import './style.css'
import {
  generateMosaic,
  selectKeywords,
  type KeywordCandidate,
} from './mosaic'

const SAMPLE_TEXT =
  '我一直以为记忆会忠实地保存一切，后来才发现，每一次回想都在重新编造过去。'

const app = document.querySelector<HTMLDivElement>('#app')

if (!app) {
  throw new Error('找不到应用挂载节点 #app')
}

app.innerHTML = `
  <div class="page-shell">
    <header class="hero">
      <div class="hero__index" aria-hidden="true">TEXT / EROSION / 01</div>
      <div class="hero__content">
        <h1>文字马赛克</h1>
        <p>让文字损坏，只留下几处可辨认的痕迹。</p>
      </div>
      <div class="hero__mark" aria-hidden="true">※</div>
    </header>

    <main>
      <section class="workspace" aria-label="文字马赛克生成器">
        <article class="panel panel--input">
          <div class="panel__heading">
            <div>
              <span class="panel__number">01</span>
              <h2>原始文本</h2>
            </div>
            <span id="input-count" class="counter">0 字</span>
          </div>
          <label class="sr-only" for="source-text">输入原始文本</label>
          <textarea
            id="source-text"
            maxlength="3000"
            spellcheck="false"
            placeholder="在这里粘贴一段中文……"
          ></textarea>
        </article>

        <article class="panel panel--output">
          <div class="panel__heading panel__heading--dark">
            <div>
              <span class="panel__number">02</span>
              <h2>损坏结果</h2>
            </div>
            <span id="output-ratio" class="counter">—</span>
          </div>
          <div id="mosaic-output" class="mosaic-output" role="status"></div>
          <div class="output-actions">
            <button id="reroll-button" class="button button--light" type="button">
              换一版
            </button>
            <button id="copy-button" class="button button--outline" type="button">
              复制文本
            </button>
          </div>
        </article>
      </section>

      <section class="control-deck" aria-label="生成参数">
        <div class="control-deck__title">
          <span>CONTROL SIGNAL</span>
          <h2>侵蚀参数</h2>
        </div>

        <div class="controls">
          <label class="control" for="retention-control">
            <span class="control__heading">
              <span>显影</span>
              <output id="retention-value">14%</output>
            </span>
            <span class="control__hint">留下多少原文词语</span>
            <input id="retention-control" type="range" min="5" max="40" value="14" />
          </label>

          <label class="control" for="volume-control">
            <span class="control__heading">
              <span>体量</span>
              <output id="volume-value">100%</output>
            </span>
            <span class="control__hint">结果相对原文的总长度</span>
            <input id="volume-control" type="range" min="85" max="115" value="100" />
          </label>

          <label class="control" for="disorder-control">
            <span class="control__heading">
              <span>扰动</span>
              <output id="disorder-value">58%</output>
            </span>
            <span class="control__hint">局部伸缩、重复与叠字强度</span>
            <input id="disorder-control" type="range" min="0" max="100" value="58" />
          </label>
        </div>
      </section>

      <section class="keyword-stage" aria-labelledby="keyword-title">
        <div class="keyword-stage__heading">
          <div>
            <span class="panel__number">03</span>
            <h2 id="keyword-title">保留词</h2>
            <p>点按词语切换显影状态，原始顺序不会改变。</p>
          </div>
          <button id="reselect-button" class="text-button" type="button">自动重选</button>
        </div>
        <div id="keyword-list" class="keyword-list"></div>
      </section>
    </main>

    <footer>
      <span>LOCAL PROCESSING</span>
      <p>文本只在当前浏览器中处理，不会上传。</p>
    </footer>
  </div>

