feat: lunar calendar support for countdowns

tests/test_countdowns.py

@@ -1,5 +1,11 @@
 from datetime import date
 
+from backend.lunar_support import (
+    lunar_label_with_year,
+    lunar_to_solar_safe,
+    next_lunar_occurrence,
+    solar_to_lunar_text,
+)
 from backend.mvp import countdown_occurrence, countdown_status
 
 
@@ -23,6 +29,17 @@ def create_countdown(client, **overrides):
     return client.post("/api/v1/countdowns", json=payload)
 
 
+def test_lunar_date_math_labels_leap_month_and_finds_next_occurrence():
+    assert lunar_to_solar_safe(2025, -6, 1) == date(2025, 7, 25)
+    assert lunar_to_solar_safe(2026, -6, 1) is None
+    assert solar_to_lunar_text(date(2026, 9, 14)) == "农历八月初四"
+    assert solar_to_lunar_text(date(2025, 7, 25)) == "农历闰六月初一"
+    assert lunar_label_with_year(date(2025, 7, 25)) == "农历二〇二五年闰六月初一"
+    assert next_lunar_occurrence(8, 4, True, "none", date(2026, 9, 1)) == date(2026, 9, 14)
+    assert next_lunar_occurrence(8, 4, True, "none", date(2026, 9, 15)) == date(2027, 9, 4)
+    assert next_lunar_occurrence(-6, 1, True, "yearly", date(2026, 1, 1)) == date(2036, 7, 23)
+
+
 def test_countdown_date_math_uses_date_only_recurrence_semantics():
     assert countdown_status(date(2026, 9, 10), date(2026, 9, 6)) == (4, "还有 4 天")
     assert countdown_status(date(2026, 9, 6), date(2026, 9, 6)) == (0, "就是今天")
@@ -32,6 +49,41 @@ def test_countdown_date_math_uses_date_only_recurrence_semantics():
     assert countdown_occurrence(date(2026, 9, 1), "weekly", date(2026, 9, 8)) == date(2026, 9, 8)
 
 
+def test_lunar_countdown_crud_validation_and_display(client):
+    boot(client)
+    created = create_countdown(
+        client,
+        title="农历生日",
+        event_date="2026-01-01",
+        kind="birthday",
+        calendar_mode="lunar",
+        lunar_month=8,
+        lunar_day=4,
+        ignore_year=True,
+    )
+    assert created.status_code == 201
+    item = created.json()
+    assert item["event_date"] == "2026-09-14"
+    assert item["calendar_mode"] == "lunar"
+    assert item["lunar_month"] == 8
+    assert item["lunar_day"] == 4
+    assert item["ignore_year"] is True
+    assert item["lunar_text"] == "农历八月初四"
+
+    updated = client.patch(
+        f"/api/v1/countdowns/{item['id']}",
+        json={"lunar_month": -6, "lunar_day": 1, "event_date": "2025-01-01"},
+    )
+    assert updated.status_code == 200
+    assert updated.json()["event_date"] == "2025-07-25"
+    assert updated.json()["lunar_text"] == "农历闰六月初一"
+
+    assert create_countdown(client, calendar_mode="lunar", lunar_month=8).status_code == 422
+    assert create_countdown(client, calendar_mode="lunar", lunar_month=0, lunar_day=1).status_code == 422
+    assert create_countdown(client, calendar_mode="lunar", lunar_month=-6, lunar_day=1, event_date="2026-01-01").status_code == 422
+    assert create_countdown(client, calendar_mode="solar", lunar_month=8, lunar_day=4).status_code == 422
+
+
 def test_countdown_crud_single_pin_archive_restore_and_purge(client):
     boot(client)
     first = create_countdown(client).json()
@@ -96,19 +148,38 @@ def test_countdown_validation_and_user_isolation(client):
 
 def test_countdowns_backup_replace_and_merge_round_trip(client):
     boot(client)
-    active = create_countdown(client, title="周年", kind="anniversary", repeat_rule="yearly", pinned=True).json()
+    active = create_countdown(
+        client,
+        title="周年",
+        event_date="2025-01-01",
+        kind="anniversary",
+        repeat_rule="yearly",
+        pinned=True,
+        calendar_mode="lunar",
+        lunar_month=-6,
+        lunar_day=1,
+        ignore_year=True,
+    ).json()
     archived = create_countdown(client, title="旧日", event_date="2020-01-02").json()
     client.delete(f"/api/v1/countdowns/{archived['id']}")
 
     exported = client.get("/api/v1/export").json()
     assert {item["title"] for item in exported["countdowns"]} == {"周年", "旧日"}
-    assert next(item for item in exported["countdowns"] if item["title"] == "周年")["pinned"] is True
+    exported_lunar = next(item for item in exported["countdowns"] if item["title"] == "周年")
+    assert exported_lunar["pinned"] is True
+    assert exported_lunar["calendar_mode"] == "lunar"
+    assert exported_lunar["lunar_month"] == -6
+    assert exported_lunar["lunar_day"] == 1
+    assert exported_lunar["ignore_year"] is True
     assert next(item for item in exported["countdowns"] if item["title"] == "旧日")["archived_at"]
 
     create_countdown(client, title="干扰数据")
     restored = client.post("/api/v1/restore", params={"mode": "replace"}, json=exported)
     assert restored.status_code == 200
-    assert {item["title"] for item in client.get("/api/v1/countdowns").json()} == {"周年"}
+    restored_active = next(item for item in client.get("/api/v1/countdowns").json() if item["title"] == "周年")
+    assert restored_active["calendar_mode"] == "lunar"
+    assert restored_active["lunar_month"] == -6
+    assert restored_active["ignore_year"] is True
     assert {item["title"] for item in client.get("/api/v1/countdowns", params={"archived": True}).json()} == {"旧日"}
 
     merged = client.post("/api/v1/restore", params={"mode": "merge"}, json=exported)