// ?page=N parsing, out-of-range detection and the page window.
import { test } from 'node:test'
import assert from 'node:assert/strict'
import { pageOutOfRange, paginationWindow, parsePageParam } from '../app/utils/pagination.ts'

test('a missing page is page 1', () => {
  assert.equal(parsePageParam(undefined), 1)
  assert.equal(parsePageParam(null), 1)
})

test('a string of digits above 0 is that page', () => {
  assert.equal(parsePageParam('1'), 1)
  assert.equal(parsePageParam('2'), 2)
  assert.equal(parsePageParam('017'), 17)
})

test('anything else is a 404 (null)', () => {
  for (const raw of ['0', '-1', '1.5', 'abc', '', ' 2', '2 ', '1e3', '0x2', '99999999999999999999']) {
    assert.equal(parsePageParam(raw), null, JSON.stringify(raw))
  }
  assert.equal(parsePageParam(['2']), null)
  assert.equal(parsePageParam(2), null)
})

test('pageOutOfRange: past the last page only, page 1 never', () => {
  assert.equal(pageOutOfRange(3, 2), true)
  assert.equal(pageOutOfRange(2, 2), false)
  assert.equal(pageOutOfRange(1, 0), false)
  assert.equal(pageOutOfRange(1, 1), false)
  assert.equal(pageOutOfRange(2, 0), true)
})

test('paginationWindow centres on the current page', () => {
  assert.deepEqual(paginationWindow(5, 10), [3, 4, 5, 6, 7])
})

test('paginationWindow stays full width near either end', () => {
  assert.deepEqual(paginationWindow(1, 10), [1, 2, 3, 4, 5])
  assert.deepEqual(paginationWindow(10, 10), [6, 7, 8, 9, 10])
  assert.deepEqual(paginationWindow(9, 10, 3), [8, 9, 10])
})

test('paginationWindow clips to the page count and handles empty input', () => {
  assert.deepEqual(paginationWindow(1, 2), [1, 2])
  assert.deepEqual(paginationWindow(1, 0), [])
  assert.deepEqual(paginationWindow(1, 5, 0), [])
})