feat: add long-term rental independent billing in generate logic

apps/server/src/bills/bills.service.ts

@@ -73,18 +73,44 @@ export class BillsService {
       const occupancies = await this.occRepo
         .createQueryBuilder('o')
         .leftJoinAndSelect('o.student', 'student')
+        .leftJoinAndSelect('o.room', 'room')
         .where('o.roomId = :roomId', { roomId })
         .andWhere('o.billingStartDate <= :periodEnd', { periodEnd })
         .andWhere('(o.billingEndDate IS NULL OR o.billingEndDate >= :periodStart)', { periodStart })
         .getMany();
 
-      if (occupancies.length === 0) continue;
+
+      // 分离长租与短租入住记录
+      const shortTermOccs = occupancies.filter((o) => o.rentalType !== 'long');
+      const longTermOccs = occupancies.filter((o) => o.rentalType === 'long');
+
+      // 长租：按月租费独立计费，不参与人天数分摊
+      for (const occ of longTermOccs) {
+        const monthlyRate = Number(occ.room?.monthlyRate || 0);
+        if (!studentBillData.has(occ.studentId)) {
+          studentBillData.set(occ.studentId, { shared: 0, items: [] });
+        }
+        const data = studentBillData.get(occ.studentId)!;
+        data.shared += monthlyRate;
+        data.items.push({
+          roomId,
+          expenseType: 'rent',
+          description: `长租月租费 (${occ.room?.roomNumber || '未知房间'})`,
+          days: 0,
+          totalRoomDays: 0,
+          roomTotalAmount: monthlyRate,
+          studentAmount: monthlyRate,
+        });
+      }
+
+      // 短租：原人天数加权分摊逻辑
+      if (shortTermOccs.length === 0) continue;
 
       // 计算每个学生的计费天数
       const studentDays: { studentId: number; days: number }[] = [];
       let totalDays = 0;
 
-      for (const occ of occupancies) {
+      for (const occ of shortTermOccs) {
         const start = new Date(
           Math.max(new Date(occ.billingStartDate).getTime(), pStart.getTime()),
         );