feat: add attachment support and sync endpoint for cohort questions

migrations/1775229793448-migrations.ts

@@ -0,0 +1,57 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+export class Migrations1775229793448 implements MigrationInterface {
+    name = 'Migrations1775229793448';
+
+    public async up(queryRunner: QueryRunner): Promise<void> {
+        // Migrate questions from string[] to {text, attachments}[]
+        await queryRunner.query(`
+            UPDATE cohort_week
+            SET questions = (
+                SELECT COALESCE(jsonb_agg(jsonb_build_object('text', elem.value #>> '{}', 'attachments', '[]'::jsonb)), '[]'::jsonb)
+                FROM jsonb_array_elements(questions) AS elem(value)
+            )
+            WHERE jsonb_typeof(questions) = 'array'
+              AND jsonb_array_length(questions) > 0
+              AND jsonb_typeof(questions -> 0) = 'string'
+        `);
+
+        // Migrate bonusQuestion from string[] to {text, attachments}[]
+        await queryRunner.query(`
+            UPDATE cohort_week
+            SET "bonusQuestion" = (
+                SELECT COALESCE(jsonb_agg(jsonb_build_object('text', elem.value #>> '{}', 'attachments', '[]'::jsonb)), '[]'::jsonb)
+                FROM jsonb_array_elements("bonusQuestion") AS elem(value)
+            )
+            WHERE jsonb_typeof("bonusQuestion") = 'array'
+              AND jsonb_array_length("bonusQuestion") > 0
+              AND jsonb_typeof("bonusQuestion" -> 0) = 'string'
+        `);
+    }
+
+    public async down(queryRunner: QueryRunner): Promise<void> {
+        // Revert questions from {text, attachments}[] back to string[]
+        await queryRunner.query(`
+            UPDATE cohort_week
+            SET questions = (
+                SELECT COALESCE(jsonb_agg(elem.value -> 'text'), '[]'::jsonb)
+                FROM jsonb_array_elements(questions) AS elem(value)
+            )
+            WHERE jsonb_typeof(questions) = 'array'
+              AND jsonb_array_length(questions) > 0
+              AND jsonb_typeof(questions -> 0) = 'object'
+        `);
+
+        // Revert bonusQuestion from {text, attachments}[] back to string[]
+        await queryRunner.query(`
+            UPDATE cohort_week
+            SET "bonusQuestion" = (
+                SELECT COALESCE(jsonb_agg(elem.value -> 'text'), '[]'::jsonb)
+                FROM jsonb_array_elements("bonusQuestion") AS elem(value)
+            )
+            WHERE jsonb_typeof("bonusQuestion") = 'array'
+              AND jsonb_array_length("bonusQuestion") > 0
+              AND jsonb_typeof("bonusQuestion" -> 0) = 'object'
+        `);
+    }
+}

package.json

@@ -53,6 +53,7 @@
     "eta": "^3.5.0",
     "ical-generator": "^10.1.0",
     "js-yaml": "^4.1.0",
+    "mime-types": "^3.0.2",
     "nest-winston": "^1.10.2",
     "nodemailer": "^7.0.10",
     "pdf-lib": "^1.17.1",
@@ -70,6 +71,7 @@
     "@types/express": "^4.17.13",
     "@types/jest": "29.5.0",
     "@types/js-yaml": "^4.0.9",
+    "@types/mime-types": "^3.0.1",
     "@types/node": "18.15.11",
     "@types/secp256k1": "^4.0.6",
     "@types/supertest": "^2.0.11",

src/cohorts/cohorts.config.model.ts

@@ -5,6 +5,7 @@ import {
     IsBoolean,
     IsInt,
     IsNumberString,
+    IsOptional,
     IsString,
     Max,
     Min,
@@ -13,17 +14,29 @@ import {
 } from 'class-validator';
 import { Type } from 'class-transformer';
 
+export class QuestionConfig {
+    @IsString()
+    text!: string;
+
+    @IsOptional()
+    @IsArray()
+    @IsString({ each: true })
+    attachments?: string[];
+}
+
 export class CohortWeekConfig {
     @IsBoolean()
     hasExercise!: boolean;
 
     @IsArray()
-    @IsString({ each: true })
-    questions!: string[];
+    @ValidateNested({ each: true })
+    @Type(() => QuestionConfig)
+    questions!: QuestionConfig[];
 
