const lookup = new WeakMap() 

let id = 0;

export const els = selectAll(document.body)

export const parentOf = el => lookup.get(el)

export function selectAll(parent) {

  const els = { id, el: parent, all: {} }

  const allEls = [...parent.querySelectorAll('*')]

  id++

  for (let i in allEls) {

    const el = allEls[i]

    // any element can lookup `els`

    lookup.set(el, els)

    const tag = el.tagName.toLowerCase()

    if (el.id) {

      els[el.id] = el

      tag === 'template' &&

        (els[el.id + 'Tmpl'] = () => {

          const instanceEl = el.content

            .cloneNode(true)

            .firstElementChild

          return selectAll(

            instanceEl

          )

        })

    }

    if (el.classList.length > 0) {

      const name = el.classList[0]

      if (!els[name]) { 

        els[name] = el

        els.all[name] = [el]

      } else {

        els.all[name].push(el)

      }

    }

  }

  return els;

}