import { mkdtempSync, readdirSync, readFileSync, rmSync } from "node:fs";
import { tmpdir } from "node:os";
import path from "node:path";
import { afterEach, describe, expect, it } from "vitest";
import { createTestSession, type TestSession } from "../../../test/harness";

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

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

	it("loads in real Pi extension runtime", async () => {
		const extensionPath = path.resolve(import.meta.dirname, "../index.ts");
		t = await createTestSession({ extensions: [extensionPath] });

		expect(t.session.extensionRunner.extensions).toHaveLength(1);
		expect(t.session.extensionRunner.extensions[0].path).toBe(extensionPath);
	});

	it("writes its opt-in lifecycle trace inside the harness sandbox", async () => {
		const root = mkdtempSync(path.join(tmpdir(), "pi-ext-runtime-debug-"));
		try {
			const extensionPath = path.resolve(import.meta.dirname, "../index.ts");
			t = await createTestSession({
				cwd: root,
				extensions: [extensionPath],
				env: { PI_RUNTIME_DEBUG: "1" },
			});
			const runner = t.session.extensionRunner;
			await runner.emit({ type: "session_start", reason: "startup" });
			await runner.emit({ type: "session_shutdown", reason: "quit" });
			const stateHome = t.env.XDG_STATE_HOME;
			if (!stateHome) throw new Error("missing sandbox state home");
			const directory = path.join(stateHome, "pi-ext", "debug", "runtime");
			const [file] = readdirSync(directory);
			const events = readFileSync(path.join(directory, file), "utf8")
				.trim()
				.split("\n")
				.map((line) => JSON.parse(line).event);
			expect(events).toEqual(
				expect.arrayContaining(["session.start", "session.shutdown"]),
			);
		} finally {
			t?.dispose();
			t = undefined;
			rmSync(root, { recursive: true, force: true });
		}
	});
});