<?php

namespace App\Http\Controllers\Public;

use App\Http\Controllers\Controller;
use App\Models\PosDevice;
use App\Models\PosSaleLine;
use App\Services\Pos\DeviceService;
use App\Services\Pos\KitchenBoardService;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\View\View;
use Symfony\Component\HttpFoundation\StreamedResponse;

/**
 * Token-gated kitchen display for unattended tablets (no staff login).
 */
class KitchenDisplayController extends Controller
{
    public function __construct(
        private DeviceService $devices,
        private KitchenBoardService $board,
    ) {}

    public function show(string $token): View
    {
        $device = $this->findKitchenDevice($token);
        $this->devices->recordHeartbeat($device);

        return view('pos.kitchen.public', [
            'device' => $device,
            'locationName' => $device->location?->name ?? 'Kitchen',
            'stations' => $this->board->stations($device->owner_ref),
            'feedUrl' => route('pos.kitchen-display.feed', ['token' => $token]),
            'streamUrl' => route('pos.kitchen-display.stream', ['token' => $token]),
            'bumpUrl' => route('pos.kitchen-display.bump', ['token' => $token, 'line' => '__ID__']),
        ]);
    }

    public function feed(string $token): JsonResponse
    {
        $device = $this->findKitchenDevice($token);
        $this->devices->recordHeartbeat($device);

        return response()->json($this->board->payload($device->owner_ref));
    }

    public function stream(Request $request, string $token): StreamedResponse
    {
        $device = $this->findKitchenDevice($token);
        $this->devices->recordHeartbeat($device);
        $owner = $device->owner_ref;
        $deviceId = $device->id;
        $request->session()->save();

        $response = new StreamedResponse(function () use ($owner, $deviceId) {
            while (ob_get_level() > 0) {
                @ob_end_flush();
            }
            @set_time_limit(0);

            $start = time();
            $lastHash = null;

            while (true) {
                if ($deviceId) {
                    $live = PosDevice::query()->find($deviceId);
                    if ($live) {
                        app(DeviceService::class)->recordHeartbeat($live);
                    }
                }

                $payload = $this->board->payload($owner);
                $json = json_encode($payload);
                $hash = md5((string) $json);

                if ($hash !== $lastHash) {
                    echo 'data: '.$json."\n\n";
                    $lastHash = $hash;
                } else {
                    echo ": ping\n\n";
                }
                @ob_flush();
                @flush();

                if (connection_aborted() || (time() - $start) >= 25) {
                    break;
                }
                sleep(1);
            }
        });

        $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;
    }

    public function bump(string $token, PosSaleLine $line): JsonResponse
    {
        $device = $this->findKitchenDevice($token);
        $this->devices->recordHeartbeat($device);

        return response()->json($this->board->bumpLine($line, $device->owner_ref));
    }

    private function findKitchenDevice(string $token): PosDevice
    {
        $device = $this->devices->findByToken($token);
        abort_unless($device && $device->type === 'kitchen_display', 404);

        return $device->loadMissing('location');
    }
}