/*!
   * raw-body
   * Copyright(c) 2013-2014 Jonathan Ong
   * Copyright(c) 2014-2015 Douglas Christopher Wilson
   * MIT Licensed
   */
  
  'use strict'
  
  /**
   * Module dependencies.
   * @private
   */
  
  var bytes = require('bytes')
  var iconv = require('iconv-lite')
  var unpipe = require('unpipe')
  
  /**
   * Module exports.
   * @public
   */
  
  module.exports = getRawBody
  
  /**
   * Module variables.
   * @private
   */
  
  var iconvEncodingMessageRegExp = /^Encoding not recognized: /
  
  /**
   * Get the decoder for a given encoding.
   *
   * @param {string} encoding
   * @private
   */
  
  function getDecoder (encoding) {
    if (!encoding) return null
  
    try {
      return iconv.getDecoder(encoding)
    } catch (e) {
      // error getting decoder
      if (!iconvEncodingMessageRegExp.test(e.message)) throw e
  
      // the encoding was not found
      throw createError(415, 'specified encoding unsupported', 'encoding.unsupported', {
        encoding: encoding
      })
    }
  }
  
  /**
   * Get the raw body of a stream (typically HTTP).
   *
   * @param {object} stream
   * @param {object|string|function} [options]
   * @param {function} [callback]
   * @public
   */
  
  function getRawBody (stream, options, callback) {
    var done = callback
    var opts = options || {}
  
    if (options === true || typeof options === 'string') {
      // short cut for encoding
      opts = {
        encoding: options
      }
    }
  
    if (typeof options === 'function') {
      done = options
      opts = {}
    }
  
    // validate callback is a function, if provided
    if (done !== undefined && typeof done !== 'function') {
      throw new TypeError('argument callback must be a function')
    }
  
    // require the callback without promises
    if (!done && !global.Promise) {
      throw new TypeError('argument callback is required')
    }
  
    // get encoding
    var encoding = opts.encoding !== true
      ? opts.encoding
      : 'utf-8'
  
    // convert the limit to an integer
    var limit = bytes.parse(opts.limit)
  
    // convert the expected length to an integer
    var length = opts.length != null && !isNaN(opts.length)
      ? parseInt(opts.length, 10)
      : null
  
    if (done) {
      // classic callback style
      return readStream(stream, encoding, length, limit, done)
    }
  
    return new Promise(function executor (resolve, reject) {
      readStream(stream, encoding, length, limit, function onRead (err, buf) {
        if (err) return reject(err)
        resolve(buf)
      })
    })
  }
  
  /**
   * Halt a stream.
   *
   * @param {Object} stream
   * @private
   */
  
  function halt (stream) {
    // unpipe everything from the stream
    unpipe(stream)
  
    // pause stream
    if (typeof stream.pause === 'function') {
      stream.pause()
    }
  }
  
  /**
   * Make a serializable error object.
   *
   * To create serializable errors you must re-set message so
   * that it is enumerable and you must re configure the type
   * property so that is writable and enumerable.
   *
   * @param {number} status
   * @param {string} message
   * @param {string} type
   * @param {object} props
   * @private
   */
  
  function createError (status, message, type, props) {
    var error = new Error()
  
    // capture stack trace
    Error.captureStackTrace(error, createError)
  
    // set free-form properties
    for (var prop in props) {
      error[prop] = props[prop]
    }
  
    // set message
    error.message = message
  
    // set status
    error.status = status
    error.statusCode = status
  
    // set type
    Object.defineProperty(error, 'type', {
      value: type,
      enumerable: true,
      writable: true,
      configurable: true
    })
  
    return error
  }
  
  /**
   * Read the data from the stream.
   *
   * @param {object} stream
   * @param {string} encoding
   * @param {number} length
   * @param {number} limit
   * @param {function} callback
   * @public
   */
  
  function readStream (stream, encoding, length, limit, callback) {
    var complete = false
    var sync = true
  
    // check the length and limit options.
    // note: we intentionally leave the stream paused,
    // so users should handle the stream themselves.
    if (limit !== null && length !== null && length > limit) {
      return done(createError(413, 'request entity too large', 'entity.too.large', {
        expected: length,
        length: length,
        limit: limit
      }))
    }
  
    // streams1: assert request encoding is buffer.
    // streams2+: assert the stream encoding is buffer.
    //   stream._decoder: streams1
    //   state.encoding: streams2
    //   state.decoder: streams2, specifically < 0.10.6
    var state = stream._readableState
    if (stream._decoder || (state && (state.encoding || state.decoder))) {
      // developer error
      return done(createError(500, 'stream encoding should not be set', 'stream.encoding.set'))
    }
  
    var received = 0
    var decoder
  
    try {
      decoder = getDecoder(encoding)
    } catch (err) {
      return done(err)
    }
  
    var buffer = decoder
      ? ''
      : []
  
    // attach listeners
    stream.on('aborted', onAborted)
    stream.on('close', cleanup)
    stream.on('data', onData)
    stream.on('end', onEnd)
    stream.on('error', onEnd)
  
    // mark sync section complete
    sync = false
  
    function done () {
      var args = new Array(arguments.length)
  
      // copy arguments
      for (var i = 0; i < args.length; i++) {
        args[i] = arguments[i]
      }
  
      // mark complete
      complete = true
  
      if (sync) {
        process.nextTick(invokeCallback)
      } else {
        invokeCallback()
      }
  
      function invokeCallback () {
        cleanup()
  
        if (args[0]) {
          // halt the stream on error
          halt(stream)
        }
  
        callback.apply(null, args)
      }
    }
  
    function onAborted () {
      if (complete) return
  
      done(createError(400, 'request aborted', 'request.aborted', {
        code: 'ECONNABORTED',
        expected: length,
        length: length,
        received: received
      }))
    }
  
    function onData (chunk) {
      if (complete) return
  
      received += chunk.length
      decoder
        ? buffer += decoder.write(chunk)
        : buffer.push(chunk)
  
      if (limit !== null && received > limit) {
        done(createError(413, 'request entity too large', 'entity.too.large', {
          limit: limit,
          received: received
        }))
      }
    }
  
    function onEnd (err) {
      if (complete) return
      if (err) return done(err)
  
      if (length !== null && received !== length) {
        done(createError(400, 'request size did not match content length', 'request.size.invalid', {
          expected: length,
          length: length,
          received: received
        }))
      } else {
        var string = decoder
          ? buffer + (decoder.end() || '')
          : Buffer.concat(buffer)
        done(null, string)
      }
    }
  
    function cleanup () {
      buffer = null
  
      stream.removeListener('aborted', onAborted)
      stream.removeListener('data', onData)
      stream.removeListener('end', onEnd)
      stream.removeListener('error', onEnd)
      stream.removeListener('close', cleanup)
    }
  }