frontend/src/utils/htmlParser/stringify.ts

import type { AST, ElementAST, ElementAttribute } from './types'
import { voidTags } from './tags'

export const formatAttributes = (attributes: ElementAttribute[]) => {
  return attributes.reduce((attrs, attribute) => {
    const { key, value } = attribute
    if (value === null) return `${attrs} ${key}`
    if (key === 'style' && !value) return ''

    const quoteEscape = value.indexOf('\'') !== -1
    const quote = quoteEscape ? '"' : '\''
    return `${attrs} ${key}=${quote}${value}${quote}`
  }, '')
}

export const toHTML = (tree: AST[]) => {
  const htmlStrings: string[] = tree.map(node => {
    if (node.type === 'text') return node.content
    if (node.type === 'comment') return `<!--${node.content}-->`

    const { tagName, attributes, children } = node as ElementAST
    const isSelfClosing = voidTags.includes(tagName.toLowerCase())

    if (isSelfClosing) return `<${tagName}${formatAttributes(attributes)}>`
    return `<${tagName}${formatAttributes(attributes)}>${toHTML(children)}</${tagName}>`
  })
  return htmlStrings.join('')
}