Files
Reactive-Resume/apps/server/src/printer/printer.service.ts
2023-11-05 12:31:42 +01:00

309 lines
11 KiB
TypeScript

import { HttpService } from "@nestjs/axios";
import { InternalServerErrorException, Logger } from "@nestjs/common";
import { Injectable } from "@nestjs/common";
import { ConfigService } from "@nestjs/config";
import fontkit from "@pdf-lib/fontkit";
import { ResumeDto } from "@reactive-resume/dto";
import { getFontUrls, pageSizeMap, withTimeout } from "@reactive-resume/utils";
import retry from "async-retry";
import { readFile } from "fs/promises";
import { join } from "path";
import { PDFDocument } from "pdf-lib";
import { connect } from "puppeteer";
import { Config } from "../config/schema";
import { ErrorMessage } from "../constants/error-message";
import { StorageService } from "../storage/storage.service";
import { UtilsService } from "../utils/utils.service";
const MM_TO_PX = 3.78;
const PREVIEW_TIMEOUT = 5000; // 5 seconds
const PRINTER_TIMEOUT = 15000; // 15 seconds
@Injectable()
export class PrinterService {
private readonly logger = new Logger(PrinterService.name);
private browserEndpoint: string;
constructor(
private readonly configService: ConfigService<Config>,
private readonly storageService: StorageService,
private readonly httpService: HttpService,
private readonly utils: UtilsService,
) {
const chromeUrl = this.configService.getOrThrow<string>("CHROME_URL");
const chromeToken = this.configService.getOrThrow<string>("CHROME_TOKEN");
this.browserEndpoint = `${chromeUrl}?token=${chromeToken}`;
}
private getBrowser() {
try {
return connect({ browserWSEndpoint: this.browserEndpoint });
} catch (error) {
throw new InternalServerErrorException(ErrorMessage.InvalidBrowserConnection, error.message);
}
}
async getVersion() {
const browser = await this.getBrowser();
const version = await browser.version();
browser.disconnect();
return version;
}
async printResume(resume: ResumeDto) {
return this.utils.getCachedOrSet(
`user:${resume.userId}:storage:resumes:${resume.id}`,
async () => {
const start = performance.now();
const url = await retry(() => withTimeout(this.generateResume(resume), PRINTER_TIMEOUT), {
retries: 3,
randomize: true,
onRetry: (_, attempt) => {
this.logger.debug(`Retrying resume print job: Attempt #${attempt}`);
},
});
const duration = Number(performance.now() - start).toFixed(0);
const numPages = resume.data.metadata.layout.length;
this.logger.debug(`Chrome took ${duration}ms to print ${numPages} page(s)`);
return url;
},
);
}
async printPreview(resume: ResumeDto) {
return this.utils.getCachedOrSet(
`user:${resume.userId}:storage:previews:${resume.id}`,
async () => {
return withTimeout(this.generatePreview(resume), PREVIEW_TIMEOUT);
},
);
}
async generateResume(resume: ResumeDto) {
const browser = await this.getBrowser();
try {
const page = await browser.newPage();
let url = this.utils.getUrl();
const publicUrl = this.configService.getOrThrow<string>("PUBLIC_URL");
const storageUrl = this.configService.getOrThrow<string>("STORAGE_URL");
if ([publicUrl, storageUrl].some((url) => url.includes("localhost"))) {
// Switch client URL from `localhost` to `host.docker.internal` in development
// This is required because the browser is running in a container and the client is running on the host machine.
