/**
 * @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 {ChangeDetectorRef as ViewEngine_ChangeDetectorRef} from '../change_detection/change_detector_ref';
import {InjectionToken} from '../di/injection_token';
import {Injector} from '../di/injector';
import {inject} from '../di/injector_compatibility';
import {ComponentFactory as viewEngine_ComponentFactory, ComponentRef as viewEngine_ComponentRef} from '../linker/component_factory';
import {ComponentFactoryResolver as viewEngine_ComponentFactoryResolver} from '../linker/component_factory_resolver';
import {ElementRef as viewEngine_ElementRef} from '../linker/element_ref';
import {NgModuleRef as viewEngine_NgModuleRef} from '../linker/ng_module_factory';
import {RendererFactory2} from '../render/api';
import {Type} from '../type';

import {assertComponentType, assertDefined} from './assert';
import {LifecycleHooksFeature, createRootComponent, createRootComponentView, createRootContext} from './component';
import {getComponentDef} from './definition';
import {NodeInjector} from './di';
import {createLViewData, createNodeAtIndex, createTView, createViewNode, elementCreate, locateHostElement, refreshDescendantViews} from './instructions';
import {ComponentDef, RenderFlags} from './interfaces/definition';
import {TContainerNode, TElementContainerNode, TElementNode, TNode, TNodeType, TViewNode} from './interfaces/node';
import {RElement, RendererFactory3, domRendererFactory3} from './interfaces/renderer';
import {FLAGS, HEADER_OFFSET, INJECTOR, LViewData, LViewFlags, RootContext, TVIEW} from './interfaces/view';
import {enterView, leaveView} from './state';
import {defaultScheduler, getTNode} from './util';
import {createElementRef} from './view_engine_compatibility';
import {RootViewRef, ViewRef} from './view_ref';

export class ComponentFactoryResolver extends viewEngine_ComponentFactoryResolver {
  resolveComponentFactory<T>(component: Type<T>): viewEngine_ComponentFactory<T> {
    ngDevMode && assertComponentType(component);
    const componentDef = getComponentDef(component) !;
    return new ComponentFactory(componentDef);
  }
}

function toRefArray(map: {[key: string]: string}): {propName: string; templateName: string;}[] {
  const array: {propName: string; templateName: string;}[] = [];
  for (let nonMinified in map) {
    if (map.hasOwnProperty(nonMinified)) {
      const minified = map[nonMinified];
      array.push({propName: minified, templateName: nonMinified});
    }
  }
  return array;
}

/**
 * Default {@link RootContext} for all components rendered with {@link renderComponent}.
 */
export const ROOT_CONTEXT = new InjectionToken<RootContext>(
    'ROOT_CONTEXT_TOKEN',
    {providedIn: 'root', factory: () => createRootContext(inject(SCHEDULER))});

/**
 * A change detection scheduler token for {@link RootContext}. This token is the default value used
 * for the default `RootContext` found in the {@link ROOT_CONTEXT} token.
 */
export const SCHEDULER = new InjectionToken<((fn: () => void) => void)>('SCHEDULER_TOKEN', {
  providedIn: 'root',
  factory: () => defaultScheduler,
});

/**
 * A function used to wrap the `RendererFactory2`.
 * Used in tests to change the `RendererFactory2` into a `DebugRendererFactory2`.
 */
export const WRAP_RENDERER_FACTORY2 =
    new InjectionToken<(rf: RendererFactory2) => RendererFactory2>('WRAP_RENDERER_FACTORY2');

const NOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR = {};

function createChainedInjector(rootViewInjector: Injector, moduleInjector: Injector): Injector {
  return {
    get: <T>(token: Type<T>| InjectionToken<T>, notFoundValue?: T): T => {
      const value = rootViewInjector.get(token, NOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR);

      if (value !== NOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR) {
        // Return the value from the root element injector when
        // - it provides it
        //   (value !== NOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR)
        return value;
      }

      return moduleInjector.get(token, notFoundValue);
    }
  };
}

/**
 * Render3 implementation of {@link viewEngine_ComponentFactory}.
 */
export class ComponentFactory<T> extends viewEngine_ComponentFactory<T> {
  selector: string;
  componentType: Type<any>;
  ngContentSelectors: string[];

  get inputs(): {propName: string; templateName: string;}[] {
    return toRefArray(this.componentDef.inputs);
  }

  get outputs(): {propName: string; templateName: string;}[] {
    return toRefArray(this.componentDef.outputs);
  }

  constructor(private componentDef: ComponentDef<any>) {
    super();
    this.componentType = componentDef.type;
    this.selector = componentDef.selectors[0][0] as string;
    this.ngContentSelectors = [];
  }

  create(
      injector: Injector, projectableNodes?: any[][]|undefined, rootSelectorOrNode?: any,
      ngModule?: viewEngine_NgModuleRef<any>|undefined): viewEngine_ComponentRef<T> {
    const isInternalRootView = rootSelectorOrNode === undefined;

    let rendererFactory: RendererFactory3;

    if (ngModule) {
      const wrapper = ngModule.injector.get(WRAP_RENDERER_FACTORY2, (v: RendererFactory2) => v);
      rendererFactory = wrapper(ngModule.injector.get(RendererFactory2)) as RendererFactory3;
    } else {
      rendererFactory = domRendererFactory3;
    }

