import { interpret } from 'xstate';
import { waitFor } from 'xstate/lib/waitFor';

import type { PaginationMachineService } from './paginationMachine';
import { paginationMachine } from './paginationMachine';

describe('paginationMachine', () => {
  let service: PaginationMachineService;
  const onPageChange = jest.fn();

  beforeEach(async () => {
    const machine = paginationMachine
      .withContext({
        pages: [],
        pagesCount: 100,
        currentPage: 1,
        pagesToDisplay: 6,
      })
      .withConfig({
        actions: {
          onPageChange,
        },
      });

    service = interpret(machine).start();
    await waitFor(service, (state) => state.matches('idle'));
  });

  afterEach(() => {
    service.stop();
  });

  it('should be in idle state correctly when currentPage is 1', () => {
    service.send('GOTO', { input: 1 });
    const state = service.getSnapshot();

    expect(state.matches('idle')).toBe(true);
    expect(state.context.currentPage).toBe(1);
    expect(state.context.pages).toEqual([1, 2, 3, 4, -1, 100]);
  });

  it('should be in idle state correctly when currentPage is 100', () => {
    service.send('GOTO', { input: 100 });
    const state = service.getSnapshot();

    expect(state.matches('idle')).toBe(true);
    expect(state.context.currentPage).toBe(100);
    expect(state.context.pages).toEqual([1, -1, 97, 98, 99, 100]);
  });

  it('should go back if current is 100 and set next', () => {
    service.send('GOTO', { input: 100 });
    service.send('NEXT');
    const state = service.getSnapshot();

    expect(state.matches('idle')).toBe(true);
    expect(state.context.currentPage).toBe(1);
    expect(state.context.pages).toEqual([1, 2, 3, 4, -1, 100]);
  });

  it('should go to end if current is 1 and set previous', () => {
    service.send('GOTO', { input: 1 });
    service.send('PREV');
    const state = service.getSnapshot();

    expect(state.matches('idle')).toBe(true);
    expect(state.context.currentPage).toBe(100);
    expect(state.context.pages).toEqual([1, -1, 97, 98, 99, 100]);
  });
});