@page "/qr"
@layout EmptyLayout
@using Microsoft.AspNetCore.Components
@using QRPay.Models
@using QRPay.Services

<PageTitle>QR Preview</PageTitle>

<div class="qr-route-page">
    <h1 class="visually-hidden">QR payment preview</h1>

    @if (_errors.Count > 0)
    {
        <div class="qr-route-error" role="alert">
            <p>Unable to generate QR code.</p>
            @foreach (var error in _errors)
            {
                <p>@error</p>
            }
        </div>
    }
    else if (!string.IsNullOrEmpty(_qrCodeDataUri))
    {
        <img class="qr-route-image" src="@_qrCodeDataUri" alt="Payment QR code" />
    }
</div>

@code {
    [SupplyParameterFromQuery(Name = "amount")]
    public string? Amount { get; set; }

    [SupplyParameterFromQuery(Name = "iban")]
    public string? Iban { get; set; }

    [SupplyParameterFromQuery(Name = "name")]
    public string? Name { get; set; }

    [SupplyParameterFromQuery(Name = "remark")]
    public string? Remark { get; set; }

    private readonly List<string> _errors = [];
    private string _qrCodeDataUri = string.Empty;

    protected override void OnParametersSet()
    {
        _errors.Clear();
        _qrCodeDataUri = string.Empty;

        decimal? parsedAmount = null;

        if (!string.IsNullOrWhiteSpace(Amount))
        {
            if (PaymentRequest.TryParseAmount(Amount, out var amount))
            {
                parsedAmount = amount;
            }
            else
            {
                _errors.Add("Invalid amount format. Use a dot as the decimal separator, for example 12.50.");
            }
        }

        var paymentRequest = new PaymentRequest
        {
            Amount = parsedAmount,
            IBAN = Iban ?? string.Empty,
            Name = Name ?? string.Empty,
            Remark = Remark ?? string.Empty
        };

        _errors.AddRange(paymentRequest.ValidateForQrRoute());

        if (_errors.Count == 0)
        {
            _qrCodeDataUri = PaymentQrCodeService.GenerateDataUri(paymentRequest);
        }
    }
}