import {
	mkdtempSync,
	readFileSync,
	rmSync,
	statSync,
	writeFileSync,
} from "node:fs";
import { tmpdir } from "node:os";
import path from "node:path";
import { afterEach, describe, expect, it } from "vitest";
import {
	loadRoutingState,
	routingStatePath,
	saveRoutingState,
} from "../src/state.ts";

let root: string | undefined;
afterEach(() => {
	if (root) rmSync(root, { recursive: true, force: true });
	root = undefined;
});

describe("gratis routing state file", () => {
	it("lives under the user state dir, honoring XDG_STATE_HOME", () => {
		expect(routingStatePath("linux", {}, "/home/u")).toBe(
			"/home/u/.local/state/pi/gratis/routing.json",
		);
		expect(routingStatePath("linux", { XDG_STATE_HOME: "/x" }, "/home/u")).toBe(
			"/x/pi/gratis/routing.json",
		);
		expect(routingStatePath("darwin", {}, "/Users/u")).toBe(
			"/Users/u/Library/Application Support/pi/gratis/routing.json",
		);
		expect(
			routingStatePath("win32", { LOCALAPPDATA: "C:\\Local" }, "C:\\Users\\u"),
		).toBe("C:\\Local\\pi\\gratis\\routing.json");
	});

	it("saves atomically with owner-only permissions and loads it back", async () => {
		root = mkdtempSync(path.join(tmpdir(), "gratis-state-"));
		const file = path.join(root, "pi", "gratis", "routing.json");

		await saveRoutingState(file, { version: 1, models: {}, backends: {} });

		expect(await loadRoutingState(file)).toEqual({
			version: 1,
			models: {},
			backends: {},
		});
		expect(JSON.parse(readFileSync(file, "utf8")).version).toBe(1);
		if (process.platform !== "win32") {
			expect(statSync(file).mode & 0o777).toBe(0o600);
			expect(statSync(path.dirname(file)).mode & 0o777).toBe(0o700);
		}
	});

	it("treats a missing or corrupt file as no state", async () => {
		root = mkdtempSync(path.join(tmpdir(), "gratis-state-"));
		const file = path.join(root, "routing.json");
		expect(await loadRoutingState(file)).toBeUndefined();

		writeFileSync(file, "{ not json");
		expect(await loadRoutingState(file)).toBeUndefined();
	});
});