feat: lunar calendar support for countdowns

backend/mvp.py

@@ -16,6 +16,13 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from .auth import current_user
 from .config import get_settings
 from .db import get_db
+from .lunar_support import (
+    lunar_label_with_year,
+    lunar_to_solar_safe,
+    next_lunar_occurrence,
+    solar_to_lunar_parts,
+    solar_to_lunar_text,
+)
 from .models import (
     Attachment,
     AuditLog,
@@ -290,15 +297,41 @@ def countdown_status(display_date: date, today: date) -> tuple[int, str]:
 class CountdownInput(BaseModel):
     title: str = Field(min_length=1, max_length=200)
     event_date: date
+    calendar_mode: str = Field("solar", pattern="^(solar|lunar)$")
+    lunar_month: int | None = None
+    lunar_day: int | None = None
+    ignore_year: bool = False
     kind: str = Field("countdown", pattern="^(countdown|anniversary|birthday)$")
     repeat_rule: str = Field("none", pattern="^(none|weekly|monthly|yearly)$")
     icon: str = Field("📅", min_length=1, max_length=32)
     pinned: bool = False
 
+    @model_validator(mode="after")
+    def calendar_fields_valid(self):
+        if self.calendar_mode == "solar":
+            if self.lunar_month is not None or self.lunar_day is not None:
+                raise ValueError("solar countdown cannot include lunar fields")
+            return self
+        if self.lunar_month is None or self.lunar_day is None:
+            raise ValueError("lunar_month and lunar_day are required")
+        if self.lunar_month == 0 or not -12 <= self.lunar_month <= 12:
+            raise ValueError("lunar_month must be 1..12 or -1..-12 for leap months")
+        if not 1 <= self.lunar_day <= 30:
+            raise ValueError("lunar_day must be 1..30")
+        converted = lunar_to_solar_safe(self.event_date.year, self.lunar_month, self.lunar_day)
+        if converted is None:
+            raise ValueError("lunar date does not exist in the selected year")
+        self.event_date = converted
+        return self
+
 
 class CountdownUpdate(BaseModel):
     title: str | None = Field(None, min_length=1, max_length=200)
     event_date: date | None = None
+    calendar_mode: str | None = Field(None, pattern="^(solar|lunar)$")
+    lunar_month: int | None = None
+    lunar_day: int | None = None
+    ignore_year: bool | None = None
     kind: str | None = Field(None, pattern="^(countdown|anniversary|birthday)$")
     repeat_rule: str | None = Field(None, pattern="^(none|weekly|monthly|yearly)$")
     icon: str | None = Field(None, min_length=1, max_length=32)
@@ -308,18 +341,43 @@ class CountdownUpdate(BaseModel):
         for field in self.model_fields_set:
             if getattr(self, field) is None:
                 raise ValueError(f"{field} cannot be null")
+        if self.lunar_month is not None and (self.lunar_month == 0 or not -12 <= self.lunar_month <= 12):
+            raise ValueError("lunar_month must be 1..12 or -1..-12 for leap months")
+        if self.lunar_day is not None and not 1 <= self.lunar_day <= 30:
+            raise ValueError("lunar_day must be 1..30")
         return self
 
