<?php

namespace App\Http\Controllers\Public;

use App\Http\Controllers\Controller;
use App\Models\PosCustomerDisplay;
use App\Models\PosSale;
use App\Services\Pos\CustomerDisplayService;
use App\Services\Pos\DeviceService;
use App\Services\Pos\ReceiptEmailService;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\View\View;
use RuntimeException;
use Symfony\Component\HttpFoundation\StreamedResponse;

class CustomerDisplayController extends Controller
{
    public function __construct(
        private CustomerDisplayService $displays,
        private ReceiptEmailService $receiptEmail,
        private DeviceService $devices,
    ) {}

    public function show(string $token): View
    {
        $display = $this->find($token);
        $this->devices->touchByToken($token);

        return view('pos.customer-display', [
            'display' => $display,
            'state' => $this->displays->publicState($display),
            'stateUrl' => route('pos.customer-display.state', ['token' => $token]),
            'streamUrl' => route('pos.customer-display.stream', ['token' => $token]),
            'actionUrl' => route('pos.customer-display.action', ['token' => $token]),
        ]);
    }

    public function state(string $token): JsonResponse
    {
        $display = $this->find($token);
        $this->devices->touchByToken($token);

        return response()->json($this->displays->publicState($display));
    }

    public function stream(Request $request, string $token): StreamedResponse
    {
        $display = $this->find($token);
        $id = $display->id;
        $request->session()->save();

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

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

            while (true) {
                $display = PosCustomerDisplay::query()->find($id);
                if (! $display) {
                    echo "event: end\ndata: {}\n\n";
                    break;
                }

                $payload = $this->displays->publicState($display);
                $json = json_encode($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;
                }
                usleep(400000);
            }
        });

        $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 action(Request $request, string $token): JsonResponse
    {
        $display = $this->find($token);

        $data = $request->validate([
            'type' => ['required', 'string', 'in:tip,signature,receipt_email,payment_option'],
            'tip_percent' => ['nullable', 'numeric', 'min:0', 'max:100'],
            'tip_minor' => ['nullable', 'integer', 'min:0'],
            'signature_data_url' => ['nullable', 'string', 'max:500000'],
            'email' => ['nullable', 'email', 'max:255'],
            'payment_option' => ['nullable', 'string', 'max:40'],
        ]);

        $action = ['type' => $data['type']];

        if ($data['type'] === 'tip') {
            $action['tip_percent'] = $data['tip_percent'] ?? null;
            $action['tip_minor'] = $data['tip_minor'] ?? null;
            // Reflect selection on the screen immediately.
            $payload = $display->payload ?? [];
            $tip = $payload['tip'] ?? [];
            $tip['selected_percent'] = $data['tip_percent'] ?? null;
            $tip['selected_minor'] = $data['tip_minor'] ?? null;
            $payload['tip'] = $tip;
            $display->update(['payload' => $payload, 'last_pushed_at' => now()]);
        }

        if ($data['type'] === 'signature') {
            $action['signature_data_url'] = $data['signature_data_url'] ?? null;
            $payload = $display->payload ?? [];
            $sig = $payload['signature'] ?? [];
            $sig['data_url'] = $data['signature_data_url'] ?? null;
            $payload['signature'] = $sig;
            $display->update(['payload' => $payload, 'last_pushed_at' => now()]);
        }

        if ($data['type'] === 'receipt_email') {
            $action['email'] = $data['email'] ?? null;
            $emailResult = $this->emailReceiptForDisplay($display, (string) ($data['email'] ?? ''));
            $action['email_sent'] = $emailResult['ok'];
            $action['email_message'] = $emailResult['message'];
        }

        if ($data['type'] === 'payment_option') {
            $action['payment_option'] = $data['payment_option'] ?? null;
        }

        $this->displays->recordCustomerAction($display->fresh(), $action);

        return response()->json([
            'ok' => true,
            'state' => $this->displays->publicState($display->fresh()),
            'email_sent' => $action['email_sent'] ?? null,
            'message' => $action['email_message'] ?? null,
        ]);
    }

    /** @return array{ok: bool, message: string} */
    private function emailReceiptForDisplay(PosCustomerDisplay $display, string $email): array
    {
        $payload = is_array($display->payload) ? $display->payload : [];
        $saleId = (int) ($payload['sale_id'] ?? $payload['receipt']['sale_id'] ?? 0);
        $reference = (string) ($payload['sale_reference'] ?? $payload['receipt']['reference'] ?? '');

        $sale = null;
        if ($saleId > 0) {
            $sale = PosSale::query()
                ->where('id', $saleId)
                ->where('location_id', $display->location_id)
                ->first();
        }
        if (! $sale && $reference !== '') {
            $sale = PosSale::query()
                ->where('reference', $reference)
                ->where('location_id', $display->location_id)
                ->first();
        }

        if (! $sale) {
            return ['ok' => false, 'message' => 'No receipt is ready to email yet.'];
        }

        try {
            return $this->receiptEmail->send($sale, $email);
        } catch (RuntimeException $e) {
            return ['ok' => false, 'message' => $e->getMessage()];
        }
    }

    private function find(string $token): PosCustomerDisplay
    {
        return PosCustomerDisplay::query()
            ->where('token', $token)
            ->with('location')
            ->firstOrFail();
    }
}