FrontOffice/src/FrontOffice.Main/Pages/DiscountStore/Cart.razor.cs

using Microsoft.AspNetCore.Components;
using FrontOffice.Main.Utilities;

namespace FrontOffice.Main.Pages.DiscountStore;

public partial class Cart : IDisposable
{
    [Inject] private DiscountCartService DiscountCart { get; set; } = default!;
    [Inject] private VATService VAT { get; set; } = default!;
    [Inject] private AuthDialogService AuthDialogService { get; set; } = default!;
    [Inject] private AuthService AuthService { get; set; } = default!;

    protected override async Task OnInitializedAsync()
    {
        if (!await AuthService.IsAuthenticatedAsync())
        {
            await AuthDialogService.ShowAuthDialogAsync();
        }
        await DiscountCart.EnsureInitializedAsync();
        DiscountCart.OnChange += StateHasChanged;
    }

    private async Task IncrementQty(long productId)
    {
        var item = DiscountCart.Items.FirstOrDefault(i => i.ProductId == productId);
        if (item is null) return;
        await DiscountCart.UpdateQuantityAsync(productId, item.Quantity + 1);
    }

    private async Task DecrementQty(long productId)
    {
        var item = DiscountCart.Items.FirstOrDefault(i => i.ProductId == productId);
        if (item is null) return;
        if (item.Quantity <= 1)
        {
            await DiscountCart.RemoveAsync(productId);
        }
        else
        {
            await DiscountCart.UpdateQuantityAsync(productId, item.Quantity - 1);
        }
    }

    private async Task Remove(long productId)
    {
        await DiscountCart.RemoveAsync(productId);
    }

    private void ProceedCheckout()
    {
        Navigation.NavigateTo(RouteConstants.DiscountStore.Checkout);
    }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
        {
            await VAT.LoadAsync();
            StateHasChanged();
        }
    }

    private long VatAmount => VAT.CalculateVAT(DiscountCart.FinalPrice);
    private long TotalWithVat => DiscountCart.FinalPrice + VatAmount;

    private static string FormatPrice(long price) => $"{price:N0} ";

    private static string GetImageUrl(string? imageUrl)
        => string.IsNullOrWhiteSpace(imageUrl) ? "/images/product-placeholder.svg" : imageUrl.TrimStart('/');

    public void Dispose()
    {
        DiscountCart.OnChange -= StateHasChanged;
    }
}