openclaw/dist/extensions/document-extract/document-extractor.js

Multi-channel AI gateway with extensible messaging integrations

//#region extensions/document-extract/document-extractor.ts
const MAX_EXTRACTED_TEXT_CHARS = 2e5;
const MAX_RENDER_DIMENSION = 1e4;
let pdfEnginePromise = null;
async function loadPdfEngine() {
	if (!pdfEnginePromise) pdfEnginePromise = import("clawpdf").then(({ createEngine }) => createEngine()).catch((err) => {
		pdfEnginePromise = null;
		throw new Error("Dependency clawpdf is required for PDF extraction", { cause: err });
	});
	return pdfEnginePromise;
}
function toDocumentImage({ bytes, mimeType }) {
	return {
		type: "image",
		data: Buffer.from(bytes.buffer, bytes.byteOffset, bytes.byteLength).toString("base64"),
		mimeType
	};
}
function isPdfPasswordError(err) {
	return Boolean(err && typeof err === "object" && err.code === "password");
}
async function openPdfDocument(params) {
	try {
		return params.password ? await params.engine.open(params.input, { password: params.password }) : await params.engine.open(params.input);
	} catch (err) {
		if (isPdfPasswordError(err)) throw new Error("PDF requires a password or password is incorrect.", { cause: err });
		throw err;
	}
}
async function extractPdfContent(request) {
	const pdf = await openPdfDocument({
		engine: await loadPdfEngine(),
		input: request.buffer,
		...request.password ? { password: request.password } : {}
	});
	try {
		const pages = request.pageNumbers ? request.pageNumbers.filter((p) => Number.isInteger(p) && p >= 1 && p <= pdf.pageCount).slice(0, request.maxPages) : void 0;
		if (request.pageNumbers?.length && pages?.length === 0) throw new Error(`No requested PDF pages exist in this ${pdf.pageCount}-page document.`);
		const pageSelection = pages ? { pages } : { maxPages: request.maxPages };
		const text = (await pdf.extract({
			mode: "text",
			...pageSelection,
			maxTextChars: MAX_EXTRACTED_TEXT_CHARS
		})).text;
		if (text.trim().length >= request.minTextChars) return {
			text,
			images: []
		};
		const imagePages = pages ?? Array.from({ length: Math.min(pdf.pageCount, request.maxPages) }, (_, i) => i + 1);
		try {
			const images = [];
			let remainingPixels = request.maxPixels;
			for (const [index, pageNumber] of imagePages.entries()) {
				if (remainingPixels <= 0) break;
				const pagesRemaining = imagePages.length - index;
				const maxPixelsPerPage = Math.max(1, Math.ceil(remainingPixels / pagesRemaining));
				const imageResult = await pdf.extract({
					mode: "images",
					pages: [pageNumber],
					image: {
						maxDimension: MAX_RENDER_DIMENSION,
						maxPixels: maxPixelsPerPage,
						forms: true
					}
				});
				for (const image of imageResult.images) {
					images.push(toDocumentImage(image));
					remainingPixels -= image.width * image.height;
				}
			}
			return {
				text,
				images
			};
		} catch (err) {
			request.onImageExtractionError?.(err);
			if (!text.trim()) throw new Error("PDF image extraction failed with no extractable text.", { cause: err });
			return {
				text,
				images: []
			};
		}
	} finally {
		pdf.destroy();
	}
}
function createPdfDocumentExtractor() {
	return {
		id: "pdf",
		label: "PDF",
		mimeTypes: ["application/pdf"],
		autoDetectOrder: 10,
		extract: extractPdfContent
	};
}
//#endregion
export { createPdfDocumentExtractor };