import { readdirSync, readFileSync } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { afterEach, describe, expect, it } from "vitest";
import {
	createPiSession,
	type PiSession,
} from "../../../test/fixture/create-pi-session.ts";

describe("tps contract", () => {
	let session: PiSession | undefined;

	afterEach(async () => {
		await session?.dispose();
		session = undefined;
	});

	it("loads in real Pi extension runtime", async () => {
		const extensionPath = fileURLToPath(
			new URL("../index.ts", import.meta.url),
		);
		session = await createPiSession({ extensionPaths: [extensionPath] });

		expect(session.errors).toEqual([]);
		expect(session.extensions).toHaveLength(1);
		expect(session.extensions[0]!.path).toBe(extensionPath);
	});

	it("writes debug lifecycle records in its sandbox when enabled", async () => {
		const extensionPath = fileURLToPath(
			new URL("../index.ts", import.meta.url),
		);
		session = await createPiSession({
			env: { PI_TPS_DEBUG: "1" },
			extensionPaths: [extensionPath],
		});
		const runner = session.session.extensionRunner;
		await runner.emit({ type: "session_start", reason: "startup" });
		await runner.emit({ type: "agent_start" });
		await runner.emit({ type: "agent_end", messages: [] });
		await runner.emit({ type: "session_shutdown", reason: "quit" });

		const directory = path.join(
			session.cwd,
			".test-state",
			"pi-ext",
			"debug",
			"tps",
		);
		const records = readFileSync(
			path.join(directory, readdirSync(directory)[0]!),
			"utf8",
		)
			.trim()
			.split("\n")
			.map((line) => JSON.parse(line));
		expect(records).toEqual(
			expect.arrayContaining([
				expect.objectContaining({ event: "session.start" }),
				expect.objectContaining({ event: "session.shutdown" }),
				expect.objectContaining({ event: "rate.finish", outcome: "idle" }),
			]),
		);
	});
});