src/renderDocx.ts - master - melnik-demyan/ipdocgen

src/renderDocx.ts
101 строка4 KB
Demyan Melnik
Increase signature size + migrate client data
11 июн 2026, 14:34
11 июн 2026, 14:34e279ca3
import fs from 'fs';
import path from 'path';
import JSZip from 'jszip';
// @ts-ignore — html-to-docx ships no type definitions
import htmlToDocx from 'html-to-docx';

const MIME_BY_EXT: Record<string, string> = {
	'.png': 'image/png',
	'.jpg': 'image/jpeg',
	'.jpeg': 'image/jpeg',
	'.gif': 'image/gif',
	'.webp': 'image/webp',
	'.svg': 'image/svg+xml',
};

const inlineLocalImages = (html: string): string =>
	html.replace(/<img([^>]*?)src=["']([^"']+)["']([^>]*)>/gi, (match, pre, src, post) => {
		if (/^(https?:|data:)/i.test(src)) return match;
		const filePath = path.resolve(src.replace(/^\.\.?\//, ''));
		if (!fs.existsSync(filePath)) return match.replace(src, '');
		const ext = path.extname(filePath).toLowerCase();
		const mime = MIME_BY_EXT[ext] ?? 'application/octet-stream';
		const data = fs.readFileSync(filePath).toString('base64');
		return `<img${pre}src="data:${mime};base64,${data}"${post}>`;
	});

const DOCX_OPTIONS = {
	font: 'Arial',
	fontSize: 20,
	complexScriptFontSize: 20,
	margins: {
		top: 1134,
		right: 1134,
		bottom: 1134,
		left: 1134,
		header: 720,
		footer: 720,
		gutter: 0,
	},
	table: {
		row: {
			cantSplit: true,
		},
	},
};

const keepFirstTableRowWithBody = (xml: string): string =>
	xml.replace(/<w:tbl>([\s\S]*?)<\/w:tbl>/g, (_match, tblContent: string) => {
		const newContent = tblContent.replace(
			/<w:tr>[\s\S]*?<\/w:tr>/,
			(trMatch) => trMatch.replace(/<w:pPr>/g, '<w:pPr><w:keepNext/>'),
		);
		return `<w:tbl>${newContent}</w:tbl>`;
	});

const SIG_MAX_H_EMU = 1080000;
const SIG_MAX_W_EMU = 3000000;
const CLIENT_SIG_SCALE = 1.6;

const floatSignatureImages = (xml: string): string =>
	xml.replace(/<w:drawing>[\s\S]*?<\/w:drawing>/g, (drawing) => {
		if (!/descr="bgsig/.test(drawing)) return drawing;
		const extentMatch = drawing.match(/<wp:extent cx="(\d+)" cy="(\d+)"\s*\/>/);
		const graphicMatch = drawing.match(/<a:graphic[\s\S]*?<\/a:graphic>/);
		if (!extentMatch || !graphicMatch) return drawing;

		const isClient = /descr="bgsig-left"/.test(drawing);
		const maxH = isClient ? SIG_MAX_H_EMU * CLIENT_SIG_SCALE : SIG_MAX_H_EMU;
		const maxW = isClient ? SIG_MAX_W_EMU * CLIENT_SIG_SCALE : SIG_MAX_W_EMU;

		const cx = parseInt(extentMatch[1], 10);
		const cy = parseInt(extentMatch[2], 10);
		const scale = Math.min(maxH / cy, maxW / cx);
		const newCx = Math.round(cx * scale);
		const newCy = Math.round(cy * scale);

		const graphic = graphicMatch[0].replace(
			/<a:ext cx="\d+" cy="\d+"\s*\/>/,
			`<a:ext cx="${newCx}" cy="${newCy}"/>`,
		);

		return `<w:drawing><wp:anchor distT="0" distB="0" distL="0" distR="0" simplePos="0" relativeHeight="251658240" behindDoc="1" locked="0" layoutInCell="1" allowOverlap="1"><wp:simplePos x="0" y="0"/><wp:positionH relativeFrom="column"><wp:posOffset>360000</wp:posOffset></wp:positionH><wp:positionV relativeFrom="margin"><wp:align>center</wp:align></wp:positionV><wp:extent cx="${newCx}" cy="${newCy}"/><wp:effectExtent l="0" t="0" r="0" b="0"/><wp:wrapNone/><wp:docPr id="1" name="bgsig"/><wp:cNvGraphicFramePr><a:graphicFrameLocks xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main" noChangeAspect="1"/></wp:cNvGraphicFramePr>${graphic}</wp:anchor></w:drawing>`;
	});

const postProcess = (xml: string): string =>
	floatSignatureImages(keepFirstTableRowWithBody(xml));

const finalizeDocx = async (buffer: Buffer): Promise<Buffer> => {
	const zip = await JSZip.loadAsync(buffer);
	const file = zip.file('word/document.xml');
	if (!file) return buffer;
	const xml = await file.async('string');
	zip.file('word/document.xml', postProcess(xml));
	return await zip.generateAsync({type: 'nodebuffer'});
};

export const renderDocx = async (html: string): Promise<Buffer> => {
	const prepared = inlineLocalImages(html);
	const result = (await htmlToDocx(prepared, undefined, DOCX_OPTIONS)) as Buffer;
	return await finalizeDocx(result);
};