index.js

const index = require('../index');
const YAML = require('yaml');
const fs = require('fs');
const express = require('express');
const router = express.Router();

router.use(function timeLog (req,res,next) {
    console.log('Time: ',Date.now())
    res.header('Access-Control-Allow-Origin', '*');
    next();
})

const serverless = YAML.parse(fs.readFileSync('./serverless.yml','utf8'));

function comparePathsWithRegex(apiPath, actualPath) {
  // Regex pattern to match path segments, path parameters, and optional query string
  const pathRegex = new RegExp(`^${apiPath.replace(/\{([^}]+)}/g, "([^/]+)")}(?:\\?.*)?$`);

  return pathRegex.test(actualPath);
}
function extractPathParams(serverlessPath, actualPath) {
	const params = {};
	const serverlessParts = serverlessPath.split("/");
	const actualParts = actualPath.split("/");

	if (serverlessParts.length !== actualParts.length) {
		throw new Error("Serverless path and actual path have different lengths");
	}

	for (let i = 0; i < serverlessParts.length; i++) {
		const serverlessPart = serverlessParts[i];
		const actualPart = actualParts[i];
		if (serverlessPart && serverlessPart[0] === "{") {
			const key = serverlessPart.slice(1, -1);
			params[key] = actualPart;
		} else if (serverlessPart !== actualPart) {
			throw new Error("Serverless path and actual path do not match at segment:", i);
		}
	}
	return params;
}

router.all('*', async (req,res) => {
    let path = req.url,
		evt = req.body || {},
		cxt = {};
	path = path.replace('/api','/')

	for (var i in serverless.functions) {
		let f = serverless.functions[i]
		for (var x in f.events) {
			let e = f.events[x];
			if (e.httpApi && 
				comparePathsWithRegex(e.httpApi.path,path) &&
				req.method.toLocaleLowerCase() == e.httpApi.method.toLocaleLowerCase()) {
				cxt.httpMethod = req.method
				try {
					let pathParmam = extractPathParams(e.httpApi.path, path);
					evt.pathParameters = pathParmam;
					//console.log("evt",evt,"req.body",req.body)
					Object.keys(req.body).forEach((k) => { evt[k] = req.body[k] });

					let result = await index.handler[String(f.handler).replace('index.handler.','')](evt,cxt);
					res.header('Content-Type', 'application/json')
					res.status(result.statusCode).send(result.body);
				}
				catch (e) {
					console.log("API Error",e);
					res.status(500).send();
				}
			}
			else if (e.httpApi && 
				comparePathsWithRegex(e.httpApi.path,path) &&
				req.method == 'OPTIONS' &&
				res.headersSent == false) {
				res.header('Access-Control-Allow-Methods', 'GET,POST,OPTIONS');
				res.header('Access-Control-Allow-Headers', 'Content-Type');
				res.header('Access-Control-Allow-Origin', '*');
				res.status(200).send();
			}
		}
	}
});

module.exports = router;