add summary

app/main.py

@@ -88,6 +88,35 @@ def _wants_add_next(submit_action: str | None) -> bool:
     return submit_action == "save_and_add_next"
 
 
+def _format_average(total: int, divisor: int) -> str:
+    if divisor == 0:
+        return "0.0"
+    return f"{total / divisor:.1f}"
+
+
+def _build_boxes_overview_summary(db: Session) -> dict[str, int | str]:
+    box_count = db.query(func.count(Box.id)).scalar() or 0
+    item_count = db.query(func.count(Item.id)).scalar() or 0
+    subitem_count = db.query(func.count(SubItem.id)).scalar() or 0
+    container_item_count = (
+        db.query(func.count(Item.id))
+        .filter(Item.is_container.is_(True))
+        .scalar()
+        or 0
+    )
+
+    return {
+        "box_count": box_count,
+        "item_count": item_count,
+        "item_and_subitem_count": item_count + subitem_count,
+        "avg_items_per_box": _format_average(item_count, box_count),
+        "avg_subitems_per_container_item": _format_average(
+            subitem_count,
+            container_item_count,
+        ),
+    }
+
+
 def _build_search_results(db: Session, query: str) -> list[dict]:
     keyword = f"%{query.lower()}%"
     results: list[dict] = []
@@ -231,10 +260,11 @@ def create_app() -> FastAPI:
     @app.get("/boxes")
     def list_boxes(request: Request, db: Session = Depends(get_db)):
         boxes = db.query(Box).order_by(Box.id.desc()).all()
+        summary = _build_boxes_overview_summary(db)
         return templates.TemplateResponse(
             request=request,
             name="boxes/index.html",
-            context={"page_title": "箱子", "boxes": boxes},
+            context={"page_title": "箱子", "boxes": boxes, "summary": summary},
         )
 
     @app.get("/boxes/new")

app/static/style.css

@@ -231,6 +231,25 @@ button:focus-visible {
     gap: 10px;
 }
 
+.summary-section {
+    margin-bottom: 18px;
+}
+
+.summary-block {
+    padding-top: 12px;
+    padding-bottom: 12px;
+}
+
+.summary-list {
+    margin: 0;
+    padding-left: 18px;
+    color: #333;
+}
+
+.summary-list li + li {
+    margin-top: 6px;
+}
+
 .compact-row {
     display: grid;
     grid-template-columns: auto 1fr auto;

app/templates/boxes/index.html

@@ -15,6 +15,22 @@
     <a class="button button-primary" href="/boxes/new">新建箱子</a>
 </div>
 
+<section class="stack summary-section">
+    <div class="section-heading">
+        <h2>当前概览</h2>
+        <p class="muted">快速查看当前装箱记录的核心统计。</p>
+    </div>
+    <section class="card summary-block">
+        <ul class="summary-list">
+            <li><strong>箱子总数：</strong>{{ summary.box_count }}</li>
+            <li><strong>物品总数（不含子物品）：</strong>{{ summary.item_count }}</li>
+            <li><strong>物品总数（含子物品）：</strong>{{ summary.item_and_subitem_count }}</li>
+            <li><strong>平均每箱物品数：</strong>{{ summary.avg_items_per_box }}</li>
+            <li><strong>平均每个容器型 Item 的子物品数：</strong>{{ summary.avg_subitems_per_container_item }}</li>
+        </ul>
+    </section>
+</section>
+
 {% if boxes %}
 <div class="overview-grid">
     {% for box in boxes %}

tests/test_app.py

@@ -178,6 +178,53 @@ def test_boxes_overview_renders_cleanly_when_note_is_empty(client, db_session):
     assert "状态：" not in response.text
 
 
+def test_boxes_overview_summary_shows_expected_counts_and_averages(client, db_session):
+    first_box = Box(name="卧室箱")
+    second_box = Box(name="书房箱")
+    regular_item = Item(name="书", box=first_box, is_container=False)
+    container_item = Item(name="配件袋", box=first_box, is_container=True)
+    second_container_item = Item(name="文件袋", box=second_box, is_container=True)
+    db_session.add_all(
+        [
+            first_box,
+            second_box,
+            regular_item,
+            container_item,
+            second_container_item,
+            SubItem(name="转接头", parent_item=container_item),
+            SubItem(name="数据线", parent_item=container_item),
+        ]
+    )
+    db_session.commit()
+
+    response = client.get("/boxes")
+
+    assert response.status_code == 200
+    assert "当前概览" in response.text
+    assert "箱子总数" in response.text
+    assert "物品总数（不含子物品）" in response.text
+    assert "物品总数（含子物品）" in response.text
+    assert "平均每箱物品数" in response.text
+    assert "平均每个容器型 Item 的子物品数" in response.text
+    assert "箱子总数：</strong>2" in response.text
+    assert "物品总数（不含子物品）：</strong>3" in response.text
+    assert "物品总数（含子物品）：</strong>5" in response.text
+    assert "平均每箱物品数：</strong>1.5" in response.text
+    assert "平均每个容器型 Item 的子物品数：</strong>1.0" in response.text
+
+
+def test_boxes_overview_summary_handles_empty_data_safely(client):
+    response = client.get("/boxes")
+
+    assert response.status_code == 200
+    assert "当前概览" in response.text
+    assert "箱子总数：</strong>0" in response.text
+    assert "物品总数（不含子物品）：</strong>0" in response.text
+    assert "物品总数（含子物品）：</strong>0" in response.text
+    assert "平均每箱物品数：</strong>0.0" in response.text
+    assert "平均每个容器型 Item 的子物品数：</strong>0.0" in response.text
+
+
 def test_can_create_box(client, db_session):
     response = create_box(client, name="Kitchen Box")