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

describe("continuity debug", () => {
	let session: PiSession | undefined;

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

	it("writes its lifecycle JSONL through the standalone factory", async () => {
		session = await createPiSession({
			extensionPaths: [fileURLToPath(new URL("../index.ts", import.meta.url))],
			env: { PI_CONTINUITY_DEBUG: "1" },
		});
		expect(session.errors).toEqual([]);
		await session.session.extensionRunner.emit({
			type: "session_start",
			reason: "startup",
		});
		await session.session.extensionRunner.emit({
			type: "session_compact",
			compactionEntry: { id: "compact-debug" } as CompactionEntry,
			fromExtension: false,
			reason: "overflow",
			willRetry: true,
		});
		await session.session.extensionRunner.emit({
			type: "session_shutdown",
			reason: "quit",
		});

		if (!session.env["XDG_STATE_HOME"])
			throw new Error("missing sandbox state home");
		const directory = path.join(
			session.env["XDG_STATE_HOME"],
			"pi-ext",
			"debug",
			"continuity",
		);
		const records = await vi.waitFor(() => {
			const [file] = readdirSync(directory);
			if (!file) throw new Error("no debug file yet");
			const parsed = readFileSync(path.join(directory, file), "utf8")
				.trim()
				.split("\n")
				.filter((line) => line.length > 0)
				.map((line) => JSON.parse(line));
			const events = parsed.map((record) => record.event);
			if (
				!["session.start", "session.shutdown", "continuation"].every((event) =>
					events.includes(event),
				)
			)
				throw new Error("debug records not flushed yet");
			return parsed;
		});
		expect(records.map((record) => record.event)).toEqual(
			expect.arrayContaining([
				"session.start",
				"session.shutdown",
				"continuation",
			]),
		);
		expect(records).toContainEqual(
			expect.objectContaining({
				event: "continuation",
				outcome: "skipped-retry",
			}),
		);
	});
});