/**
 * What "Apply" in the Project settings dialog (#183) actually carries out. The dialog itself is a
 * widget and needs a canvas; the rule behind it is a pure function and is tested here.
 */
import { describe, expect, it } from 'vitest';
import { settingsChanges, type ProjectSettings } from '../../src/editor/ProjectSettingsDialog';

const before: ProjectSettings = {
  name: 'Demo project',
  playFrom: 'start',
  whilePlaying: 'balanced',
  collisionLayers: ['Default', 'Enemies'],
  symbolScale: 1,
};

describe('project settings', () => {
  it('reports nothing to do when nothing was touched', () => {
    expect(settingsChanges(before, { ...before, collisionLayers: ['Default', 'Enemies'] })).toEqual({});
  });

  it('renames only when the name really differs', () => {
    expect(settingsChanges(before, { ...before, name: 'Tetris' }).name).toBe('Tetris');
    expect(settingsChanges(before, { ...before, name: 'Demo project' }).name).toBeUndefined();
  });

  it('trims the name and keeps the old one when only blanks are left', () => {
    expect(settingsChanges(before, { ...before, name: '  Tetris  ' }).name).toBe('Tetris');
    expect(settingsChanges(before, { ...before, name: '   ' }).name).toBeUndefined();
  });

  it('writes the layers when one was added, renamed or dropped', () => {
    const changed = (layers: string[]) => settingsChanges(before, { ...before, collisionLayers: layers });
    expect(changed(['Default', 'Enemies', 'Pickups']).collisionLayers).toEqual([
      'Default',
      'Enemies',
      'Pickups',
    ]);
    expect(changed(['Default', 'Foes']).collisionLayers).toEqual(['Default', 'Foes']);
    expect(changed(['Default']).collisionLayers).toEqual(['Default']);
  });

  it('hands back a copy of the layers, not the array the dialog goes on editing', () => {
    const edited = ['Default', 'Foes'];
    const change = settingsChanges(before, { ...before, collisionLayers: edited });
    edited.push('Later');
    expect(change.collisionLayers).toEqual(['Default', 'Foes']);
  });

  it('writes the symbol scale only when it changed, kept inside 0.1 to 4', () => {
    expect(settingsChanges(before, { ...before, symbolScale: 1 }).symbolScale).toBeUndefined();
    expect(settingsChanges(before, { ...before, symbolScale: 0.5 }).symbolScale).toBe(0.5);
    expect(settingsChanges(before, { ...before, symbolScale: 0.01 }).symbolScale).toBe(0.1);
    expect(settingsChanges(before, { ...before, symbolScale: 9 }).symbolScale).toBe(4);
    expect(settingsChanges(before, { ...before, symbolScale: Number.NaN }).symbolScale).toBeUndefined();
  });

  it('writes the start-scene switch only when it changed (#226)', () => {
    expect(settingsChanges(before, { ...before, playFrom: 'active' }).playFrom).toBe('active');
    expect(settingsChanges(before, { ...before, playFrom: 'start' }).playFrom).toBeUndefined();
  });

  it('writes the While playing preset only when it changed (#265)', () => {
    expect(settingsChanges(before, { ...before, whilePlaying: 'live' }).whilePlaying).toBe('live');
    expect(settingsChanges(before, { ...before, whilePlaying: 'balanced' }).whilePlaying).toBeUndefined();
  });
});