// provided by outer context: APP_CONSTANTS, JS_APP_FRONTEND

const setup_safer_eval = function (lst_idents) {
	const runCodeWithCustomFunction = (obj) => {
		return Function(...lst_idents.map(x=>x[0]), `"use strict";return (${obj});`.trim())(...lst_idents.map(x=>x[1]))
	}
	return runCodeWithCustomFunction
}
const do_safereval_strscript = function (obj_eval_defines, the_strscript) {
	const lst_idents = Object.entries(obj_eval_defines).map(([k,v])=>[k,v]).toSorted((a,b)=>(a[0]-b[0]))
	const the_eval_func = setup_safer_eval(lst_idents)
	const the_eval_result = the_eval_func(`
(function(){
${the_strscript}
return
})()
`.trim())
	return the_eval_result
}

class FramerockUtils {
	constructor () {
		
		this._ws = undefined
		
		this.setup_transport    = this._setup_transport.bind(this)
		this.teardown_transport = this._teardown_transport.bind(this)
		
		return
		
	}
	_setup_transport ({ on_open, on_close }) {
		
		console.info('SETUP TRANSPORT')
		
		this._ws = new WebSocket(`ws://${window.location.host}/ws`)
		const ws = this._ws
		ws.binaryType = 'arraybuffer'
		
		const func_on_open = () => {
			console.info('WS OPEN')
			on_open && on_open()
			return
		}
		const func_on_close = (event) => {
			console.info('WS CLOSE')
			on_close && on_close(event)
			return
		}
		const func_on_message = (e) => {
			console.info('WS MESSAGE')
			return
		}
		const func_on_error = () => {
			console.info('WS ERROR')
			return
		}
		
		ws.addEventListener('open'   , func_on_open)
		ws.addEventListener('close'  , func_on_close)
		ws.addEventListener('message', func_on_message)
		ws.addEventListener('error'  , func_on_error)
		
		return
		
	}
	_teardown_transport () {
		
		console.info('TEARDOWN TRANSPORT')
		
		// NOTE: has no effect if ws already closed
		this._ws.close()
		
		return
		
	}
}

const FRAMEROCK_UTILS = new FramerockUtils()

do_safereval_strscript({ FRAMEROCK_UTILS }, JS_APP_FRONTEND)