shopadmin/ShopAdmin/Components/CreateProduct.razor.cs

using LiteCharms.Features.S3.Abstractions;
using Microsoft.AspNetCore.Components.Forms;
using System.ComponentModel.DataAnnotations;
using static LiteCharms.Features.S3.Constants;

namespace ShopAdmin.Components;

public partial class CreateProduct([FromKeyedServices(BookshopBucketName)] IS3Service s3Service)
{
    private readonly CancellationTokenSource cancellationTokenSource = new();
    private CancellationToken cancellationToken;

    protected string? ActivePreviewUrl { get; set; }

    protected CreateProductModel ProductModel { get; set; } = new();

    private const long MaxAllowedFileSize = 1024 * 1024 * 5;

    protected override void OnInitialized()
    {
        base.OnInitialized();

        cancellationToken = cancellationTokenSource.Token;

        if (ProductModel.Thumbnails.Count == 0)
            ProductModel.Thumbnails = [.. Enumerable.Repeat(string.Empty, 5)];
    }

    // Your saving logic goes here when the ledger button is clicked
    public Task HandleValidSubmit() => Task.CompletedTask;

    // Checks if a valid URL asset exists at the specified position
    public bool HasAssetAt(int index) => ProductModel?.Thumbnails == null || index >= ProductModel.Thumbnails.Count
        ? false
        : !string.IsNullOrWhiteSpace(ProductModel.Thumbnails[index]);

    // Handles uploading the primary image node
    private async Task HandleMainImageUpload(InputFileChangeEventArgs e)
    {
        try
        {
            var file = e.File;

            if (file == null) return;

            using var stream = new MemoryStream();

            await file.OpenReadStream(MaxAllowedFileSize).CopyToAsync(stream, cancellationToken);

            var result = await s3Service.UploadFileAsync(file.Name,stream, 
                MimeTypes.GetMimeType(file.Name), cancellationToken);

            if (result.IsSuccess)
            {
                ProductModel.ImageUrl = result.Value;

                StateHasChanged();
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Main Image Upload Exception: {ex.Message}");
        }
    }

    public void SetPreviewActive(string? url)
    {
        if (!string.IsNullOrWhiteSpace(url))
        {
            ActivePreviewUrl = url;
            StateHasChanged();
        }
    }

    public void ClosePreviewDrawer()
    {
        ActivePreviewUrl = null;
        StateHasChanged();
    }

    // Handles uploading a thumbnail image into its specific slot index
    private async Task HandleThumbnailUpload(InputFileChangeEventArgs e, int index)
    {
        try
        {
            var file = e.File;

            if (file == null) return;

            using var stream = new MemoryStream();

            await file.OpenReadStream(MaxAllowedFileSize, cancellationToken).CopyToAsync(stream, cancellationToken);

            var result = await s3Service.UploadFileAsync(file.Name, stream, 
                MimeTypes.GetMimeType(file.Name), cancellationToken);

            if (result.IsSuccess && index < ProductModel.Thumbnails.Count)
            {
                ProductModel.Thumbnails[index] = result.Value;

                StateHasChanged();
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Thumbnail Slot {index} Upload Exception: {ex.Message}");
        }
    }

    public void ClearMainImage()
    {
        if (ActivePreviewUrl == ProductModel.ImageUrl)
        {
            ActivePreviewUrl = null;
        }
        ProductModel.ImageUrl = null;
    }

    public void RemoveThumbnailAt(int index)
    {
        if (index >= 0 && index < ProductModel.Thumbnails.Count)
        {
            if (ActivePreviewUrl == ProductModel.Thumbnails[index])
            {
                ActivePreviewUrl = null;
            }
            ProductModel.Thumbnails[index] = string.Empty;
        }
    }
}

public class CreateProductModel
{
    [Required(ErrorMessage = "Product name is required.")]
    public string? Name { get; set; }

    [Required(ErrorMessage = "Summary is required.")]
    public string? Summary { get; set; }

    [Required(ErrorMessage = "Description is required.")]
    public string? Description { get; set; }

    [Range(0.01, double.MaxValue, ErrorMessage = "Price must be greater than zero.")]
    public decimal Price { get; set; }

    [Required(ErrorMessage = "Primary image is required.")]
    public string? ImageUrl { get; set; }

    public List<string> Thumbnails { get; set; } = [];
}