import { ComponentFactory, ComponentFactoryResolver, Injectable, Type } from '@angular/core';
import * as chartsPage from '../../data/charts-page.json';
import * as componentsPage from '../../data/components-page.json';
import * as cssPage from '../../data/css-page.json';
import { IDocumentationPage } from '../../interfaces/IDocumentationPage';

@Injectable({
  providedIn: 'root',
})
export class ResolverService {
  private static readonly resolvers: DocumentationResolver[] = [];

  registerResolver(resolver: ComponentFactoryResolver, components: Type<any>[]) {
    ResolverService.resolvers.push({ resolver, components });
  }

  resolveComponentFactory(component: Type<any>): ComponentFactory<any> {
    // try resolving component in all available modules
    for (const { resolver, components } of ResolverService.resolvers) {
      if (components.indexOf(component) !== -1) {
        return resolver.resolveComponentFactory(component);
      }
    }

    throw new Error('Component does not exist in any module: ' + component);
  }

  static resolveCategoryData(page: DocumentationPage, categoryTitle: string) {
    let data: IDocumentationPage;

    switch (page) {
      case DocumentationPage.Charts:
        data = chartsPage as IDocumentationPage;
        break;

      case DocumentationPage.Components:
        data = componentsPage as IDocumentationPage;
        break;

      case DocumentationPage.Css:
        data = cssPage as IDocumentationPage;
        break;
    }

    // find the matching section
    const match = data.categories.find(category => category.title === categoryTitle);

    if (!match) {
      throw new Error(`The section "${categoryTitle}" does not exist!`);
    }

    return match;
  }
}

export enum DocumentationPage {
  Charts,
  Components,
  Css,
}

export interface DocumentationResolver {
  resolver: ComponentFactoryResolver;
  components: Type<any>[];
}