// bench/churn.ts
import { Bench } from "tinybench";
import { type Box, box } from "./../engine/lib/box.ts";
import {
	createDictionary,
	deleteEntry,
	getEntry,
	setEntry,
} from "./../engine/lib/Dictionary.ts";
import MapArray from "./../engine/lib/MapArray.ts";

const bench = new Bench({ name: "churn", time: 1000 });

const SIZE = 999;
const baseData: Array<[string, Box<number>]> = [];
{
	let i = SIZE;
	while (i-- > 0) baseData.push([String(i), box(i)]);
}

// Churn keys: a rotating window of "new" entities not in the base set,
// so every set/delete pair actually does real insert+remove work
// rather than repeatedly hitting the same already-resident key.
const CHURN_N = 100;
const churnKeys = Array.from({ length: CHURN_N }, (_, i) => `churn-${i}`);

let sink = 0; // anti-DCE: something observable reads this later

function freshMapArray() {
	return new MapArray(structuredClone(baseData));
}
function freshDictionary() {
	return createDictionary(structuredClone(baseData));
}
function freshMap() {
	return new Map(structuredClone(baseData));
}

// Each task rebuilds nothing per-iteration except doing insert+remove
// on a fixed churn window against a persistent SIZE-element base structure —
// this mirrors "N entities steady-state, M entering/leaving per frame".
const ma = freshMapArray();
const dict = freshDictionary();
const map = freshMap();

bench
	.add("MapArray churn (set+delete)", () => {
		for (const key of churnKeys) {
			ma.set(key, box(1));
		}
		for (const key of churnKeys) {
			ma.delete(key);
		}
		sink += ma.entries().length;
	})
	.add("Dictionary churn (set+delete)", () => {
		for (const key of churnKeys) {
			setEntry(dict, [key, box(1)]);
		}
		for (const key of churnKeys) {
			deleteEntry(dict, key);
		}
		sink += dict.entries.length;
	})
	.add("Map churn (set+delete)", () => {
		for (const key of churnKeys) {
			map.set(key, box(1));
		}
		for (const key of churnKeys) {
			map.delete(key);
		}
		sink += map.size;
	});

await bench.run();
console.table(bench.table());
console.log("sink (ignore):", sink);