<?php
namespace Relay\Notify;

use Relay\Jobs\Job;
use Relay\Jobs\JobRepository;
use Relay\Support\SiteInfo;

/**
 * Tells people when a job ends (spec §3.4): job.completed / job.failed for jobs run here, incoming.pull /
 * incoming.push when another site pulled from or pushed to this one. Email via wp_mail, webhook as a JSON
 * POST (5 s timeout). A failed notification is logged on the job and never fails it. No secrets are sent.
 */
final class Notifier
{
    private NotificationSettings $settings;
    private JobRepository $jobs;

    public function __construct(NotificationSettings $settings, JobRepository $jobs)
    {
        $this->settings = $settings;
        $this->jobs = $jobs;
    }

    /** Hooked to relay_job_finished. */
    public function finished(Job $job): void
    {
        $event = self::event($job);
        $s = $this->settings->get();
        if ($event === null || empty($s['events'][$event]) || (!$s['email']['on'] && !$s['webhook']['on'])) {
            return;
        }
        $message = self::message($job, $event);
        foreach ($this->send($s, $message) as $channel => $result) {
            if ($result !== true) {
                /* translators: 1: "email" or "webhook", 2: error message */
                $this->jobs->event($job->id, 'warning', 'notify.failed', sprintf(__('The %1$s notification could not be sent: %2$s', 'siterelay'), $channel, $result));
            }
        }
    }

    /** A test message to the channels in $s (or the saved settings). @return array<string, true|string> channel => true or the error */
    public function test(?array $s = null): array
    {
        $s = $s ?? $this->settings->get();
        $site = SiteInfo::plain_name((string) get_bloginfo('name'));
        $text = sprintf(
            /* translators: %s: site name */
            __('Test from SiteRelay on %s: notifications work.', 'siterelay'),
            $site
        );
        return $this->send($s, ['subject' => '[SiteRelay] ' . $text, 'body' => $text . "\n\n" . home_url(), 'payload' => ['text' => $text, 'event' => 'test', 'site' => ['name' => $site, 'url' => home_url()]]]);
    }

    public static function event(Job $job): ?string
    {
        if ($job->status === Job::COMPLETED) {
            return $job->role === 'receiver' ? 'incoming.' . ($job->direction === 'push' ? 'push' : 'pull') : 'job.completed';
        }
        return in_array($job->status, [Job::FAILED, Job::ABANDONED], true) ? 'job.failed' : null;
    }

    /** @return array{subject: string, body: string, payload: array} */
    public static function message(Job $job, string $event): array
    {
        $site = SiteInfo::plain_name((string) get_bloginfo('name'));
        $title = self::title($job);
        $url = \Relay\Admin\Menu::url('#/jobs/' . $job->id);
        $outcome = $job->status === Job::COMPLETED ? __('completed', 'siterelay') : ($job->status === Job::ABANDONED ? __('was abandoned', 'siterelay') : __('failed', 'siterelay'));
        /* translators: 1: job title, e.g. "Pull from example.com", 2: "completed" or "failed", 3: site name */
        $line = sprintf(__('%1$s %2$s on %3$s', 'siterelay'), $title, $outcome, $site);
        $body = [$line, '', __('Site:', 'siterelay') . ' ' . home_url()];
        if ($job->key_label !== '' && $job->role === 'receiver') {
            $body[] = __('Access key:', 'siterelay') . ' ' . $job->key_label;
        }
        if ($job->started_at !== null) {
            $body[] = __('Started:', 'siterelay') . ' ' . $job->started_at . ' UTC';
        }
        if ($job->finished_at !== null) {
            $body[] = __('Finished:', 'siterelay') . ' ' . $job->finished_at . ' UTC';
        }
        if (is_array($job->error)) {
            $body[] = '';
            $body[] = (string) ($job->error['message'] ?? '');
            if (!empty($job->error['hint'])) {
                $body[] = (string) $job->error['hint'];
            }
        }
        $body[] = '';
        $body[] = __('Details:', 'siterelay') . ' ' . $url;
        return [
            'subject' => '[SiteRelay] ' . $line,
            'body' => implode("\n", $body),
            'payload' => [
                'text' => $line . ': ' . $url,
                'event' => $event,
                'site' => ['name' => $site, 'url' => home_url()],
                'job' => [
                    'id' => $job->id,
                    'type' => $job->type,
                    'role' => $job->role,
                    'direction' => $job->direction,
                    'status' => $job->status,
                    'title' => $title,
                    'peer_url' => $job->peer_url,
                    'key_label' => $job->key_label,
                    'started_at' => $job->started_at,
                    'finished_at' => $job->finished_at,
                    'error' => is_array($job->error) ? ['code' => $job->error['code'] ?? '', 'message' => $job->error['message'] ?? ''] : null,
                    'url' => $url,
                ],
            ],
        ];
    }

    /** The job's title, as in History ("Pull from example.com"). */
    public static function title(Job $job): string
    {
        $host = (string) wp_parse_url($job->peer_url, PHP_URL_HOST);
        switch ($job->type) {
            case 'pull':
                /* translators: %s: other site's host name */
                return $job->role === 'receiver' ? sprintf(__('Incoming pull from %s', 'siterelay'), $host) : sprintf(__('Pull from %s', 'siterelay'), $host);
            case 'push':
                /* translators: %s: other site's host name */
                return $job->role === 'receiver' ? sprintf(__('Incoming push from %s', 'siterelay'), $host) : sprintf(__('Push to %s', 'siterelay'), $host);
            case 'export':
                return __('Database export', 'siterelay');
            case 'find_replace':
                return __('Find & Replace', 'siterelay');
            case 'backup':
                return __('Backup', 'siterelay');
            case 'backup_restore':
                return __('Restore from a backup', 'siterelay');
            case 'import':
                return __('Database import', 'siterelay');
            default:
                return __('Undo', 'siterelay');
        }
    }

    /** @return array<string, true|string> */
    private function send(array $s, array $message): array
    {
        $out = [];
        if (!empty($s['email']['on'])) {
            $to = NotificationSettings::recipients((string) $s['email']['to']);
            $out['email'] = $to !== [] && wp_mail($to, $message['subject'], $message['body']) ? true : __('wp_mail() could not send the email. Check the site\'s mail setup.', 'siterelay');
        }
        if (!empty($s['webhook']['on'])) {
            $response = wp_remote_post((string) $s['webhook']['url'], [
                'timeout' => 5,
                'redirection' => 0,
                'headers' => ['Content-Type' => 'application/json'],
                'body' => (string) wp_json_encode($message['payload']),
                'user-agent' => 'SiteRelay/' . RELAY_VERSION . '; ' . home_url(),
            ]);
            $code = is_wp_error($response) ? 0 : (int) wp_remote_retrieve_response_code($response);
            /* translators: %s: HTTP status code or error message */
            $out['webhook'] = $code >= 200 && $code < 300 ? true : sprintf(__('the webhook answered %s', 'siterelay'), is_wp_error($response) ? $response->get_error_message() : 'HTTP ' . $code);
        }
        return $out;
    }
}