HORIZON PROJECT

var makeError = require('./lib/make-error')

var makeMiddleware = require('./lib/make-middleware')

var diskStorage = require('./storage/disk')

var memoryStorage = require('./storage/memory')

function allowAll (req, file, cb) {

  cb(null, true)

}

function Multer (options) {

  if (options.storage) {

    this.storage = options.storage

  } else if (options.dest) {

    this.storage = diskStorage({ destination: options.dest })

  } else {

    this.storage = memoryStorage()

  }

  this.limits = options.limits

  this.preservePath = options.preservePath

  this.fileFilter = options.fileFilter || allowAll

}

Multer.prototype._makeMiddleware = function (fields, fileStrategy) {

  function setup () {

    var fileFilter = this.fileFilter

    var filesLeft = Object.create(null)

    fields.forEach(function (field) {

      if (typeof field.maxCount === 'number') {

        filesLeft[field.name] = field.maxCount

      } else {

        filesLeft[field.name] = Infinity

      }

    })

    function wrappedFileFilter (req, file, cb) {

      if ((filesLeft[file.fieldname] || 0) <= 0) {

        return cb(makeError('LIMIT_UNEXPECTED_FILE', file.fieldname))

      }

      filesLeft[file.fieldname] -= 1

      fileFilter(req, file, cb)

    }

    return {

      limits: this.limits,

      preservePath: this.preservePath,

      storage: this.storage,

      fileFilter: wrappedFileFilter,

      fileStrategy: fileStrategy

    }

  }

  return makeMiddleware(setup.bind(this))

}

Multer.prototype.single = function (name) {

  return this._makeMiddleware([{ name: name, maxCount: 1 }], 'VALUE')

}

Multer.prototype.array = function (name, maxCount) {

  return this._makeMiddleware([{ name: name, maxCount: maxCount }], 'ARRAY')

}

Multer.prototype.fields = function (fields) {

  return this._makeMiddleware(fields, 'OBJECT')

}

Multer.prototype.none = function () {

  return this._makeMiddleware([], 'NONE')

}

Multer.prototype.any = function () {

  function setup () {

    return {

      limits: this.limits,

      preservePath: this.preservePath,

      storage: this.storage,

      fileFilter: this.fileFilter,

      fileStrategy: 'ARRAY'

    }

  }

  return makeMiddleware(setup.bind(this))

}

function multer (options) {

  if (options === undefined) {

    return new Multer({})

  }

  if (typeof options === 'object' && options !== null) {

    return new Multer(options)

  }

  throw new TypeError('Expected object for argument options')

}

module.exports = multer

module.exports.diskStorage = diskStorage

module.exports.memoryStorage = memoryStorage