tailwind-ctp-intellisense/packages/tailwindcss-language-service/src/util/html.ts

import type { TextDocument, Position } from 'vscode-languageserver'
import { State } from './state'

export const HTML_LANGUAGES = [
  'aspnetcorerazor',
  'blade',
  'django-html',
  'edge',
  'ejs',
  'erb',
  'gohtml',
  'GoHTML',
  'haml',
  'handlebars',
  'hbs',
  'html',
  'HTML (Eex)',
  'HTML (EEx)',
  'html-eex',
  'jade',
  'leaf',
  'liquid',
  'markdown',
  'mdx',
  'mustache',
  'njk',
  'nunjucks',
  'php',
  'razor',
  'slim',
  'twig',
]

export function isHtmlDoc(state: State, doc: TextDocument): boolean {
  const userHtmlLanguages = Object.keys(
    state.editor.userLanguages
  ).filter((lang) => HTML_LANGUAGES.includes(state.editor.userLanguages[lang]))

  return (
    [...HTML_LANGUAGES, ...userHtmlLanguages].indexOf(doc.languageId) !== -1
  )
}

export function isVueDoc(doc: TextDocument): boolean {
  return doc.languageId === 'vue'
}

export function isSvelteDoc(doc: TextDocument): boolean {
  return doc.languageId === 'svelte'
}

export function isHtmlContext(
  state: State,
  doc: TextDocument,
  position: Position
): boolean {
  let str = doc.getText({
    start: { line: 0, character: 0 },
    end: position,
  })

  if (isHtmlDoc(state, doc) && !isInsideTag(str, ['script', 'style'])) {
    return true
  }

  if (isVueDoc(doc)) {
    return isInsideTag(str, ['template'])
  }

  if (isSvelteDoc(doc)) {
    return !isInsideTag(str, ['script', 'style'])
  }

  return false
}

export function isInsideTag(str: string, tag: string | string[]): boolean {
  let open = 0
  let close = 0
  let match: RegExpExecArray
  let tags = Array.isArray(tag) ? tag : [tag]
  let regex = new RegExp(`<(?<slash>/?)(?:${tags.join('|')})\\b`, 'ig')
  while ((match = regex.exec(str)) !== null) {
    if (match.groups.slash) {
      close += 1
    } else {
      open += 1
    }
  }
  return open > 0 && open > close
}