import { fetchWrapper } from '@KTXC/utils/helpers/fetch-wrapper';

/**
 * User Service
 * Provides methods for managing user profile and settings with batched updates
 */

// Pending updates for profile and settings
let pendingProfileUpdates: Record<string, any> = {};
let pendingSettingsUpdates: Record<string, any> = {};
let profileUpdateTimer: ReturnType<typeof setTimeout> | null = null;
let settingsUpdateTimer: ReturnType<typeof setTimeout> | null = null;

// Default debounce delay in milliseconds
const DEBOUNCE_DELAY = 500;

export const userService = {
  /**
   * Update profile field(s) with debouncing
   * Multiple calls within the debounce window will be batched into a single request
   */
  updateProfile(fields: Record<string, any>): Promise<void> {
    return new Promise((resolve, reject) => {
      // Merge new fields with pending updates
      Object.assign(pendingProfileUpdates, fields);

      // Clear existing timer
      if (profileUpdateTimer) {
        clearTimeout(profileUpdateTimer);
      }

      // Set new timer to batch updates
      profileUpdateTimer = setTimeout(async () => {
        const updates = { ...pendingProfileUpdates };
        pendingProfileUpdates = {};
        profileUpdateTimer = null;

        try {
          await fetchWrapper.put('/user/profile', { data: updates });
          resolve();
        } catch (error) {
          reject(error);
        }
      }, DEBOUNCE_DELAY);
    });
  },

  /**
   * Update profile field(s) immediately without debouncing
   */
  async updateProfileImmediate(fields: Record<string, any>): Promise<void> {
    // Cancel pending debounced update
    if (profileUpdateTimer) {
      clearTimeout(profileUpdateTimer);
      profileUpdateTimer = null;
    }

    // Merge with pending updates and send immediately
    const updates = { ...pendingProfileUpdates, ...fields };
    pendingProfileUpdates = {};

    return fetchWrapper.put('/user/profile', { data: updates });
  },

  /**
   * Flush any pending profile updates immediately
   */
  async flushProfileUpdates(): Promise<void> {
    if (profileUpdateTimer) {
      clearTimeout(profileUpdateTimer);
      profileUpdateTimer = null;
    }

    if (Object.keys(pendingProfileUpdates).length > 0) {
      const updates = { ...pendingProfileUpdates };
      pendingProfileUpdates = {};
      return fetchWrapper.put('/user/profile', { data: updates });
    }
  },

  /**
   * Update setting(s) with debouncing
   * Multiple calls within the debounce window will be batched into a single request
   */
  updateSettings(settings: Record<string, any>): Promise<void> {
    return new Promise((resolve, reject) => {
      // Merge new settings with pending updates
      Object.assign(pendingSettingsUpdates, settings);

      // Clear existing timer
      if (settingsUpdateTimer) {
        clearTimeout(settingsUpdateTimer);
      }

      // Set new timer to batch updates
      settingsUpdateTimer = setTimeout(async () => {
        const updates = { ...pendingSettingsUpdates };
        pendingSettingsUpdates = {};
        settingsUpdateTimer = null;

        try {
          await fetchWrapper.put('/user/settings', { data: updates });
          resolve();
        } catch (error) {
          reject(error);
        }
      }, DEBOUNCE_DELAY);
    });
  },

  /**
   * Update setting(s) immediately without debouncing
   */
  async updateSettingsImmediate(settings: Record<string, any>): Promise<void> {
    // Cancel pending debounced update
    if (settingsUpdateTimer) {
      clearTimeout(settingsUpdateTimer);
      settingsUpdateTimer = null;
    }

    // Merge with pending updates and send immediately
    const updates = { ...pendingSettingsUpdates, ...settings };
    pendingSettingsUpdates = {};

    return fetchWrapper.put('/user/settings', { data: updates });
  },

  /**
   * Flush any pending settings updates immediately
   */
  async flushSettingsUpdates(): Promise<void> {
    if (settingsUpdateTimer) {
      clearTimeout(settingsUpdateTimer);
      settingsUpdateTimer = null;
    }

    if (Object.keys(pendingSettingsUpdates).length > 0) {
      const updates = { ...pendingSettingsUpdates };
      pendingSettingsUpdates = {};
      return fetchWrapper.put('/user/settings', { data: updates });
    }
  },

  /**
   * Flush all pending updates (profile and settings)
   */
  async flushAll(): Promise<void> {
    await Promise.all([
      this.flushProfileUpdates(),
      this.flushSettingsUpdates(),
    ]);
  },
};