import { async_run } from 'framerock'
const run_process_gui = (runtime_conf, cwd_for_spawn, args_for_spawn) => {
	const jsbuild_app_frontend = async function () {
		return `
const streams = {}
const elems_terminals = {}
const async_process_stream = async function (stream_id, stream_key, callback) {
	for await (let chunk of streams[stream_id][stream_key].readable) {
		callback(chunk)
	}
	return
}
const setup_dom = function () {
	document.body.style = 'height: 100%;'
	document.head.insertAdjacentHTML('beforeend', '<style type="text/css">html, body{ height: 100%; width: 100%; margin: 0px; padding: 0px;}</style>')
	const elem_root = document.createElement('div')
	elem_root.style = 'height: 100%; width: 100%; display: flex; font-size: 16px;'
	for (let [ stream_key, style ] of [
		['stderr', { backgroundColor: '#333' }], 
		['stdout', { backgroundColor: '#000' }]
	]) {
		const elem_terminal = document.createElement('div')
		elems_terminals[stream_key] = elem_terminal
		Object.assign(elem_terminal.style, {
			flex: '1', fontFamily: 'monospace', color: '#FFF', height: '100%', overflow: 'auto', padding: '20px', boxSizing: 'border-box', whiteSpace: 'pre',
			...style
		})
		elem_root.appendChild(elem_terminal)
	}
	document.body.appendChild(elem_root)
	return
}

const on_open = function () {	
	const main_streamid = '1'
	streams[main_streamid] = {
		prev_message_idx: -1,
		stdout: new TextDecoderStream(),
		stderr: new TextDecoderStream(),
	}
	for (let stream_key of ['stdout', 'stderr']) {
		async_process_stream(main_streamid, stream_key, (chunk) => {elems_terminals[stream_key].textContent += chunk;}).then(()=>{}).catch(console.error)
	}
	FRAMEROCK_UTILS.transport_send_bytes(new TextEncoder().encode(JSON.stringify([ 'SPAWN_PROCESS_INIT', { stream_id: main_streamid } ])))
	console.info(['Process Spawned'])
	return
}
const on_message = function (event) {
	const [ evt_type, evt_data ] = JSON.parse(new TextDecoder().decode(event.data))
	if (evt_type === 'SPAWN_PROCESS_EVENT') {
		const [ stream_id, msg_idx, payload ] = evt_data
		const stream = streams[stream_id]
		if (stream === undefined) {
			console.error(['Unexpected: missing ref to stream:', stream_id])
			return
		}
		if (msg_idx !== stream.prev_message_idx+1) {
			console.error('received message out of order, skipping')
			return
		}
		stream.prev_message_idx = msg_idx*1
		const [ evt_subtype, evt_subdata ] = payload
		if (evt_subtype === 'stream_chunk') {
			const [ stream_key, stream_data ] = evt_subdata
			if (stream_data === null) {
				stream[stream_key].writable.close()
			}
			else {
				const writer = stream[stream_key].writable.getWriter()
				writer.write(new Uint8Array(stream_data))
				writer.releaseLock()
			}
		}
		else if (evt_subtype === 'exited') {
			console.info(['Process Exited', evt_subdata])
		}
	}
	return
}
setup_dom()
FRAMEROCK_UTILS.setup_transport({ on_open, on_message })
`.trim()
	}
	const handle_transport_bytes = function (utils, message) {
		const [ evt_type, evt_data ] = JSON.parse(new TextDecoder().decode(message))
		if (evt_type === 'SPAWN_PROCESS_INIT') {
			let msg_idx = 0
			const wrap_send = (payload) => {
				utils.transport_send_bytes(new TextEncoder().encode(JSON.stringify([ 'SPAWN_PROCESS_EVENT', [ evt_data.stream_id, msg_idx*1, payload ] ])))
				msg_idx++
				return
			}
			const onExit = (p, exitCode, signalCode, error) => {
				wrap_send(['exited', { exitCode, signalCode }])
				return
			}
			const proc = Bun.spawn(args_for_spawn, { cwd: cwd_for_spawn, stdout: 'pipe', stderr: 'pipe', onExit })
			const async_handle_chunks = async (stream_key) => {
				for await (const chunk of proc[stream_key]) {
					wrap_send(['stream_chunk', [ stream_key, [ ...chunk ] ]])
				}
				wrap_send(['stream_chunk', [ stream_key, null ]])
				return
			}
			Promise.all([ async_handle_chunks('stdout'), async_handle_chunks('stderr') ]).then(()=>{}).catch(console.error)
		}
		return
	}
	async_run({ config: { ...runtime_conf }, jsbuild_app_frontend, handle_transport_bytes }).then(()=>{}).catch(console.error)
	return
}
export { run_process_gui }