import {
  Command, Mark, markInputRule, markPasteRule,
} from '@tiptap/core'

export type ItalicCommand = () => Command

declare module '@tiptap/core/src/Editor' {
  interface Commands {
    italic: ItalicCommand,
  }
}

export const starInputRegex = /(?:^|\s)((?:\*)((?:[^*]+))(?:\*))$/gm
export const starPasteRegex = /(?:^|\s)((?:\*)((?:[^*]+))(?:\*))/gm
export const underscoreInputRegex = /(?:^|\s)((?:_)((?:[^_]+))(?:_))$/gm
export const underscorePasteRegex = /(?:^|\s)((?:_)((?:[^_]+))(?:_))/gm

export default new Mark()
  .name('italic')
  .schema(() => ({
    parseDOM: [
      {
        tag: 'em',
      },
      {
        tag: 'i',
        getAttrs: node => (node as HTMLElement).style.fontStyle !== 'normal' && null,
      },
      {
        style: 'font-style=italic',
      },
    ],
    toDOM: () => ['em', 0],
  }))
  .commands(({ name }) => ({
    italic: () => ({ commands }) => {
      return commands.toggleMark(name)
    },
  }))
  .keys(({ editor }) => ({
    'Mod-i': () => editor.italic(),
  }))
  .inputRules(({ type }) => [
    markInputRule(starInputRegex, type),
    markInputRule(underscoreInputRegex, type),
  ])
  .pasteRules(({ type }) => [
    markPasteRule(starPasteRegex, type),
    markPasteRule(underscorePasteRegex, type),
  ])
  .create()