<?php
namespace Zadex\Forms\Integrations;

defined('ABSPATH') || exit;

use WP_Error;

/**
 * MailerLite (new API, `https://connect.mailerlite.com/api`, `Authorization: Bearer <token>`).
 *
 *  - POST /subscribers {email, fields: {name, last_name, …}, groups: [group id]}  (create or update)
 *  - lists (groups): GET /groups?limit=100 → data[{id, name}]
 */
final class MailerLite extends EmailProvider
{
    public const BASE = 'https://connect.mailerlite.com/api';

    public function id(): string
    {
        return 'mailerlite';
    }

    public function label(): string
    {
        return 'MailerLite';
    }

    public function configured(): bool
    {
        return Credentials::has('mailerlite_api_key');
    }

    public function needs_list(): bool
    {
        return false; // a subscriber without a group is valid.
    }

    /** @return array<string, string> */
    private function headers(): array
    {
        return ['Authorization' => 'Bearer ' . Credentials::get('mailerlite_api_key')];
    }

    public function lists()
    {
        if (!$this->configured()) {
            return new WP_Error('zadex_integration_not_configured', 'MailerLite API token missing.');
        }
        $r = Http::request('GET', self::BASE . '/groups?limit=100', ['headers' => $this->headers() + ['Accept' => 'application/json']]);
        return $r instanceof WP_Error ? $r : self::options($r['json']['data'] ?? [], 'id', 'name');
    }

    public function subscribe(array $contact)
    {
        $fields = $contact['fields'];
        if ($contact['first_name'] !== '' && !isset($fields['name'])) {
            $fields['name'] = $contact['first_name'];
        }
        if ($contact['last_name'] !== '' && !isset($fields['last_name'])) {
            $fields['last_name'] = $contact['last_name'];
        }
        $body = ['email' => $contact['email']];
        if ($fields) {
            $body['fields'] = $fields;
        }
        if ($contact['list'] !== '') {
            $body['groups'] = [$contact['list']];
        }
        $r = Http::json('POST', self::BASE . '/subscribers', $body, $this->headers());
        return $r instanceof WP_Error ? $r : true;
    }
}