<?php

namespace App\Support;

use App\Http\Services\SignRSA;
use App\Models\Setting;
use App\Support\Cache\CacheKey;
use Illuminate\Mail\MailManager;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Config;
use Illuminate\Support\Facades\Schema;

final class MailSettings
{
    private const TTL_SECONDS = 3600;

    private const NON_DELIVERING_MAILERS = ['array', 'log'];

    public static function cacheKey(): string
    {
        return CacheKey::build('settings', 'smtp');
    }

    public static function apply(): void
    {
        $settings = self::resolve();
        if ($settings === null) {
            return;
        }

        $config = config('mail');
        if (!in_array($config['default'], self::NON_DELIVERING_MAILERS, true)) {
            $config['default'] = $settings['transport'];
        }
        $config['from'] = [
            'address' => $settings['from_address'] ?: ($config['from']['address'] ?? null) ?: 'no-reply@example.com',
            'name'    => $settings['from_name'],
        ];
        $config['mailers'][$settings['transport']] = array_merge(
            $config['mailers'][$settings['transport']] ?? [],
            $settings['mailer'],
        );

        Config::set('mail', $config);
    }

    public static function transport(): ?string
    {
        return self::resolve()['transport'] ?? null;
    }

    /**
     * @return array{cc: array<int, string>, bcc: array<int, string>}
     */
    public static function recipients(): array
    {
        $settings = self::resolve();

        return [
            'cc' => $settings['cc'] ?? [],
            'bcc' => $settings['bcc'] ?? [],
        ];
    }

    public static function refresh(object $mailer): void
    {
        self::apply();
        if ($mailer instanceof MailManager) {
            $mailer->forgetMailers();
        }
    }

    private static function resolve(): ?array
    {
        return Cache::remember(self::cacheKey(), self::TTL_SECONDS, function () {
            if (!Schema::hasTable('setting')) {
                return null;
            }

            $mail = Setting::where('key', 'smtp')->first();
            $setting = Setting::where('key', 'setting')->first();

            if (!$mail || !$setting) {
                return null;
            }

            $mail = json_decode($mail->value);
            $company = json_decode($setting->value)->company ?? 'Your Company';

            $password = '';
            if (isset($mail->password)) {
                $decrypted = (new SignRSA())->DecryptFunc($mail->password);
                $password = $decrypted ?: $mail->password;
            }

            $transport = ($mail->transport ?? null) ?: 'smtp';
            $encryption = $mail->encryption ?? null;

            if ($encryption === 0 || $encryption === '0' || $encryption === 'starttls') {
                $encryption = 'tls';
            }

            return [
                'transport'    => $transport,
                'from_address' => ($mail->from_address ?? null) ?: ($mail->user ?? null),
                'from_name'    => ($mail->from_name ?? null) ?: $company,
                'cc'           => self::emailList($mail->cc ?? []),
                'bcc'          => self::emailList($mail->bcc ?? []),
                'mailer'       => array_filter([
                    'transport'  => $transport,
                    'host'       => $mail->host ?? '',
                    'port'       => $mail->port ?? 587,
                    'encryption' => $encryption,
                    'username'   => $mail->user ?? '',
                    'password'   => $password,
                ], fn ($value) => $value !== null),
            ];
        });
    }

    /**
     * @return array<int, string>
     */
    private static function emailList(mixed $value): array
    {
        $emails = is_array($value) ? $value : preg_split('/[,;\s]+/', (string) $value, -1, PREG_SPLIT_NO_EMPTY);

        return array_values(array_unique(array_filter(
            array_map(fn ($email) => strtolower(trim((string) $email)), $emails ?: []),
            fn (string $email) => filter_var($email, FILTER_VALIDATE_EMAIL) !== false,
        )));
    }
}