {
        return $this->request('DELETE', '/webhooks/' . (int)$webhook_id);
    }

    // -------------------------------------------------------------------------
    // HTTP transport
    // -------------------------------------------------------------------------

    private function request($method, $endpoint, array $params = [], $body = null) {
        $url = self::BASE_URL . $endpoint;

        if (!empty($params)) {
            $url .= '?' . http_build_query($params);
        }

        $headers = [
            'Authorization: Bearer ' . $this->token,
            'Accept-Version: ' . self::API_VERSION,
            'Content-Type: application/hal+json',
            'Accept: application/json',
        ];

        $ch = curl_init();
        curl_setopt_array($ch, [
            CURLOPT_URL            => $url,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_HTTPHEADER     => $headers,
            CURLOPT_TIMEOUT        => 30,
            CURLOPT_SSL_VERIFYPEER => true,
            CURLOPT_USERAGENT      => 'OpenCart-Reverb/1.0',
        ]);

        if (in_array($method, ['POST', 'PUT', 'DELETE'])) {
            if ($method === 'POST') {
                curl_setopt($ch, CURLOPT_POST, true);
            } else {
                curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $method);
            }
            if ($body !== null) {
                curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($body));
            }
        }

        $response   = curl_exec($ch);
        $http_code  = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $curl_error = curl_error($ch);
        curl_close($ch);

        if ($curl_error) {
            throw new RuntimeException('cURL error: ' . $curl_error);
        }

        $decoded = json_decode($response, true);

        if ($http_code >= 400) {
            $message = 'HTTP ' . $http_code;
            if (!empty($decoded['message'])) {
                $message = $decoded['message'];
            } elseif (!empty($decoded['errors'])) {
                $message = implode(', ', (array)$decoded['errors']);
            }
            throw new RuntimeException('Reverb API error: ' . $message, $http_code);
        }

        return $decoded;
    }
}