import { afterEach, beforeEach, describe, expect, it, vi, type MockInstance } from 'vitest'
import { flushPromises, mount, type VueWrapper } from '@vue/test-utils'
import { createPinia, setActivePinia } from 'pinia'
import { createRouter, createMemoryHistory } from 'vue-router'
import ReaderView from '../views/ReaderView.vue'
import ReviewView from '../views/ReviewView.vue'
import { POSITION_KEY_PREFIX } from '../composables/readingPosition'
import { useSessionStore } from '../stores/session'

const user = { id: 42, username: 'fictional-experience', role: 'learner' as const }
const sha = 'c'.repeat(64)
const text = 'Curiosity opens the first door.\nThe second door stays closed.\n'

const ok = (data: unknown) => new Response(JSON.stringify({ code: 200, data }))
let wrapper: VueWrapper | undefined

const reviewItem = {
  id: 5, term: 'curiosity', originalForm: 'Curiosity', definition: '好奇心', examples: ['Curious minds ask.'],
  status: 'new' as const, level: 0, kind: 'word' as const, wordCount: 1, dueAt: '2026-09-15T00:00:00Z', reviewCount: 0,
}

function mockApi(handlers: Record<string, (init?: RequestInit) => unknown>): MockInstance {
  return vi.spyOn(globalThis, 'fetch').mockImplementation(async (input, init) => {
    const url = String(input)
    for (const [fragment, handler] of Object.entries(handlers)) {
      if (url.includes(fragment)) return ok(handler(init))
    }
    return ok({})
  })
}

async function mountWith(component: unknown, path: string) {
  const router = createRouter({
    history: createMemoryHistory(),
    routes: [
      { path: '/', component: { template: '<div>LibraryStub</div>' } },
      { path: '/chapters/:id', component: component as never },
      { path: '/review', component: component as never },
    ],
  })
  await router.push(path)
  await router.isReady()
  wrapper = mount(component as never, { attachTo: document.body, global: { plugins: [router] } })
  await flushPromises()
  await flushPromises()
  return wrapper
}

describe('review shortcuts in the page', () => {
  beforeEach(() => { localStorage.clear(); setActivePinia(createPinia()) })
  afterEach(() => { vi.restoreAllMocks(); wrapper?.unmount() })

  it('reveals and grades from the keyboard', async () => {
    const answers: string[] = []
    useSessionStore().user = { ...user }
    mockApi({
      '/reviews/queue': () => ({ items: [reviewItem], total: 1 }),
      '/answers': (init) => {
        answers.push(JSON.parse(String(init?.body)).grade)
        return {
          result: 'applied', duplicate: false, grade: 'correct', requeued: false, statusBefore: 'new', statusAfter: 'learning',
          levelBefore: 0, levelAfter: 1, dueAtBefore: reviewItem.dueAt, dueAtAfter: '2026-09-20T00:00:00Z', item: reviewItem,
        }
      },
    })
    const view = await mountWith(ReviewView, '/review')
    expect(view.find('[data-testid="review-card"]').exists()).toBe(true)
    expect(view.get('[data-testid="review-shortcuts"]').text()).toContain('空格')

    // Space shows the answer instead of grading anything.
    document.dispatchEvent(new KeyboardEvent('keydown', { key: ' ', bubbles: true }))
    await flushPromises()
    expect(view.get('[data-testid="review-definition"]').text()).toContain('好奇心')
    expect(answers).toEqual([])

