import { writable, get } from 'svelte/store';
import { MudConnection } from './MudConnection';
import type { GmcpHandler } from '$lib/gmcp/GmcpHandler';
import { connectionStatus } from '$lib/stores/mudStore';

// Store for active MUD connections (persistent across tab switches)
export const activeConnections = writable<{ [key: string]: MudConnection }>({});

/**
 * ConnectionManager - Singleton service to manage MUD connections
 * This ensures connections stay alive even when components are unmounted during tab switches
 */
export class ConnectionManager {
  private static instance: ConnectionManager;
  
  // Private constructor for singleton pattern
  private constructor() {
    console.log('ConnectionManager initialized');
  }
  
  /**
   * Get the singleton instance of ConnectionManager
   */
  public static getInstance(): ConnectionManager {
    if (!ConnectionManager.instance) {
      ConnectionManager.instance = new ConnectionManager();
    }
    return ConnectionManager.instance;
  }
  
  /**
   * Get an existing connection without creating a new one
   */
  public getExistingConnection(profileId: string): MudConnection | null {
    const connections = get(activeConnections);
    return connections[profileId] || null;
  }

  /**
   * Create a new connection or return an existing one
   */
  public getConnection(profileId: string, options: {
    host: string;
    port: number;
    useSSL?: boolean;
    gmcpHandler?: GmcpHandler;
  }): MudConnection {
    // Get current connections
    const connections = get(activeConnections);
    
    // Check if a connection already exists for this profile
    if (connections[profileId]) {
      console.log(`Returning existing connection for profile ${profileId}`);
      return connections[profileId];
    }
    
    // Create a new connection
    console.log(`Creating new connection for profile ${profileId}`);
    const connection = new MudConnection({
      host: options.host,
      port: options.port,
      useSSL: options.useSSL,
      gmcpHandler: options.gmcpHandler
    });
    
    // Set up event handlers
    this.setupConnectionEvents(connection, profileId);
    
    // Store the connection
    activeConnections.update(connections => ({
      ...connections,
      [profileId]: connection
    }));
    
    // Return the connection
    return connection;
  }
  
  /**
   * Connect to a MUD server
   */
  public connect(profileId: string, options: {
    host: string;
    port: number;
    useSSL?: boolean;
    gmcpHandler?: GmcpHandler;
  }): void {
    const connection = this.getConnection(profileId, options);
    
    // Update connection status
    connectionStatus.update(statuses => ({
      ...statuses,
      [profileId]: 'connecting'
    }));
    
    // Connect
    connection.connect();
  }
  
  /**
   * Disconnect from a MUD server
   */
  public disconnect(profileId: string): void {
    const connections = get(activeConnections);
    
    if (connections[profileId]) {
      connections[profileId].disconnect();
      
      // Update connection status
      connectionStatus.update(statuses => ({
        ...statuses,
        [profileId]: 'disconnected'
      }));
    }
  }
  
  /**
   * Send text to a MUD server
   */
  public send(profileId: string, text: string): void {
    const connections = get(activeConnections);
    
    if (connections[profileId]) {
      connections[profileId].send(text);
    }
  }
  
  /**
   * Close a connection and remove it
   */
  public closeConnection(profileId: string): void {
    const connections = get(activeConnections);
    
    if (connections[profileId]) {
      // Disconnect first
      connections[profileId].disconnect();
      
      // Then remove from store
      activeConnections.update(connections => {
        const newConnections = { ...connections };
        delete newConnections[profileId];
        return newConnections;
      });
      
      // Update connection status
      connectionStatus.update(statuses => {
        const newStatuses = { ...statuses };
        delete newStatuses[profileId];
        return newStatuses;
      });
    }
  }
  
  /**
   * Set up event handlers for a connection
   */
  private setupConnectionEvents(connection: MudConnection, profileId: string): void {
    // Handle connection established
    connection.on('connected', () => {
      console.log(`ConnectionManager: Connection established for profile ${profileId}`);
      
      // Update connection status
      connectionStatus.update(statuses => ({
        ...statuses,
        [profileId]: 'connected'
      }));
    });
    
    // Handle connection closed
    connection.on('disconnected', () => {
      console.log(`ConnectionManager: Connection closed for profile ${profileId}`);
      
      // Update connection status
      connectionStatus.update(statuses => ({
        ...statuses,
        [profileId]: 'disconnected'
      }));
    });
    
    // Handle connection error
    connection.on('error', (error) => {
      console.error(`ConnectionManager: Connection error for profile ${profileId}:`, error);
      
      // Update connection status
      connectionStatus.update(statuses => ({
        ...statuses,
        [profileId]: 'error'
      }));
    });
  }
}