feat: 付费体系重构 P0 - 配额独立化/简历付费下载/PDF生成

backend/src/modules/user/quota.service.ts

@@ -0,0 +1,92 @@
+import { Injectable, HttpException, HttpStatus } from '@nestjs/common'
+import { InjectModel } from '@nestjs/mongoose'
+import { Model } from 'mongoose'
+import { User, UserDocument } from './user.schema'
+
+const FREE_OPTIMIZE_LIMIT = 3
+
+@Injectable()
+export class QuotaService {
+  constructor(
+    @InjectModel(User.name) private userModel: Model<UserDocument>,
+  ) {}
+
+  async checkAndDeductInterview(userId: string) {
+    const user = await this.userModel.findById(userId).exec()
+    if (!user) throw new HttpException('用户不存在', HttpStatus.NOT_FOUND)
+    if (user.plan !== 'free') return
+
+    if ((user.interviewCredits || 0) <= 0) {
+      throw new HttpException('面试次数已用完，请购买面试次数或开通会员', HttpStatus.FORBIDDEN)
+    }
+    user.interviewCredits = (user.interviewCredits || 0) - 1
+    user.interviewCount = (user.interviewCount || 0) + 1
+    await user.save()
+  }
+
+  async checkAndDeductOptimize(userId: string) {
+    const user = await this.userModel.findById(userId).exec()
+    if (!user) throw new HttpException('用户不存在', HttpStatus.NOT_FOUND)
+    if (user.plan !== 'free') return
+
+    // 优先扣付费额度
+    if ((user.resumeOptimizeCredits || 0) > 0) {
+      user.resumeOptimizeCredits = (user.resumeOptimizeCredits || 0) - 1
+      await user.save()
+      return
+    }
+
+    // 免费额度
+    if ((user.freeOptimizeUsed || 0) < FREE_OPTIMIZE_LIMIT) {
+      user.freeOptimizeUsed = (user.freeOptimizeUsed || 0) + 1
+      await user.save()
+      return
+    }
+
+    throw new HttpException('简历优化次数已用完，请购买优化次数或开通会员', HttpStatus.FORBIDDEN)
+  }
+
+  async checkDownload(userId: string, resume: { paidDownload?: boolean }): Promise<boolean> {
+    const user = await this.userModel.findById(userId).exec()
+    if (!user) throw new HttpException('用户不存在', HttpStatus.NOT_FOUND)
+
+    if (resume.paidDownload) return true
+    if ((user.resumeDownloadCredits || 0) > 0) return true
+    return false
+  }
+
+  async deductDownload(userId: string, resume: { paidDownload?: boolean; _id?: any }) {
+    const user = await this.userModel.findById(userId).exec()
+    if (!user) throw new HttpException('用户不存在', HttpStatus.NOT_FOUND)
+
+    if (resume.paidDownload) return
+    if ((user.resumeDownloadCredits || 0) > 0) {
+      user.resumeDownloadCredits = (user.resumeDownloadCredits || 0) - 1
+      await user.save()
+    }
+  }
+
+  async grantCredits(userId: string, type: 'interview' | 'optimize' | 'download', amount: number) {
+    const user = await this.userModel.findById(userId).exec()
+    if (!user) throw new HttpException('用户不存在', HttpStatus.NOT_FOUND)
+
+    if (type === 'interview') user.interviewCredits = (user.interviewCredits || 0) + amount
+    else if (type === 'optimize') user.resumeOptimizeCredits = (user.resumeOptimizeCredits || 0) + amount
+    else if (type === 'download') user.resumeDownloadCredits = (user.resumeDownloadCredits || 0) + amount
+
+    await user.save()
+  }
+
+  async setPlanQuota(userId: string, plan: string, credits: { interview: number; resumeOptimize: number; resumeDownload: number }) {
+    const user = await this.userModel.findById(userId).exec()
+    if (!user) throw new HttpException('用户不存在', HttpStatus.NOT_FOUND)
+
+    user.remaining = 999
+    user.interviewCredits = credits.interview
+    user.resumeOptimizeCredits = credits.resumeOptimize
+    user.resumeDownloadCredits = credits.resumeDownload
+    user.freeOptimizeUsed = FREE_OPTIMIZE_LIMIT  // 会员不再消耗免费次数
+
+    await user.save()
+  }
+}

backend/src/modules/user/user.module.ts

@@ -3,6 +3,7 @@ import { MongooseModule } from '@nestjs/mongoose'
 import { JwtModule } from '@nestjs/jwt'
 import { UserController } from './user.controller'
 import { UserService } from './user.service'
+import { QuotaService } from './quota.service'
 import { User, UserSchema } from './user.schema'
 
 @Module({
@@ -14,7 +15,7 @@ import { User, UserSchema } from './user.schema'
     }),
   ],
   controllers: [UserController],
-  providers: [UserService],
-  exports: [UserService],
+  providers: [UserService, QuotaService],
+  exports: [UserService, QuotaService],
 })
 export class UserModule {}

backend/src/modules/user/user.schema.ts

@@ -35,6 +35,19 @@ export class User {
   @Prop({ default: 0 })
   sprintRemaining: number  // 冲刺版剩余次数（语音分析等）
 
+  // --- 新版独立额度（产品改造 v2） ---
+  @Prop({ default: 1 })
+  interviewCredits: number       // AI 面试可用次数（含首次免费）
+
+  @Prop({ default: 0 })
+  resumeOptimizeCredits: number  // 简历优化可用次数
+
+  @Prop({ default: 0 })
+  resumeDownloadCredits: number  // 简历下载可用次数
+
+  @Prop({ default: 0 })
+  freeOptimizeUsed: number       // 已使用免费优化次数（上限 3）
+
   @Prop({ default: 'user' })
   role: string       // 'user' | 'admin'
 

backend/src/modules/user/user.service.ts

@@ -211,6 +211,10 @@ export class UserService {
       isSystemAdmin: user.isSystemAdmin || false,
       remaining: user.remaining,
       interviewCount: user.interviewCount,
+      interviewCredits: user.interviewCredits ?? 1,
+      resumeOptimizeCredits: user.resumeOptimizeCredits ?? 0,
+      resumeDownloadCredits: user.resumeDownloadCredits ?? 0,
+      freeOptimizeUsed: user.freeOptimizeUsed ?? 0,
     }
   }
 }