import PrismicDOM from 'prismic-dom'
import { PrismicBlockType, PrismicBlock, TransformBlock } from '../types'

const getType = (block: PrismicBlock | number | string | PrismicBlock[]): PrismicBlockType | undefined => {
  if (!block) {
    return undefined
  }

  if (typeof block === 'string' || typeof block === 'number') {
    return 'text'
  }

  if (Array.isArray(block)) {
    return 'html'
  }

  if (block.dimensions && block.url) {
    return 'image'
  }

  if (block.embed_url) {
    return 'embed'
  }

  if (block.link_type) {
    return block.kind === 'image' ? 'image' : 'link'
  }

  return undefined
}

const getElement = (block: PrismicBlock | number | string): PrismicBlock | PrismicBlock[] => {
  if (typeof block === 'object') {
    return block
  }

  return [{
    type: 'paragraph',
    text: block,
    spans: []
  }]
}

const transformBlock: TransformBlock<PrismicBlock | PrismicBlock[] | number | string> = (block): string => {
  const blockType = getType(block)
  const element = getElement(block) as PrismicBlock

  switch (blockType) {
    case 'html':
      return PrismicDOM.RichText.asHtml(element.map(elem => ({
        ...elem,
        type: elem.type || 'paragraph',
        text: elem.text || '',
        spans: Array.isArray(elem.spans) ? elem.spans : []
      })))
    case 'image':
      const { height, width, url, alt, name } = element
      return `<img src="${url || ''}" height="${height || ''}" width="${width || ''}" alt="${alt || name || ''}" />`
    case 'text':
      return PrismicDOM.RichText.asText(element)
    case 'embed':
      return element.html || ''
    case 'link':
      return PrismicDOM.Link.url(element, doc => `<a href="${doc.url}">${doc.url}</a>`)
    default:
      return ''
  }
}

export { transformBlock }