'use strict'

const balanced = require('balanced-match')

module.exports = function parse(content, opts) {
  var regexpStart = new RegExp(opts.prefix + '[ ]*' + opts.name + '([^{}]*)\\{')
  var regexpEnd = opts.suffix ? new RegExp('^\\s*' + opts.suffix) : false
  var replacement
  var result = ''
  var matchStart
  var matchBody
  var matchEnd
  var startEnd
  var before

  while (matchStart = regexpStart.exec(content)) { // eslint-disable-line
    startEnd = matchStart.index + matchStart[0].length
    matchBody = balanced('{', '}', content.slice(startEnd - 1))

    if (matchBody && matchBody.start === 0) {
      matchEnd = regexpEnd ? regexpEnd.exec(matchBody.post) : true

      if (matchEnd) {
        before = content.slice(0, matchStart.index)
        matchEnd = regexpEnd ? matchEnd[0].length : 0
        replacement = opts.handler({
          before: before,
          args: matchStart[1],
          body: matchBody.body
        })

        if (replacement !== undefined) {
          result += before + parse(replacement.toString(), opts)
          content = content.slice(startEnd + matchBody.end + matchEnd)
          continue
        }
      }
    }

    result += content.slice(0, startEnd)
    content = content.slice(startEnd)
  }

  result += content

  return result
}