<?php

declare(strict_types=1);

namespace App\Http\Controllers\Radio;

use App\Enums\RadioSettings;
use App\Http\Controllers\Controller;
use App\Http\Controllers\Concerns\HasRadioSettings;
use App\Services\Community\RadioScheduleService;
use App\Services\Community\RadioStreamService;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Cache;
use Symfony\Component\HttpFoundation\StreamedResponse;

class SseController extends Controller
{
    use HasRadioSettings;
    private const int SSE_KEEPALIVE = 15;

    public function __construct(
        private readonly RadioStreamService $streamService,
        private readonly RadioScheduleService $scheduleService,
    ) {}

    public function stream(Request $request): StreamedResponse
    {
        $channels = $request->query('channels', 'now-playing,listeners,dj');

        $wanted = array_flip(array_map('trim', explode(',', $channels)));

        $response = new StreamedResponse(function () use ($wanted): void {
            $last = [
                'now-playing' => null,
                'listeners' => null,
                'dj' => null,
            ];

            $this->sendSseComment('connected');

            while (! connection_aborted()) {
                $sent = false;

                if (isset($wanted['now-playing'])) {
                    $data = $this->getNowPlaying();
                    if ($data !== $last['now-playing']) {
                        $this->sendSseEvent('now-playing', $data);
                        $last['now-playing'] = $data;
                        $sent = true;
                    }
                }

                if (isset($wanted['listeners'])) {
                    $count = $this->getListeners();
                    if ($count !== $last['listeners']) {
                        $this->sendSseEvent('listeners', ['count' => $count]);
                        $last['listeners'] = $count;
                        $sent = true;
                    }
                }

                if (isset($wanted['dj'])) {
                    $dj = $this->getCurrentDj();
                    if ($dj !== $last['dj']) {
                        $this->sendSseEvent('dj', $dj);
                        $last['dj'] = $dj;
                        $sent = true;
                    }
                }

                if (! $sent) {
                    $this->sendSseComment('keepalive');
                }

                ob_flush();
                flush();

                sleep(5);
            }
        });

        $response->headers->set('Content-Type', 'text/event-stream');
        $response->headers->set('Cache-Control', 'no-cache');
        $response->headers->set('Connection', 'keep-alive');
        $response->headers->set('X-Accel-Buffering', 'no');

        return $response;
    }

    private function sendSseEvent(string $event, mixed $data): void
    {
        echo "event: {$event}\n";
        echo 'data: ' . json_encode($data) . "\n\n";
    }

    private function sendSseComment(string $comment): void
    {
        echo ": {$comment}\n\n";
    }

    private function getNowPlaying(): ?array
    {
        $autoDj = Cache::get('radio_auto_dj_active');

        if ($autoDj !== null) {
            return [
                'enabled' => true,
                'song' => $autoDj['title'],
                'artist' => $autoDj['artist'] ?? null,
                'title' => $autoDj['title'],
                'is_auto_dj' => true,
            ];
        }

        $cached = Cache::get('radio_nowplaying');

        if ($cached !== null) {
            $cached['is_auto_dj'] = false;

            return $cached;
        }

        $apiUrl = $this->getSetting(RadioSettings::NowPlayingEnabled)
            ? ($this->getSetting(RadioSettings::NowPlayingApiUrl) ?: $this->getAzureCastApiUrl())
            : null;

        $result = $apiUrl ? $this->streamService->getNowPlaying($apiUrl) : ['enabled' => false, 'song' => null];

        $result['is_auto_dj'] = false;

        Cache::put('radio_nowplaying', $result, 10);

        return $result;
    }

    private function getListeners(): int
    {
        return (int) Cache::remember('radio_listeners', 30, function () {
            $apiUrl = $this->getSetting(RadioSettings::ListenersEnabled)
                ? ($this->getSetting(RadioSettings::ListenersApiUrl) ?: $this->getAzureCastApiUrl())
                : null;

            return $apiUrl ? $this->streamService->getListenersCount($apiUrl) : 0;
        });
    }

    private function getCurrentDj(): ?array
    {
        $autoDj = Cache::get('radio_auto_dj_active');

        $dj = $this->scheduleService->getCurrentDJ(
            $this->getSetting(RadioSettings::CurrentDjId)
        );

        if ($dj === null && $autoDj !== null) {
            return [
                'username' => 'Auto DJ',
                'look' => null,
                'show_name' => 'Auto DJ',
                'is_auto_dj' => true,
                'song' => $autoDj['title'] ?? null,
            ];
        }

        if ($dj !== null) {
            $dj['is_auto_dj'] = false;
        }

        return $dj;
    }

    private function getAzureCastApiUrl(): ?string
    {
        $baseUrl = $this->getSetting(RadioSettings::AzureCastBaseUrl);
        $stationId = (int) $this->getSetting(RadioSettings::AzureCastStationId, '1');

        if (! $baseUrl) {
            return null;
        }

        return rtrim($baseUrl, '/') . '/api/nowplaying/' . $stationId;
    }
}