feat: optimize documents printing

.env.example

@@ -49,4 +49,7 @@ SIGNUP_ALLOWED_DOMAINS=
 SIGNUP_ALLOWED_EMAILS=
 
 # API rate limit (points,duration,block duration).
-API_RATE_LIMIT=120,60,600
+API_RATE_LIMIT=120,60,600
+
+# Gotenberg API for PDF printing.
+GOTENBERG_url=http://localhost:9000

docker-compose.yml

@@ -47,6 +47,11 @@ services:
       restart_policy:
         condition: unless-stopped
 
+  gotenberg:
+    image: gotenberg/gotenberg:7
+    ports:
+      - "9000:3000"
+
 # Volumes
 volumes:
   mysql:

packages/server/src/lib/Chromiumly/Chromiumly.ts

@@ -0,0 +1,23 @@
+import { ChromiumRoute, LibreOfficeRoute, PdfEngineRoute } from './_types';
+
+export class Chromiumly {
+  public static readonly GOTENBERG_ENDPOINT = '';
+
+  public static readonly CHROMIUM_PATH = 'forms/chromium/convert';
+  public static readonly PDF_ENGINES_PATH = 'forms/pdfengines';
+  public static readonly LIBRE_OFFICE_PATH = 'forms/libreoffice';
+
+  public static readonly CHROMIUM_ROUTES = {
+    url: ChromiumRoute.URL,
+    html: ChromiumRoute.HTML,
+    markdown: ChromiumRoute.MARKDOWN,
+  };
+
+  public static readonly PDF_ENGINE_ROUTES = {
+    merge: PdfEngineRoute.MERGE,
+  };
+
+  public static readonly LIBRE_OFFICE_ROUTES = {
+    convert: LibreOfficeRoute.CONVERT,
+  };
+}

packages/server/src/lib/Chromiumly/ConvertUtils.ts

@@ -0,0 +1,66 @@
+import FormData from 'form-data';
+import { GotenbergUtils } from './GotenbergUtils';
+import { PageProperties } from './_types';
+
+export class ConverterUtils {
+  public static injectPageProperties(
+    data: FormData,
+    pageProperties: PageProperties
+  ): void {
+    if (pageProperties.size) {
+      GotenbergUtils.assert(
+        pageProperties.size.width >= 1.0 && pageProperties.size.height >= 1.5,
+        'size is smaller than the minimum printing requirements (i.e. 1.0 x 1.5 in)'
+      );
+
+      data.append('paperWidth', pageProperties.size.width);
+      data.append('paperHeight', pageProperties.size.height);
+    }
+    if (pageProperties.margins) {
+      GotenbergUtils.assert(
+        pageProperties.margins.top >= 0 &&
+          pageProperties.margins.bottom >= 0 &&
+          pageProperties.margins.left >= 0 &&
+          pageProperties.margins.left >= 0,
+        'negative margins are not allowed'
+      );
+      data.append('marginTop', pageProperties.margins.top);
+      data.append('marginBottom', pageProperties.margins.bottom);
+      data.append('marginLeft', pageProperties.margins.left);
+      data.append('marginRight', pageProperties.margins.right);
+    }
+    if (pageProperties.preferCssPageSize) {
+      data.append(
+        'preferCssPageSize',
+        String(pageProperties.preferCssPageSize)
+      );
+    }
+    if (pageProperties.printBackground) {
+      data.append('printBackground', String(pageProperties.printBackground));
+    }
+    if (pageProperties.landscape) {
+      data.append('landscape', String(pageProperties.landscape));
+    }
+    if (pageProperties.scale) {
+      GotenbergUtils.assert(
+        pageProperties.scale >= 0.1 && pageProperties.scale <= 2.0,
+        'scale is outside of [0.1 - 2] range'
+      );
+      data.append('scale', pageProperties.scale);
+    }
+
+    if (pageProperties.nativePageRanges) {
+      GotenbergUtils.assert(
+        pageProperties.nativePageRanges.from > 0 &&
+          pageProperties.nativePageRanges.to > 0 &&
+          pageProperties.nativePageRanges.to >=
+            pageProperties.nativePageRanges.from,
+        'page ranges syntax error'
+      );
+      data.append(
+        'nativePageRanges',
+        `${pageProperties.nativePageRanges.from}-${pageProperties.nativePageRanges.to}`
+      );
+    }
+  }
+}

packages/server/src/lib/Chromiumly/Converter.ts

@@ -0,0 +1,9 @@
+import { Chromiumly, ChromiumRoute } from '../../main.config';
+
+export abstract class Converter {
+  readonly endpoint: string;
+
+  constructor(route: ChromiumRoute) {
+    this.endpoint = `${Chromiumly.GOTENBERG_ENDPOINT}/${Chromiumly.CHROMIUM_PATH}/${Chromiumly.CHROMIUM_ROUTES[route]}`;
+  }
+}

