background.js

/*
 * Chat Relay: Relay for AI Chat Interfaces
 * Copyright (C) 2025 Jamison Moore
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see https://www.gnu.org/licenses/.
 */
// AI Chat Relay - Background Script

// Default settings
const DEFAULT_SETTINGS = {
  serverHost: 'localhost',
  serverPort: 3003,
  serverProtocol: 'ws'
};

let relaySocket = null;
let reconnectInterval = 5000;
let reconnectTimer = null;
let activeTabId = null;
let serverUrl = '';
let lastRequestId = null; // User's global lastRequestId
let processingRequest = false; // User's global processing flag
let pendingRequests = []; // User's command queue
let lastSuccessfullyProcessedMessageText = null; // Text of the last message successfully processed (AI response or duplicate handled)
const pendingRequestDetails = new Map(); // Stores { text: string } for active requests, keyed by requestId

// Supported domains for chat interfaces
const supportedDomains = ['gemini.google.com', 'aistudio.google.com', 'chatgpt.com', 'claude.ai'];

// ===== DEBUGGER RELATED GLOBALS =====
const BG_LOG_PREFIX = '[BG DEBUGGER]';
let debuggerAttachedTabs = new Map(); // tabId -> { providerName, patterns, isFetchEnabled, isAttached, lastKnownRequestId }


// Load settings and connect to the relay server
function loadSettingsAndConnect() {
  console.log("BACKGROUND: Loading settings and connecting to relay server");
  chrome.storage.sync.get(DEFAULT_SETTINGS, (items) => {
    serverUrl = `${items.serverProtocol}://${items.serverHost}:${items.serverPort}`;
    console.log("BACKGROUND: Using server URL:", serverUrl);
    connectToRelayServer();
  });
}

// Connect to the relay server
function connectToRelayServer() {
  if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
    console.log("BACKGROUND: Relay WS: Already connected.");
    return;
  }

  if (!navigator.onLine) {
    console.warn("BACKGROUND: Network offline. Deferring connection attempt.");
    if (reconnectTimer) clearTimeout(reconnectTimer);
    reconnectTimer = setTimeout(connectToRelayServer, reconnectInterval);
    return;
  }

  const healthCheckUrl = serverUrl.replace(/^ws/, 'http') + '/health';
  console.log("BACKGROUND: Performing HTTP pre-check to", healthCheckUrl);

  fetch(healthCheckUrl)
    .then(response => {
      if (!response.ok) {
        // Server responded, but not with a 2xx status (e.g., 404, 500)
        console.warn(`BACKGROUND: HTTP pre-check to ${healthCheckUrl} received non-OK status: ${response.status}. Server might be having issues. Deferring WebSocket attempt.`);
        return Promise.reject(new Error(`Server responded with ${response.status}`));
      }
      return response.json(); // Attempt to parse JSON
    })
    .then(healthData => {
      console.log(`BACKGROUND: HTTP pre-check to ${healthCheckUrl} successful. Server status: ${healthData.status}, Active Connections: ${healthData.activeBrowserConnections}. Proceeding with WebSocket connection.`);
      attemptWebSocketConnection();
    })
    .catch(fetchError => {
      // This catches network errors (server down) or errors from the .then() chain (non-OK response, JSON parse error)
      console.warn(`BACKGROUND: HTTP pre-check to ${healthCheckUrl} failed: ${fetchError.message}. Server is likely down, unreachable, or health endpoint is misbehaving. Deferring WebSocket attempt.`);
      relaySocket = null;
      if (reconnectTimer) clearTimeout(reconnectTimer);
      reconnectTimer = setTimeout(connectToRelayServer, reconnectInterval);
    });
}

function attemptWebSocketConnection() {
  console.log("BACKGROUND: Relay WS: Attempting to connect to", serverUrl);
  try {
    relaySocket = new WebSocket(serverUrl);

    relaySocket.onopen = () => {
      console.log("BACKGROUND: Relay WS: Connection established with relay server.");
      reconnectInterval = 5000; // Reset reconnect interval on successful connection
      if (reconnectTimer) clearTimeout(reconnectTimer);
      reconnectTimer = null;

      // Notify the server that this extension instance is ready
      if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
        const readyMessage = { type: 'EXTENSION_READY' };
        relaySocket.send(JSON.stringify(readyMessage));
        console.log("BACKGROUND: Relay WS: Sent EXTENSION_READY to server.");
      }
    };

    relaySocket.onmessage = (event) => {
      console.log("BACKGROUND: Relay WS: Message received from relay server:", event.data);
      try {
        const command = JSON.parse(event.data);
        if (command.type === 'SEND_CHAT_MESSAGE') {
          console.log("BACKGROUND: Received SEND_CHAT_MESSAGE command with requestId:", command.requestId);
          
