import { describe, it, expect, vi, beforeEach, beforeAll, afterAll, afterEach } from 'vitest';
import { __setMocked, persistentWritable } from './persistentStore';
import { get } from 'svelte/store';

describe('persistentWritable', () => {
	let _storage: Record<string, string> = {};
	const storageMock = {
		setItem: vi.fn(),
		getItem: vi.fn()
	};

	beforeEach(() => {
		vi.resetAllMocks();
		vi.stubGlobal('localStorage', storageMock);
		_storage = {};
		storageMock.setItem.mockImplementation((key: string, value: string) => {
			_storage[key] = value;
		});
		storageMock.getItem.mockImplementation((key: string) => {
			const res = _storage[key];
			if (res) {
				return res;
			}
			return null;
		});
	});

	describe('in browser', () => {
		beforeAll(() => {
			__setMocked(true);
		});

		afterAll(() => {
			__setMocked(false);
		});

		it('should not create multiple stores', () => {
			const firstStore = persistentWritable<number>('browser-multiple', 0);

			const secondStore = persistentWritable<number>('browser-multiple', 1);

			expect(firstStore).toStrictEqual(secondStore);
			expect(get(secondStore)).toEqual(0);

			expect(storageMock.getItem).toHaveBeenCalledOnce();
			expect(storageMock.getItem.mock.calls[0]).toEqual(['browser-multiple']);
			expect(storageMock.setItem).toHaveBeenCalledTimes(0);
		});

		it('should update localStorage', () => {
			const store = persistentWritable<string>('browser-update', 'foo');
			expect(storageMock.getItem).toHaveBeenCalledOnce();
			store.set('bar');
			expect(storageMock.setItem.mock.calls[0]).toEqual(['browser-update', '"bar"']);
			expect(_storage['browser-update']).toEqual('"bar"');
		});

		it('should initialize from localStorage', () => {
			_storage['browser-existing'] = '"bar"';
			const store = persistentWritable<string>('browser-existing', 'foo');
			expect(get(store)).toEqual('bar');
		});
	});

	describe('in server', () => {
		beforeAll(() => {
			__setMocked(false);
		});

		afterEach(() => {
			expect(storageMock.setItem).toHaveBeenCalledTimes(0);
			expect(storageMock.getItem).toHaveBeenCalledTimes(0);
		});

		it('should not create multiple stores', () => {
			const firstStore = persistentWritable<number>('server-multiple', 0);
			const secondStore = persistentWritable<number>('server-multiple', 0);
			expect(firstStore).toStrictEqual(secondStore);
			expect(get(secondStore)).toEqual(0);
		});

		it('should not update localStorage', () => {
			const store = persistentWritable<string>('server-update', 'foo');
			store.set('foobar');
			expect(get(store)).toEqual('foobar');
		});
	});
});