/*!

* Chai - expectTypes utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .expectTypes(obj, types)
*
* Ensures that the object being tested against is of a valid type.
*
*     utils.expectTypes(this, ['array', 'object', 'string']);
*
* @param {Mixed} obj constructed Assertion
* @param {Array} type A list of allowed types for this assertion
* @namespace Utils
* @name expectTypes
* @api public
*/

var AssertionError = require('assertion-error'); var flag = require('./flag'); var type = require('type-detect');

module.exports = function expectTypes(obj, types) {

var flagMsg = flag(obj, 'message');
var ssfi = flag(obj, 'ssfi');

flagMsg = flagMsg ? flagMsg + ': ' : '';

obj = flag(obj, 'object');
types = types.map(function (t) { return t.toLowerCase(); });
types.sort();

// Transforms ['lorem', 'ipsum'] into 'a lorem, or an ipsum'
var str = types.map(function (t, index) {
  var art = ~[ 'a', 'e', 'i', 'o', 'u' ].indexOf(t.charAt(0)) ? 'an' : 'a';
  var or = types.length > 1 && index === types.length - 1 ? 'or ' : '';
  return or + art + ' ' + t;
}).join(', ');

var objType = type(obj).toLowerCase();

if (!types.some(function (expected) { return objType === expected; })) {
  throw new AssertionError(
    flagMsg + 'object tested must be ' + str + ', but ' + objType + ' given',
    undefined,
    ssfi
  );
}

};