feat: filter issues by label — URL param and quick-filter chips (#150)

Closes #150

Working as Legolas (Frontend Engineer)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: mpaulosky

src/Domain/DTOs/IssueSearchRequest.cs

@@ -60,6 +60,11 @@ public record IssueSearchRequest
 	/// </summary>
 	public bool IncludeArchived { get; init; }
 
+	/// <summary>
+	///   Gets the labels to filter by (AND semantics - issue must have ALL specified labels).
+	/// </summary>
+	public IReadOnlyList<string>? LabelFilter { get; init; }
+
 	/// <summary>
 	///   Gets an empty search request with default values.
 	/// </summary>
@@ -74,5 +79,6 @@ public record IssueSearchRequest
 		!string.IsNullOrWhiteSpace(CategoryFilter) ||
 		!string.IsNullOrWhiteSpace(AuthorId) ||
 		DateFrom.HasValue ||
-		DateTo.HasValue;
+		DateTo.HasValue ||
+		(LabelFilter?.Count > 0);
 }

src/Domain/Features/Issues/Queries/SearchIssuesQuery.cs

@@ -40,13 +40,14 @@ public async Task<Result<PagedResult<IssueDto>>> Handle(
 
 		_logger.LogInformation(
 			"Searching issues - SearchText: {SearchText}, Status: {Status}, Category: {Category}, " +
-			"Author: {Author}, DateFrom: {DateFrom}, DateTo: {DateTo}, Page: {Page}, PageSize: {PageSize}",
+			"Author: {Author}, DateFrom: {DateFrom}, DateTo: {DateTo}, Labels: {Labels}, Page: {Page}, PageSize: {PageSize}",
 			request.SearchText ?? "None",
 			request.StatusFilter ?? "All",
 			request.CategoryFilter ?? "All",
 			request.AuthorId ?? "All",
 			request.DateFrom?.ToString() ?? "None",
 			request.DateTo?.ToString() ?? "None",
+			request.LabelFilter?.Count > 0 ? string.Join(", ", request.LabelFilter) : "None",
 			request.Page,
 			request.PageSize);
 
@@ -116,6 +117,15 @@ public async Task<Result<PagedResult<IssueDto>>> Handle(
 			issues = issues.Where(i => i.DateCreated <= toDate).ToList();
 		}
 
+		// Apply label filter (AND semantics - issue must have ALL specified labels)
+		if (request.LabelFilter?.Count > 0)
+		{
+			issues = issues
+				.Where(i => request.LabelFilter.All(label =>
+					i.Labels.Contains(label, StringComparer.OrdinalIgnoreCase)))
+				.ToList();
+		}
+
 		var totalCount = issues.Count;
 
 		// Apply pagination

src/Web/Components/Pages/Issues/Index.razor

@@ -50,6 +50,28 @@
 							 DateTo="@_dateTo" DateToChanged="OnDateToChanged" Statuses="@_statuses" Categories="@_categories"
 							 TotalResults="@((int?)_totalItems)" OnFiltersApplied="OnFiltersApplied" OnFiltersCleared="OnFiltersCleared" />
 
+	<!-- Active Label Filters -->
+	@if (_labelFilter?.Count > 0)
+	{
+		<div class="flex flex-wrap items-center gap-2">
+			<span class="text-sm text-gray-700 dark:text-gray-300">Active label filters:</span>
+			@foreach (var label in _labelFilter)
+			{
+				<button type="button" @onclick="() => RemoveLabelFilter(label)"
+								class="inline-flex items-center gap-1.5 px-3 py-1 rounded-full text-xs font-medium bg-blue-100 text-blue-800 dark:bg-blue-900 dark:text-blue-200 hover:bg-blue-200 dark:hover:bg-blue-800 transition-colors">
+					@label
+					<svg class="h-3 w-3" fill="currentColor" viewBox="0 0 20 20">
+						<path fill-rule="evenodd" d="M4.293 4.293a1 1 0 011.414 0L10 8.586l4.293-4.293a1 1 0 111.414 1.414L11.414 10l4.293 4.293a1 1 0 01-1.414 1.414L10 11.414l-4.293 4.293a1 1 0 01-1.414-1.414L8.586 10 4.293 5.707a1 1 0 010-1.414z" clip-rule="evenodd" />
+					</svg>
+				</button>
+			}
+			<button type="button" @onclick="ClearAllLabelFilters"
+							class="text-xs text-gray-600 dark:text-gray-400 hover:text-gray-900 dark:hover:text-gray-200 underline">
+				Clear all
+			</button>
+		</div>
+	}
+
 	<!-- Quick sort: Top Voted -->
 	<div class="flex items-center gap-2">
 		<button type="button" @onclick="ToggleTopVoted"
@@ -185,6 +207,19 @@
 											</time>
 										</div>
 									</div>
+									@if (issue.Labels.Count > 0)
+									{
+										<div class="mt-2 flex flex-wrap gap-1.5">
+											@foreach (var label in issue.Labels)
+											{
+												<button type="button" @onclick="() => AddLabelFilter(label)" @onclick:stopPropagation="true"
+																class="inline-flex items-center px-2 py-0.5 rounded text-xs font-medium bg-blue-100 text-blue-800 dark:bg-blue-900 dark:text-blue-200 hover:bg-blue-200 dark:hover:bg-blue-800 transition-colors cursor-pointer"
+																title="Filter by this label">
+													@label
+												</button>
+											}
+										</div>
+									}
 								</div>
 							</a>
 						</div>
@@ -231,6 +266,7 @@
 	private string? _categoryFilter;
 	private DateOnly? _dateFrom;
 	private DateOnly? _dateTo;
+	private List<string>? _labelFilter;
 
