import { describe, expect, it } from 'vitest';
import { pagerPages, requestedPage } from '#web-runtime/layouts/components/blog-pager';

describe('requestedPage', () => {
  it('defaults to page 1 with no search params at all', () => {
    expect(requestedPage()).toBe(1);
    expect(requestedPage({})).toBe(1);
  });

  it('parses a plain string value', () => {
    expect(requestedPage({ page: '3' })).toBe(3);
  });

  it('takes the first entry when the param is repeated', () => {
    expect(requestedPage({ page: ['4', '9'] })).toBe(4);
  });

  it('falls back to 1 for an empty repeated param', () => {
    expect(requestedPage({ page: [] })).toBe(1);
  });

  it('falls back to 1 for values that are not numbers', () => {
    expect(requestedPage({ page: 'abc' })).toBe(1);
    expect(requestedPage({ page: '' })).toBe(1);
    expect(requestedPage({ page: undefined })).toBe(1);
  });

  it('falls back to 1 for zero and negative pages', () => {
    expect(requestedPage({ page: '0' })).toBe(1);
    expect(requestedPage({ page: '-2' })).toBe(1);
  });

  it('truncates decimals via parseInt (pinned behavior)', () => {
    expect(requestedPage({ page: '2.9' })).toBe(2);
  });

  it('accepts numbers with trailing junk, as parseInt does (pinned behavior)', () => {
    expect(requestedPage({ page: '3abc' })).toBe(3);
  });
});

describe('pagerPages', () => {
  it('shows a single page as itself', () => {
    expect(pagerPages(1, 1)).toEqual([1]);
  });

  it('shows every page when the range is small', () => {
    expect(pagerPages(2, 3)).toEqual([1, 2, 3]);
    expect(pagerPages(3, 4)).toEqual([1, 2, 3, 4]);
  });

  it('windows a large range around the current page, keeping the first and last', () => {
    expect(pagerPages(5, 10)).toEqual([1, 4, 5, 6, 10]);
  });

  it('anchors the window at the start when on page 1', () => {
    expect(pagerPages(1, 10)).toEqual([1, 2, 10]);
  });

  it('anchors the window at the end when on the last page', () => {
    expect(pagerPages(10, 10)).toEqual([1, 9, 10]);
  });

  it('deduplicates when the window overlaps the anchors', () => {
    expect(pagerPages(2, 2)).toEqual([1, 2]);
    expect(pagerPages(2, 4)).toEqual([1, 2, 3, 4]);
  });

  it('always returns a sorted ascending list', () => {
    const pages = pagerPages(37, 80);
    expect(pages).toEqual([...pages].sort((a, b) => a - b));
    expect(pages).toEqual([1, 36, 37, 38, 80]);
  });
});