class EPSElementBuilder {
  // Templates
  static baseButton(text, { size = 'sm', color = 'primary' }) {
    const button = gradioApp().getElementById('txt2img_generate').cloneNode()
    button.id = ''
    button.classList.remove('gr-button-lg', 'gr-button-primary', 'lg', 'primary')
    button.classList.add(
      // gradio 3.16
      `gr-button-${size}`,
      `gr-button-${color}`,
      // gradio 3.22
      size,
      color
    )
    button.textContent = text

    return button
  }

  static tagFields() {
    const fields = document.createElement('div')
    fields.style.display = 'flex'
    fields.style.flexDirection = 'row'
    fields.style.flexWrap = 'wrap'
    fields.style.minWidth = 'min(320px, 100%)'
    fields.style.maxWidth = '100%'
    fields.style.flex = '1 calc(50% - 20px)'
    fields.style.borderWidth = '1px'
    fields.style.borderColor = 'var(--block-border-color,#374151)'
    fields.style.borderRadius = 'var(--block-radius,8px)'
    fields.style.padding = '8px'
    fields.style.height = 'fit-content'

    return fields
  }

  // Elements
  static openButton({ onClick }) {
    const button = EPSElementBuilder.baseButton('🔯提示词', { size: 'sm', color: 'secondary' })
    button.classList.add('easy_prompt_selector_button')
    button.addEventListener('click', onClick)

    return button
  }

  static areaContainer(id = undefined) {
    const container = gradioApp().getElementById('txt2img_results').cloneNode()
    container.id = id
    container.style.gap = 0
    container.style.display = 'none'

    return container
  }

  static tagButton({ title, onClick, onRightClick, color = 'primary' }) {
    const button = EPSElementBuilder.baseButton(title, { color })
    button.style.height = '2rem'
    button.style.flexGrow = '0'
    button.style.margin = '2px'

    button.addEventListener('click', onClick)
    button.addEventListener('contextmenu', onRightClick)

    return button
  }

  static dropDown(id, options, { onChange }) {
    const select = document.createElement('select')
    select.id = id

    // gradio 3.16
    select.classList.add('gr-box', 'gr-input')

    // gradio 3.22
    select.style.color = 'var(--body-text-color)'
    select.style.backgroundColor = 'var(--body-background-fill)'
    select.style.borderColor = 'var(--block-border-color)'
    select.style.borderRadius = 'var(--block-radius)'
    select.style.margin = '2px'
    select.addEventListener('change', (event) => { onChange(event.target.value) })

    const none = ['空']
    none.concat(options).forEach((key) => {
      const option = document.createElement('option')
      option.value = key
      option.textContent = key
      select.appendChild(option)
    })

    return select
  }

  static checkbox(text, { onChange }) {
    const label = document.createElement('label')
    label.style.display = 'flex'
    label.style.alignItems = 'center'

    const checkbox = gradioApp().querySelector('input[type=checkbox]').cloneNode()
    checkbox.checked = false
    checkbox.addEventListener('change', (event) => {
       onChange(event.target.checked)
    })

    const span = document.createElement('span')
    span.style.marginLeft = 'var(--size-2, 8px)'
    span.textContent = text

    label.appendChild(checkbox)
    label.appendChild(span)

    return label
  }
}

class EasyPromptSelector {
  PATH_FILE = 'tmp/easyPromptSelector.txt'
  AREA_ID = 'easy-prompt-selector'
  SELECT_ID = 'easy-prompt-selector-select'
  CONTENT_ID = 'easy-prompt-selector-content'
  TO_NEGATIVE_PROMPT_ID = 'easy-prompt-selector-to-negative-prompt'

  constructor(yaml, gradioApp) {
    this.yaml = yaml
    this.gradioApp = gradioApp
    this.visible = false
    this.toNegative = false
    this.tags = undefined
  }

  async init() {
    this.tags = await this.parseFiles()

    const tagArea = gradioApp().querySelector(`#${this.AREA_ID}`)
    if (tagArea != null) {
      this.visible = false
      this.changeVisibility(tagArea, this.visible)
      tagArea.remove()
    }

    gradioApp()
      .getElementById('txt2img_toprow')
      .after(this.render())
  }

  async readFile(filepath) {
    const response = await fetch(`file=${filepath}?${new Date().getTime()}`);

    return await response.text();
  }

  async parseFiles() {
    const text = await this.readFile(this.PATH_FILE);
    if (text === '') { return {} }

    const paths = text.split(/\r\n|\n/)

    const tags = {}
    for (const path of paths) {
      const filename = path.split('/').pop().split('.').slice(0, -1).join('.')
      const data = await this.readFile(path)
      yaml.loadAll(data, function (doc) {
        tags[filename] = doc
      })
    }

    return tags
  }

  // Render
  render() {
    const row = document.createElement('div')
    row.style.display = 'flex'
    row.style.alignItems = 'center'
    row.style.gap = '10px'

