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

using Microsoft.AspNetCore.Components;
using CMSMicroservice.Protobuf.Protos.UserAddress;
using FrontOffice.Main.Utilities;
using MudBlazor;

namespace FrontOffice.Main.Pages.DiscountStore;

public partial class Checkout
{
    [Inject] private DiscountCartService DiscountCart { get; set; } = default!;
    [Inject] private DiscountOrderService DiscountOrderService { get; set; } = default!;
    [Inject] private UserAddressContract.UserAddressContractClient UserAddressContract { get; set; } = default!;

    private List<CustomerAddressModel> _addresses = new();
    private CustomerAddressModel? _selectedAddress;
    private bool _loadingAddresses;

    private string? _notes;
    private bool _placing;

    private const decimal VAT_RATE = 0.10m;

    /// <summary>مبلغ درگاه قبل از مالیات (جمع کل - تخفیف)</summary>
    private long NetGatewayAmount => DiscountCart.TotalPrice - DiscountCart.TotalDiscount;

    /// <summary>مالیات بر ارزش افزوده ۱۰٪</summary>
    private long VatAmount => (long)(NetGatewayAmount * VAT_RATE);

    /// <summary>مبلغ نهایی قابل پرداخت (شامل VAT)</summary>
    private long FinalGatewayAmount => NetGatewayAmount + VatAmount;

    private bool CanPlaceOrder => DiscountCart.Items.Count > 0 && _selectedAddress is not null;

    protected override async Task OnInitializedAsync()
    {
        await DiscountCart.EnsureInitializedAsync();
        await LoadAddresses();
    }

    private async Task LoadAddresses()
    {
        _loadingAddresses = true;
        try
        {
            var response = await UserAddressContract.GetCustomerAddressesAsync(new());
            if (response?.Models?.Any() == true)
            {
                _addresses = response.Models.ToList();
                _selectedAddress = _addresses.FirstOrDefault(a => a.IsDefault) ?? _addresses.First();
            }
            else
            {
                _addresses = new();
            }
        }
        catch (Exception ex)
        {
            Snackbar.Add($"خطا در بارگذاری آدرس‌ها: {ex.Message}", Severity.Error);
            _addresses = new();
        }
        finally
        {
            _loadingAddresses = false;
            await InvokeAsync(StateHasChanged);
        }
    }

    private async Task PlaceOrder()
    {
        if (!CanPlaceOrder || _selectedAddress is null)
        {
            Snackbar.Add("لطفاً آدرس را انتخاب کنید.", Severity.Warning);
            return;
        }

        _placing = true;
        try
        {
            // Always use 100% discount — send full price, server will apply max from wallet
            var result = await DiscountOrderService.PlaceOrderAsync(
                _selectedAddress.Id,
                DiscountCart.TotalPrice,
                _notes);

            if (!result.Success)
            {
                Snackbar.Add(result.Message, Severity.Error);
                return;
            }

            // If there's a gateway payment URL, redirect to it
            if (!string.IsNullOrWhiteSpace(result.PaymentUrl) && result.GatewayAmount > 0)
            {
                Snackbar.Add("در حال انتقال به درگاه پرداخت...", Severity.Info);
                await DiscountCart.ClearAsync();
                Navigation.NavigateTo(result.PaymentUrl, forceLoad: true);
                return;
            }

            // If fully paid via discount balance (no gateway needed)
            await DiscountCart.ClearAsync();
            Snackbar.Add("سفارش با موفقیت ثبت شد!", Severity.Success);
            Navigation.NavigateTo($"{RouteConstants.DiscountStore.OrderDetail}{result.OrderId}");
        }
        catch (Exception ex)
        {
            Snackbar.Add($"خطا در ثبت سفارش: {ex.Message}", Severity.Error);
        }
        finally
        {
            _placing = false;
        }
    }

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

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