url = url.replace("localhost", "host.docker.internal");
await page.setRequestInterception(true);
// Intercept requests of `localhost` to `host.docker.internal` in development
page.on("request", (request) => {
if (request.url().startsWith(storageUrl)) {
const modifiedUrl = request.url().replace("localhost", `host.docker.internal`);
request.continue({ url: modifiedUrl });
} else {
request.continue();
}
});
}
// Set the data of the resume to be printed in the browser's session storage
const format = resume.data.metadata.page.format;
const numPages = resume.data.metadata.layout.length;
await page.evaluateOnNewDocument((data: string) => {
sessionStorage.setItem("resume", data);
}, JSON.stringify(resume.data));
await page.goto(`${url}/printer`, { waitUntil: "networkidle0" });
await page.emulateMediaType("print");
const pagesBuffer: Buffer[] = [];
// Hide all the pages (elements with [data-page] attribute) using CSS
const hidePages = () => {
return page.$eval("iframe", (frame) => {
frame.contentDocument?.documentElement.querySelectorAll("[data-page]").forEach((page) => {
page.setAttribute("style", "display: none");
});
});
};
const processPage = (index: number) => {
// Calculate the height of the page based on the format, convert mm to pixels
const pageSize = {
width: pageSizeMap[format].width * MM_TO_PX,
height: pageSizeMap[format].height * MM_TO_PX,
};
return page.$eval(
"iframe",
(frame, index, pageSize) => {
const page = frame.contentDocument?.querySelector(`[data-page="${index}"]`);
page?.setAttribute("style", "display: block");
return {
width: Math.max(pageSize.width, page?.scrollWidth ?? 0),
height: Math.max(pageSize.height, page?.scrollHeight ?? 0),
};
},
index,
pageSize,
);
};
// Loop through all the pages and print them, by first displaying them, printing the PDF and then hiding them back
for (let index = 1; index <= numPages; index++) {
await hidePages();
const { width, height } = await processPage(index);
const buffer = await page.pdf({ width, height });
pagesBuffer.push(buffer);
await hidePages();
}
// Using 'pdf-lib', merge all the pages from their buffers into a single PDF
const pdf = await PDFDocument.create();
pdf.registerFontkit(fontkit);
// Get information about fonts used in the resume from the metadata
const fontData = resume.data.metadata.typography.font;
// Handle Special Case for CMU Serif as it is not available on Google Fonts
if (fontData.family === "CMU Serif") {
const fontsBuffer = await Promise.all([
readFile(join(__dirname, "assets/fonts/computer-modern/regular.ttf")),
readFile(join(__dirname, "assets/fonts/computer-modern/italic.ttf")),
readFile(join(__dirname, "assets/fonts/computer-modern/bold.ttf")),
]);
await Promise.all(
fontsBuffer.map((buffer) => {
// Convert Buffer to ArrayBuffer
const arrayBuffer = buffer.buffer.slice(
buffer.byteOffset,
buffer.byteOffset + buffer.byteLength,
);
return pdf.embedFont(arrayBuffer);
}),
);
} else {
const fontUrls = getFontUrls(fontData.family, fontData.variants);
// Load all the fonts from the URLs using HttpService
const responses = await Promise.all(
fontUrls.map((url) =>
this.httpService.axiosRef.get(url, {
responseType: "arraybuffer",
}),
),
);
const fontsBuffer = responses.map((response) => response.data as ArrayBuffer);
// Embed all the fonts in the PDF
await Promise.all(fontsBuffer.map((buffer) => pdf.embedFont(buffer)));
}
for (let index = 0; index < pagesBuffer.length; index++) {
const page = await PDFDocument.load(pagesBuffer[index]);
const copiedPage = await pdf.copyPages(page, [0]);
pdf.addPage(copiedPage[0]);
}
// Save the PDF to storage and return the URL to download the resume
// Store the URL in cache for future requests, under the previously generated hash digest
const buffer = Buffer.from(await pdf.save());
// This step will also save the resume URL in cache
const resumeUrl = await this.storageService.uploadObject(
resume.userId,
"resumes",
buffer,
resume.id,
);
// Close all the pages and disconnect from the browser
await page.close();
browser.disconnect();
return resumeUrl;
} catch (error) {
throw new InternalServerErrorException(ErrorMessage.ResumePrinterError, error);
}
}
async generatePreview(resume: ResumeDto) {
const browser = await this.getBrowser();
try {
const page = await browser.newPage();
let url = this.utils.getUrl();
const publicUrl = this.configService.getOrThrow<string>("PUBLIC_URL");
const storageUrl = this.configService.getOrThrow<string>("STORAGE_URL");
if ([publicUrl, storageUrl].some((url) => url.includes("localhost"))) {
// Switch client URL from `localhost` to `host.docker.internal` in development
// This is required because the browser is running in a container and the client is running on the host machine.
url = url.replace("localhost", "host.docker.internal");
await page.setRequestInterception(true);
// Intercept requests of `localhost` to `host.docker.internal` in development
page.on("request", (request) => {
if (request.url().startsWith(storageUrl)) {
const modifiedUrl = request.url().replace("localhost", `host.docker.internal`);
request.continue({ url: modifiedUrl });
} else {
request.continue();
}
});
}
// Set the data of the resume to be printed in the browser's session storage
const format = resume.data.metadata.page.format;
await page.evaluateOnNewDocument((data: string) => {
sessionStorage.setItem("resume", data);
}, JSON.stringify(resume.data));
await page.setViewport({
width: Math.round(pageSizeMap[format].width * MM_TO_PX),
height: Math.round(pageSizeMap[format].height * MM_TO_PX),
});
await page.goto(`${url}/printer`, { waitUntil: "networkidle0" });
// Save the JPEG to storage and return the URL
// Store the URL in cache for future requests, under the previously generated hash digest
const buffer = await page.screenshot({ quality: 80, type: "jpeg" });
// Generate a hash digest of the resume data, this hash will be used to check if the resume has been updated
const previewUrl = await this.storageService.uploadObject(
resume.userId,
"previews",
buffer,
resume.id,
);
// Close all the pages and disconnect from the browser
await page.close();
browser.disconnect();
return previewUrl;
} catch (error) {
throw new InternalServerErrorException(ErrorMessage.ResumePreviewError, error);
}
}
}