<?php

declare(strict_types=1);

namespace FatBottom\Services;

use FatBottom\Core\Config;
use RuntimeException;

final class Mailer
{
    public function __construct(private readonly Config $config)
    {
    }

    public function send(string $to, string $subject, string $html): bool
    {
        if (!(bool) $this->config->get('mailgun.enabled', false)) {
            $this->writeToLog($to, $subject, $html);
            return true;
        }

        if (!function_exists('curl_init')) {
            throw new RuntimeException('The PHP cURL extension is required for Mailgun.');
        }

        $domain = (string) $this->config->get('mailgun.domain');
        $apiKey = (string) $this->config->get('mailgun.api_key');
        if ($domain === '' || $apiKey === '') {
            throw new RuntimeException('Mailgun is enabled but its credentials are incomplete.');
        }

        $from = sprintf(
            '%s <%s>',
            $this->config->get('mailgun.from_name', 'Fat Bottom Grille'),
            $this->config->get('mailgun.from_email')
        );

        $curl = curl_init('https://api.mailgun.net/v3/' . rawurlencode($domain) . '/messages');
        curl_setopt_array($curl, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_USERPWD => 'api:' . $apiKey,
            CURLOPT_POST => true,
            CURLOPT_POSTFIELDS => [
                'from' => $from,
                'to' => $to,
                'subject' => $subject,
                'html' => $html,
            ],
            CURLOPT_TIMEOUT => 20,
        ]);
        $response = curl_exec($curl);
        $status = (int) curl_getinfo($curl, CURLINFO_RESPONSE_CODE);
        $error = curl_error($curl);
        curl_close($curl);

        if ($response === false || $status < 200 || $status >= 300) {
            throw new RuntimeException('Mailgun delivery failed: ' . ($error ?: 'HTTP ' . $status));
        }

        return true;
    }

    private function writeToLog(string $to, string $subject, string $html): void
    {
        $directory = BASE_PATH . '/storage/logs';
        if (!is_dir($directory)) {
            mkdir($directory, 0775, true);
        }
        $line = sprintf(
            "[%s] TO: %s | SUBJECT: %s\n%s\n\n",
            date('c'),
            $to,
            $subject,
            trim(strip_tags($html))
        );
        file_put_contents($directory . '/mail.log', $line, FILE_APPEND | LOCK_EX);
    }
}