<?php

namespace App\Jobs\InboxPipeline;

use App\Profile;
use App\Util\ActivityPub\Helpers;
use App\Util\ActivityPub\HttpSignature;
use Cache;
use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Foundation\Bus\Dispatchable;
use Illuminate\Http\Client\ConnectionException;
use Illuminate\Queue\InteractsWithQueue;
use Illuminate\Queue\SerializesModels;
use Illuminate\Support\Facades\Http;

class InboxWorker implements ShouldQueue
{
    use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;

    protected $headers;

    protected $payload;

    public $timeout = 300;

    public $tries = 1;

    public $maxExceptions = 1;

    /**
     * Create a new job instance.
     *
     * @return void
     */
    public function __construct($headers, $payload)
    {
        $this->headers = $headers;
        $this->payload = $payload;
    }

    /**
     * Execute the job.
     *
     * @return void
     */
    public function handle()
    {
        $profile = null;
        $headers = $this->headers;

        if (empty($headers) || empty($this->payload) || ! isset($headers['signature']) || ! isset($headers['date'])) {
            return;
        }

        $payload = json_decode($this->payload, true, 8);

        if ($this->verifySignature($headers, $payload) == true) {
            if (isset($payload['id'])) {
                $lockKey = 'pf:ap:user-inbox:activity:' . hash('sha256', $payload['id']);
                if (! Cache::add($lockKey, 1, 3600)) {
                    // Already processed after valid signature check
                    return 1;
                }
            }

            ActivityHandler::dispatch($headers, $profile, $payload)->onQueue('shared');

            return;
        } else {
            return;
        }
    }

    protected function verifySignature($headers, $payload)
    {
        $body = $this->payload;
        $bodyDecoded = $payload;
        $signature = is_array($headers['signature']) ? $headers['signature'][0] : $headers['signature'];
        $date = is_array($headers['date']) ? $headers['date'][0] : $headers['date'];
        if (! $signature) {
            return false;
        }
        if (! $date) {
            return false;
        }
        if (
            ! now()->parse($date)->gt(now()->subDays(1)) ||
            ! now()->parse($date)->lt(now()->addDays(1))
        ) {
            return false;
        }
        if (! isset($bodyDecoded['id'])) {
            return false;
        }
        $signatureData = HttpSignature::parseSignatureHeader($signature);

        if (! isset($signatureData['keyId'], $signatureData['signature'], $signatureData['headers']) || isset($signatureData['error'])) {
            return false;
        }

        $keyId = Helpers::validateUrl($signatureData['keyId']);
        $id = Helpers::validateUrl($bodyDecoded['id']);
        $keyDomain = parse_url($keyId, PHP_URL_HOST);
        $idDomain = parse_url($id, PHP_URL_HOST);
        $actorDomain = parse_url($payload['actor'] ?? '', PHP_URL_HOST);
        if (
            isset($bodyDecoded['object'])
            && is_array($bodyDecoded['object'])
            && isset($bodyDecoded['object']['attributedTo'])
        ) {
            $attr = Helpers::pluckval($bodyDecoded['object']['attributedTo']);
            if (is_array($attr)) {
                if (isset($attr['id'])) {
                    $attr = $attr['id'];
                } else {
                    $attr = '';
                }
            }
            if (parse_url($attr, PHP_URL_HOST) !== $keyDomain) {
                return false;
            }
        }
        if (
            !$keyDomain || !$idDomain || !$actorDomain
            || $keyDomain !== $idDomain || $keyDomain !== $actorDomain
        ) {
            return false;
        }
        $actor = Profile::whereKeyId($keyId)->first();
        if (! $actor) {
            $actorUrl = Helpers::pluckval($bodyDecoded['actor']);
            $actor = Helpers::profileFirstOrNew($actorUrl);
        }
        if (! $actor) {
            return false;
        }
        $pkey = openssl_pkey_get_public($actor->public_key);
        if (! $pkey) {
            return false;
        }
        $inboxPath = '/f/inbox';
        [$verified, $headers] = HttpSignature::verify($pkey, $signatureData, $headers, $inboxPath, $body);
        if ($verified == 1) {
            return true;
        } else {
            return false;
        }
    }

    protected function blindKeyRotation($headers, $payload)
    {
        $signature = is_array($headers['signature']) ? $headers['signature'][0] : $headers['signature'];
        $date = is_array($headers['date']) ? $headers['date'][0] : $headers['date'];
        if (! $signature) {
            return;
        }
        if (! $date) {
            return;
        }
        if (
            ! now()->parse($date)->gt(now()->subDays(1)) ||
            ! now()->parse($date)->lt(now()->addDays(1))
        ) {
            return;
        }
        $signatureData = HttpSignature::parseSignatureHeader($signature);
        if (! isset($signatureData['keyId'], $signatureData['signature'], $signatureData['headers']) || isset($signatureData['error'])) {
            return;
        }

        $keyId = Helpers::validateUrl($signatureData['keyId']);
        $actor = Profile::whereKeyId($keyId)->whereNotNull('remote_url')->first();
        if (! $actor) {
            return;
        }
        if (Helpers::validateUrl($actor->remote_url) == false) {
            return;
        }

        try {
            $res = Http::withOptions(['allow_redirects' => false])->timeout(20)->withHeaders([
                'Accept' => 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"',
                'User-Agent' => 'PixelfedBot v0.1 - https://pixelfed.org',
            ])->get($actor->remote_url);
        } catch (ConnectionException $e) {
            return false;
        }

        if (! $res->ok()) {
            return false;
        }

        $res = json_decode($res->body(), true, 8);
        if (! $res || empty($res) || ! isset($res['publicKey']) || ! isset($res['publicKey']['id'])) {
            return;
        }
        if ($res['publicKey']['id'] !== $actor->key_id) {
            return;
        }
        $actor->public_key = $res['publicKey']['publicKeyPem'];
        $actor->save();

        return $this->verifySignature($headers, $payload);
    }
}
