<?php

namespace App\Http\Controllers\Site;

use App\Http\Controllers\Controller;
use App\Services\LivePriceCacheService;
use App\Services\PriceStreamService;
use Illuminate\Http\Request;
use Symfony\Component\HttpFoundation\StreamedResponse;

class PriceStreamController extends Controller
{
    public function stream(Request $request): StreamedResponse
    {
        $service = app(PriceStreamService::class);

        if (! $service->isEnabled()) {
            abort(404);
        }

        return response()->stream(function () use ($service) {
            @set_time_limit(0);

            if (function_exists('apache_setenv')) {
                @apache_setenv('no-gzip', '1');
            }

            @ini_set('zlib.output_compression', '0');
            @ini_set('implicit_flush', '1');

            while (ob_get_level() > 0) {
                @ob_end_flush();
            }

            $send = static function (string $event, $data): void {
                echo 'event: '.$event."\n";
                echo 'data: '.json_encode($data, JSON_UNESCAPED_UNICODE)."\n\n";
                @flush();
            };

            $cache = app(LivePriceCacheService::class);
            $last = $cache->get() ?? $cache->buildFromDatabase();
            if (is_array($last) && $last !== []) {
                $send('last', $last);
            }

            $lastId = $service->currentSeq();
            $heartbeatTicks = 0;

            while (! connection_aborted()) {
                foreach ($service->consumeSince($lastId) as $event) {
                    $send((string) $event['event'], $event['data']);
                    $lastId = (int) $event['id'];
                }

                $heartbeatTicks++;
                if ($heartbeatTicks >= 30) {
                    echo ': ping '.time()."\n\n";
                    @flush();
                    $heartbeatTicks = 0;
                }

                usleep(500000);
            }
        }, 200, [
            'Content-Type' => 'text/event-stream; charset=UTF-8',
            'Cache-Control' => 'no-cache, no-store, must-revalidate',
            'Connection' => 'keep-alive',
            'X-Accel-Buffering' => 'no',
        ]);
    }
}