import test from "node:test";
import assert from "node:assert/strict";
import os from "node:os";
import path from "node:path";
import { mkdtempSync } from "node:fs";
import { createDefaultRegistry } from "../src/commands/registry.js";

function streamOf(items) {
	return (async function* () {
		for (const item of items) yield item;
	})();
}

test("diff.last reports changed on first run and not changed on same input", async () => {
	const tmp = mkdtempSync(path.join(os.tmpdir(), "lobster-diff-"));
	const env = { ...process.env, LOBSTER_STATE_DIR: tmp };
	const registry = createDefaultRegistry();
	const cmd = registry.get("diff.last");

	const first = await cmd.run({
		input: streamOf([{ a: 1 }]),
		args: { _: [], key: "k" },
		ctx: {
			stdin: process.stdin,
			stdout: process.stdout,
			stderr: process.stderr,
			env,
			registry,
			mode: "tool",
			render: { json() {}, lines() {} },
		},
	});
	const out1 = [];
	for await (const it of first.output) out1.push(it);
	assert.equal(out1[0].changed, true);

	const second = await cmd.run({
		input: streamOf([{ a: 1 }]),
		args: { _: [], key: "k" },
		ctx: {
			stdin: process.stdin,
			stdout: process.stdout,
			stderr: process.stderr,
			env,
			registry,
			mode: "tool",
			render: { json() {}, lines() {} },
		},
	});
	const out2 = [];
	for await (const it of second.output) out2.push(it);
	assert.equal(out2[0].changed, false);

	const third = await cmd.run({
		input: streamOf([{ a: 2 }]),
		args: { _: [], key: "k" },
		ctx: {
			stdin: process.stdin,
			stdout: process.stdout,
			stderr: process.stderr,
			env,
			registry,
			mode: "tool",
			render: { json() {}, lines() {} },
		},
	});
	const out3 = [];
	for await (const it of third.output) out3.push(it);
	assert.equal(out3[0].changed, true);
});