 
 def countdown_dict(row: Countdown, today: date | None = None):
     today = today or datetime.now(ZoneInfo("Asia/Shanghai")).date()
-    display_date = countdown_occurrence(row.event_date, row.repeat_rule, today)
+    if row.calendar_mode == "lunar" and (row.ignore_year or row.repeat_rule != "none"):
+        display_date = next_lunar_occurrence(
+            row.lunar_month, row.lunar_day, row.ignore_year, row.repeat_rule, today
+        ) or row.event_date
+    else:
+        repeat_rule = "yearly" if row.ignore_year else row.repeat_rule
+        display_date = countdown_occurrence(row.event_date, repeat_rule, today)
     days, day_text = countdown_status(display_date, today)
+    lunar_year = None
+    lunar_text = None
+    if row.calendar_mode == "lunar":
+        lunar_year, _, _ = solar_to_lunar_parts(row.event_date)
+        lunar_text = (
+            solar_to_lunar_text(display_date)
+            if row.ignore_year or row.repeat_rule != "none"
+            else lunar_label_with_year(row.event_date)
+        )
     return {
         "id": row.id,
         "title": row.title,
         "event_date": row.event_date,
         "display_date": display_date,
+        "calendar_mode": row.calendar_mode,
+        "lunar_year": lunar_year,
+        "lunar_month": row.lunar_month,
+        "lunar_day": row.lunar_day,
+        "ignore_year": row.ignore_year,
+        "lunar_text": lunar_text,
         "kind": row.kind,
         "repeat_rule": row.repeat_rule,
         "icon": row.icon,
@@ -367,7 +425,30 @@ async def list_countdowns(archived: bool = False, user: User = Depends(current_u
 @router.patch("/countdowns/{countdown_id}")
 async def edit_countdown(countdown_id: UUID, payload: CountdownUpdate, user: User = Depends(current_user), db: AsyncSession = Depends(get_db)):
     row = await owned_countdown(db, user.id, countdown_id)
-    for key, value in payload.model_dump(exclude_unset=True).items():
+    values = payload.model_dump(exclude_unset=True)
+    combined = {
+        "event_date": values.get("event_date", row.event_date),
+        "calendar_mode": values.get("calendar_mode", row.calendar_mode),
+        "lunar_month": values.get("lunar_month", row.lunar_month),
+        "lunar_day": values.get("lunar_day", row.lunar_day),
+        "ignore_year": values.get("ignore_year", row.ignore_year),
+    }
+    if combined["calendar_mode"] == "solar":
+        if combined["lunar_month"] is not None or combined["lunar_day"] is not None:
+            if "calendar_mode" not in values:
+                raise HTTPException(422, "公历倒数日不能设置农历日期")
+            combined["lunar_month"] = combined["lunar_day"] = None
+    else:
+        if combined["lunar_month"] is None or combined["lunar_day"] is None:
+            raise HTTPException(422, "农历倒数日需要月份和日期")
+        converted = lunar_to_solar_safe(
+            combined["event_date"].year, combined["lunar_month"], combined["lunar_day"]
+        )
+        if converted is None:
+            raise HTTPException(422, "所选年份不存在该农历日期")
+        combined["event_date"] = converted
+    values.update(combined)
+    for key, value in values.items():
         setattr(row, key, value)
     row.updated_at = utcnow()
     audit(db, user.id, "update", "countdown", row.id)
@@ -672,7 +753,7 @@ async def export_json(user: User = Depends(current_user), db: AsyncSession = Dep
         "lists": [serialize(x, ["id", "folder_id", "name", "is_inbox", "position", "deleted_at"]) for x in lists],
         "tasks": [serialize(x, ["id", "list_id", "parent_id", "title", "description", "priority", "completed", "due_at", "external_id", "deleted_at"]) for x in tasks],
         "habits": [serialize(x, ["id", "name", "kind", "target", "max_value", "schedule_type", "weekdays", "month_days", "interval_days", "start_date", "archived_at"]) for x in habits],
-        "countdowns": [serialize(x, ["id", "title", "event_date", "kind", "repeat_rule", "icon", "pinned", "archived_at", "created_at", "updated_at"]) for x in countdowns],
+        "countdowns": [serialize(x, ["id", "title", "event_date", "calendar_mode", "lunar_month", "lunar_day", "ignore_year", "kind", "repeat_rule", "icon", "pinned", "archived_at", "created_at", "updated_at"]) for x in countdowns],
     }
 
 
@@ -766,11 +847,18 @@ async def restore_json(payload: dict, mode: str = Query("merge", pattern="^(merg
             item = CountdownInput(
                 title=raw["title"],
                 event_date=date.fromisoformat(raw["event_date"]),
+                calendar_mode=raw.get("calendar_mode", "solar"),
+                lunar_month=raw.get("lunar_month"),
+                lunar_day=raw.get("lunar_day"),
+                ignore_year=bool(raw.get("ignore_year", False)),
                 kind=raw.get("kind", "countdown"),
                 repeat_rule=raw.get("repeat_rule", "none"),
                 icon=raw.get("icon", "📅"),
                 pinned=bool(raw.get("pinned", False)) and not has_pinned_countdown,
             )
+            # Backups store the canonical solar anchor; validation above converts
+            # lunar input again, so preserve the exact exported anchor on restore.
+            item.event_date = date.fromisoformat(raw["event_date"])
         except (KeyError, TypeError, ValueError) as exc:
             raise HTTPException(422, "无效的倒数日备份数据") from exc
         row = Countdown(