/**
 * Deep Link Utilities
 * Handles deep linking functionality for FCM notifications and chat navigation
 */

import { Platform } from 'react-native';
import { 
  ALLOWED_DOMAIN, 
  NAVIGATION_DELAYS, 
  URL_PATTERNS, 
  DEEP_LINK_PREFIX 
} from './constants';

/**
 * Interface for notification data
 */
export interface NotificationData {
  channel_id?: string;
  conversation_id?: string;
  deep_link?: string;
  title?: string;
  body?: string;
  channel_name?: string;
  author_name?: string;
  notification_type?: string;
}

/**
 * Interface for navigation state
 */
export interface NavigationState {
  currentChannel: string | null;
  isNavigating: boolean;
  navigationAttempts: number;
}

/**
 * Deep Link Handler Class
 */
export class DeepLinkHandler {
  private updateWebViewUrl: (url: string) => void;
  private setIsNavigating: (navigating: boolean) => void;
  private setCurrentChannel: (channel: string | null) => void;
  private setNavigationAttempts: (attempts: number) => void;
  private navigationState: NavigationState;

  constructor(
    updateWebViewUrl: (url: string) => void,
    setIsNavigating: (navigating: boolean) => void,
    setCurrentChannel: (channel: string | null) => void,
    setNavigationAttempts: (attempts: number) => void,
    navigationState: NavigationState
  ) {
    this.updateWebViewUrl = updateWebViewUrl;
    this.setIsNavigating = setIsNavigating;
    this.setCurrentChannel = setCurrentChannel;
    this.setNavigationAttempts = setNavigationAttempts;
    this.navigationState = navigationState;
  }

  /**
   * Handle deep linking from notifications (killed app case)
   * @param data - Notification data containing channel information
   */
  handleKilledAppDeepLink(data: NotificationData): void {
    console.log('🔗 Processing deep link from notification (killed app case):', data);
    
    const channelId = this.extractChannelId(data);
    if (!channelId) {
      console.warn('⚠️ No channel ID found in deep link data:', data);
      return;
    }

    // Minimal delay for killed app initialization
    setTimeout(() => {
      console.log('🔗 Setting initial WebView URL for killed app navigation to channel:', channelId);
      
      // Set navigation state
      this.setIsNavigating(true);
      this.setCurrentChannel(channelId);
      
      // Construct and set the target URL directly (works better for killed app)
      const chatUrl = this.buildChatUrl(channelId);
      console.log('🔗 Initial chat URL for killed app:', chatUrl);
      this.updateWebViewUrl(chatUrl);
      
      // Reset navigation state after shorter delay
      setTimeout(() => {
        this.setIsNavigating(false);
      }, NAVIGATION_DELAYS.KILLED_APP_RESET);
    }, NAVIGATION_DELAYS.KILLED_APP);
  }

  /**
   * Handle WebView URL update from notification (foreground/background)
   * @param data - Notification data containing channel information
   */
  handleForegroundBackgroundDeepLink(data: NotificationData): void {
    console.log('🔗 Updating WebView URL from notification:', data);
    
    const channelId = this.extractChannelId(data);
    if (!channelId) {
      console.warn('⚠️ No channel ID found in notification data:', data);
      return;
    }

    // Check if we're already navigating to this channel
    if (this.navigationState.isNavigating && this.navigationState.currentChannel === channelId) {
      console.log('🔗 Already navigating to channel:', channelId);
      return;
    }
    
    console.log('🔗 Navigating to channel via WebView URL update:', channelId);
    
    // Set navigation state to prevent loops
    this.setIsNavigating(true);
    this.setNavigationAttempts(0);
    this.setCurrentChannel(channelId);
    
    // Step 1: First navigate to mail app (without specific channel)
    const mailAppUrl = `${ALLOWED_DOMAIN}/web${URL_PATTERNS.MAIL_APP}`;
    console.log('🔗 Step 1: Navigating to mail app:', mailAppUrl);
    this.updateWebViewUrl(mailAppUrl);
    
