project init

apps/api/src/courses/lessons.service.ts

@@ -0,0 +1,141 @@
+import { Injectable, NotFoundException, ForbiddenException } from '@nestjs/common';
+import { PrismaService } from '../common/prisma/prisma.service';
+import { Lesson } from '@coursecraft/database';
+import { CoursesService } from './courses.service';
+import { ChaptersService } from './chapters.service';
+import { CreateLessonDto } from './dto/create-lesson.dto';
+import { UpdateLessonDto } from './dto/update-lesson.dto';
+
+@Injectable()
+export class LessonsService {
+  constructor(
+    private prisma: PrismaService,
+    private coursesService: CoursesService,
+    private chaptersService: ChaptersService
+  ) {}
+
+  async create(chapterId: string, userId: string, dto: CreateLessonDto): Promise<Lesson> {
+    const chapter = await this.chaptersService.findById(chapterId);
+    if (!chapter) {
+      throw new NotFoundException('Chapter not found');
+    }
+
+    const isOwner = await this.coursesService.checkOwnership(chapter.courseId, userId);
+    if (!isOwner) {
+      throw new ForbiddenException('You can only edit your own courses');
+    }
+
+    // Get max order
+    const maxOrder = await this.prisma.lesson.aggregate({
+      where: { chapterId },
+      _max: { order: true },
+    });
+
+    const order = (maxOrder._max.order ?? -1) + 1;
+
+    return this.prisma.lesson.create({
+      data: {
+        chapterId,
+        title: dto.title,
+        content: dto.content as any,
+        order,
+        durationMinutes: dto.durationMinutes,
+      },
+    });
+  }
+
+  async findById(id: string): Promise<Lesson | null> {
+    return this.prisma.lesson.findUnique({
+      where: { id },
+      include: {
+        chapter: {
+          select: {
+            id: true,
+            title: true,
+            courseId: true,
+          },
+        },
+      },
+    });
+  }
+
+  async update(lessonId: string, userId: string, dto: UpdateLessonDto): Promise<Lesson> {
+    const lesson = await this.prisma.lesson.findUnique({
+      where: { id: lessonId },
+      include: {
+        chapter: {
+          select: { courseId: true },
+        },
+      },
+    });
+
+    if (!lesson) {
+      throw new NotFoundException('Lesson not found');
+    }
+
+    const isOwner = await this.coursesService.checkOwnership(lesson.chapter.courseId, userId);
+    if (!isOwner) {
+      throw new ForbiddenException('You can only edit your own courses');
+    }
+
+    return this.prisma.lesson.update({
+      where: { id: lessonId },
+      data: {
+        title: dto.title,
+        content: dto.content as any,
+        durationMinutes: dto.durationMinutes,
+        videoUrl: dto.videoUrl,
+      },
+    });
+  }
+
+  async delete(lessonId: string, userId: string): Promise<void> {
+    const lesson = await this.prisma.lesson.findUnique({
+      where: { id: lessonId },
+      include: {
+        chapter: {
+          select: { courseId: true },
+        },
+      },
+    });
+
+    if (!lesson) {
+      throw new NotFoundException('Lesson not found');
+    }
+
+    const isOwner = await this.coursesService.checkOwnership(lesson.chapter.courseId, userId);
+    if (!isOwner) {
+      throw new ForbiddenException('You can only edit your own courses');
+    }
+
+    await this.prisma.lesson.delete({
+      where: { id: lessonId },
+    });
+  }
+
+  async reorder(chapterId: string, userId: string, lessonIds: string[]): Promise<Lesson[]> {
+    const chapter = await this.chaptersService.findById(chapterId);
+    if (!chapter) {
+      throw new NotFoundException('Chapter not found');
+    }
+
+    const isOwner = await this.coursesService.checkOwnership(chapter.courseId, userId);
+    if (!isOwner) {
+      throw new ForbiddenException('You can only edit your own courses');
+    }
+
+    await Promise.all(
+      lessonIds.map((id, index) =>
+        this.prisma.lesson.update({
+          where: { id },
+          data: { order: index },
+        })
+      )
+    );
+
+    return this.prisma.lesson.findMany({
+      where: { chapterId },
+      orderBy: { order: 'asc' },
+    });
+  }
+}