(function(global) {
  var karma = global.__karma__;
  var requirejs = global.requirejs
  var locationPathname = global.location.pathname;
  var root = 'src';
  karma.config.args.forEach(function(value, index) {
    if (value === 'aurelia-root') {
      root = karma.config.args[index + 1];
    }
  });

  if (!karma || !requirejs) {
    return;
  }

  function normalizePath(path) {
    var normalized = []
    var parts = path
      .split('?')[0] // cut off GET params, used by noext requirejs plugin
      .split('/')

    for (var i = 0; i < parts.length; i++) {
      if (parts[i] === '.') {
        continue
      }

      if (parts[i] === '..' && normalized.length && normalized[normalized.length - 1] !== '..') {
        normalized.pop()
        continue
      }

      normalized.push(parts[i])
    }

    return normalized.join('/')
  }

  function patchRequireJS(files, originalLoadFn, locationPathname) {
    var IS_DEBUG = /debug\.html$/.test(locationPathname)

    requirejs.load = function (context, moduleName, url) {
      url = normalizePath(url)

      if (files.hasOwnProperty(url) && !IS_DEBUG) {
        url = url + '?' + files[url]
      }

      if (url.indexOf('/base') !== 0) {
        url = '/base/' + url;
      }

      return originalLoadFn.call(this, context, moduleName, url)
    }

    var originalDefine = global.define;
    global.define = function(name, deps, m) {
      if (typeof name === 'string') {
        originalDefine('/base/' + root + '/' + name, [name], function (result) { return result; });
      }

      return originalDefine(name, deps, m);
    }
  }

  function requireTests() {
    var TEST_REGEXP = /(spec)\.js$/i;
    var allTestFiles = ['/base/test/unit/setup.js'];

    Object.keys(window.__karma__.files).forEach(function(file) {
      if (TEST_REGEXP.test(file)) {
        allTestFiles.push(file);
      }
    });

    require(allTestFiles, window.__karma__.start);
  }

  karma.loaded = function() {}; // make it async
  patchRequireJS(karma.files, requirejs.load, locationPathname);
  requireTests();
})(window);