// src/services/websocket.js

import { createSession, API_BASE_URL } from "./apiService";

/**
 * Gets a session ID from localStorage or creates a new one via the API.
 * @returns {Promise<string>} The session ID.
 */
export const getSessionId = async () => {
  let sessionId = localStorage.getItem("sessionId");
  if (!sessionId) {
    // No existing session, so create one via API
    const session = await createSession();
    sessionId = session.id;
    
    // Store it in localStorage for reuse
    localStorage.setItem("sessionId", sessionId);
  }
  
  console.log("Using session ID:", sessionId);
  return sessionId;
};

/**
 * Connects to the WebSocket server, establishing a new session first.
 * @param {function(Object): void} onMessageCallback - Callback for incoming messages.
 * @param {function(): void} onOpenCallback - Callback when the connection is opened.
 * @param {function(): void} onCloseCallback - Callback when the connection is closed.
 * @param {function(Error): void} onErrorCallback - Callback when an error occurs.
 * @returns {Promise<{ws: WebSocket, sessionId: string}>} The WebSocket instance and the session ID.
 */
export const connectToWebSocket = async (
  onMessageCallback,
  onOpenCallback,
  onCloseCallback,
  onErrorCallback
) => {
  try {
    let sessionId = localStorage.getItem("sessionId");
    
    // NOTE: The line `sessionId = null;` has been removed as it was for testing purposes
    // and would force a new session on every connection.
    sessionId = null
    if (!sessionId) {
      // No existing session, so create one via API
      const session = await createSession();
      sessionId = session.id;
    
      // Store it in localStorage for reuse
      localStorage.setItem("sessionId", sessionId);
    }
    
    // You now have a valid sessionId, either reused or newly created
    console.log("Using session ID:", sessionId);

    // Correct the WebSocket URL based on the API_BASE_URL protocol.
    // Use `wss` for `https` and `ws` for `http`.
    const url = new URL(API_BASE_URL);
    const wsProtocol = url.protocol === "https:" ? "wss" : "ws";

    let pathname = url.pathname;
    // Check if the pathname is just a single slash, if so, don't append it to avoid a double slash
    if (pathname === "/") {
      pathname = "";
    }

    const websocketUrl = `${wsProtocol}://${url.host}${pathname}/ws/workspace/${sessionId}`;
    
    console.log("Connecting to WebSocket URL:", websocketUrl);
    const ws = new WebSocket(websocketUrl);

    ws.onopen = () => {
      console.log("WebSocket connected");
      if (onOpenCallback) onOpenCallback();
    };

    ws.onmessage = (event) => {
      const message = JSON.parse(event.data);
      if (onMessageCallback) onMessageCallback(message);
    };

    ws.onclose = () => {
      console.log("WebSocket disconnected");
      if (onCloseCallback) onCloseCallback();
    };

    ws.onerror = (error) => {
      console.error("WebSocket error:", error);
      if (onErrorCallback) onErrorCallback(error);
    };

    return { ws, sessionId };

  } catch (error) {
    console.error("Failed to create session or connect to WebSocket:", error);
    if (onErrorCallback) onErrorCallback(error);
    throw error;
  }
};