<?php

namespace App\Notifications\ImageScan;

use App\Notifications\CustomEmailNotification;
use App\Notifications\Dto\DiscordMessage;
use App\Notifications\Dto\PushoverMessage;
use App\Notifications\Dto\SlackMessage;
use Illuminate\Notifications\Messages\MailMessage;

/**
 * The daily security digest of a team (spec 15.8): resources that became update_available or check_needed, or got a
 * new fixing version, with their status, the primary action, and a link; ignores that end soon; failing servers.
 * Chat and webhook channels get no vulnerability IDs and no counts; the email adds the why-list of each resource (at
 * most MAIL_ID_LIMIT rows in total).
 */
class VulnerabilityDigest extends CustomEmailNotification
{
    public const TITLE = 'Daily security digest';

    public const BUTTON = 'Open security status';

    public const MAIL_ID_LIMIT = 10;

    /** Text limits: Discord embed description, Telegram message, Slack section text, Pushover message. */
    public const DISCORD_LIMIT = 4096;

    public const TELEGRAM_LIMIT = 4096;

    public const SLACK_LIMIT = 3000;

    public const PUSHOVER_LIMIT = 1024;

    private const NAME_LIMIT = 100;

    private const SENTENCE_LIMIT = 500;

    public string $teamUrl;

    /**
     * @param  array{resources: list<array{name: string, uuid: string, url: ?string, status: string, badge: string, action: ?string, why: list<array{title: string, display_id: string, link: ?string, score: ?float, severity: string, signal: ?string}>}>, ignores: list<array{resource: ?string, id: ?string, package: ?string, expires_at: string}>, servers: list<array{name: string, url: string}>}  $digest
     */
    public function __construct(public array $digest)
    {
        $this->onQueue('high');
        $this->teamUrl = rtrim(base_url(), '/').'/vulnerabilities';
    }

    public function via(object $notifiable): array
    {
        return $notifiable->getEnabledChannels('image_vulnerabilities');
    }

    public function toMail(?object $notifiable = null): MailMessage
    {
        $budget = self::MAIL_ID_LIMIT;
        $resources = array_map(function (array $resource) use (&$budget): array {
            $why = array_slice($resource['why'], 0, max(0, $budget));
            $budget -= count($why);

            return [
                'name' => NotificationText::mailMarkdown($resource['name']),
                'url' => $resource['url'],
                'summary' => NotificationText::mailMarkdown($this->resourceSentence($resource)),
                'why' => array_map(NotificationText::mailWhy(...), $why),
            ];
        }, $this->digest['resources']);

        $ignores = array_map(function (array $ignore) use (&$budget): array {
            $id = $ignore['id'];
            if ($id !== null && $budget > 0) {
                $budget--;
            } elseif ($id !== null) {
                $id = 'A vulnerability';
            }
            $subject = match (true) {
                $id !== null && $ignore['package'] !== null => "{$id} in {$ignore['package']}",
                $id !== null => $id,
                default => "Package {$ignore['package']}",
            };

            return [
                'subject' => NotificationText::mailMarkdown($subject),
                'resource' => $ignore['resource'] === null ? null : NotificationText::mailMarkdown($ignore['resource']),
                'expires_at' => $ignore['expires_at'],
            ];
        }, $this->digest['ignores']);

        return (new MailMessage)
            ->subject('Coolify: '.self::TITLE)
            ->view('emails.image-vulnerabilities', [
                'intro' => 'Changes in the security status of your resources since the last digest.',
                'resources' => $resources,
                'ignores' => $ignores,
                'servers' => array_map(fn (array $server): array => ['name' => NotificationText::mailMarkdown($server['name']), 'url' => $server['url']], $this->digest['servers']),
                'url' => $this->teamUrl,
            ]);
    }

    public function toDiscord(): DiscordMessage
    {
        $suffix = "\n\n[".self::BUTTON."]({$this->teamUrl})";
        $lines = $this->chatLines(
            fn (array $resource): string => '• '.($resource['url'] === null
                ? NotificationText::discord($this->name($resource))
                : '['.NotificationText::discord($this->name($resource)).']('.$resource['url'].')')
                .': '.NotificationText::discord($this->resourceSentence($resource)),
            NotificationText::discord(...),
            self::DISCORD_LIMIT - mb_strlen($suffix),
        );

        return new DiscordMessage(
            title: self::TITLE,
            description: implode("\n", $lines).$suffix,
            color: DiscordMessage::warningColor(),
        );
    }

