R62 A1-A6：2026年中国法定假期日历

server/src/routes/leave.js

@@ -8,7 +8,7 @@ const { ensureCutoverAllowed } = require("../services/cutover");
 const {
   DEFAULT_ATTACHMENT_MIME_TYPES,
   calculateRequestedDays,
-  calculateRequestedDaysByWorkingCalendar,
+  calculateRequestedDaysPreviewByWorkingCalendar,
   createLeaveLedgerEntry,
   formatDateOnly,
   leaveRangesOverlap,
@@ -37,6 +37,13 @@ const createLeaveSchema = z
   })
   .strict();
 
+const workingDaysPreviewQuerySchema = z.object({
+  startDate: DATE_ONLY_SCHEMA,
+  endDate: DATE_ONLY_SCHEMA,
+  startSession: SESSION_SCHEMA,
+  endSession: SESSION_SCHEMA,
+});
+
 const leaveListQuerySchema = z.object({
   status: STATUS_SCHEMA.optional(),
   scope: z.enum(["own", "all"]).optional(),
@@ -189,9 +196,49 @@ function parseCreateBody(body) {
   };
 }
 
-async function resolveRequestedDaysForCreate(fastify, employee, body) {
+function parseWorkingDaysPreviewQuery(query) {
+  const parsed = workingDaysPreviewQuerySchema.safeParse(query ?? {});
+  if (!parsed.success) {
+    throw buildValidationError(parsed.error.flatten());
+  }
+
+  const startDate = new Date(`${parsed.data.startDate}T00:00:00.000Z`);
+  const endDate = new Date(`${parsed.data.endDate}T00:00:00.000Z`);
+
+  if (Number.isNaN(startDate.getTime()) || Number.isNaN(endDate.getTime())) {
+    throw buildValidationError({ date: "invalid" });
+  }
+
+  const requestedDays = calculateRequestedDays({
+    startDate,
+    endDate,
+    startSession: parsed.data.startSession,
+    endSession: parsed.data.endSession,
+  });
+
+  return {
+    startDate,
+    endDate,
+    startSession: parsed.data.startSession,
+    endSession: parsed.data.endSession,
+    requestedDays,
+  };
+}
+
+function buildNaturalWorkingDaysPreview(body) {
+  return {
+    requestedDays: body.requestedDays,
+    naturalRequestedDays: body.requestedDays,
+    holidayDayCount: 0,
+    weekendDayCount: 0,
+    adjustedWorkdayCount: 0,
+    calendarApplied: false,
+  };
+}
+
+async function resolveWorkingDaysPreview(fastify, employee, body) {
   if (!employee?.legal_entity_id) {
-    return body.requestedDays;
+    return buildNaturalWorkingDaysPreview(body);
   }
 
   const featureFlag = await evaluateFeatureFlag({
@@ -203,7 +250,7 @@ async function resolveRequestedDaysForCreate(fastify, employee, body) {
   });
 
   if (!featureFlag.enabled) {
-    return body.requestedDays;
+    return buildNaturalWorkingDaysPreview(body);
   }
 
   const legalEntity = await fastify.prisma.legalEntity.findUnique({
@@ -232,10 +279,10 @@ async function resolveRequestedDaysForCreate(fastify, employee, body) {
 
   const calendar = legalEntity?.default_holiday_calendar;
   if (!calendar || calendar.archived_at) {
-    return body.requestedDays;
+    return buildNaturalWorkingDaysPreview(body);
   }
 
-  return calculateRequestedDaysByWorkingCalendar({
+  return calculateRequestedDaysPreviewByWorkingCalendar({
     startDate: body.startDate,
     endDate: body.endDate,
     startSession: body.startSession,
@@ -244,6 +291,11 @@ async function resolveRequestedDaysForCreate(fastify, employee, body) {
   });
 }
 
+async function resolveRequestedDaysForCreate(fastify, employee, body) {
+  const preview = await resolveWorkingDaysPreview(fastify, employee, body);
+  return preview.requestedDays;
+}
+
 async function collectCreatePayload(request) {
   if (typeof request.isMultipart === "function" && request.isMultipart()) {
     const fields = {};
@@ -519,6 +571,20 @@ async function leaveRoutes(fastify) {
     },
   );
 
+  fastify.get(
+    "/leave-requests/working-days",
+    {
+      schema: { tags: ["Leave"], summary: "Preview Leave Working Days" },
+      preHandler: fastify.authenticate,
+    },
+    async (request, reply) => {
+      const query = parseWorkingDaysPreviewQuery(request.query);
+      const preview = await resolveWorkingDaysPreview(fastify, request.employee, query);
+
+      return sendData(reply, request, preview);
+    },
+  );
+
   fastify.post(
     "/leave-requests",
     {