First basic version

.gitignore

@@ -1,6 +1,7 @@
 tmp/
 *.tmp
 tmp.*
+*.tmp.*
 
 dist/
 

package.json

@@ -1,13 +1,14 @@
 {
     "name": "mail2pdf",
-    "version": "1.0.0",
+    "version": "0.0.0",
     "description": "Render emails stored as .eml files to PDF.",
     "main": "dist/index.js",
     "types": "dist/index.d.ts",
     "author": "Benjamin Altpeter <hi@bn.al>",
     "repository": "https://github.com/baltpeter/mail2pdf",
     "license": "MIT",
     "devDependencies": {
+        "@types/mailparser": "^3.0.2",
         "@types/node": "^14.14.20",
         "@typescript-eslint/eslint-plugin": "^4.12.0",
         "@typescript-eslint/parser": "^4.12.0",
@@ -23,7 +24,8 @@
     "scripts": {
         "build": "tsc",
         "watch": "tsc -w",
-        "start": "node dist/index.js"
+        "start": "node dist/index.js",
+        "test": "echo 'TODO: No test specified yet.'"
     },
     "husky": {
         "hooks": {
@@ -37,5 +39,11 @@
         "*.{ts,js}": [
             "eslint --fix"
         ]
+    },
+    "dependencies": {
+        "handlebars": "^4.7.7",
+        "mailparser": "^3.1.0",
+        "pretty-bytes": "^5.6.0",
+        "puppeteer": "^8.0.0"
     }
 }

src/index.ts

@@ -1 +1,74 @@
-export { demo } from './demo';
+import { promises as fs } from 'fs';
+import { join } from 'path';
+import { simpleParser, AddressObject } from 'mailparser';
+import puppeteer from 'puppeteer';
+import handlebars from 'handlebars';
+import prettyBytes from 'pretty-bytes';
+import StreamModule = require('stream');
+import Stream = StreamModule.Stream;
+
+type Template = 'thunderbird';
+type Language = 'en';
+
+// The header and footer templates don't respect the page styles. They need their own styles, otherwise they will be
+// tiny, see: https://github.com/puppeteer/puppeteer/issues/1822#issuecomment-530533300
+const headerFooter = (html: string, align = 'left') =>
+    `<div style="font-size: 10px; margin: 10px 20px; width: 100%; text-align: ${align}; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;">${html}</div>`;
+const addressesToString = (addr?: AddressObject | AddressObject[]) =>
+    addr instanceof Array ? addr.reduce((acc, cur) => acc + ', ' + cur.text, '') : addr?.text;
+
+/**
+ * Generate a PDF from the provided .eml file.
+ *
+ * @param eml The email in .eml format to process. Either provide a file path as a string, which will then be read from
+ *            the filesystem, or the content of the .eml file as a `Buffer` or `Stream`.
+ * @param options.out_path The file path where the generated PDF should be stored (optional).
+ * @param options.language The language to be used for the labels in the generated PDF (optional, defaults to `en`).
+ *                         Currently, only English is supported.
+ * @param options.template_name The template to use (optional, defaults to `thunderbird`). Currently, only `thunderbird`
+ *                              is supported which will generate output similar to Thunderbird’s “Print to PDF” feature.
+ *
+ * @returns A `Buffer` containing the generated PDF.
+ */
+export default async function mail2pdf(
+    eml: string | Buffer | Stream,
+    options?: { out_path?: string; language?: Language; template_name?: Template }
+): Promise<Buffer> {
+    options = { language: 'en', template_name: 'thunderbird', ...options };
+
+    const mail = await simpleParser(typeof eml === 'string' ? await fs.readFile(eml) : eml);
+
+    const template = handlebars.compile(
+        (await fs.readFile(join(__dirname, '..', 'templates', options.template_name + '.hbr'))).toString()
+    );
+    const html = template({
+        subject: mail.subject,
+        has_html_body: mail.html !== false,
+        body: mail.html || mail.textAsHtml,
+        from: mail.from?.text,
+        date: mail.date?.toISOString(),
+        to: addressesToString(mail.to),
+        cc: addressesToString(mail.cc),
+        bcc: addressesToString(mail.bcc),
+        priority: mail.priority,
+        attachments: mail.attachments
+            .filter((a) => a.contentDisposition === 'attachment')
+            .map((a) => ({ ...a, filename: a.filename || '<unnamed>', prettySize: prettyBytes(a.size) })),
+    });
+
+    const browser = await puppeteer.launch({ headless: true });
+    const page = await browser.newPage();
+    await page.setContent(html);
+    const pdf = await page.pdf({
+        format: 'a4',
+        margin: { top: '20mm', bottom: '20mm', right: '20mm', left: '20mm' },
+        displayHeaderFooter: true,
+        headerTemplate: headerFooter('<span class="title"></span>'),
+        footerTemplate: headerFooter('<span class="pageNumber"></span>/<span class="totalPages"></span>', 'right'),
+        printBackground: true,
+        ...(options.out_path ? { path: options.out_path } : {}),
+    });
+    await browser.close();
+
+    return pdf;
+}