    const hostRNode = isInternalRootView ?
        elementCreate(this.selector, rendererFactory.createRenderer(null, this.componentDef)) :
        locateHostElement(rendererFactory, rootSelectorOrNode);

    const rootFlags = this.componentDef.onPush ? LViewFlags.Dirty | LViewFlags.IsRoot :
                                                 LViewFlags.CheckAlways | LViewFlags.IsRoot;
    const rootContext: RootContext =
        ngModule && !isInternalRootView ? ngModule.injector.get(ROOT_CONTEXT) : createRootContext();

    const renderer = rendererFactory.createRenderer(hostRNode, this.componentDef);
    const rootViewInjector =
        ngModule ? createChainedInjector(injector, ngModule.injector) : injector;
    // Create the root view. Uses empty TView and ContentTemplate.
    const rootView: LViewData = createLViewData(
        renderer, createTView(-1, null, 1, 0, null, null, null), rootContext, rootFlags, undefined,
        rootViewInjector);

    // rootView is the parent when bootstrapping
    const oldView = enterView(rootView, null);

    let component: T;
    let tElementNode: TElementNode;
    try {
      if (rendererFactory.begin) rendererFactory.begin();

      const componentView =
          createRootComponentView(hostRNode, this.componentDef, rootView, renderer);
      tElementNode = getTNode(0, rootView) as TElementNode;

      // Transform the arrays of native nodes into a structure that can be consumed by the
      // projection instruction. This is needed to support the reprojection of these nodes.
      if (projectableNodes) {
        let index = 0;
        const tView = rootView[TVIEW];
        const projection: TNode[] = tElementNode.projection = [];
        for (let i = 0; i < projectableNodes.length; i++) {
          const nodeList = projectableNodes[i];
          let firstTNode: TNode|null = null;
          let previousTNode: TNode|null = null;
          for (let j = 0; j < nodeList.length; j++) {
            if (tView.firstTemplatePass) {
              // For dynamically created components such as ComponentRef, we create a new TView for
              // each insert. This is not ideal since we should be sharing the TViews.
              // Also the logic here should be shared with `component.ts`'s `renderComponent`
              // method.
              tView.expandoStartIndex++;
              tView.blueprint.splice(++index + HEADER_OFFSET, 0, null);
              tView.data.splice(index + HEADER_OFFSET, 0, null);
              rootView.splice(index + HEADER_OFFSET, 0, null);
            }
            const tNode =
                createNodeAtIndex(index, TNodeType.Element, nodeList[j] as RElement, null, null);
            previousTNode ? (previousTNode.next = tNode) : (firstTNode = tNode);
            previousTNode = tNode;
          }
          projection.push(firstTNode !);
        }
      }

      // TODO: should LifecycleHooksFeature and other host features be generated by the compiler and
      // executed here?
      // Angular 5 reference: https://stackblitz.com/edit/lifecycle-hooks-vcref
      component = createRootComponent(
          componentView, this.componentDef, rootView, rootContext, [LifecycleHooksFeature]);

      refreshDescendantViews(rootView, RenderFlags.Create);
    } finally {
      leaveView(oldView, true);
      if (rendererFactory.end) rendererFactory.end();
    }

    const componentRef = new ComponentRef(
        this.componentType, component,
        createElementRef(viewEngine_ElementRef, tElementNode, rootView), rootView, tElementNode);

    if (isInternalRootView) {
      // The host element of the internal root view is attached to the component's host view node
      componentRef.hostView._tViewNode !.child = tElementNode;
    }
    return componentRef;
  }
}

const componentFactoryResolver: ComponentFactoryResolver = new ComponentFactoryResolver();

/**
 * Creates a ComponentFactoryResolver and stores it on the injector. Or, if the
 * ComponentFactoryResolver
 * already exists, retrieves the existing ComponentFactoryResolver.
 *
 * @returns The ComponentFactoryResolver instance to use
 */
export function injectComponentFactoryResolver(): viewEngine_ComponentFactoryResolver {
  return componentFactoryResolver;
}

/**
 * Represents an instance of a Component created via a {@link ComponentFactory}.
 *
 * `ComponentRef` provides access to the Component Instance as well other objects related to this
 * Component Instance and allows you to destroy the Component Instance via the {@link #destroy}
 * method.
 *
 */
export class ComponentRef<T> extends viewEngine_ComponentRef<T> {
  destroyCbs: (() => void)[]|null = [];
  instance: T;
  hostView: ViewRef<T>;
  changeDetectorRef: ViewEngine_ChangeDetectorRef;
  componentType: Type<T>;

  constructor(
      componentType: Type<T>, instance: T, public location: viewEngine_ElementRef,
      private _rootView: LViewData,
      private _tNode: TElementNode|TContainerNode|TElementContainerNode) {
    super();
    this.instance = instance;
    this.hostView = this.changeDetectorRef = new RootViewRef<T>(_rootView);
    this.hostView._tViewNode = createViewNode(-1, _rootView);
    this.componentType = componentType;
  }

  get injector(): Injector { return new NodeInjector(this._tNode, this._rootView); }

  destroy(): void {
    ngDevMode && assertDefined(this.destroyCbs, 'NgModule already destroyed');
    this.destroyCbs !.forEach(fn => fn());
    this.destroyCbs = null;
  }
  onDestroy(callback: () => void): void {
    ngDevMode && assertDefined(this.destroyCbs, 'NgModule already destroyed');
    this.destroyCbs !.push(callback);
  }
}