Tasks.Module/Components/Pages/CategoriesPage.razor

@page "/tasks/categories"
@using Tasks.Module.Models
@using Tasks.Module.Services
@using Tasks.Module.Components.Dialogs
@inject ICategoryService CategoryService
@inject IDialogService Dialog
@inject ISnackbar Snackbar

<div class="min-h-screen bg-gradient-to-br from-slate-50 to-slate-100">
    <div class="max-w-4xl mx-auto py-8 px-4">
        @* Header *@
        <div class="mb-8">
            <h1 class="text-3xl font-bold text-slate-800">Categories</h1>
            <p class="text-slate-500 mt-1">Manage your task categories</p>
        </div>

        @* Toolbar *@
        <div class="bg-white rounded-2xl shadow-md p-4 mb-4">
            <div class="d-flex align-center gap-3">
                <MudTextField T="string" 
                              @bind-Value:get="searchText"
                              @bind-Value:set="OnSearchChanged"
                              Placeholder="Search categories..."
                              DisableUnderLine="true"
                              Adornment="Adornment.Start"
                              AdornmentIcon="@Icons.Material.Filled.Search"
                              Style="max-width: 300px;" />
                <MudSpacer />
                <MudButton Variant="Variant.Filled" 
                           Color="Color.Primary" 
                           StartIcon="@Icons.Material.Filled.Add"
                           OnClick="AddRootCategory">
                    Add Category
                </MudButton>
            </div>
        </div>

        @* Categories Tree *@
        @if (isLoading)
        {
            <div class="flex justify-center py-12">
                <MudProgressLinear Color="Color.Primary" Indeterminate="true" />
            </div>
        }
        else if (filteredCategories.Count == 0 && string.IsNullOrEmpty(searchText))
        {
            <div class="bg-white rounded-2xl shadow-lg p-12 text-center">
                <MudIcon Icon="@Icons.Material.Filled.FolderOpen" Size="Size.Large" Color="Color.Default" Class="mb-4" />
                <h3 class="text-lg font-semibold text-slate-700">No categories yet</h3>
                <p class="text-slate-500 mt-2">Click "Add Category" to create your first category</p>
            </div>
        }
        else
        {
            <div class="bg-white rounded-2xl shadow-lg">
                @foreach (var category in filteredCategories)
                {
                    <CategoryTreeItem Category="category" 
                                      OnAddChild="AddChildCategory"
                                      OnDelete="DeleteCategory"
                                      OnUpdate="UpdateCategory"
                                      SearchText="searchText" />
                }
            </div>
        }
    </div>
</div>

@code {
    private List<CategoryDto> categories = new();
    private List<CategoryDto> filteredCategories = new();
    private bool isLoading = true;
    private string searchText = string.Empty;

    protected override async Task OnInitializedAsync()
    {
        await LoadCategories();
    }

    private async Task LoadCategories()
    {
        isLoading = true;
        try
        {
            categories = await CategoryService.GetHierarchyAsync();
            ApplyFilter();
        }
        finally
        {
            isLoading = false;
        }
    }

    private void ApplyFilter()
    {
        if (string.IsNullOrWhiteSpace(searchText))
        {
            filteredCategories = categories;
        }
        else
        {
            filteredCategories = FilterTree(categories, searchText.ToLower());
        }
    }

    private List<CategoryDto> FilterTree(List<CategoryDto> cats, string search)
    {
        var result = new List<CategoryDto>();
        foreach (var cat in cats)
        {
            var filteredChildren = FilterTree(cat.Children, search);
            if (cat.Name.ToLower().Contains(search) || filteredChildren.Count > 0)
            {
                var copy = new CategoryDto
                {
                    Id = cat.Id,
                    Name = cat.Name,
                    Description = cat.Description,
                    ParentId = cat.ParentId,
                    CreatedAt = cat.CreatedAt,
                    UpdatedAt = cat.UpdatedAt,
                    Children = filteredChildren
                };
                result.Add(copy);
            }
        }
        return result;
    }

    private void OnSearchChanged(string value)
    {
        searchText = value;
        ApplyFilter();
    }

    private async Task AddRootCategory()
    {
        await AddCategory(null);
    }

    private async Task AddCategory(string? parentId)
    {
        var dto = new CreateCategoryDto { ParentId = parentId };
        
        var parameters = new DialogParameters<CreateCategoryDialog> 
        { 
            { x => x.Category, dto },
            { x => x.IsChild, parentId != null }
        };
        
        var options = new DialogOptions { CloseOnEscapeKey = true, MaxWidth = MaxWidth.Small, FullWidth = true };
        var dialog = await Dialog.ShowAsync<CreateCategoryDialog>("Add Category", parameters, options);
        var result = await dialog.Result;
        
        if (result is { Canceled: false })
        {
            try
            {
                await CategoryService.CreateAsync(dto);
                await LoadCategories();
                Snackbar.Add("Category created", Severity.Success);
            }
            catch (Exception ex)
            {
                Snackbar.Add($"Error: {ex.Message}", Severity.Error);
            }
        }
    }

    private async Task AddChildCategory(CategoryDto parent)
    {
        await AddCategory(parent.Id);
    }

    private async Task DeleteCategory(CategoryDto category)
    {
        var childCount = category.Children.Count;
        var (success, hasChildren, _, _) = await CategoryService.DeleteAsync(category.Id, false);
        
        if (!success && hasChildren)
        {
            var confirmed = await Dialog.ShowMessageBox(
                "Delete Category",
                $"\"{category.Name}\" has {childCount} child category(ries). Delete all?",
                yesText: "Delete All", cancelText: "Cancel");
            
            if (confirmed == true)
            {
                var result = await CategoryService.DeleteAsync(category.Id, true);
                if (result.success)
                {
                    Snackbar.Add("Category deleted", Severity.Success);
                    await LoadCategories();
                }
            }
        }
        else if (success)
        {
            Snackbar.Add("Category deleted", Severity.Success);
            await LoadCategories();
        }
    }

    private async Task UpdateCategory(CategoryDto category)
    {
        var dto = new UpdateCategoryDto 
        { 
            Id = category.Id,
            Name = category.Name,
            Description = category.Description,
            ParentId = category.ParentId
        };
        
        var parameters = new DialogParameters<CreateCategoryDialog> 
        { 
            { x => x.Category, dto },
            { x => x.IsUpdate, true },
            { x => x.IsChild, category.ParentId != null }
        };
        
        var options = new DialogOptions { CloseOnEscapeKey = true, MaxWidth = MaxWidth.Small, FullWidth = true };
        var dialog = await Dialog.ShowAsync<CreateCategoryDialog>("Update Category", parameters, options);
        var result = await dialog.Result;
        
        if (result is { Canceled: false })
        {
            try
            {
                await CategoryService.UpdateAsync(dto);
                Snackbar.Add("Category updated", Severity.Success);
                await LoadCategories();
            }
            catch (Exception ex)
            {
                Snackbar.Add($"Error: {ex.Message}", Severity.Error);
            }
        }
    }
}