@benev/slate/s/flatstate/parts/proxy_handlers.ts

frontend web stuff

import {Locker} from "./locker.js"
import {Reaction} from "./types.js"
import {Stopper} from "./stopper.js"
import {Tracker} from "./tracker.js"
import {Recorder} from "./recorder.js"
import {Scheduler} from "./scheduler.js"
import {save_reaction} from "./save_reaction.js"
import {CircularFlatstateError} from "./errors.js"

export function proxy_handlers(
		tracker: Tracker,
		recorder: Recorder,
		locker: Locker,
		stopper: Stopper,
		scheduler: Scheduler,
	): ProxyHandler<any> {

	function actuate([symbol, reaction]: [symbol, Reaction<any>]) {
		if ("lean" in reaction) {
			reaction.actor()
		}
		else {
			const {payload, recording} = recorder.record(reaction.collector)
			stopper.add(symbol, save_reaction(symbol, recording, tracker, reaction))
			if (reaction.responder)
				reaction.responder(payload)
		}
	}

	return {

		get: (state, key: string) => {
			recorder.record_that_key_was_accessed(state, key)
			return state[key]
		},

		set: (state, key: string, value: any) => {
			if (locker.locked)
				throw new CircularFlatstateError(key)

			state[key] = value
			const reactions = [...tracker.grab_keymap(state).grab_symbolmap(key)]

			for (const entry of reactions) {
				const [symbol] = entry
				scheduler.add(symbol, () => locker.lock(() => actuate(entry)))
			}

			return true
		},
	}
}