/**
 * @license
 * Copyright Google Inc. All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import {GetTestability, Injectable, Testability, TestabilityRegistry, setTestabilityGetter} from '@angular/core';

import {getDOM} from '../dom/dom_adapter';
import {ListWrapper} from '../facade/collection';
import {global, isPresent} from '../facade/lang';

export class BrowserGetTestability implements GetTestability {
  static init() { setTestabilityGetter(new BrowserGetTestability()); }

  addToWindow(registry: TestabilityRegistry): void {
    global.getAngularTestability = (elem: any, findInAncestors: boolean = true) => {
      var testability = registry.findTestabilityInTree(elem, findInAncestors);
      if (testability == null) {
        throw new Error('Could not find testability for element.');
      }
      return testability;
    };

    global.getAllAngularTestabilities = () => { return registry.getAllTestabilities(); };

    global.getAllAngularRootElements = () => registry.getAllRootElements();

    var whenAllStable = (callback: any /** TODO #9100 */) => {
      var testabilities = global.getAllAngularTestabilities();
      var count = testabilities.length;
      var didWork = false;
      var decrement = function(didWork_: any /** TODO #9100 */) {
        didWork = didWork || didWork_;
        count--;
        if (count == 0) {
          callback(didWork);
        }
      };
      testabilities.forEach(function(testability: any /** TODO #9100 */) {
        testability.whenStable(decrement);
      });
    };

    if (!global['frameworkStabilizers']) {
      global['frameworkStabilizers'] = ListWrapper.createGrowableSize(0);
    }
    global['frameworkStabilizers'].push(whenAllStable);
  }

  findTestabilityInTree(registry: TestabilityRegistry, elem: any, findInAncestors: boolean):
      Testability {
    if (elem == null) {
      return null;
    }
    var t = registry.getTestability(elem);
    if (isPresent(t)) {
      return t;
    } else if (!findInAncestors) {
      return null;
    }
    if (getDOM().isShadowRoot(elem)) {
      return this.findTestabilityInTree(registry, getDOM().getHost(elem), true);
    }
    return this.findTestabilityInTree(registry, getDOM().parentElement(elem), true);
  }
}