import { describe, it, expect } from 'vitest';
import { feedBase, defaultView, parseView, viewUrl } from './feednav.js';

const view = (path, def) => parseView(new URL('https://x' + path), def);

describe('feedBase', () => {
  it('is /news only under the /news path; everything else is /', () => {
    expect(feedBase('/news')).toBe('/news');
    expect(feedBase('/news?view=highlights')).toBe('/news');
    expect(feedBase('/')).toBe('/');
    expect(feedBase('/?view=latest')).toBe('/');
    expect(feedBase('')).toBe('/');
    expect(feedBase(undefined)).toBe('/');
  });
});

describe('defaultView', () => {
  it('/news leads with Latest; / (frozen) leads with Highlights', () => {
    expect(defaultView('/news')).toBe('latest');
    expect(defaultView('/')).toBe('today');
  });
});

describe('parseView', () => {
  it('bare path resolves to the base default', () => {
    expect(view('/')).toBe('today');              // / default (frozen)
    expect(view('/news', 'latest')).toBe('latest'); // /news default = Latest
  });
  it('Brief is reachable via ?view=highlights, with ?view=today as an alias', () => {
    expect(view('/news?view=highlights', 'latest')).toBe('today');
    expect(view('/news?view=today', 'latest')).toBe('today');     // alias kept
    expect(view('/?view=today')).toBe('today');
  });
  it('reads the standard views regardless of base', () => {
    expect(view('/news?view=latest', 'latest')).toBe('latest');
    expect(view('/?view=following')).toBe('following');
    expect(view('/?tag=clean-energy')).toBe('tag:clean-energy');
    expect(view('/?source=7')).toBe('source:7');
    expect(view('/?q=solar')).toBe('search');
  });
  it('prioritizes search > source > tag > view, ignores whitespace q', () => {
    expect(view('/?q=a&source=7&tag=b&view=latest')).toBe('search');
    expect(view('/?source=7&tag=b&view=latest')).toBe('source:7');
    expect(view('/?tag=b&view=latest')).toBe('tag:b');
    expect(view('/?q=%20')).toBe('today');
  });
});

describe('viewUrl', () => {
  it('the base default is the bare path; the Brief is ?view=highlights', () => {
    // /news: Latest is the default (bare), Highlights is explicit
    expect(viewUrl('/news', 'latest', 'latest')).toBe('/news');
    expect(viewUrl('/news', 'today', 'latest')).toBe('/news?view=highlights');
    expect(viewUrl('/news', 'following', 'latest')).toBe('/news?view=following');
    // / (frozen): Highlights is the default (bare), Latest is explicit
    expect(viewUrl('/', 'today', 'today')).toBe('/');
    expect(viewUrl('/', 'latest', 'today')).toBe('/?view=latest');
  });
  it('round-trips: a generated link parses back to the same view', () => {
    expect(view(viewUrl('/news', 'today', 'latest'), 'latest')).toBe('today');
    expect(view(viewUrl('/news', 'latest', 'latest'), 'latest')).toBe('latest');
    expect(view(viewUrl('/', 'latest', 'today').replace('/', '/'), 'today')).toBe('latest');
  });
  it('encodes tag/source/view values', () => {
    expect(viewUrl('/news', 'tag:good news', 'latest')).toBe('/news?tag=good%20news');
    expect(viewUrl('/', 'source:42', 'today')).toBe('/?source=42');
  });
});