 	// Pagination state
 	private int _currentPage = 1;
@@ -266,7 +302,8 @@
 		!string.IsNullOrWhiteSpace(_statusFilter) ||
 		!string.IsNullOrWhiteSpace(_categoryFilter) ||
 		_dateFrom.HasValue ||
-		_dateTo.HasValue;
+		_dateTo.HasValue ||
+		(_labelFilter?.Count > 0);
 
 	private IEnumerable<IssueDto> DisplayedIssues =>
 		_sortByVotes
@@ -356,6 +393,21 @@
 		{
 			_currentPage = Math.Max(1, pageNumber);
 		}
+
+		if (query.TryGetValue("label", out var labels))
+		{
+			_labelFilter = labels.ToString()
+				.Split(',', StringSplitOptions.RemoveEmptyEntries)
+				.Select(l => l.Trim())
+				.Where(l => !string.IsNullOrWhiteSpace(l))
+				.Distinct(StringComparer.OrdinalIgnoreCase)
+				.ToList();
+
+			if (_labelFilter.Count == 0)
+			{
+				_labelFilter = null;
+			}
+		}
 	}
 
 	private void UpdateQueryParameters()
@@ -392,6 +444,11 @@
 			queryParams["page"] = _currentPage.ToString();
 		}
 
+		if (_labelFilter?.Count > 0)
+		{
+			queryParams["label"] = string.Join(",", _labelFilter);
+		}
+
 		var newUrl = QueryHelpers.AddQueryString("/issues", queryParams!);
 		NavigationManager.NavigateTo(newUrl, forceLoad: false, replace: true);
 	}
@@ -431,6 +488,7 @@
 				CategoryFilter = _categoryFilter,
 				DateFrom = _dateFrom,
 				DateTo = _dateTo,
+				LabelFilter = _labelFilter,
 				Page = _currentPage,
 				PageSize = PAGE_SIZE,
 				IncludeArchived = false
@@ -503,6 +561,52 @@
 		_categoryFilter = null;
 		_dateFrom = null;
 		_dateTo = null;
+		_labelFilter = null;
+		_currentPage = 1;
+		UpdateQueryParameters();
+		await LoadIssuesAsync();
+	}
+
+	private async Task AddLabelFilter(string label)
+	{
+		if (string.IsNullOrWhiteSpace(label))
+		{
+			return;
+		}
+
+		_labelFilter ??= [];
+
+		if (!_labelFilter.Contains(label, StringComparer.OrdinalIgnoreCase))
+		{
+			_labelFilter.Add(label);
+			_currentPage = 1;
+			UpdateQueryParameters();
+			await LoadIssuesAsync();
+		}
+	}
+
+	private async Task RemoveLabelFilter(string label)
+	{
+		if (_labelFilter is null || string.IsNullOrWhiteSpace(label))
+		{
+			return;
+		}
+
+		_labelFilter.RemoveAll(l => l.Equals(label, StringComparison.OrdinalIgnoreCase));
+
+		if (_labelFilter.Count == 0)
+		{
+			_labelFilter = null;
+		}
+
+		_currentPage = 1;
+		UpdateQueryParameters();
+		await LoadIssuesAsync();
+	}
+
+	private async Task ClearAllLabelFilters()
+	{
+		_labelFilter = null;
 		_currentPage = 1;
 		UpdateQueryParameters();
 		await LoadIssuesAsync();