          // Store details for this new request
          pendingRequestDetails.set(command.requestId, { messageContent: command.message }); // Changed key 'text' to 'messageContent'
          let messagePreview = "";
          const messageValue = command.message;
          if (typeof messageValue === 'string') {
            messagePreview = `String: "${messageValue.substring(0, 50)}..."`;
          } else if (messageValue instanceof ArrayBuffer) {
            messagePreview = `ArrayBuffer data (size: ${messageValue.byteLength} bytes)`;
          } else if (messageValue instanceof Blob) {
            messagePreview = `Blob data (size: ${messageValue.size} bytes, type: ${messageValue.type})`;
          } else if (messageValue && typeof messageValue === 'object' && messageValue !== null) {
            messagePreview = `Object data (type: ${Object.prototype.toString.call(messageValue)})`;
          } else {
            messagePreview = `Data type: ${typeof messageValue}, Value: ${String(messageValue).substring(0,50)}`;
          }
          console.log(`BACKGROUND: Stored details for requestId: ${command.requestId}, message: ${messagePreview}`);

          // Add to the queue
          pendingRequests.push(command);
          console.log(`BACKGROUND: Added command with requestId: ${command.requestId} to queue. Queue length: ${pendingRequests.length}`);
          
          // Attempt to process the next request in the queue
          processNextRequest();
        }
      } catch (error) {
        console.error("BACKGROUND: Relay WS: Error processing message from relay server:", error);
      }
    };

    relaySocket.onerror = (errorEvent) => {
      console.warn("BACKGROUND: Relay WS: WebSocket connection error (event):", errorEvent);
      // onclose will typically follow and handle reconnection logic
    };

    relaySocket.onclose = (closeEvent) => {
      console.log(`BACKGROUND: Relay WS: Connection closed (event). Code: ${closeEvent.code}, Reason: '${closeEvent.reason || 'N/A'}', Cleanly: ${closeEvent.wasClean}. Will attempt reconnect (via connectToRelayServer) in ${reconnectInterval / 1000}s.`);
      relaySocket = null;
      if (reconnectTimer) clearTimeout(reconnectTimer);
      // Retry the entire connectToRelayServer process, which includes the HTTP pre-check
      reconnectTimer = setTimeout(connectToRelayServer, reconnectInterval);
    };
  } catch (instantiationError) {
    console.error("BACKGROUND: Relay WS: Error instantiating WebSocket:", instantiationError);
    relaySocket = null;
    if (reconnectTimer) clearTimeout(reconnectTimer);
    console.log(`BACKGROUND: Relay WS: Instantiation failed. Will attempt reconnect (via connectToRelayServer) in ${reconnectInterval / 1000}s.`);
    // Retry the entire connectToRelayServer process
    reconnectTimer = setTimeout(connectToRelayServer, reconnectInterval);
  }
}

// Forward commands to content script
async function forwardCommandToContentScript(command) { // command will include original requestId
  try {
    console.log("BACKGROUND: Forwarding command to content script:", command);
    let targetTabIdForCommand = null;
    
    if (activeTabId) {
      try {
        console.log(`BACKGROUND: Attempting to use stored activeTabId: ${activeTabId}`);
        // Test send to ensure tab is still valid for this command before associating requestId
        await new Promise((resolve, reject) => {
            chrome.tabs.sendMessage(activeTabId, { type: "PING_TAB" }, response => { // Ping before associating
                if (chrome.runtime.lastError || !response || !response.success) {
                    console.warn(`BACKGROUND: Ping to stored tab ${activeTabId} failed or no ack:`, chrome.runtime.lastError ? chrome.runtime.lastError.message : "No response/success false");
                    activeTabId = null; // Invalidate activeTabId
                    reject(new Error("Ping failed"));
                } else {
                    console.log(`BACKGROUND: Ping to stored tab ${activeTabId} successful.`);
                    targetTabIdForCommand = activeTabId;
                    resolve();
                }
            });
        });
      } catch (error) {
        // Fall through to findAndSendToSuitableTab if ping fails
        console.warn(`BACKGROUND: Error using stored activeTabId ${activeTabId}, will find new tab:`, error);
      }
    }
    