    // Step 2: After a minimal delay, navigate to specific channel
    setTimeout(() => {
      const chatUrl = this.buildChatUrl(channelId);
      console.log('🔗 Step 2: Navigating to specific channel:', chatUrl);
      this.updateWebViewUrl(chatUrl);
      
      // Reset navigation state after final navigation
      setTimeout(() => {
        this.setIsNavigating(false);
      }, NAVIGATION_DELAYS.NAVIGATION_RESET);
    }, NAVIGATION_DELAYS.TWO_STEP_NAVIGATION);
    
    console.log('✅ WebView navigation sequence started');
  }

  /**
   * Navigate to specific channel (direct navigation for killed app)
   * @param channelId - Channel ID to navigate to
   */
  navigateToChannel(channelId: string): void {
    if (!channelId) {
      console.warn('⚠️ No channel ID provided for navigation');
      return;
    }

    // Check if we're already navigating to this channel
    if (this.navigationState.isNavigating && this.navigationState.currentChannel === channelId) {
      console.log('🔗 Already navigating to channel:', channelId);
      return;
    }

    console.log('🔗 Navigating to channel (killed app - direct navigation):', channelId);
    this.setCurrentChannel(channelId);
    this.setIsNavigating(true);
    this.setNavigationAttempts(0);
    
    // For killed app case, direct navigation works better
    const chatUrl = this.buildChatUrl(channelId);
    console.log('🔗 Chat URL (direct):', chatUrl);
    
    // Update WebView URL directly - this works well for killed app
    this.updateWebViewUrl(chatUrl);
    
    console.log('✅ WebView URL updated (direct navigation)');
    
    // Reset navigation state after delay
    setTimeout(() => {
      this.setIsNavigating(false);
    }, NAVIGATION_DELAYS.KILLED_APP);
  }

  /**
   * Handle deep link URLs
   * @param deepLink - Deep link URL to process
   */
  handleDeepLink(deepLink: string): void {
    console.log('🔗 Processing deep link:', deepLink);
    
    // Parse deep link: myapp://chat/{channel_id}
    if (deepLink.startsWith(DEEP_LINK_PREFIX)) {
      const channelId = deepLink.replace(DEEP_LINK_PREFIX, '');
      console.log('🔗 Extracted channel ID:', channelId);
      this.navigateToChannel(channelId);
    } else {
      console.warn('⚠️ Unknown deep link format:', deepLink);
    }
  }

  /**
   * Extract channel ID from notification data
   * @param data - Notification data
   * @returns Channel ID or null if not found
   */
  private extractChannelId(data: NotificationData): string | null {
    // Extract channel ID from different possible fields
    if (data.channel_id) {
      console.log('🔗 Found channel_id:', data.channel_id);
      return data.channel_id;
    } else if (data.conversation_id) {
      console.log('🔗 Found conversation_id:', data.conversation_id);
      return data.conversation_id;
    } else if (data.deep_link && data.deep_link.includes('chat/')) {
      const channelId = data.deep_link.replace(DEEP_LINK_PREFIX, '');
      console.log('🔗 Extracted channel_id from deep_link:', channelId);
      return channelId;
    }
    
    return null;
  }

  /**
   * Build chat URL for specific channel
   * @param channelId - Channel ID
   * @returns Complete chat URL
   */
  private buildChatUrl(channelId: string): string {
    return `${ALLOWED_DOMAIN}/web${URL_PATTERNS.MAIL_APP}${URL_PATTERNS.CHAT_CHANNEL(channelId)}`;
  }
}

/**
 * Create deep link handler instance
 */
export function createDeepLinkHandler(
  updateWebViewUrl: (url: string) => void,
  setIsNavigating: (navigating: boolean) => void,
  setCurrentChannel: (channel: string | null) => void,
  setNavigationAttempts: (attempts: number) => void,
  navigationState: NavigationState
): DeepLinkHandler {
  return new DeepLinkHandler(
    updateWebViewUrl,
    setIsNavigating,
    setCurrentChannel,
    setNavigationAttempts,
    navigationState
  );
}