<?php

namespace App\Support;

use App\Models\Setting;
use Illuminate\Support\Facades\Crypt;
use Illuminate\Support\Facades\Mail;
use Throwable;

/**
 * Applies the operator's DB-stored SMTP settings (Settings\Email) to runtime config. ONE shared
 * entry point for every process shape:
 *
 *   - web request        → AppServiceProvider::boot() (per request)
 *   - queue worker       → Queue::before hook (per job)
 *   - LONG-LIVED loops   → AlertNotifier::notify() (per notification)
 *
 * The last one matters most: the metrics poller (clusev:poll-metrics under supervisor) runs for
 * days. Laravel bakes the DEFAULT MAILER NAME into a mailable at Mail::to()->queue() time, so a
 * loop that booted before SMTP was configured would bake `log` into every alert mail forever —
 * the worker then "sends" them into laravel.log no matter how correct its own config is. Applying
 * fresh settings immediately before queueing bakes the right mailer name.
 *
 * Mail::purge() drops the cached mailer instance so a config change actually rebuilds the
 * transport in long-lived processes instead of reusing the old connection.
 */
class MailSettings
{
    /** True when a usable SMTP transport is configured (host + from set) — drives the alerts
     *  "no delivery channel" warning. Mirrors the guard in apply() below. */
    public static function isConfigured(): bool
    {
        try {
            return ((string) (Setting::get('mail_host') ?? '')) !== ''
                && ((string) (Setting::get('mail_from_address') ?? '')) !== '';
        } catch (Throwable) {
            return false; // settings not migrated yet
        }
    }

    public static function apply(): void
    {
        try {
            $host = Setting::get('mail_host');
            $from = Setting::get('mail_from_address');

            if ($host === null || $host === '' || $from === null || $from === '') {
                return; // unconfigured -> keep the safe default mailer
            }

            $encryption = Setting::get('mail_encryption', 'tls');
            // The password is a SECRET whose target is $host: read it uncached so a stale cached
            // value can't be paired with a freshly-changed host (credential exfil). See Setting::uncached.
            $storedPassword = Setting::uncached('mail_password');
            $password = null;
            if ($storedPassword !== null && $storedPassword !== '') {
                $password = Crypt::decryptString($storedPassword);
            }

            $changed = config('mail.default') !== 'smtp'
                || config('mail.mailers.smtp.host') !== $host;

            config([
                'mail.default' => 'smtp',
                'mail.mailers.smtp.host' => $host,
                'mail.mailers.smtp.port' => (int) (Setting::get('mail_port', '587') ?? 587),
                'mail.mailers.smtp.username' => Setting::get('mail_username') ?: null,
                'mail.mailers.smtp.password' => $password ?: null,
                'mail.mailers.smtp.encryption' => $encryption === 'none' ? null : $encryption,
                'mail.from.address' => $from,
                'mail.from.name' => Setting::get('mail_from_name') ?: $from,
            ]);

            if ($changed) {
                Mail::purge('smtp'); // rebuild the cached transport with the new settings
            }
        } catch (Throwable) {
            // Settings table not migrated yet (install/migrate) or an undecryptable value —
            // leave the default mailer untouched. Never break the caller.
        }
    }
}