const propUrl = document.body.dataset.editUrl + '.prop'

const preparePropertyEdition = (node) => node.dataset.old = node.innerText

const updateProperty = (node) => {
  if (node.dataset.old == node.innerText) return

  const body = `${node.dataset.property}: ${node.innerText.trim()}`

  if (!node.innerText && !node.value) node.parentNode.remove()

  fetch(propUrl, { method: 'PUT', body: body })
    .catch(error => console.error('Error editing property', error))
}

const pages = document.getElementById('pages')

const prepareChoiceEdition = (node) => {
  // Load list of pages from which authors can select results' page
  if (node.list && !node.dataset.old && !pages.children.length)
    fetch('/pages.txt', { cache: 'no-store' })
      .then(pages => pages.text())
      .then(pages => pages.split('\n')
        .filter(line => line)
        .map(line => `
          <option data-title="${line.replace(/.*.md:title: /g, '')}"
            data-url="${line.replace(/.md:title: .*/g, '')}">
            ${line.replace(/.*.md:title: /g, '')}
          </option>`))
      .then(options => pages.innerHTML += options.join(''))
      .catch(error => console.error('Error getting pages list', error))

  if (node.innerText || node.value)
    node.dataset.old = (node.innerText || node.value).trim()

  let newChoice = node.closest('.new_choice')
  if (newChoice
    && (newChoice.querySelector('label.text').innerText
      || newChoice.querySelector('input[type=text]').value)) {
    // Setup another new choice
    newChoice = node.closest('form.ac_choices').appendChild(newChoice.cloneNode(true))
    newChoice.querySelector('label.text').innerText = ''
    newChoice.querySelector('input[type=text]').value = ''

    setupChoiceEdition()
  }
}

const createChoice = (node) => {
  if (node.nextSibling
    && (!node.querySelector('label.text').innerText
      || !node.querySelector('input[type=text]').value)) {
    // Remove previously added new choice, which seems not required anymore
    node.nextSibling.remove()
  }

  // Only creates the new choice if both "answer" and "destination" are filled
  if (!node.querySelector('label.text').innerText || !node.querySelector('input[type=text]').value) return

  updateChoice(node.querySelector('label.text'))

  node.classList.remove('new_choice')

  setupChoiceEdition()
}

const createPage = (title) => {
  // Page automatic creation, later there should be a mechanism to remove eventual orphans :)
  const option = pages.appendChild(document.createElement('option'))
  option.dataset.title = title
  option.dataset.url = uuid()
  option.innerText = title

  fetch(`${propUrl}/../${option.dataset.url}.prop`, { method: 'PUT', body: `title: ${title}` })
    .catch(error => console.error('Error editing property', error))

  return option
}

const readPage = (node) => {
  const title = node.querySelector('input[type=text]').value.trim()
  let option = pages.querySelector(`option[data-title='${title}']`)
  if (!option) {
    option = createPage(title)
  }
  node.querySelector('a.gotoChoice').href = option.dataset.url
  return `"[${node.querySelector('label.text').innerText.trim()}](${option.dataset.url})"`
}

const updateChoice = (node) => {
  if (node.dataset.old == (node.innerText || node.value)) return

  const choice = node.closest('.ac_choice')
  const index = Array.from(node.closest('form').children).indexOf(choice)
  const body = `${node.dataset.property}[${index}]: ${readPage(choice)}`

  fetch(propUrl, { method: 'PUT', body: body })
    .catch(error => console.error('Error editing property', error))
}

const deleteChoice = (node) => {
  const choice = node.closest('.ac_choice')
  const property = choice.querySelector('label').dataset.property
  const index = Array.from(node.closest('form').children).indexOf(choice)

  fetch(propUrl, { method: 'PUT', body: `${property}[${index}]: ` })
    .catch(error => console.error('Error editing property', error))

  choice.remove()
}

// Utility method
const uuid = () => {
  const temp_url = URL.createObjectURL(new Blob())
  const uuid = temp_url.toString()
  URL.revokeObjectURL(temp_url)
  return uuid.substring(uuid.lastIndexOf('/') + 1) // remove prefix (e.g. blob:null/, blob:www.test.com/, ...)
}