    if (!targetTabIdForCommand) {
        targetTabIdForCommand = await findAndSendToSuitableTab(command, true); // Pass true to only find, not send yet
    }

    if (targetTabIdForCommand) {
        const tabInfo = debuggerAttachedTabs.get(targetTabIdForCommand);
        if (tabInfo) {
            tabInfo.lastKnownRequestId = command.requestId; // Store command's requestId for this specific tab
            console.log(BG_LOG_PREFIX, `Associated requestId ${command.requestId} with tab ${targetTabIdForCommand} for debugger.`);
        } else {
            console.warn(BG_LOG_PREFIX, `Tab ${targetTabIdForCommand} is not being debugged. Cannot associate requestId for debugger.`);
        }

        // Now actually send the command
        chrome.tabs.sendMessage(targetTabIdForCommand, command, (response) => {
          if (chrome.runtime.lastError) {
            const errorMessage = `Error sending message to content script in tab ${targetTabIdForCommand}: ${chrome.runtime.lastError.message}`;
            console.error(`BACKGROUND: ${errorMessage}`);
            
            // Send error to server
            if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
              relaySocket.send(JSON.stringify({
                type: "CHAT_RESPONSE_ERROR",
                requestId: command.requestId,
                error: `Failed to send command to content script (tab ${targetTabIdForCommand}). Detail: ${chrome.runtime.lastError.message}`
              }));
              console.log(`BACKGROUND: Sent CHAT_RESPONSE_ERROR to server for requestId: ${command.requestId} (content script send failed).`);
            } else {
              console.error(`BACKGROUND: Relay WS not OPEN, cannot send CHAT_RESPONSE_ERROR for requestId: ${command.requestId} (content script send failed).`);
            }

            if (lastRequestId === command.requestId) { 
                processingRequest = false;
                console.log(`BACKGROUND: Reset processingRequest for requestId: ${command.requestId} (content script send failed).`);
            }
            // Attempt to process the next request in the queue as this one failed at the background script level
            processNextRequest(); 

          } else {
            console.log(`BACKGROUND: Content script in tab ${targetTabIdForCommand} acknowledged command:`, response);
            // If content script acknowledges, it's responsible for sending a response/error back.
            // No need to call processNextRequest() here; content script's response will trigger it.
          }
        });

    } else {
        const errorMsg = "Could not find any suitable tab for command.";
        console.error(`BACKGROUND: ${errorMsg} for requestId: ${command.requestId}.`);
        
        if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
            relaySocket.send(JSON.stringify({
                type: "CHAT_RESPONSE_ERROR",
                requestId: command.requestId,
                error: errorMsg
            }));
            console.log(`BACKGROUND: Sent CHAT_RESPONSE_ERROR to server for requestId: ${command.requestId} (no suitable tab).`);
        } else {
            console.error(`BACKGROUND: Relay WS not OPEN, cannot send CHAT_RESPONSE_ERROR for requestId: ${command.requestId} (no suitable tab).`);
        }

        if (lastRequestId === command.requestId) {
            processingRequest = false;
            console.log(`BACKGROUND: Reset processingRequest for requestId: ${command.requestId} (no suitable tab).`);
        }
        // Ensure processNextRequest is called to handle any queued items,
        // even if this one failed.
        processNextRequest();
    }

  } catch (error) {
    console.error("BACKGROUND: Error in forwardCommandToContentScript for requestId:", command.requestId, error);
    // Send an error back to the server if an unexpected error occurs during forwarding
    if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
        relaySocket.send(JSON.stringify({
            type: "CHAT_RESPONSE_ERROR",
            requestId: command.requestId,
            error: `Internal error in background script while forwarding command: ${error.message}`
        }));
        console.log(`BACKGROUND: Sent CHAT_RESPONSE_ERROR to server for requestId: ${command.requestId} (exception).`);
    } else {
        console.error(`BACKGROUND: Relay WS not OPEN, cannot send CHAT_RESPONSE_ERROR for requestId: ${command.requestId} (exception).`);
    }

    if (lastRequestId === command.requestId) {
        processingRequest = false;
        console.log(`BACKGROUND: Reset processingRequest for requestId: ${command.requestId} (exception).`);
    }
  }
}

