import { CommandRunner } from '@task-stream/api/shared/application';
import { Injectable } from '@nestjs/common';
import { QueryBus } from '@nestjs/cqrs';
import {
  CreateCalendarFeedCommand,
  GetCalendarIcsQuery,
  GetMyCalendarFeedQuery,
  RevokeCalendarFeedCommand,
} from './calendar/calendar';
import { CalendarFeed } from './ports/calendar-feeds.repository';

/** A person's calendar subscription (iCalendar), behind a secret URL. */
@Injectable()
export class CalendarService {
  constructor(
    private readonly commands: CommandRunner,
    private readonly queryBus: QueryBus,
  ) {}

  mine(userId: string): Promise<CalendarFeed | null> {
    return this.queryBus.execute(new GetMyCalendarFeedQuery(userId));
  }

  /** A new secret URL; the previous one, if any, stops working. */
  create(userId: string): Promise<CalendarFeed> {
    return this.commands.execute(new CreateCalendarFeedCommand(userId));
  }

  revoke(userId: string): Promise<void> {
    return this.commands.execute(new RevokeCalendarFeedCommand(userId));
  }

  /** The calendar behind `token`, or null if no feed has it. */
  ics(token: string, webUrl: string): Promise<string | null> {
    return this.queryBus.execute(new GetCalendarIcsQuery(token, webUrl));
  }
}