const ts = require('typescript');
const crypto = require('crypto');
const scriptCache = {};
module.exports = function() {
	let originalCompiler = null;

	const tsCompiler = (script, cb) => {
		const hash = crypto
			.createHash('md5')
			.update(script)
			.digest('hex');
		if (!scriptCache[hash]) {
			script = ts.transpileModule(script, {
				compilerOptions: { module: ts.ModuleKind.CommonJS, target: ts.ScriptTarget.ES5 }
			}).outputText;
			console.log(`Compiled code with has ${hash} to: \n${script}`);
			originalCompiler(script, cb);
			scriptCache[hash] = script;
		} else {
			console.log('Using ts cache');
			originalCompiler(scriptCache[hash], cb);
		}
	};
	return function(req, res, next) {
		console.log('I have middleware');
		const { compiler } = req.webtaskContext;
		if (originalCompiler === null && compiler.nodejsCompiler) {
			originalCompiler = compiler.nodejsCompiler;
		}
		compiler.nodejsCompiler = tsCompiler;
		return next();
	};
};