HORIZON PROJECT

var Writable = require('readable-stream').Writable

var inherits = require('inherits')

if (typeof Uint8Array === 'undefined') {

  var U8 = require('typedarray').Uint8Array

} else {

  var U8 = Uint8Array

}

function ConcatStream(opts, cb) {

  if (!(this instanceof ConcatStream)) return new ConcatStream(opts, cb)

  if (typeof opts === 'function') {

    cb = opts

    opts = {}

  }

  if (!opts) opts = {}

  var encoding = opts.encoding

  var shouldInferEncoding = false

  if (!encoding) {

    shouldInferEncoding = true

  } else {

    encoding =  String(encoding).toLowerCase()

    if (encoding === 'u8' || encoding === 'uint8') {

      encoding = 'uint8array'

    }

  }

  Writable.call(this, { objectMode: true })

  this.encoding = encoding

  this.shouldInferEncoding = shouldInferEncoding

  if (cb) this.on('finish', function () { cb(this.getBody()) })

  this.body = []

}

module.exports = ConcatStream

inherits(ConcatStream, Writable)

ConcatStream.prototype._write = function(chunk, enc, next) {

  this.body.push(chunk)

  next()

}

ConcatStream.prototype.inferEncoding = function (buff) {

  var firstBuffer = buff === undefined ? this.body[0] : buff;

  if (Buffer.isBuffer(firstBuffer)) return 'buffer'

  if (typeof Uint8Array !== 'undefined' && firstBuffer instanceof Uint8Array) return 'uint8array'

  if (Array.isArray(firstBuffer)) return 'array'

  if (typeof firstBuffer === 'string') return 'string'

  if (Object.prototype.toString.call(firstBuffer) === "[object Object]") return 'object'

  return 'buffer'

}

ConcatStream.prototype.getBody = function () {

  if (!this.encoding && this.body.length === 0) return []

  if (this.shouldInferEncoding) this.encoding = this.inferEncoding()

  if (this.encoding === 'array') return arrayConcat(this.body)

  if (this.encoding === 'string') return stringConcat(this.body)

  if (this.encoding === 'buffer') return bufferConcat(this.body)

  if (this.encoding === 'uint8array') return u8Concat(this.body)

  return this.body

}

var isArray = Array.isArray || function (arr) {

  return Object.prototype.toString.call(arr) == '[object Array]'

}

function isArrayish (arr) {

  return /Array\]$/.test(Object.prototype.toString.call(arr))

}

function isBufferish (p) {

  return typeof p === 'string' || isArrayish(p) || (p && typeof p.subarray === 'function')

}

function stringConcat (parts) {

  var strings = []

  var needsToString = false

  for (var i = 0; i < parts.length; i++) {

    var p = parts[i]

    if (typeof p === 'string') {

      strings.push(p)

    } else if (Buffer.isBuffer(p)) {

      strings.push(p)

    } else if (isBufferish(p)) {

      strings.push(new Buffer(p))

    } else {

      strings.push(new Buffer(String(p)))

    }

  }

  if (Buffer.isBuffer(parts[0])) {

    strings = Buffer.concat(strings)

    strings = strings.toString('utf8')

  } else {

    strings = strings.join('')

  }

  return strings

}

function bufferConcat (parts) {

  var bufs = []

  for (var i = 0; i < parts.length; i++) {

    var p = parts[i]

    if (Buffer.isBuffer(p)) {

      bufs.push(p)

    } else if (isBufferish(p)) {

      bufs.push(new Buffer(p))

    } else {

      bufs.push(new Buffer(String(p)))

    }

  }

  return Buffer.concat(bufs)

}

function arrayConcat (parts) {

  var res = []

  for (var i = 0; i < parts.length; i++) {

    res.push.apply(res, parts[i])

  }

  return res

}

function u8Concat (parts) {

  var len = 0

  for (var i = 0; i < parts.length; i++) {

    if (typeof parts[i] === 'string') {

      parts[i] = new Buffer(parts[i])

    }

    len += parts[i].length

  }

  var u8 = new U8(len)

  for (var i = 0, offset = 0; i < parts.length; i++) {

    var part = parts[i]

    for (var j = 0; j < part.length; j++) {

      u8[offset++] = part[j]

    }

  }

  return u8

}