import { Decoration, NodeView as ProseMirrorNodeView } from 'prosemirror-view'
import { NodeSelection } from 'prosemirror-state'
import { Node as ProseMirrorNode } from 'prosemirror-model'
import { Editor as CoreEditor } from './Editor'
import { Node } from './Node'
import isiOS from './utilities/isiOS'
import { NodeViewRendererProps } from './types'

interface NodeViewRendererOptions {
  stopEvent: ((event: Event) => boolean) | null,
  update: ((node: ProseMirrorNode, decorations: Decoration[]) => boolean) | null,
}

export class NodeView<Component, Editor extends CoreEditor = CoreEditor> implements ProseMirrorNodeView {

  component: Component

  editor: Editor

  extension: Node

  node: ProseMirrorNode

  decorations: Decoration[]

  getPos: any

  isDragging = false

  options: NodeViewRendererOptions = {
    stopEvent: null,
    update: null,
  }

  constructor(component: Component, props: NodeViewRendererProps, options?: Partial<NodeViewRendererOptions>) {
    this.component = component
    this.options = { ...this.options, ...options }
    this.editor = props.editor as Editor
    this.extension = props.extension
    this.node = props.node
    this.decorations = props.decorations
    this.getPos = props.getPos
    this.mount()
  }

  mount() {
    // eslint-disable-next-line
    return
  }

  get dom(): Element | null {
    return null
  }

  get contentDOM(): Element | null {
    return null
  }

  onDragStart(event: DragEvent) {
    const { view } = this.editor
    const target = (event.target as HTMLElement)

    // get the drag handle element
    // `closest` is not available for text nodes so we may have to use its parent
    const dragHandle = target.nodeType === 3
      ? target.parentElement?.closest('[data-drag-handle]')
      : target.closest('[data-drag-handle]')

    if (
      !this.dom
      || this.contentDOM?.contains(target)
      || !dragHandle
    ) {
      return
    }

    let x = 0
    let y = 0

    // calculate offset for drag element if we use a different drag handle element
    if (this.dom !== dragHandle) {
      const domBox = this.dom.getBoundingClientRect()
      const handleBox = dragHandle.getBoundingClientRect()

      x = handleBox.x - domBox.x + event.offsetX
      y = handleBox.y - domBox.y + event.offsetY
    }

    event.dataTransfer?.setDragImage(this.dom, x, y)

    // we need to tell ProseMirror that we want to move the whole node
    // so we create a NodeSelection
    const selection = NodeSelection.create(view.state.doc, this.getPos())
    const transaction = view.state.tr.setSelection(selection)

    view.dispatch(transaction)
  }

  stopEvent(event: Event) {
    if (!this.dom) {
      return false
    }

    if (typeof this.options.stopEvent === 'function') {
      return this.options.stopEvent(event)
    }

    const target = (event.target as HTMLElement)
    const isInElement = this.dom.contains(target) && !this.contentDOM?.contains(target)

    // any event from child nodes should be handled by ProseMirror
    if (!isInElement) {
      return false
    }

    const isInput = ['INPUT', 'BUTTON', 'SELECT', 'TEXTAREA'].includes(target.tagName)
      || target.isContentEditable

    // any input event within node views should be ignored by ProseMirror
    if (isInput) {
      return true
    }

    const { isEditable } = this.editor
    const { isDragging } = this
    const isDraggable = !!this.node.type.spec.draggable
    const isSelectable = NodeSelection.isSelectable(this.node)
    const isCopyEvent = event.type === 'copy'
    const isPasteEvent = event.type === 'paste'
    const isCutEvent = event.type === 'cut'
    const isClickEvent = event.type === 'mousedown'
    const isDragEvent = event.type.startsWith('drag') || event.type === 'drop'

    // ProseMirror tries to drag selectable nodes
    // even if `draggable` is set to `false`
    // this fix prevents that
    if (!isDraggable && isSelectable && isDragEvent) {
      event.preventDefault()
    }

    if (isDraggable && isDragEvent && !isDragging) {
      event.preventDefault()
      return false
    }

    // we have to store that dragging started
    if (isDraggable && isEditable && !isDragging && isClickEvent) {
      const dragHandle = target.closest('[data-drag-handle]')
      const isValidDragHandle = dragHandle
        && (this.dom === dragHandle || (this.dom.contains(dragHandle)))

      if (isValidDragHandle) {
        this.isDragging = true

        document.addEventListener('dragend', () => {
          this.isDragging = false
        }, { once: true })

        document.addEventListener('mouseup', () => {
          this.isDragging = false
        }, { once: true })
      }
    }

    // these events are handled by prosemirror
    if (
      isDragging
      || isCopyEvent
      || isPasteEvent
      || isCutEvent
      || (isClickEvent && isSelectable)
    ) {
      return false
    }

    return true
  }

  ignoreMutation(mutation: MutationRecord | { type: 'selection', target: Element }) {
    if (!this.dom || !this.contentDOM) {
      return true
    }

    // a leaf/atom node is like a black box for ProseMirror
    // and should be fully handled by the node view
    if (this.node.isLeaf || this.node.isAtom) {
      return true
    }

    // ProseMirror should handle any selections
    if (mutation.type === 'selection') {
      return false
    }

    // try to prevent a bug on iOS that will break node views on enter
    // this is because ProseMirror can’t preventDispatch on enter
    // this will lead to a re-render of the node view on enter
    // see: https://github.com/ueberdosis/tiptap/issues/1214
    if (this.dom.contains(mutation.target) && mutation.type === 'childList' && isiOS()) {
      const changedNodes = [
        ...Array.from(mutation.addedNodes),
        ...Array.from(mutation.removedNodes),
      ] as HTMLElement[]

      // we’ll check if every changed node is contentEditable
      // to make sure it’s probably mutated by ProseMirror
      if (changedNodes.every(node => node.isContentEditable)) {
        return false
      }
    }

    // we will allow mutation contentDOM with attributes
    // so we can for example adding classes within our node view
    if (this.contentDOM === mutation.target && mutation.type === 'attributes') {
      return true
    }

    // ProseMirror should handle any changes within contentDOM
    if (this.contentDOM.contains(mutation.target)) {
      return false
    }

    return true
  }

  updateAttributes(attributes: {}) {
    this.editor.commands.command(({ tr }) => {
      const pos = this.getPos()

      tr.setNodeMarkup(pos, undefined, {
        ...this.node.attrs,
        ...attributes,
      })

      return true
    })
  }

  deleteNode(): void {
    const from = this.getPos()
    const to = from + this.node.nodeSize

    this.editor.commands.deleteRange({ from, to })
  }
}