  <div id="toast" class="toast" role="status" aria-live="polite"></div>
`

const sourceInput = getElement<HTMLTextAreaElement>('source-text')
const inputCount = getElement<HTMLSpanElement>('input-count')
const outputRatio = getElement<HTMLSpanElement>('output-ratio')
const mosaicOutput = getElement<HTMLDivElement>('mosaic-output')
const keywordList = getElement<HTMLDivElement>('keyword-list')
const toast = getElement<HTMLDivElement>('toast')
const retentionControl = getElement<HTMLInputElement>('retention-control')
const volumeControl = getElement<HTMLInputElement>('volume-control')
const disorderControl = getElement<HTMLInputElement>('disorder-control')
const retentionValue = getElement<HTMLOutputElement>('retention-value')
const volumeValue = getElement<HTMLOutputElement>('volume-value')
const disorderValue = getElement<HTMLOutputElement>('disorder-value')
const rerollButton = getElement<HTMLButtonElement>('reroll-button')
const copyButton = getElement<HTMLButtonElement>('copy-button')
const reselectButton = getElement<HTMLButtonElement>('reselect-button')

let candidates: KeywordCandidate[] = []
let selectionSeed = 5
let noiseSeed = Date.now()
let toastTimer = 0

function getElement<T extends HTMLElement>(id: string): T {
  const element = document.getElementById(id)

  if (!element) {
    throw new Error(`找不到页面元素 #${id}`)
  }

  return element as T
}

function showToast(message: string): void {
  window.clearTimeout(toastTimer)
  toast.textContent = message
  toast.classList.add('toast--visible')
  toastTimer = window.setTimeout(() => {
    toast.classList.remove('toast--visible')
  }, 1800)
}

function getRetention(): number {
  return Number(retentionControl.value)
}

function renderKeywords(): void {
  keywordList.replaceChildren()

  if (candidates.length === 0) {
    const empty = document.createElement('p')
    empty.className = 'keyword-list__empty'
    empty.textContent = sourceInput.value.trim()
      ? '没有识别到可保留的词语，可以尝试输入更长的中文文本。'
      : '输入文字后，这里会出现可保留的词语。'
    keywordList.append(empty)
    return
  }

  for (const candidate of candidates) {
    const button = document.createElement('button')
    button.type = 'button'
    button.className = 'keyword-token'
    button.textContent = candidate.text
    button.setAttribute('aria-pressed', String(candidate.selected))

    if (candidate.selected) {
      button.classList.add('keyword-token--selected')
    }

    button.addEventListener('click', () => {
      candidate.selected = !candidate.selected
      renderKeywords()
      renderOutput()
    })
    keywordList.append(button)
  }
}

function refreshCandidates(): void {
  candidates = selectKeywords(sourceInput.value, getRetention(), selectionSeed)
  renderKeywords()
  renderOutput()
}

function renderOutput(): void {
  const result = generateMosaic(sourceInput.value, candidates, {
    volume: Number(volumeControl.value),
    disorder: Number(disorderControl.value),
    seed: noiseSeed,
  })

  mosaicOutput.textContent = result.output || '等待文字进入损坏区'
  mosaicOutput.classList.toggle('mosaic-output--empty', result.output === '')
  inputCount.textContent = `${result.inputLength} 字`
  outputRatio.textContent =
    result.inputLength === 0
      ? '—'
      : `${result.outputLength} 字 / ${Math.round((result.outputLength / result.inputLength) * 100)}%`
}

function syncControls(): void {
  retentionValue.value = `${retentionControl.value}%`
  volumeValue.value = `${volumeControl.value}%`
  disorderValue.value = `${disorderControl.value}%`
}

sourceInput.addEventListener('input', () => {
  selectionSeed += 1
  noiseSeed += 1
  refreshCandidates()
})

retentionControl.addEventListener('input', () => {
  syncControls()
  refreshCandidates()
})

volumeControl.addEventListener('input', () => {
  syncControls()
  renderOutput()
})

disorderControl.addEventListener('input', () => {
  syncControls()
  renderOutput()
})

rerollButton.addEventListener('click', () => {
  noiseSeed += 1
  renderOutput()
})

reselectButton.addEventListener('click', () => {
  selectionSeed += 1
  refreshCandidates()
})

copyButton.addEventListener('click', async () => {
  const text = mosaicOutput.textContent ?? ''

  if (!sourceInput.value || !text) {
    showToast('还没有可以复制的结果')
    return
  }

  try {
    await navigator.clipboard.writeText(text)
    showToast('已复制纯文本')
  } catch (error) {
    console.error('复制文字马赛克失败', error)
    showToast('复制失败，请手动选择文本')
  }
})

sourceInput.value = SAMPLE_TEXT
syncControls()
refreshCandidates()