'use strict'

var markdownLineEnding = require('../character/markdown-line-ending.js')
var prefixSize = require('../util/prefix-size.js')
var subtokenize = require('../util/subtokenize.js')
var factorySpace = require('./factory-space.js')

// No name because it must not be turned off.
var content = {
  tokenize: tokenizeContent,
  resolve: resolveContent,
  interruptible: true,
  lazy: true
}
var continuationConstruct = {
  tokenize: tokenizeContinuation,
  partial: true
} // Content is transparent: it’s parsed right now. That way, definitions are also
// parsed right now: before text in paragraphs (specifically, media) are parsed.

function resolveContent(events) {
  subtokenize(events)
  return events
}

function tokenizeContent(effects, ok) {
  var previous
  return start

  function start(code) {
    effects.enter('content')
    previous = effects.enter('chunkContent', {
      contentType: 'content'
    })
    return data(code)
  }

  function data(code) {
    if (code === null) {
      return contentEnd(code)
    }

    if (markdownLineEnding(code)) {
      return effects.check(
        continuationConstruct,
        contentContinue,
        contentEnd
      )(code)
    } // Data.

    effects.consume(code)
    return data
  }

  function contentEnd(code) {
    effects.exit('chunkContent')
    effects.exit('content')
    return ok(code)
  }

  function contentContinue(code) {
    effects.consume(code)
    effects.exit('chunkContent')
    previous = previous.next = effects.enter('chunkContent', {
      contentType: 'content',
      previous: previous
    })
    return data
  }
}

function tokenizeContinuation(effects, ok, nok) {
  var self = this
  return startLookahead

  function startLookahead(code) {
    effects.enter('lineEnding')
    effects.consume(code)
    effects.exit('lineEnding')
    return factorySpace(effects, prefixed, 'linePrefix')
  }

  function prefixed(code) {
    if (code === null || markdownLineEnding(code)) {
      return nok(code)
    }

    if (
      self.parser.constructs.disable.null.indexOf('codeIndented') > -1 ||
      prefixSize(self.events, 'linePrefix') < 4
    ) {
      return effects.interrupt(self.parser.constructs.flow, nok, ok)(code)
    }

    return ok(code)
  }
}

module.exports = content