// Helper function to find a suitable tab and send the command
async function findAndSendToSuitableTab(command, justFinding = false) {
  try {
    console.log("BACKGROUND: Finding suitable tab for command:", command);
    const allTabs = await chrome.tabs.query({});
    const matchingTabs = allTabs.filter(tab => {
      if (!tab.url) return false;
      return supportedDomains.some(domain => tab.url.includes(domain));
    });
    
    console.log(`BACKGROUND: Found ${matchingTabs.length} tabs matching supported domains`);
    
    if (matchingTabs.length > 0) {
      const activeMatchingTabs = matchingTabs.filter(tab => tab.active);
      const targetTab = activeMatchingTabs.length > 0 ? activeMatchingTabs[0] : matchingTabs[0];
      console.log(`BACKGROUND: Selected tab ${targetTab.id} (${targetTab.url})`);
      activeTabId = targetTab.id; // Update global activeTabId

      if (justFinding) {
          return targetTab.id;
      }
      
      console.warn("BACKGROUND: findAndSendToSuitableTab called with justFinding=false. Sending is now handled by caller.");
      return targetTab.id; 

    } else {
      console.error("BACKGROUND: Could not find any tabs matching supported domains.");
      return null;
    }
  } catch (error) {
    console.error("BACKGROUND: Error finding suitable tab:", error);
    return null;
  }
}

// Process the next request in the queue
function processNextRequest() {
  console.log("BACKGROUND: Processing next request, queue length:", pendingRequests.length);
  if (processingRequest && pendingRequests.length > 0) {
      console.log("BACKGROUND: Still processing a request, deferring processNextRequest call.");
      return; 
  }
  
  if (pendingRequests.length > 0) {
    const nextCommand = pendingRequests.shift();
    console.log("BACKGROUND: Processing next command from queue:", nextCommand);
    
    // Ensure details are stored if this came from the pendingRequests queue
    // (though ideally they are stored when initially received from server)
    if (!pendingRequestDetails.has(nextCommand.requestId) && nextCommand.message !== undefined) {
        pendingRequestDetails.set(nextCommand.requestId, { messageContent: nextCommand.message }); // Use messageContent
        let preview = typeof nextCommand.message === 'string' ? `"${nextCommand.message.substring(0,30)}..."` : `Type: ${typeof nextCommand.message}`;
        console.log(`BACKGROUND: Stored details (messageContent) for queued requestId: ${nextCommand.requestId} (Message: ${preview}) while processing queue.`);
    }

    processingRequest = true;
    lastRequestId = nextCommand.requestId;
    
    // Add a delay before forwarding the command
    setTimeout(() => {
        forwardCommandToContentScript({
          action: "SEND_CHAT_MESSAGE",
          requestId: nextCommand.requestId,
          messageContent: nextCommand.message,
          settings: nextCommand.settings,
          lastProcessedText: lastSuccessfullyProcessedMessageText // Pass the text of the last successfully processed message
        });
    }, 500); // 500ms delay
  } else {
    console.log("BACKGROUND: No pending requests to process.");
  }
}

// Helper function to check if a URL is supported by a given provider
// This might need to be more sophisticated if provider domains are complex
function isUrlSupportedByProvider(url, providerName) {
    // This function would need access to the provider definitions or a shared config
    // For AIStudioProvider:
    if (providerName === "AIStudioProvider") {
        return url.includes("aistudio.google.com");
    }
    // For GeminiProvider:
    if (providerName === "GeminiProvider") {
        return url.includes("gemini.google.com");
    }
    // For ChatGPTProvider:
    if (providerName === "ChatGptProvider") { // Match the casing used by the provider's .name property
        return url.includes("chatgpt.com");
    }
    // For ClaudeProvider:
    if (providerName === "ClaudeProvider") { // Match the casing used by the provider's .name property
        return url.includes("claude.ai");
    }
    // Add other providers if necessary
    console.warn(BG_LOG_PREFIX, `isUrlSupportedByProvider: Unknown providerName '${providerName}'`);
    return false;
}

// Listen for tab updates
chrome.tabs.onUpdated.addListener(async (tabId, changeInfo, tab) => {
  if (changeInfo.status === 'complete' && tab.url) {
    const isSupportedDomain = supportedDomains.some(domain => tab.url.includes(domain));
    if (isSupportedDomain) {
      console.log(`BACKGROUND: A supported tab ${tabId} (${tab.url}) was updated. Checking if it should be the active tab.`);
      // Potentially update activeTabId, but be careful if multiple supported tabs are open.
      // The existing logic for activeTabId update via messages from content script might be more reliable.
      // For now, let's ensure it's set if it's the *only* active one or becomes active.
      if (tab.active || !activeTabId) {
           // Check if this tab is actually one of the supported types before making it active
           // This is a bit redundant with supportedDomains check but good for clarity
           const currentProvider = providerUtils.getProviderForUrl(tab.url); // Assuming providerUtils is accessible or we have a similar utility
           if (currentProvider) {
                activeTabId = tabId;
                console.log(`BACKGROUND: Set ${tabId} (${tab.url}) as the active tab.`);
           }
      }
    }
  }

