import { ICalendarEvent } from '../types/CalendarTypes';
import { IEventRepository, UpdateSource } from './IEventRepository';

interface RawEventData {
  id: string;
  title: string;
  start: string | Date;
  end: string | Date;
  type: string;
  color?: string;
  allDay?: boolean;
  [key: string]: unknown;
}

/**
 * MockEventRepository - Loads event data from local JSON file (LEGACY)
 *
 * This repository implementation fetches mock event data from a static JSON file.
 * DEPRECATED: Use IndexedDBEventRepository for offline-first functionality.
 *
 * Data Source: data/mock-events.json
 *
 * NOTE: Create/Update/Delete operations are not supported - throws errors.
 * This is intentional to encourage migration to IndexedDBEventRepository.
 */
export class MockEventRepository implements IEventRepository {
  private readonly dataUrl = 'data/mock-events.json';

  public async loadEvents(): Promise<ICalendarEvent[]> {
    try {
      const response = await fetch(this.dataUrl);

      if (!response.ok) {
        throw new Error(`Failed to load mock events: ${response.status} ${response.statusText}`);
      }

      const rawData: RawEventData[] = await response.json();

      return this.processCalendarData(rawData);
    } catch (error) {
      console.error('Failed to load event data:', error);
      throw error;
    }
  }

  /**
   * NOT SUPPORTED - MockEventRepository is read-only
   * Use IndexedDBEventRepository instead
   */
  public async createEvent(event: Omit<ICalendarEvent, 'id'>, source?: UpdateSource): Promise<ICalendarEvent> {
    throw new Error('MockEventRepository does not support createEvent. Use IndexedDBEventRepository instead.');
  }

  /**
   * NOT SUPPORTED - MockEventRepository is read-only
   * Use IndexedDBEventRepository instead
   */
  public async updateEvent(id: string, updates: Partial<ICalendarEvent>, source?: UpdateSource): Promise<ICalendarEvent> {
    throw new Error('MockEventRepository does not support updateEvent. Use IndexedDBEventRepository instead.');
  }

  /**
   * NOT SUPPORTED - MockEventRepository is read-only
   * Use IndexedDBEventRepository instead
   */
  public async deleteEvent(id: string, source?: UpdateSource): Promise<void> {
    throw new Error('MockEventRepository does not support deleteEvent. Use IndexedDBEventRepository instead.');
  }

  private processCalendarData(data: RawEventData[]): ICalendarEvent[] {
    return data.map((event): ICalendarEvent => ({
      ...event,
      start: new Date(event.start),
      end: new Date(event.end),
      type: event.type,
      allDay: event.allDay || false,
      syncStatus: 'synced' as const
    }));
  }
}