    public function toSlack(): SlackMessage
    {
        $suffix = "\n\n<{$this->teamUrl}|".self::BUTTON.'>';
        $lines = $this->chatLines(
            fn (array $resource): string => '• '.($resource['url'] === null
                ? NotificationText::slack($this->name($resource))
                : '<'.$resource['url'].'|'.NotificationText::slack($this->name($resource)).'>')
                .': '.NotificationText::slack($this->resourceSentence($resource)),
            NotificationText::slack(...),
            self::SLACK_LIMIT - mb_strlen($suffix),
        );

        return new SlackMessage(
            title: self::TITLE,
            description: implode("\n", $lines).$suffix,
            color: SlackMessage::warningColor(),
        );
    }

    public function toTelegram(): array
    {
        $prefix = 'Coolify: '.self::TITLE."\n\n";
        $lines = $this->chatLines(
            fn (array $resource): string => '• '.NotificationText::plain($this->name($resource)).': '.NotificationText::plain($this->resourceSentence($resource))
                .($resource['url'] === null ? '' : "\n  ".$resource['url']),
            NotificationText::plain(...),
            self::TELEGRAM_LIMIT - mb_strlen($prefix),
        );

        return [
            'message' => $prefix.implode("\n", $lines),
            'buttons' => [['text' => self::BUTTON, 'url' => $this->teamUrl]],
        ];
    }

    public function toPushover(): PushoverMessage
    {
        $button = ['text' => self::BUTTON, 'url' => $this->teamUrl];
        // PushoverMessage appends each button to the message as a link.
        $buttonLength = mb_strlen("&nbsp;<a href='{$button['url']}'>{$button['text']}</a>");
        $lines = $this->chatLines(
            fn (array $resource): string => '• '.($resource['url'] === null
                ? NotificationText::html($this->name($resource))
                : "<a href='".NotificationText::html($resource['url'])."'>".NotificationText::html($this->name($resource)).'</a>')
                .': '.NotificationText::html($this->resourceSentence($resource)),
            NotificationText::html(...),
            self::PUSHOVER_LIMIT - $buttonLength,
        );

        return new PushoverMessage(
            title: self::TITLE,
            message: implode("\n", $lines),
            buttons: [$button],
            level: 'warning',
        );
    }

    public function toWebhook(): array
    {
        return [
            'success' => false,
            'message' => self::TITLE,
            'event' => 'image_vulnerabilities_digest',
            'url' => $this->teamUrl,
            'resources' => array_map(fn (array $resource): array => [
                'name' => $resource['name'],
                'uuid' => $resource['uuid'],
                'url' => $resource['url'],
                'status' => $resource['status'],
                'action' => $resource['action'],
            ], $this->digest['resources']),
            'ignores_ending' => $this->digest['ignores'] !== [],
            'servers_failing' => array_map(fn (array $server): array => ['name' => $server['name'], 'url' => $server['url']], $this->digest['servers']),
        ];
    }

    /**
     * The lines of a chat message that fit in $budget characters: resources, then ignores and failing servers,
     * without IDs or counts, then "And N more." for the rest.
     *
     * @param  callable(array<string, mixed>): string  $resourceLine
     * @param  callable(string): string  $escape
     * @return list<string>
     */
    private function chatLines(callable $resourceLine, callable $escape, int $budget): array
    {
        $lines = array_map($resourceLine, $this->digest['resources']);

        $ignores = count($this->digest['ignores']);
        if ($ignores > 0) {
            $lines[] = $ignores === 1 ? 'An ignore ends within 7 days.' : 'Some ignores end within 7 days.';
        }

        foreach ($this->digest['servers'] as $server) {
            $lines[] = $escape('Image scans failed for 2 days on '.NotificationText::limit($server['name'], self::NAME_LIMIT).'.');
        }

        return NotificationText::fitLines($lines, $budget);
    }

    /**
     * @param  array<string, mixed>  $resource
     */
    private function name(array $resource): string
    {
        return NotificationText::limit($resource['name'], self::NAME_LIMIT);
    }

    /**
     * "Security update. Update to 1.28." / "Check needed. Check again: the last check was 3 days ago."
     *
     * @param  array<string, mixed>  $resource
     */
    private function resourceSentence(array $resource): string
    {
        return NotificationText::limit(trim($resource['badge'].'. '.($resource['action'] ?? '')), self::SENTENCE_LIMIT);
    }
}