import { afterEach, describe, expect, it } from "vitest";
import { createTestSession, type TestSession } from "../../../test/harness";
import contextSizeExtension, { __test } from "../index";

describe("context-size pi-test-harness", () => {
	let t: TestSession | undefined;

	afterEach(() => {
		t?.dispose();
		t = undefined;
	});

	it("loads in real Pi extension runtime", async () => {
		t = await createTestSession({ extensionFactories: [contextSizeExtension] });

		expect(t.session.extensionRunner.extensions).toHaveLength(1);
	});

	it("renders the tui view as a bar alone", () => {
		expect(__test.renderThinBar(26)).toBe("━━━───────");
		expect(__test.renderThinBar(null)).toBe("──────────");
	});

	it("spells out the non-tui label with human-readable headroom", () => {
		expect(
			__test.buildPlainLabel({
				tokens: 262_000,
				contextWindow: 1_000_000,
				percent: 26.2,
			}),
		).toBe("context 26% used, 738k left");

		expect(
			__test.buildPlainLabel({
				tokens: null,
				contextWindow: 1_000_000,
				percent: null,
			}),
		).toBe("context unknown");
	});

	it("scales token counts through k and M", () => {
		expect(__test.formatTokens(940)).toBe("940");
		expect(__test.formatTokens(1_180)).toBe("1.2k");
		expect(__test.formatTokens(262_000)).toBe("262k");
		expect(__test.formatTokens(1_618_000)).toBe("1.6M");
		expect(__test.formatTokens(121_527_000)).toBe("122M");
	});
});