'use client'

import type { Editor } from '@tiptap/react'
import { useTiptapEditor } from '@admin/hooks/content-editor/use-tiptap-editor'
import { findNodePosition } from '@admin/utils/editor/find-node-position'
import { getSelectedBlockNodes } from '@admin/utils/editor/get-selected-block-nodes'
import { isNodeInSchema } from '@admin/utils/editor/is-node-in-schema'
import { isNodeTypeSelected } from '@admin/utils/editor/is-node-type-selected'
import { isValidPosition } from '@admin/utils/editor/is-valid-position'
import { selectionWithinConvertibleTypes } from '@admin/utils/editor/selection-within-convertible-types'
import { NodeSelection, TextSelection } from '@tiptap/pm/state'
import {
  Heading5Icon as HeadingFiveIcon,
  Heading4Icon as HeadingFourIcon,
  Heading1Icon as HeadingOneIcon,
  Heading6Icon as HeadingSixIcon,
  Heading3Icon as HeadingThreeIcon,
  Heading2Icon as HeadingTwoIcon
} from 'lucide-react'
import { useCallback, useEffect, useState } from 'react'

export type Level = 1 | 2 | 3 | 4 | 5 | 6

export interface UseHeadingConfig {
  editor?: Editor | null
  level: Level
  hideWhenUnavailable?: boolean
  onToggled?: () => void
}

export const headingIcons = {
  1: HeadingOneIcon,
  2: HeadingTwoIcon,
  3: HeadingThreeIcon,
  4: HeadingFourIcon,
  5: HeadingFiveIcon,
  6: HeadingSixIcon
}

export const HEADING_SHORTCUT_KEYS: Record<Level, string> = {
  1: 'ctrl+alt+1',
  2: 'ctrl+alt+2',
  3: 'ctrl+alt+3',
  4: 'ctrl+alt+4',
  5: 'ctrl+alt+5',
  6: 'ctrl+alt+6'
}

export function canToggle(editor: Editor | null, level?: Level, turnInto: boolean = true): boolean {
  if (!editor || !editor.isEditable) return false
  if (!isNodeInSchema('heading', editor) || isNodeTypeSelected(editor, ['image'])) return false

  if (!turnInto) {
    return level ? editor.can().setNode('heading', { level }) : editor.can().setNode('heading')
  }

  if (
    !selectionWithinConvertibleTypes(editor, [
      'paragraph',
      'heading',
      'bulletList',
      'orderedList',
      'taskList',
      'blockquote',
      'codeBlock'
    ])
  )
    return false

  return level
    ? editor.can().setNode('heading', { level }) || editor.can().clearNodes()
    : editor.can().setNode('heading') || editor.can().clearNodes()
}

export function isHeadingActive(editor: Editor | null, level?: Level | Level[]): boolean {
  if (!editor || !editor.isEditable) return false

  if (Array.isArray(level)) {
    return level.some((l) => editor.isActive('heading', { level: l }))
  }

  return level ? editor.isActive('heading', { level }) : editor.isActive('heading')
}

export function toggleHeading(editor: Editor | null, level: Level | Level[]): boolean {
  if (!editor || !editor.isEditable) return false

  const levels = Array.isArray(level) ? level : [level]
  const toggleLevel = levels.find((l) => canToggle(editor, l))

  if (!toggleLevel) return false

  try {
    const view = editor.view
    let state = view.state
    let tr = state.tr

    const blocks = getSelectedBlockNodes(editor)

    const isPossibleToTurnInto =
      selectionWithinConvertibleTypes(editor, [
        'paragraph',
        'heading',
        'bulletList',
        'orderedList',
        'taskList',
        'blockquote',
        'codeBlock'
      ]) && blocks.length === 1

    if (
      (state.selection.empty || state.selection instanceof TextSelection) &&
      isPossibleToTurnInto
    ) {
      const pos = findNodePosition({
        editor,
        node: state.selection.$anchor.node(1)
      })?.pos
      if (!isValidPosition(pos)) return false

      tr = tr.setSelection(NodeSelection.create(state.doc, pos))
      view.dispatch(tr)
      state = view.state
    }

    const selection = state.selection
    let chain = editor.chain().focus()

    if (selection instanceof NodeSelection) {
      const firstChild = selection.node.firstChild?.firstChild
      const lastChild = selection.node.lastChild?.lastChild

      const from = firstChild ? selection.from + firstChild.nodeSize : selection.from + 1

      const to = lastChild ? selection.to - lastChild.nodeSize : selection.to - 1

      const resolvedFrom = state.doc.resolve(from)
      const resolvedTo = state.doc.resolve(to)

      chain = chain.setTextSelection(TextSelection.between(resolvedFrom, resolvedTo)).clearNodes()
    }

    const isActive = levels.some((l) => editor.isActive('heading', { level: l }))

    const toggle = isActive
      ? chain.setNode('paragraph')
      : chain.setNode('heading', { level: toggleLevel })

    toggle.run()

    editor.chain().focus().selectTextblockEnd().run()

    return true
  } catch {
    return false
  }
}

export function shouldShowButton(props: {
  editor: Editor | null
  level?: Level | Level[]
  hideWhenUnavailable: boolean
}): boolean {
  const { editor, level, hideWhenUnavailable } = props

  if (!editor || !editor.isEditable) return false

  if (!hideWhenUnavailable) {
    return true
  }

  if (!isNodeInSchema('heading', editor)) return false

  if (!editor.isActive('code')) {
    if (Array.isArray(level)) {
      return level.some((l) => canToggle(editor, l))
    }
    return canToggle(editor, level)
  }

  return true
}

export function useHeading(config: UseHeadingConfig) {
  const { editor: providedEditor, level, hideWhenUnavailable = false, onToggled } = config

  const { editor } = useTiptapEditor(providedEditor)
  const [isVisible, setIsVisible] = useState<boolean>(true)
  const canToggleState = canToggle(editor, level)
  const isActive = isHeadingActive(editor, level)

  useEffect(() => {
    if (!editor) return

    const handleSelectionUpdate = () => {
      setIsVisible(shouldShowButton({ editor, level, hideWhenUnavailable }))
    }

    handleSelectionUpdate()

    editor.on('selectionUpdate', handleSelectionUpdate)

    return () => {
      editor.off('selectionUpdate', handleSelectionUpdate)
    }
  }, [editor, level, hideWhenUnavailable])

  const handleToggle = useCallback(() => {
    if (!editor) return false

    const success = toggleHeading(editor, level)
    if (success) {
      onToggled?.()
    }
    return success
  }, [editor, level, onToggled])

  return {
    isVisible,
    isActive,
    handleToggle,
    canToggle: canToggleState,
    label: `Heading ${level}`,
    shortcutKeys: HEADING_SHORTCUT_KEYS[level],
    Icon: headingIcons[level]
  }
}