ff-admin-server/src/helpers/pdfExport.ts

import puppeteer, { Browser } from "puppeteer";
import { TemplateHelper } from "./templateHelper";
import { PermissionModule } from "../type/permissionTypes";
import { FileSystemHelper } from "./fileSystemHelper";
import { PDFDocument } from "pdf-lib";
import { StringHelper } from "./stringHelper";

export abstract class PdfExport {
  private static browserInstance: undefined | Browser = undefined;
  private static timeout: undefined | NodeJS.Timeout = undefined;
  private static printing = new Map<string, string>();

  private static async renderTemplate(
    template: `${PermissionModule}` | `${PermissionModule}.${string}`,
    title: string,
    data: any,
    customTemplate?: {
      headerId?: number;
      footerId?: number;
      bodyId?: string | number;
      headerHeight: number;
      footerHeight: number;
    }
  ): Promise<{ header: string; footer: string; body: string; headerMargin?: number; footerMargin?: number }> {
    if (!customTemplate) {
      return await TemplateHelper.renderFileForModule({
        module: template,
        headerData: data,
        bodyData: data,
        footerData: data,
        title: title,
      });
    } else {
      return await TemplateHelper.renderFileForCustom({
        module: template,
        customTemplate,
        headerData: data,
        bodyData: data,
        footerData: data,
        title: title,
      });
    }
  }

  static async renderFile({
    template,
    title = "pdf-export FF Admin",
    filename = null,
    data = {},
    saveToDisk = true,
    folder = "",
    customTemplate = undefined,
  }: {
    template: `${PermissionModule}` | `${PermissionModule}.${string}`;
    title?: string;
    filename?: string;
    data?: any;
    saveToDisk?: boolean;
    folder?: string;
    customTemplate?: {
      headerId?: number;
      footerId?: number;
      bodyId?: string | number;
      headerHeight: number;
      footerHeight: number;
    };
  }) {
    try {
      clearTimeout(this.timeout);
    } catch (err) {}
    let id = StringHelper.random(32);
    this.printing.set(id, "printing");

    if (folder != "") FileSystemHelper.createFolder(folder);

    const renderedTemplate = await this.renderTemplate(template, title, data, customTemplate);
    let { header, footer, body, headerMargin, footerMargin } = renderedTemplate;

    if (!this.browserInstance || !this.browserInstance.connected) {
      this.browserInstance = await puppeteer.launch({
        headless: true,
        args: ["--no-sandbox", "--disable-gpu", "--disable-setuid-sandbox"],
      });
    }

    const page = await this.browserInstance.newPage();
    await page.setContent(body, { waitUntil: "domcontentloaded" });

    const exportPath = FileSystemHelper.formatPath(folder, `${filename}.pdf`);

    let pdf = await page.pdf({
      ...(saveToDisk ? { path: exportPath } : {}),
      format: "A4",
      printBackground: false,
      margin: {
        top: (headerMargin ?? 15) + "mm",
        bottom: (footerMargin ?? 15) + "mm",
        left: "10mm",
        right: "10mm",
      },
      displayHeaderFooter: true,
      headerTemplate: header,
      footerTemplate: footer,
    });

    await page.close();

    this.printing.delete(id);

    if (this.printing.size == 0) {
      this.timeout = setTimeout(() => {
        this.browserInstance.close();
        this.browserInstance = undefined;
      }, 5000);
    }

    return pdf;
  }

  static async sqashToSingleFile(inputFolder: string, outputFile: string, outputFolder: string = "") {
    if (outputFolder != "") FileSystemHelper.createFolder(outputFolder);

    let pdfFilePaths = FileSystemHelper.getFilesInDirectory(inputFolder, ".pdf");

    if (pdfFilePaths.length == 0) return;

    const mergedPdf = await PDFDocument.create();

    for (const pdfPath of pdfFilePaths) {
      const pdfBytes = FileSystemHelper.readFileasBase64(inputFolder, pdfPath);
      const pdf = await PDFDocument.load(pdfBytes);
      const copiedPages = await mergedPdf.copyPages(pdf, pdf.getPageIndices());
      copiedPages.forEach((page) => mergedPdf.addPage(page));
    }

    const mergedPdfBytes = await mergedPdf.save();

    FileSystemHelper.writeFile(outputFolder, `${outputFile}.pdf`, mergedPdfBytes);
  }
}