    // A digit grades it; the queue then has nothing left.
    document.dispatchEvent(new KeyboardEvent('keydown', { key: '1', bubbles: true }))
    await flushPromises()
    expect(answers).toEqual(['correct'])
    expect(view.find('[data-testid="review-summary"]').exists()).toBe(true)
  })

  it('ignores shortcuts typed into a field and with a modifier held', async () => {
    const answers: string[] = []
    useSessionStore().user = { ...user }
    mockApi({
      '/reviews/queue': () => ({ items: [reviewItem], total: 1 }),
      '/answers': (init) => {
        answers.push(JSON.parse(String(init?.body)).grade)
        return { result: 'applied', duplicate: false, grade: 'wrong', requeued: true, statusBefore: 'new', statusAfter: 'new', levelBefore: 0, levelAfter: 0, dueAtBefore: reviewItem.dueAt, dueAtAfter: reviewItem.dueAt, item: reviewItem }
      },
    })
    const view = await mountWith(ReviewView, '/review')
    view.get('[data-testid="review-reveal"]').trigger('click')
    await flushPromises()
    // A key press inside an input belongs to the input, wherever the learner is typing.
    const field = document.createElement('input')
    document.body.append(field)
    field.dispatchEvent(new KeyboardEvent('keydown', { key: '2', bubbles: true }))
    document.dispatchEvent(new KeyboardEvent('keydown', { key: '2', ctrlKey: true, bubbles: true }))
    await flushPromises()
    expect(answers).toEqual([])
    field.remove()
    document.body.dispatchEvent(new KeyboardEvent('keydown', { key: '2', bubbles: true }))
    await flushPromises()
    expect(answers).toEqual(['wrong'])
  })
})

describe('reading position in the reader', () => {
  beforeEach(() => { localStorage.clear(); setActivePinia(createPinia()) })
  afterEach(() => { vi.restoreAllMocks(); wrapper?.unmount() })

  function readerApi() {
    return mockApi({
      '/tokens': () => ({ tokens: [{ start: 0, end: 9, text: 'Curiosity', kind: 'word' }] }),
      '/chapters/7': () => ({
        book: { id: 3, title: 'Fictional reader', language: 'en' },
        chapter: {
          id: 7, bookId: 3, ordinal: 1, title: 'Fictional chapter', status: 'ready', charCount: 31, errorReason: '',
          errorMessage: '', jobId: 9, readAt: null, createdAt: '', updatedAt: '', contentSha256: sha, originalText: text,
        },
        navigation: { previousChapterId: null, nextChapterId: null },
      }),
    })
  }

  it('restores the saved position for the same account and version', async () => {
    useSessionStore().user = { ...user }
    localStorage.setItem(`${POSITION_KEY_PREFIX}42:7`, JSON.stringify({ ratio: 0.5, sha, at: '2026-09-15T03:00:00Z' }))
    const scrollTo = vi.fn()
    vi.stubGlobal('scrollTo', scrollTo)
    // A chapter long enough to have a scrolled position.
    Object.defineProperty(document.documentElement, 'scrollHeight', { value: 4800, configurable: true })
    Object.defineProperty(window, 'innerHeight', { value: 800, configurable: true })
    readerApi()
    const view = await mountWith(ReaderView, '/chapters/7')
    expect(view.find('.reader-text').exists()).toBe(true)
    await new Promise(resolve => setTimeout(resolve, 90))
    expect(scrollTo).toHaveBeenCalledWith({ top: 2000 })
    await flushPromises()
    expect(view.get('[data-testid="position-notice"]').text()).toContain('上次阅读位置')
  })

  it('does not restore a position taken from another content version', async () => {
    useSessionStore().user = { ...user }
    localStorage.setItem(`${POSITION_KEY_PREFIX}42:7`, JSON.stringify({ ratio: 0.5, sha: 'd'.repeat(64) }))
    const scrollTo = vi.fn()
    vi.stubGlobal('scrollTo', scrollTo)
    Object.defineProperty(document.documentElement, 'scrollHeight', { value: 4800, configurable: true })
    Object.defineProperty(window, 'innerHeight', { value: 800, configurable: true })
    readerApi()
    const view = await mountWith(ReaderView, '/chapters/7')
    await new Promise(resolve => setTimeout(resolve, 90))
    expect(scrollTo).not.toHaveBeenCalled()
    expect(view.find('[data-testid="position-notice"]').exists()).toBe(false)
  })
})