templates/thunderbird.hbr

@@ -0,0 +1,119 @@
+<html>
+<head>
+    <title>{{subject}}</title>
+    <style>
+        body {
+            margin: 0;
+            font-family: system-ui, sans-serif;
+            font-size: 16px;
+            line-height: 1.4;
+            background-color: transparent !important;
+        }
+
+        * {
+            /*
+               Outlook inserts `page: <something>;` on certain elements which causes Chrome to push them onto a separate
+               page. This rule disables this as the additional pages contain mostly unnecessary whitespace and Outlook
+               doesn't even respect those rules itself when printing.
+            */
+            page: unset !important;
+        }
+
+        a {
+            color: rgb(11, 108, 218);
+        }
+
+        #header {
+            margin-bottom: 25px;
+        }
+
+        #attachments {
+            margin: 0 15px 0 10px;
+        }
+
+        #attachments h2 {
+            font-weight: normal;
+            font-size: 9pt;
+            border-bottom: 1px solid rgb(87, 87, 87);
+            line-height: 0;
+            margin: 10px -15px 15px -10px;
+        }
+
+        #attachments h2 span {
+            background-color: #fff;
+            margin-left: 10px;
+        }
+
+        table#attachments-table {
+            width: 100%;
+            border-collapse: collapse;
+        }
+
+        #attachments-table td:nth-of-type(2) {
+            text-align: right;
+        }
+
+        table#attachments-table tr td {
+            border-bottom: 1px solid rgb(87, 87, 87);
+            padding: 5px 0;
+        }
+
+        table#attachments-table tr:last-child td {
+            border: none;
+        }
+
+        ul.br-list {
+            margin: 0;
+            padding: 0;
+            list-style: none;
+        }
+
+        .mono {
+            font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;
+            font-size: 0.8em;
+        }
+    </style>
+</head>
+<body>
+    <div id="header">
+        <ul class="br-list">
+            <li><strong>Subject:</strong> {{subject}}</li>
+            {{#if from}}
+                <li><strong>From:</strong> {{from}}</li>
+            {{/if}}
+            {{#if date}}
+                <li><strong>Date:</strong> {{date}}</li>
+            {{/if}}
+            {{#if to}}
+                <li><strong>To:</strong> {{to}}</li>
+            {{/if}}
+            {{#if cc}}
+                <li><strong>CC:</strong> {{cc}}</li>
+            {{/if}}
+            {{#if bcc}}
+                <li><strong>BCC:</strong> {{bcc}}</li>
+            {{/if}}
+            {{#if priority}}
+                <li><strong>Priority:</strong> {{priority}}</li>
+            {{/if}}
+        </ul>
+    </div>
+
+    <div id="body" {{#unless has_html_body}}class="mono" {{/unless}}>
+        {{{body}}}
+    </div>
+    {{#if attachments}}
+        <div id="attachments">
+            <h2><span>Attachments:</span></h2>
+            <table id="attachments-table">
+                {{#each attachments}}
+                    <tr>
+                        <td>{{this.filename}}</td>
+                        <td>{{this.prettySize}}</td>
+                    </tr>
+                {{/each}}
+            </table>
+        </div>
+    {{/if}}
+</body>
+</html>