import { afterEach, beforeAll, describe, expect, it } from 'vitest'
import { rule } from './css'

// E1 golem15-seo-text (UI-SPEC C4): the status thresholds with a mocked
// canvas measureText, and the counter line's layout contract at 320px.

// The mocked canvas: width(text) answers the pixel width of a string.
let width: (text: string) => number = (text) => text.length * 10
HTMLCanvasElement.prototype.getContext = function () {
  return { font: '', measureText: (text: string) => ({ width: width(text) }) } as unknown as CanvasRenderingContext2D
} as unknown as typeof HTMLCanvasElement.prototype.getContext

type Measure = typeof import('../../assets/src/elements/measure')
let m: Measure
let labels: typeof import('../../assets/src/elements/labels')

beforeAll(async () => {
  m = await import('../../assets/src/elements/measure')
  labels = await import('../../assets/src/elements/labels')
  await import('../../assets/src/elements/index')
})

afterEach(() => {
  width = (text) => text.length * 10
  document.body.replaceChildren()
})

/** A string of n characters (with spaces, so it reads like text). */
function chars(n: number): string {
  return Array.from({ length: n }, (_, i) => (i % 6 === 5 ? ' ' : 'a')).join('').replace(/ $/, 'a')
}

describe('E1 status thresholds', () => {
  it('title: 29 characters are short, 30 are good', () => {
    width = () => 300
    expect(m.status(chars(29), 'title').status).toBe('short')
    expect(m.status(chars(30), 'title').status).toBe('good')
  })

  it('title: 580 px is good, 581 px is long', () => {
    width = () => 580
    expect(m.status(chars(40), 'title')).toMatchObject({ status: 'good', px: 580, maxPx: 580, chars: 40 })
    width = () => 581
    expect(m.status(chars(40), 'title')).toMatchObject({ status: 'long', px: 581 })
  })

  it('title: pixels decide long before characters decide short', () => {
    width = () => 581
    expect(m.status(chars(10), 'title').status).toBe('long')
  })

  it('description: 119 characters are short, 120 are good', () => {
    width = () => 700
    expect(m.status(chars(119), 'description').status).toBe('short')
    expect(m.status(chars(120), 'description').status).toBe('good')
  })

  it('description: 920 px is good, 921 px is long', () => {
    width = () => 920
    expect(m.status(chars(130), 'description')).toMatchObject({ status: 'good', maxPx: 920 })
    width = () => 921
    expect(m.status(chars(130), 'description').status).toBe('long')
  })

  it('an empty or blank value is empty for both measures', () => {
    for (const measure of ['title', 'description'] as const) {
      expect(m.status('', measure).status).toBe('empty')
      expect(m.status('   ', measure)).toMatchObject({ status: 'empty', chars: 0 })
    }
  })

  it('characters are counted as code points after trimming', () => {
    width = () => 100
    expect(m.status('  Zażółć gęślą  ', 'title').chars).toBe(12)
  })

  it('the element shows the status and the counter in both languages', () => {
    for (const locale of ['en', 'pl']) {
      const L = labels.labelsFor(locale)
      const node = document.createElement('golem15-seo-text') as HTMLElement & { value: string }
      node.setAttribute('ui-locale', locale)
      node.setAttribute('options', JSON.stringify({ measure: 'title' }))
      document.body.append(node)
      width = () => 400
      node.value = chars(29)
      expect(node.dataset.status).toBe('short')
      expect(node.querySelector('.seo-text__status-text')?.textContent).toBe(L.shortTitle)
      width = () => 581
      node.value = chars(35)
      expect(node.dataset.status).toBe('long')
      expect(node.querySelector('.seo-text__status-text')?.textContent).toBe(L.longTitle)
      expect(node.querySelector('.seo-text__count')?.textContent).toContain('581')
    }
  })

  it('typing emits summer-change with the right-trimmed value', () => {
    const node = document.createElement('golem15-seo-text') as HTMLElement & { value: string }
    document.body.append(node)
    const seen: string[] = []
    node.addEventListener('summer-change', (ev) => seen.push((ev as CustomEvent).detail.value))
    const input = node.querySelector('input') as HTMLInputElement
    input.value = 'Grzyby leśne  '
    input.dispatchEvent(new Event('input'))
    expect(seen).toEqual(['Grzyby leśne'])
    expect(node.value).toBe('Grzyby leśne')
  })
})

describe('E1 counter line at 320px', () => {
  // The layout contract that makes the two parts wrap without overlapping.
  it('the status and the count are separate items of a wrapping flex line with a gap', () => {
    const counter = rule('golem15-seo-text .seo-text__counter')
    expect(counter.display).toBe('flex')
    expect(counter['flex-wrap']).toBe('wrap')
    expect(Number.parseFloat(counter.gap)).toBeGreaterThan(0)
    for (const part of ['golem15-seo-text .seo-text__status', 'golem15-seo-text .seo-text__count']) {
      const decls = rule(part)
      expect(decls.position ?? 'static').toBe('static')
      expect(decls.width).toBeUndefined()
      expect(decls['white-space']).toBeUndefined()
    }
    const node = document.createElement('golem15-seo-text')
    node.style.width = '320px'
    document.body.append(node)
    const line = node.querySelector('.seo-text__counter') as HTMLElement
    expect(Array.from(line.children).map((c) => c.className)).toEqual(['seo-text__status', 'seo-text__count'])
  })
})