StandManager/StandManager/Components/Pages/Scan.razor

@page "/scan"
@using StandManager.Components.Layout
@layout PublicLayout

@inject IJSRuntime JS
@inject BodyClassService BodyClass

@rendermode InteractiveServer

<PageTitle>Scan</PageTitle>

<header class="hero pb-0">
    <div class="container">
        <div class="mb-3">
            <video @ref="videoRef" autoplay playsinline style="width:100%;max-width:400px;border:1px solid #ccc;border-radius:8px;"></video>
        </div>

        <button class="btn btn-primary" @onclick="StartScan" disabled="@isScanning">
            Avvia scansione
        </button>

        <button class="btn btn-secondary" @onclick="StopScan" disabled="@(!isScanning)">
            Ferma
        </button>

    </div>
</header>


@if (!string.IsNullOrWhiteSpace(lastResult))
{
    <div class="alert alert-success">
        <strong>QR letto:</strong> @lastResult
    </div>
}

@if (!string.IsNullOrWhiteSpace(errorMessage))
{
    <div class="alert alert-danger">
        <strong>Errore:</strong> @errorMessage
    </div>
}

@code {
    private ElementReference videoRef;
    private DotNetObjectReference<Scan>? objRef;
    private bool isScanning;
    private string? lastResult;
    private string? errorMessage;

    protected override void OnInitialized()
    {
        objRef = DotNetObjectReference.Create(this);
    }

    private async Task StartScan()
    {
        errorMessage = null;
        lastResult = null;

        if (isScanning)
            return;

        isScanning = true;
        await JS.InvokeVoidAsync("qrScanner.start", videoRef, objRef);
    }

    private async Task StopScan()
    {
        if (!isScanning)
            return;

        isScanning = false;
        await JS.InvokeVoidAsync("qrScanner.stop", videoRef);
    }

    [JSInvokable]
    public Task OnQrDecoded(string text)
    {
        lastResult = text;
        isScanning = false;
        StateHasChanged();
        return Task.CompletedTask;
    }

    [JSInvokable]
    public Task OnQrError(string message)
    {
        errorMessage = message;
        isScanning = false;
        StateHasChanged();
        return Task.CompletedTask;
    }

    public async ValueTask DisposeAsync()
    {
        if (isScanning)
        {
            await StopScan();
        }

        objRef?.Dispose();
    }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
            await BodyClass.SetBodyClass("body-marketing body-gradient");
    }
}