feat(api): bulk delete tasks by status + Clear done button

README.md

@@ -50,6 +50,7 @@ optional for local development.
 | GET    | `/api/tasks/{id}`            | Fetch one task                           |
 | PUT    | `/api/tasks/{id}`            | Partial update of title/description/status |
 | DELETE | `/api/tasks/{id}`            | Remove task (204)                        |
+| DELETE | `/api/tasks?status=done`     | Bulk remove by status, returns `{removed}` |
 
 Statuses: `todo`, `in_progress`, `done`. Errors return `{"error": "..."}` with
 400 or 404.

backend/include/taskboard/task_store.hpp

@@ -37,6 +37,9 @@ class TaskStore {
 
     bool remove(std::uint64_t id);
 
+    /// Removes every task with the given status. Returns how many were deleted.
+    std::size_t remove_by_status(Status status);
+
     Stats stats() const;
     std::size_t size() const;
     void clear();

backend/src/api.cpp

@@ -93,6 +93,20 @@ void register_routes(httplib::Server& server, TaskStore& store) {
         }
     });
 
+    // Bulk delete: DELETE /api/tasks?status=done
+    server.Delete("/api/tasks", [&store](const httplib::Request& req, httplib::Response& res) {
+        if (!req.has_param("status")) {
+            send_error(res, 400, "status query parameter is required");
+            return;
+        }
+        const auto status = status_from_string(req.get_param_value("status"));
+        if (!status) {
+            send_error(res, 400, "unknown status filter");
+            return;
+        }
+        send_json(res, 200, json{{"removed", store.remove_by_status(*status)}});
+    });
+
     server.Get(R"(/api/tasks/(\d+))", [&store](const httplib::Request& req, httplib::Response& res) {
         const auto id = parse_id(req.matches[1]);
         if (!id) {

backend/src/task_store.cpp

@@ -68,6 +68,20 @@ bool TaskStore::remove(std::uint64_t id) {
     return tasks_.erase(id) > 0;
 }
 
+std::size_t TaskStore::remove_by_status(Status status) {
+    std::lock_guard lock(mutex_);
+    std::size_t removed = 0;
+    for (auto it = tasks_.begin(); it != tasks_.end();) {
+        if (it->second.status == status) {
+            it = tasks_.erase(it);
+            ++removed;
+        } else {
+            ++it;
+        }
+    }
+    return removed;
+}
+
 Stats TaskStore::stats() const {
     std::lock_guard lock(mutex_);
     Stats s;

backend/tests/api_test.cpp

@@ -140,6 +140,26 @@ TEST_F(ApiTest, DeleteRemovesTask) {
     EXPECT_EQ(again->status, 404);
 }
 
+TEST_F(ApiTest, BulkDeleteByStatus) {
+    post_task({{"title", "a"}, {"status", "done"}});
+    post_task({{"title", "b"}});
+    post_task({{"title", "c"}, {"status", "done"}});
+
+    auto res = client_->Delete("/api/tasks?status=done");
+    ASSERT_TRUE(res);
+    EXPECT_EQ(res->status, 200);
+    EXPECT_EQ(json::parse(res->body)["removed"], 2);
+    EXPECT_EQ(store_.size(), 1u);
+
+    auto missing_param = client_->Delete("/api/tasks");
+    ASSERT_TRUE(missing_param);
+    EXPECT_EQ(missing_param->status, 400);
+
+    auto bad_status = client_->Delete("/api/tasks?status=nope");
+    ASSERT_TRUE(bad_status);
+    EXPECT_EQ(bad_status->status, 400);
+}
+
 TEST_F(ApiTest, ListFilterAndStats) {
     post_task({{"title", "a"}});
     post_task({{"title", "b"}, {"status", "done"}});

backend/tests/task_store_test.cpp

@@ -105,6 +105,18 @@ TEST(TaskStore, RemoveReportsWhetherSomethingWasDeleted) {
     EXPECT_EQ(store.size(), 0u);
 }
 
+TEST(TaskStore, RemoveByStatusDeletesOnlyMatching) {
+    TaskStore store;
+    store.create(input("a", "", Status::Done));
+    store.create(input("b", "", Status::Todo));
+    store.create(input("c", "", Status::Done));
+
+    EXPECT_EQ(store.remove_by_status(Status::Done), 2u);
+    EXPECT_EQ(store.size(), 1u);
+    EXPECT_EQ(store.list().front().title, "b");
+    EXPECT_EQ(store.remove_by_status(Status::Done), 0u);
+}
+
 TEST(TaskStore, StatsCountPerStatus) {
     TaskStore store;
     store.create(input("a", "", Status::Todo));

frontend/app.js

@@ -12,6 +12,7 @@
   const errorBox = document.getElementById("error");
   const healthDot = document.getElementById("health");
   const template = document.getElementById("task-template");
+  const clearDoneButton = document.getElementById("clear-done");
 
   async function api(path, options = {}) {
     const res = await fetch(API_BASE + path, {
@@ -57,6 +58,16 @@
     for (const key of ["total", ...STATUSES]) {
       document.getElementById(`stat-${key}`).textContent = stats[key] ?? 0;
     }
+    clearDoneButton.disabled = (stats.done ?? 0) === 0;
+  }
+
+  async function clearDone() {
+    try {
+      await api("/tasks?status=done", { method: "DELETE" });
+      await refresh();
+    } catch (err) {
+      showError(err.message);
+    }
   }
 
   async function refresh() {
@@ -116,6 +127,8 @@
     }
   });
 
+  clearDoneButton.addEventListener("click", clearDone);
+
   checkHealth();
   refresh();
   setInterval(checkHealth, 15000);

frontend/index.html

@@ -36,7 +36,10 @@ <h2>In progress</h2>
         <ul class="tasks" id="col-in_progress"></ul>
       </div>
       <div class="column" data-status="done">
-        <h2>Done</h2>
+        <div class="column-head">
+          <h2>Done</h2>
+          <button id="clear-done" class="btn-clear" type="button" title="Delete all done tasks">Clear done</button>
+        </div>
         <ul class="tasks" id="col-done"></ul>
       </div>
     </section>

frontend/styles.css

@@ -103,6 +103,10 @@ button:disabled { opacity: 0.5; cursor: default; }
   color: var(--muted);
 }
 
+.column-head { display: flex; align-items: center; justify-content: space-between; }
+.column-head h2 { margin-bottom: 8px; }
+.btn-clear { padding: 2px 8px; font-size: 0.75rem; margin-bottom: 8px; color: var(--danger); }
+
 .tasks { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 8px; }
 
 .task {