'use strict'

var modifyChildren = require('unist-util-modify-children')

module.exports = modifyChildren(mergeNonWordSentences)

// Merge a sentence into the following sentence, when the sentence does not
// contain word tokens.
function mergeNonWordSentences(child, index, parent) {
  var children = child.children
  var position = -1
  var prev
  var next

  while (children[++position]) {
    if (children[position].type === 'WordNode') {
      return
    }
  }

  prev = parent.children[index - 1]

  if (prev) {
    prev.children = prev.children.concat(children)

    // Remove the child.
    parent.children.splice(index, 1)

    // Patch position.
    if (prev.position && child.position) {
      prev.position.end = child.position.end
    }

    // Next, iterate over the node *now* at the current position (which was the
    // next node).
    return index
  }

  next = parent.children[index + 1]

  if (next) {
    next.children = children.concat(next.children)

    // Patch position.
    if (next.position && child.position) {
      next.position.start = child.position.start
    }

    // Remove the child.
    parent.children.splice(index, 1)
  }
}