import {
  Editor,
  isNodeSelection,
  isTextSelection,
  posToDOMRect,
} from '@tiptap/core'
import debounce from 'lodash/debounce'
import { EditorState, Plugin, PluginKey } from 'prosemirror-state'
import { EditorView } from 'prosemirror-view'
import tippy, { Instance, Props } from 'tippy.js'

export interface BubbleMenuPluginProps {
  pluginKey: PluginKey | string,
  editor: Editor,
  element: HTMLElement,
  tippyOptions?: Partial<Props>,
  delay?: number,
  shouldShow?: ((props: {
    editor: Editor,
    view: EditorView,
    state: EditorState,
    oldState?: EditorState,
    from: number,
    to: number,
  }) => boolean) | null,
}

export type BubbleMenuViewProps = BubbleMenuPluginProps & {
  view: EditorView,
}

export class BubbleMenuView {
  public editor: Editor

  public element: HTMLElement

  public view: EditorView

  public preventHide = false

  public tippy: Instance | undefined

  public tippyOptions?: Partial<Props>

  public delay: number

  public shouldShow: Exclude<BubbleMenuPluginProps['shouldShow'], null> = ({
    view,
    state,
    from,
    to,
  }) => {
    const { doc, selection } = state
    const { empty } = selection

    // Sometime check for `empty` is not enough.
    // Doubleclick an empty paragraph returns a node size of 2.
    // So we check also for an empty text size.
    const isEmptyTextBlock = !doc.textBetween(from, to).length
      && isTextSelection(state.selection)

    // When clicking on a element inside the bubble menu the editor "blur" event
    // is called and the bubble menu item is focussed. In this case we should
    // consider the menu as part of the ditor and keep showing the menu
    const isChildOfMenu = this.element.contains(document.activeElement)

    const hasEditorFocus = view.hasFocus() || isChildOfMenu

    if (
      !hasEditorFocus
      || empty
      || isEmptyTextBlock
      || !this.editor.isEditable
    ) {
      return false
    }

    return true
  }

  constructor({
    editor,
    element,
    view,
    tippyOptions = {},
    delay = 250,
    shouldShow,
  }: BubbleMenuViewProps) {
    this.editor = editor
    this.element = element
    this.view = view
    this.delay = delay

    if (shouldShow) {
      this.shouldShow = shouldShow
    }

    this.element.addEventListener('mousedown', this.mousedownHandler, { capture: true })
    this.view.dom.addEventListener('dragstart', this.dragstartHandler)
    this.editor.on('focus', this.focusHandler)
    this.editor.on('blur', this.blurHandler)
    this.tippyOptions = tippyOptions
    // Detaches menu content from its current parent
    this.element.remove()
    this.element.style.visibility = 'visible'
  }

  mousedownHandler = () => {
    this.preventHide = true
  }

  dragstartHandler = () => {
    this.hide()
  }

  focusHandler = () => {
    // we use `setTimeout` to make sure `selection` is already updated
    setTimeout(() => this.update(this.editor.view))
  }

  blurHandler = ({ event }: { event: FocusEvent }) => {
    if (this.preventHide) {
      this.preventHide = false

      return
    }

    if (
      event?.relatedTarget
      && this.element.parentNode?.contains(event.relatedTarget as Node)
    ) {
      return
    }

    this.hide()
  }

  tippyBlurHandler = (event : FocusEvent) => {
    this.blurHandler({ event })
  }

  createTooltip() {
    const { element: editorElement } = this.editor.options
    const editorIsAttached = !!editorElement.parentElement

    if (this.tippy || !editorIsAttached) {
      return
    }

    this.tippy = tippy(editorElement, {
      duration: 0,
      getReferenceClientRect: null,
      content: this.element,
      interactive: true,
      trigger: 'manual',
      placement: 'top',
      hideOnClick: 'toggle',
      ...this.tippyOptions,
    })

    // maybe we have to hide tippy on its own blur event as well
    if (this.tippy.popper.firstChild) {
      (this.tippy.popper.firstChild as HTMLElement).addEventListener('blur', this.tippyBlurHandler)
    }
  }

  update(view: EditorView, oldState?: EditorState) {
    const { state } = view
    const hasValidSelection = state.selection.$from.pos !== state.selection.$to.pos

    if (hasValidSelection) {
      if (this.delay > 0) {
        debounce(this.updateHandler, this.delay)(view, oldState)
      } else {
        this.updateHandler(view, oldState)
      }
    } else {
      this.hide()
    }
  }

  updateHandler = (view: EditorView, oldState?: EditorState) => {
    const { state, composing } = view
    const { doc, selection } = state
    const isSame = oldState && oldState.doc.eq(doc) && oldState.selection.eq(selection)

    if (composing || isSame) {
      return
    }

    this.createTooltip()

    // support for CellSelections
    const { ranges } = selection
    const from = Math.min(...ranges.map(range => range.$from.pos))
    const to = Math.max(...ranges.map(range => range.$to.pos))

    const shouldShow = this.shouldShow?.({
      editor: this.editor,
      view,
      state,
      oldState,
      from,
      to,
    })

    if (!shouldShow) {
      this.hide()

      return
    }

    this.tippy?.setProps({
      getReferenceClientRect: this.tippyOptions?.getReferenceClientRect || (() => {
        if (isNodeSelection(state.selection)) {
          const node = view.nodeDOM(from) as HTMLElement

          if (node) {
            return node.getBoundingClientRect()
          }
        }

        return posToDOMRect(view, from, to)
      }),
    })

    this.show()
  }

  show() {
    this.tippy?.show()
  }

  hide() {
    this.tippy?.hide()
  }

  destroy() {
    if (this.tippy?.popper.firstChild) {
      (this.tippy.popper.firstChild as HTMLElement).removeEventListener('blur', this.tippyBlurHandler)
    }
    this.tippy?.destroy()
    this.element.removeEventListener('mousedown', this.mousedownHandler, { capture: true })
    this.view.dom.removeEventListener('dragstart', this.dragstartHandler)
    this.editor.off('focus', this.focusHandler)
    this.editor.off('blur', this.blurHandler)
  }
}

export const BubbleMenuPlugin = (options: BubbleMenuPluginProps) => {
  return new Plugin({
    key: typeof options.pluginKey === 'string'
      ? new PluginKey(options.pluginKey)
      : options.pluginKey,
    view: view => new BubbleMenuView({ view, ...options }),
  })
}