    const dropDown = this.renderDropdown()
    dropDown.style.flex = '1'
    dropDown.style.minWidth = '1'
    row.appendChild(dropDown)

    const settings = document.createElement('div')
    const checkbox = EPSElementBuilder.checkbox('负面', {
      onChange: (checked) => { this.toNegative = checked }
    })
    settings.style.flex = '1'
    settings.appendChild(checkbox)

    row.appendChild(settings)

    const container = EPSElementBuilder.areaContainer(this.AREA_ID)

    container.appendChild(row)
    container.appendChild(this.renderContent())

    return container
  }

  renderDropdown() {
    const dropDown = EPSElementBuilder.dropDown(
      this.SELECT_ID,
      Object.keys(this.tags), {
        onChange: (selected) => {
          const content = gradioApp().getElementById(this.CONTENT_ID)
          Array.from(content.childNodes).forEach((node) => {
            const visible = node.id === `easy-prompt-selector-container-${selected}`
            this.changeVisibility(node, visible)
          })
        }
      }
    )

    return dropDown
  }

  renderContent() {
    const content = document.createElement('div')
    content.id = this.CONTENT_ID

    Object.keys(this.tags).forEach((key) => {
      const values = this.tags[key]

      const fields = EPSElementBuilder.tagFields()
      fields.id = `easy-prompt-selector-container-${key}`
      fields.style.display = 'none'
      fields.style.flexDirection = 'row'
      fields.style.marginTop = '10px'

      this.renderTagButtons(values, key).forEach((group) => {
        fields.appendChild(group)
      })

      content.appendChild(fields)
    })

    return content
  }

  renderTagButtons(tags, prefix = '') {
    if (Array.isArray(tags)) {
      return tags.map((tag) => this.renderTagButton(tag, tag, 'secondary'))
    } else {
      return Object.keys(tags).map((key) => {
        const values = tags[key]
        const randomKey = `${prefix}:${key}`

        if (typeof values === 'string') { return this.renderTagButton(key, values, 'secondary') }

        const fields = EPSElementBuilder.tagFields()
        fields.style.flexDirection = 'column'

        fields.append(this.renderTagButton(key, `@${randomKey}@`))

        const buttons = EPSElementBuilder.tagFields()
        buttons.id = 'buttons'
        fields.append(buttons)
        this.renderTagButtons(values, randomKey).forEach((button) => {
          buttons.appendChild(button)
        })

        return fields
      })
    }
  }

  renderTagButton(title, value, color = 'primary') {
    return EPSElementBuilder.tagButton({
      title,
      onClick: (e) => {
        e.preventDefault();

        this.addTag(value, this.toNegative || e.metaKey || e.ctrlKey)
      },
      onRightClick: (e) => {
        e.preventDefault();

        this.removeTag(value, this.toNegative || e.metaKey || e.ctrlKey)
      },
      color
    })
  }

  // Util
  changeVisibility(node, visible) {
    node.style.display = visible ? 'flex' : 'none'
  }

  addTag(tag, toNegative = false) {
    const id = toNegative ? 'txt2img_neg_prompt' : 'txt2img_prompt'
    const textarea = gradioApp().getElementById(id).querySelector('textarea')

    if (textarea.value.trim() === '') {
      textarea.value = tag
    } else if (textarea.value.trim().endsWith(',')) {
      textarea.value += ' ' + tag
    } else {
      textarea.value += ', ' + tag
    }

    updateInput(textarea)
  }

  removeTag(tag, toNegative = false) {
    const id = toNegative ? 'txt2img_neg_prompt' : 'txt2img_prompt'
    const textarea = gradioApp().getElementById(id).querySelector('textarea')

    if (textarea.value.trimStart().startsWith(tag)) {
      const matched = textarea.value.match(new RegExp(`${tag.replace(/[-\/\\^$*+?.()|\[\]{}]/g, '\\$&') },*`))
      textarea.value = textarea.value.replace(matched[0], '').trimStart()
    } else {
      textarea.value = textarea.value.replace(`, ${tag}`, '')
    }

    updateInput(textarea)
  }
}

onUiLoaded(async () => {
  yaml = window.jsyaml
  const easyPromptSelector = new EasyPromptSelector(yaml, gradioApp())

  const button = EPSElementBuilder.openButton({
    onClick: () => {
      const tagArea = gradioApp().querySelector(`#${easyPromptSelector.AREA_ID}`)
      easyPromptSelector.changeVisibility(tagArea, easyPromptSelector.visible = !easyPromptSelector.visible)
    }
  })

  const reloadButton = gradioApp().getElementById('easy_prompt_selector_reload_button')
  reloadButton.addEventListener('click', async () => {
    await easyPromptSelector.init()
  })

  const txt2imgActionColumn = gradioApp().getElementById('txt2img_actions_column')
  const container = document.createElement('div')
  container.classList.add('easy_prompt_selector_container')
  container.appendChild(button)
  container.appendChild(reloadButton)

  txt2imgActionColumn.appendChild(container)

  await easyPromptSelector.init()
})