     @IsArray()
-    @IsString({ each: true })
-    bonusQuestions!: string[];
+    @ValidateNested({ each: true })
+    @Type(() => QuestionConfig)
+    bonusQuestions!: QuestionConfig[];
 }
 
 export class CohortConfig {

src/cohorts/cohorts.config.service.ts

@@ -1,10 +1,11 @@
 import { Injectable, Logger, OnModuleInit } from '@nestjs/common';
 import { CohortType } from '@/common/enum';
 import { join } from 'path';
-import { readFileSync } from 'fs';
+import { existsSync, readFileSync } from 'fs';
 import { validateSync } from 'class-validator';
 import { plainToInstance } from 'class-transformer';
-import { CohortConfig } from '@/cohorts/cohorts.config.model';
+import { CohortConfig, QuestionConfig } from '@/cohorts/cohorts.config.model';
+import { ServiceError } from '@/common/errors';
 
 @Injectable()
 export class CohortsConfigService implements OnModuleInit {
@@ -46,6 +47,27 @@ export class CohortsConfigService implements OnModuleInit {
                 );
             }
 
+            // Validate that all referenced attachment files exist
+            const attachDir = join(
+                configDir,
+                'attachments',
+                type.toLowerCase().replace(/_/g, '-'),
+            );
+            const allQuestions: QuestionConfig[] = config.weeks.flatMap((w) => [
+                ...w.questions,
+                ...w.bonusQuestions,
+            ]);
+            for (const question of allQuestions) {
+                for (const attachment of question.attachments ?? []) {
+                    const attachPath = join(attachDir, attachment);
+                    if (!existsSync(attachPath)) {
+                        throw new ServiceError(
+                            `Missing attachment file for ${type}: ${attachPath}`,
+                        );
+                    }
+                }
+            }
+
             this.configs.set(type, config);
             this.logger.log(`Loaded config for ${type} (${fileName})`);
         }
@@ -54,7 +76,7 @@ export class CohortsConfigService implements OnModuleInit {
     getConfig(type: CohortType): CohortConfig {
         const config = this.configs.get(type);
         if (!config) {
-            throw new Error(`No config found for cohort type: ${type}`);
+            throw new ServiceError(`No config found for cohort type: ${type}`);
         }
         return config;
     }

src/cohorts/cohorts.controller.ts

@@ -7,6 +7,8 @@ import {
     Patch,
     Post,
     Query,
+    Res,
+    StreamableFile,
     UsePipes,
     ValidationPipe,
 } from '@nestjs/common';
@@ -16,6 +18,7 @@ import {
     ApiQuery,
     ApiTags,
 } from '@nestjs/swagger';
+import type { Response } from 'express';
 import {
     CreateCohortRequestDto,
     JoinWaitlistRequestDto,
@@ -94,6 +97,16 @@ export class CohortsController {
         return this.cohortsService.listMyCohorts(user, query);
     }
 
+    @Get('attachments/:id/:filename')
+    @ApiOperation({ summary: 'Stream a cohort question attachment' })
+    async getAttachment(
+        @Param('id', new ParseUUIDPipe()) id: string,
+        @Param('filename') filename: string,
+        @Res({ passthrough: true }) res: Response,
+    ): Promise<StreamableFile> {
+        return this.cohortsService.getAttachment(id, filename, res);
+    }
+
     @Get(':id')
     @ApiOperation({ summary: 'Get a cohort by ID' })
     async getCohort(
@@ -109,6 +122,17 @@ export class CohortsController {
         await this.cohortsService.createCohort(body);
     }
 
+    @Post(':cohortId/sync-questions')
+    @ApiOperation({
+        summary: 'Sync cohort week questions from config file',
+    })
+    @Roles(UserRole.TEACHING_ASSISTANT, UserRole.ADMIN)
+    async syncQuestionsFromConfig(
+        @Param('cohortId', new ParseUUIDPipe()) cohortId: string,
+    ): Promise<void> {
+        await this.cohortsService.syncQuestionsFromConfig(cohortId);
+    }
+
     @Patch(':cohortId')
     @ApiOperation({ summary: 'Update a cohort' })
     @Roles(UserRole.TEACHING_ASSISTANT, UserRole.ADMIN)