/**
 * @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 {LiteralExpr, R3DependencyMetadata, R3ResolvedDependencyType, WrappedNodeExpr} from '@angular/compiler';

import {Injector} from '../../di/injector';
import {Host, Inject, Optional, Self, SkipSelf} from '../../di/metadata';
import {ElementRef} from '../../linker/element_ref';
import {TemplateRef} from '../../linker/template_ref';
import {ViewContainerRef} from '../../linker/view_container_ref';
import {Attribute} from '../../metadata/di';
import {ReflectionCapabilities} from '../../reflection/reflection_capabilities';
import {Type} from '../../type';

let _reflect: ReflectionCapabilities|null = null;

export function getReflect(): ReflectionCapabilities {
  return (_reflect = _reflect || new ReflectionCapabilities());
}

export function reflectDependencies(type: Type<any>): R3DependencyMetadata[] {
  return convertDependencies(getReflect().parameters(type));
}

export function convertDependencies(deps: any[]): R3DependencyMetadata[] {
  return deps.map(dep => reflectDependency(dep));
}

function reflectDependency(dep: any | any[]): R3DependencyMetadata {
  const meta: R3DependencyMetadata = {
    token: new LiteralExpr(null),
    host: false,
    optional: false,
    resolved: R3ResolvedDependencyType.Token,
    self: false,
    skipSelf: false,
  };

  function setTokenAndResolvedType(token: any): void {
    if (token === ElementRef) {
      meta.resolved = R3ResolvedDependencyType.ElementRef;
    } else if (token === Injector) {
      meta.resolved = R3ResolvedDependencyType.Injector;
    } else if (token === TemplateRef) {
      meta.resolved = R3ResolvedDependencyType.TemplateRef;
    } else if (token === ViewContainerRef) {
      meta.resolved = R3ResolvedDependencyType.ViewContainerRef;
    } else {
      meta.resolved = R3ResolvedDependencyType.Token;
    }
    meta.token = new WrappedNodeExpr(token);
  }

  if (Array.isArray(dep)) {
    if (dep.length === 0) {
      throw new Error('Dependency array must have arguments.');
    }
    for (let j = 0; j < dep.length; j++) {
      const param = dep[j];
      if (param instanceof Optional || param.__proto__.ngMetadataName === 'Optional') {
        meta.optional = true;
      } else if (param instanceof SkipSelf || param.__proto__.ngMetadataName === 'SkipSelf') {
        meta.skipSelf = true;
      } else if (param instanceof Self || param.__proto__.ngMetadataName === 'Self') {
        meta.self = true;
      } else if (param instanceof Host || param.__proto__.ngMetadataName === 'Host') {
        meta.host = true;
      } else if (param instanceof Inject) {
        meta.token = new WrappedNodeExpr(param.token);
      } else if (param instanceof Attribute) {
        if (param.attributeName === undefined) {
          throw new Error(`Attribute name must be defined.`);
        }
        meta.token = new LiteralExpr(param.attributeName);
        meta.resolved = R3ResolvedDependencyType.Attribute;
      } else {
        setTokenAndResolvedType(param);
      }
    }
  } else {
    setTokenAndResolvedType(dep);
  }
  return meta;
}