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

const SIZES = [100, 250, 500, 999, 2500, 5000, 10000];
const CHURN_N = 100;
const churnKeys = Array.from({ length: CHURN_N }, (_, i) => `churn-${i}`);

let sink = 0;

function makeBaseData(size: number): Array<[string, Box<number>]> {
	const data: Array<[string, Box<number>]> = [];
	let i = size;
	while (i-- > 0) data.push([String(i), box(i)]);
	return data;
}

type Row = {
	structure: string;
	size: number;
	latencyNsAvg: number;
	latencyNsMed: number;
};
const rows: Row[] = [];

for (const size of SIZES) {
	const baseData = makeBaseData(size);

	const ma = new MapArray(structuredClone(baseData));
	const dict = createDictionary(structuredClone(baseData));
	const map = new Map(structuredClone(baseData));

	const bench = new Bench({ name: `churn @ size=${size}`, time: 500 });

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

	await bench.run();

	for (const task of bench.tasks) {
		const res = task.result;
		if (!res) continue;
		rows.push({
			structure: task.name,
			size,
			latencyNsAvg: res.latency.mean,
			latencyNsMed: res.latency.p50 ?? res.latency.mean,
		});
	}

	console.log(`-- size=${size} done --`);
	console.table(bench.table());
}

// CSV output
const header = "structure,size,latency_ns_avg,latency_ns_med";
const csvLines = rows.map(
	(r) =>
		`${r.structure},${r.size},${r.latencyNsAvg.toFixed(2)},${r.latencyNsMed.toFixed(2)}`,
);
const csv = [header, ...csvLines].join("\n");

(await Deno.writeTextFile?.("churn-sweep.csv", csv)) ??
	(await import("node:fs/promises")).then((fs) =>
		fs.writeFile("churn-sweep.csv", csv),
	);

console.log("\nWrote churn-sweep.csv");
console.log("sink (ignore):", sink);