packages/server/src/lib/Chromiumly/GotenbergUtils.ts

@@ -0,0 +1,25 @@
+import FormData from 'form-data';
+import fetch from 'node-fetch';
+
+export class GotenbergUtils {
+  public static assert(condition: boolean, message: string): asserts condition {
+    if (!condition) {
+      throw new Error(message);
+    }
+  }
+
+  public static async fetch(endpoint: string, data: FormData): Promise<Buffer> {
+    const response = await fetch(endpoint, {
+      method: 'post',
+      body: data,
+      headers: {
+        ...data.getHeaders(),
+      },
+    });
+
+    if (!response.ok) {
+      throw new Error(`${response.status} ${response.statusText}`);
+    }
+    return response.buffer();
+  }
+}

packages/server/src/lib/Chromiumly/HTMLConvert.ts

@@ -0,0 +1,38 @@
+import { constants, createReadStream, PathLike, promises } from 'fs';
+import FormData from 'form-data';
+import { GotenbergUtils } from './GotenbergUtils';
+import { IConverter, PageProperties } from './_types';
+import { PdfFormat, ChromiumRoute } from './_types';
+import { ConverterUtils } from './ConvertUtils';
+import { Converter } from './Converter';
+
+export class HtmlConverter extends Converter implements IConverter {
+  constructor() {
+    super(ChromiumRoute.HTML);
+  }
+
+  async convert({
+    html,
+    properties,
+    pdfFormat,
+  }: {
+    html: PathLike;
+    properties?: PageProperties;
+    pdfFormat?: PdfFormat;
+  }): Promise<Buffer> {
+    try {
+      await promises.access(html, constants.R_OK);
+      const data = new FormData();
+      if (pdfFormat) {
+        data.append('pdfFormat', pdfFormat);
+      }
+      data.append('index.html', createReadStream(html));
+      if (properties) {
+        ConverterUtils.injectPageProperties(data, properties);
+      }
+      return GotenbergUtils.fetch(this.endpoint, data);
+    } catch (error) {
+      throw error;
+    }
+  }
+}

packages/server/src/lib/Chromiumly/UrlConvert.ts

@@ -0,0 +1,38 @@
+import FormData from 'form-data';
+import { IConverter, PageProperties, PdfFormat, ChromiumRoute } from './_types';
+import { ConverterUtils } from './ConvertUtils';
+import { Converter } from './Converter';
+import { GotenbergUtils } from './GotenbergUtils';
+
+export class UrlConverter extends Converter implements IConverter {
+  constructor() {
+    super(ChromiumRoute.URL);
+  }
+
+  async convert({
+    url,
+    properties,
+    pdfFormat,
+  }: {
+    url: string;
+    properties?: PageProperties;
+    pdfFormat?: PdfFormat;
+  }): Promise<Buffer> {
+    try {
+      const _url = new URL(url);
+      const data = new FormData();
+
+      if (pdfFormat) {
+        data.append('pdfFormat', pdfFormat);
+      }
+      data.append('url', _url.href);
+
+      if (properties) {
+        ConverterUtils.injectPageProperties(data, properties);
+      }
+      return GotenbergUtils.fetch(this.endpoint, data);
+    } catch (error) {
+      throw error;
+    }
+  }
+}

packages/server/src/lib/Chromiumly/_types.ts

@@ -0,0 +1,51 @@
+import { PathLike } from 'fs';
+
+export type PageSize = {
+  width: number; // Paper width, in inches (default 8.5)
+  height: number; //Paper height, in inches (default 11)
+};
+
+export type PageMargins = {
+  top: number; // Top margin, in inches (default 0.39)
+  bottom: number; // Bottom margin, in inches (default 0.39)
+  left: number; // Left margin, in inches (default 0.39)
+  right: number; // Right margin, in inches (default 0.39)
+};
+
+export type PageProperties = {
+  size?: PageSize;
+  margins?: PageMargins;
+  preferCssPageSize?: boolean; // Define whether to prefer page size as defined by CSS (default false)
+  printBackground?: boolean; // Print the background graphics (default false)
+  landscape?: boolean; // Set the paper orientation to landscape (default false)
+  scale?: number; // The scale of the page rendering (default 1.0)
+  nativePageRanges?: { from: number; to: number }; // Page ranges to print
+};
+
+export interface IConverter {
+  convert({
+    ...args
+  }: {
+    [x: string]: string | PathLike | PageProperties | PdfFormat;
+  }): Promise<Buffer>;
+}
+
+export enum PdfFormat {
+  A_1a = 'PDF/A-1a',
+  A_2b = 'PDF/A-2b',
+  A_3b = 'PDF/A-3b',
+}
+
+export enum ChromiumRoute {
+  URL = 'url',
+  HTML = 'html',
+  MARKDOWN = 'markdown',
+}
+
+export enum PdfEngineRoute {
+  MERGE = 'merge',
+}
+
+export enum LibreOfficeRoute {
+  CONVERT = 'convert',
+}