feat: student certificate download

Author: ImJustNon

src/modules/student-certificate/student-certificate.controller.ts

@@ -1,5 +1,6 @@
-import { Controller, Get, Res, UseGuards } from "@nestjs/common";
-import { AllowAnonymous } from "@thallesp/nestjs-better-auth";
+import { Controller, Get, Query, Res, UseGuards } from "@nestjs/common";
+import { AllowAnonymous, Session, type UserSession } from "@thallesp/nestjs-better-auth";
+import axios from "axios";
 import { type Response } from "express";
 import { UserParticipatedGuard } from "src/common/guards/user-particicated.guard";
 import { StudentCertificateService } from "./student-certificate.service";
@@ -9,22 +10,35 @@ export class StudentCertificateController {
 	constructor(private readonly studentCertificateService: StudentCertificateService) {}
 
 	@Get("/preview")
-	// @UseGuards(UserParticipatedGuard)
-	@AllowAnonymous()
-	async certificatePreview(@Res() res: Response) {
-		const imageBuffer = await this.studentCertificateService.generateImage("asdasda");
+	@UseGuards(UserParticipatedGuard)
+	async certificatePreview(@Res() res: Response, @Session() session: UserSession) {
+		const fileUrl = await this.studentCertificateService.getCertificatePreview(res, session.user.id);
+
+		const response = await axios.get(fileUrl, {
+			responseType: "stream",
+		});
 
 		res.set({
-			"Content-Type": "image/png",
-			"Content-Disposition": `attachment; filename=${"asdas"}.png`,
+			"Content-Type": response.headers["content-type"],
 		});
 
-		res.send(imageBuffer);
+		response.data.pipe(res);
 	}
 
-	@Get("/download")
+	@Get("/")
 	@UseGuards(UserParticipatedGuard)
-	certificateDownload() {
-		return this.studentCertificateService;
+	async certificateFull(@Res() res: Response, @Session() session: UserSession) {
+		const fileUrl = await this.studentCertificateService.getCertificateFull(res, session.user.id);
+
+		const response = await axios.get(fileUrl, {
+			responseType: "stream",
+		});
+
+		res.set({
+			"Content-Type": "application/pdf",
+			"Content-Disposition": `inline; filename="certificate-${session.user.id}.pdf"`,
+		});
+
+		response.data.pipe(res);
 	}
 }

src/modules/student-certificate/student-certificate.module.ts

@@ -1,9 +1,11 @@
 import { Module } from "@nestjs/common";
+import { S3Module } from "src/core/s3/s3.module";
 import { StudentCertificateController } from "./student-certificate.controller";
 import { StudentCertificateService } from "./student-certificate.service";
 
 @Module({
 	controllers: [StudentCertificateController],
 	providers: [StudentCertificateService],
+	imports: [S3Module],
 })
 export class StudentCertificateModule {}

src/modules/student-certificate/student-certificate.service.ts

@@ -1,43 +1,68 @@
-import path from "node:path";
-import { Injectable } from "@nestjs/common";
-import { createCanvas, loadImage, registerFont } from "canvas";
+import { HttpException, Injectable, InternalServerErrorException, NotFoundException } from "@nestjs/common";
+import { Response } from "express";
+import { LoggerService } from "src/core/logger/logger.service";
 import { PrismaService } from "src/core/prisma/prisma.service";
+import { S3Service } from "src/core/s3/s3.service";
 
 @Injectable()
 export class StudentCertificateService {
-	constructor(private readonly prisma: PrismaService) {}
+	constructor(
+		private readonly prisma: PrismaService,
+		private readonly s3: S3Service,
+		private readonly logger: LoggerService,
+	) {}
 
-	async certificatePreview() {}
+	async getCertificatePreview(res: Response, userId: string): Promise<string> {
+		try {
+			const application = await this.prisma.studentApplication.findMany({
+				where: {
+					std_user_id: userId,
+				},
+			});
 
-	async generateImage(name: string): Promise<Buffer> {
-		// Load background
-		const bgPath = path.join(__dirname, "./certificate_template.png");
-		const background = await loadImage(bgPath);
+			const fileKey = `${application[0].std_application_id}.jpg`;
 
-		// Register custom font
-		const fontPath = path.join(__dirname, "./Arimo-VariableFont_wght.ttf");
-		registerFont(fontPath, { family: "CustomFont" });
+			const fileUrl = await this.s3.signedUrl(fileKey, "certificate");
 
-		// Create canvas
-		const canvas = createCanvas(background.width, background.height);
-		const ctx = canvas.getContext("2d");
+			if (!fileUrl) {
+				throw new NotFoundException("Cannot find this certificate in storage server");
+			}
 
-		// Draw background
-		ctx.drawImage(background, 0, 0);
+			return fileUrl;
+		} catch (e) {
+			this.logger.error(e);
+			if (e instanceof HttpException) {
+				throw e;
+			}
 
-		// Set font
-		ctx.font = '40px "CustomFont"';
-		ctx.fillStyle = "#000000";
+			throw new InternalServerErrorException(e);
+		}
+	}
+
+	async getCertificateFull(res: Response, userId: string) {
+		try {
+			const application = await this.prisma.studentApplication.findMany({
+				where: {
+					std_user_id: userId,
+				},
+			});
+
+			const fileKey = `${application[0].std_application_id}.pdf`;
+
+			const fileUrl = await this.s3.signedUrl(fileKey, "certificate");
 
-		// Center text
-		const textWidth = ctx.measureText(name).width;
-		const x = (canvas.width - textWidth) / 2;
-		const y = canvas.height / 2;
+			if (!fileUrl) {
+				throw new NotFoundException("Cannot find this certificate in storage server");
+			}
 
-		// Draw name
-		ctx.fillText(name, x, y);
+			return fileUrl;
+		} catch (e) {
+			this.logger.error(e);
+			if (e instanceof HttpException) {
+				throw e;
+			}
 
-		// Return image buffer
-		return canvas.toBuffer("image/png");
+			throw new InternalServerErrorException(e);
+		}
 	}
 }