feat(subjects): get all subjects that are available for selection

src/module/subject/subject.controller.ts

@@ -37,3 +37,20 @@ export const getPopularSubjects: Controller = async (_req, res) => {
     });
   }
 };
+
+export const getAvailableSubjects: Controller = async (req, res) => {
+  try {
+    const subjects = await subjectService.getAvailableSubjects(req.tutor.id);
+
+    res.json({
+      status: "success",
+      data: subjects,
+    });
+  } catch (error) {
+    logger.error(`Error when getting available subjects: ${error}`);
+    res.status(400).json({
+      status: "fail",
+      message: "Failed to get available subjects",
+    });
+  }
+};

src/module/subject/subject.repository.ts

@@ -1,6 +1,6 @@
 import type { db as dbType } from "@/db/config";
-import { desc, eq, inArray, sql } from "drizzle-orm";
 import { subjects, tutories } from "@/db/schema";
+import { and, desc, eq, inArray, notExists, sql } from "drizzle-orm";
 
 export class SubjectRepository {
   constructor(private readonly db: typeof dbType) {}
@@ -35,6 +35,31 @@ export class SubjectRepository {
     }));
   }
 
+  public async getAvailableSubjects(tutorId: string) {
+    const results = await this.db
+      .select()
+      .from(subjects)
+      .where(
+        notExists(
+          this.db
+            .select()
+            .from(tutories)
+            .where(
+              and(
+                eq(tutories.subjectId, subjects.id),
+                eq(tutories.tutorId, tutorId),
+              ),
+            ),
+        ),
+      );
+
+    return results.map((subject) => ({
+      id: subject.id,
+      name: subject.name,
+      iconUrl: subject.iconUrl,
+    }));
+  }
+
   public async createSubject(name: string, iconUrl: string) {
     const [subjectId] = await this.db
       .insert(subjects)

src/module/subject/subject.route.ts

@@ -1,5 +1,6 @@
 import * as subjectController from "@/module/subject/subject.controller";
 import { Router } from "express";
+import { jwtAuthMiddleware, verifyTutor } from "../auth/auth.middleware";
 
 // /api/v1/subjects
 const subjectRouter = Router();
@@ -17,4 +18,13 @@ subjectRouter.get(
   subjectController.getPopularSubjects,
 );
 
+subjectRouter.get(
+  "/available",
+  // #swagger.tags = ['subjects']
+  // #swagger.description = 'Get subjects that are available for selection, excluding subjects that are already selected by the tutor'
+  jwtAuthMiddleware,
+  verifyTutor,
+  subjectController.getAvailableSubjects,
+);
+
 export default subjectRouter;

src/module/subject/subject.service.ts

@@ -27,6 +27,14 @@ export class SubjectService {
     }
   }
 
+  public async getAvailableSubjects(tutorId: string) {
+    try {
+      return await this.subjectRepository.getAvailableSubjects(tutorId);
+    } catch (error) {
+      throw new Error(`Error when getting available subjects: ${error}`);
+    }
+  }
+
   public async checkSubjectExists(subjectId: string) {
     return this.subjectRepository.checkSubjectExists(subjectId);
   }