import { parse as parseContentDisposition } from 'content-disposition';
import { parse as parseContentType } from 'content-type';
import getRawBody from 'raw-body';
import type { Request, RequestHandler } from 'express';
import { parse as parseQueryString } from 'querystring';
import { Parser as XmlParser } from 'xml2js';
import { jsonParse } from 'n8n-workflow';
import config from '@/config';
import { UnprocessableRequestError } from '@/ResponseHelper';

const xmlParser = new XmlParser({
	async: true,
	normalize: true, // Trim whitespace inside text nodes
	normalizeTags: true, // Transform tags to lowercase
	explicitArray: false, // Only put properties in array if length > 1
});

const payloadSizeMax = config.getEnv('endpoints.payloadSizeMax');
export const rawBodyReader: RequestHandler = async (req, res, next) => {
	if ('content-type' in req.headers) {
		const { type: contentType, parameters } = (() => {
			try {
				return parseContentType(req);
			} catch {
				return { type: undefined, parameters: undefined };
			}
		})();
		req.contentType = contentType;
		req.encoding = (parameters?.charset ?? 'utf-8').toLowerCase() as BufferEncoding;

		const contentDispositionHeader = req.headers['content-disposition'];
		if (contentDispositionHeader?.length) {
			const {
				type,
				parameters: { filename },
			} = parseContentDisposition(contentDispositionHeader);
			req.contentDisposition = { type, filename };
		}
	}

	req.readRawBody = async () => {
		if (!req.rawBody) {
			req.rawBody = await getRawBody(req, {
				length: req.headers['content-length'],
				limit: `${String(payloadSizeMax)}mb`,
			});
			req._body = true;
		}
	};

	next();
};

export const parseBody = async (req: Request) => {
	await req.readRawBody();
	const { rawBody, contentType, encoding } = req;
	if (rawBody?.length) {
		try {
			if (contentType === 'application/json') {
				// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
				req.body = jsonParse(rawBody.toString(encoding));
			} else if (contentType?.endsWith('/xml') || contentType?.endsWith('+xml')) {
				// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
				req.body = await xmlParser.parseStringPromise(rawBody.toString(encoding));
			} else if (contentType === 'application/x-www-form-urlencoded') {
				req.body = parseQueryString(rawBody.toString(encoding), undefined, undefined, {
					maxKeys: 1000,
				});
			} else if (contentType === 'text/plain') {
				req.body = rawBody.toString(encoding);
			}
		} catch (error) {
			throw new UnprocessableRequestError('Failed to parse request body', (error as Error).message);
		}
	}
};

export const bodyParser: RequestHandler = async (req, res, next) => {
	await parseBody(req);
	if (!req.body) req.body = {};
	next();
};