import { Injectable } from '@angular/core';
import { BehaviorSubject, ReplaySubject } from 'rxjs';

/**
 * This service will be embed into `AbstractBuildingBlockPage`
 * which acts as the base class of all Building Block Pages.
 *
 * Any page being created can report it's set of `TalyPageData`
 * so it can be used in a different place, outside of the actual page component.
 */
@Injectable({ providedIn: 'root' })
export class TalyPageDataService {
  private _currentPageData!: PageDataForTemplate;
  private _pageDataSubject = new BehaviorSubject<PageDataForTemplate>({});
  private _pageIdSubject = new ReplaySubject<string>(1);

  storeData(data: PageDataForTemplate) {
    this._currentPageData = data;
    this._pageDataSubject.next(this._currentPageData);
  }

  get pageData$() {
    return this._pageDataSubject.asObservable();
  }

  get pageData() {
    return this._currentPageData;
  }

  setPageId(id: string) {
    this._pageIdSubject.next(id);
  }

  get pageId$() {
    return this._pageIdSubject.asObservable();
  }
}

export interface PageDataForTemplate extends PageData {
  stage?: Stage;
}

/**
 * @additionalProperties false
 */
export interface Navigation {
  /**
   * Hide the navigation when the user is on this particular page.
   */
  hidden?: boolean;

  /**
   * Disable navigation by clicking on the navigation menu
   */
  preventClickNavigation?: boolean;
}

/**
 * @additionalProperties false
 */
export interface PageData {
  navigation?: Navigation;
  pageActionConfig?: PageActionConfig;
}

/**
 * @additionalProperties false
 */
export interface PageActionConfig {
  /**
   * Hide the "NEXT" button on this page.
   */
  nextButtonHidden?: boolean;

  /**
   * Hide the "BACK" button on this page.
   */
  backButtonHidden?: boolean;

  /**
   * Provide a customized text for the "BACK" button of page (default is 'Back').
   * Specify either a string or different labels that are linked to conditions.
   * This value will be translatable.
   * @examples [[{"label": "My conditional label", "condition": "{$.person.firstName} === {$.person.lastName}"}], "My label"]
   */
  backButtonLabel?: string | PageActionButtonLabel[];

  /**
   * Override the default styling for the back button in the page, making it a "tertiary" button.
   * Only applies for Expert journeys.
   */
  backButtonUseTertiaryStyle?: boolean;

  /**
   * Provide a customized text for the "NEXT" button of page (default is 'Next').
   * Specify either a string or different labels that are linked to conditions.
   * This value will be translatable.
   * @examples [[{"label": "My conditional label", "condition": "{$.person.firstName} === {$.person.lastName}"}], "My label"]
   */
  nextButtonLabel?: string | PageActionButtonLabel[];

  /**
   * Provide a customized text for the "CANCEL" button of page (default is 'Cancel').
   * Specify either a string or different labels that are linked to conditions.
   * This value will be translatable.
   * @examples [[{"label": "My conditional label", "condition": "{$.person.firstName} === {$.person.lastName}"}], "My label"]
   */
  cancelButtonLabel?: string | PageActionButtonLabel[];

  /**
   * Configure additional buttons that will be shown along the Next and the Back button.
   * @default []
   * @examples [["SAVE_OFFER"]]
   */
  extraActions?: ExtraPageAction[];
}

export interface PageActionButtonLabel {
  label: string;
  condition: string;
}

/**
 * Available types of additional action buttons
 */
// Developer's note: add new page actions via unions (e.g. `'TYPE' | 'TYPE2'`).
// If we turn this list of actions into an enum we run into problems in generated
// apps that use `strict` compilation because of the way we "render" page data.
export type ExtraPageAction = 'SAVE_OFFER' | 'CANCEL_OPERATION';

export type Stage =
  | PageTitleAsStageBase
  | PageTitleAsStageWithSubline
  | PageTitleAsStageWithTopline;

export type PageTitle = string | PageTitleObject | Stage;

/**
 * @additionalProperties false
 */
export interface PageTitleObject {
  /**
   * The headline of the page title.
   */
  headline: string;
  /**
   * Specifies whether to show the page title as a stage.
   */
  showAsStage?: false;
  /**
   * The subline of the page title.
   */
  subline?: string;
}

/**
 * @additionalProperties false
 */
export interface PageTitleAsStageBase {
  /**
   * The headline of the page title.
   */
  headline: string;
  /**
   * Specifies whether to show the page title as a stage.
   */
  showAsStage: true;
  /**
   * The image on the end side of the horizontal axis (right-hand when LTR)
   */
  endImage?: string;
  /**
   * Replacement when the screen estate is limited like on the mobile layout.
   */
  narrowImage?: string;
  /**
   * The image on the start side of the horizontal axis (left-hand when LTR)
   */
  startImage?: string;
  /**
   * Flag that allows to hide the back link for specific pages, in case being displayed for the generated app
   */
  hideBackLink?: boolean;
}

/**
 * @additionalProperties false
 */
export interface PageTitleAsStageWithSubline extends PageTitleAsStageBase {
  /**
   * The subline of the page title. The subline can only be set if no topline exists.
   */
  subline: string;
}

/**
 * @additionalProperties false
 */
export interface PageTitleAsStageWithTopline extends PageTitleAsStageBase {
  /**
   * The topline of the page title. The topline can only be set if no subline exists.
   */
  topline: string;
}