'use strict'

var markdownLineEnding = require('../character/markdown-line-ending.js')
var markdownSpace = require('../character/markdown-space.js')
var factorySpace = require('./factory-space.js')

var thematicBreak = {
  name: 'thematicBreak',
  tokenize: tokenizeThematicBreak
}

function tokenizeThematicBreak(effects, ok, nok) {
  var size = 0
  var marker
  return start

  function start(code) {
    effects.enter('thematicBreak')
    marker = code
    return atBreak(code)
  }

  function atBreak(code) {
    if (code === marker) {
      effects.enter('thematicBreakSequence')
      return sequence(code)
    }

    if (markdownSpace(code)) {
      return factorySpace(effects, atBreak, 'whitespace')(code)
    }

    if (size < 3 || (code !== null && !markdownLineEnding(code))) {
      return nok(code)
    }

    effects.exit('thematicBreak')
    return ok(code)
  }

  function sequence(code) {
    if (code === marker) {
      effects.consume(code)
      size++
      return sequence
    }

    effects.exit('thematicBreakSequence')
    return atBreak(code)
  }
}

module.exports = thematicBreak