  // Handle debugger re-attachment on URL changes for already debugged tabs
  const attachmentDetails = debuggerAttachedTabs.get(tabId);
  if (attachmentDetails && attachmentDetails.isAttached && changeInfo.url && tab && tab.url) {
    // changeInfo.url is the old URL, tab.url is the new one
    console.log(BG_LOG_PREFIX, `Tab ${tabId} updated. Old URL: ${changeInfo.url}, New URL: ${tab.url}. Checking debugger status.`);

    const providerStillValidForNewUrl = isUrlSupportedByProvider(tab.url, attachmentDetails.providerName);

    if (providerStillValidForNewUrl) {
      console.log(BG_LOG_PREFIX, `Tab ${tabId} URL changed to ${tab.url}. Provider ${attachmentDetails.providerName} still valid. Re-initiating debugger attachment.`);
      const oldProviderName = attachmentDetails.providerName;
      const oldPatterns = attachmentDetails.patterns; // These patterns were from the content script for the *domain*
      
      // Detach first to ensure a clean state, then re-attach.
      // The 'isAttached' flag in attachmentDetails will be set to false by detachDebugger.
      await detachDebugger(tabId);
      
      // Check if tab still exists (it should, as we are in its onUpdated event)
      try {
        const updatedTabInfo = await chrome.tabs.get(tabId);
        if (updatedTabInfo) {
            console.log(BG_LOG_PREFIX, `Proactively re-attaching debugger to ${tabId} (${updatedTabInfo.url}) with provider ${oldProviderName}.`);
            // Content script should send SET_DEBUGGER_TARGETS on its re-initialization.
            // However, a proactive re-attachment can be beneficial.
            // The patterns might need to be re-fetched if they are URL-specific beyond the domain.
            // For now, using oldPatterns, assuming they are domain-level.
            await attachDebuggerAndEnableFetch(tabId, oldProviderName, oldPatterns);
        }
      } catch (error) {
        console.warn(BG_LOG_PREFIX, `Error getting tab info for ${tabId} during re-attachment attempt:`, error.message);
      }

    } else {
      console.log(BG_LOG_PREFIX, `Tab ${tabId} URL changed to ${tab.url}. Provider ${attachmentDetails.providerName} no longer valid or URL not supported by provider. Detaching debugger.`);
      await detachDebugger(tabId);
    }
  } else if (attachmentDetails && attachmentDetails.isAttached && changeInfo.status === 'loading' && tab && tab.url && !changeInfo.url) {
    // Sometimes URL change is only visible when status is 'loading' and tab.url is the new one.
    // This is a more aggressive check.
    const newUrl = tab.url;
    console.log(BG_LOG_PREFIX, `Tab ${tabId} is loading new URL: ${newUrl}. Checking debugger status.`);
    const providerStillValidForNewUrl = isUrlSupportedByProvider(newUrl, attachmentDetails.providerName);
    if (!providerStillValidForNewUrl) {
        console.log(BG_LOG_PREFIX, `Tab ${tabId} loading new URL ${newUrl}. Provider ${attachmentDetails.providerName} may no longer be valid. Detaching.`);
        await detachDebugger(tabId);
    }
    // If provider is still valid, we'll let the 'complete' status handler above deal with re-attachment if needed,
    // or rely on content script sending SET_DEBUGGER_TARGETS.
  }
});

// Listen for messages from Content Scripts and Popup
chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
  console.log("BACKGROUND: Received message:", message.type || message.action, "from tabId:", sender.tab ? sender.tab.id : 'popup/unknown');
  
  if (sender.tab && sender.tab.id) {
    activeTabId = sender.tab.id; // User's original logic for activeTabId
    console.log(`BACKGROUND: Updated activeTabId to ${activeTabId} from sender`);
  }

  if (message.type === "SET_DEBUGGER_TARGETS") {
      if (sender.tab && sender.tab.id) {
          const tabId = sender.tab.id;
          console.log(BG_LOG_PREFIX, `SET_DEBUGGER_TARGETS for tab ${tabId}, provider: ${message.providerName}, patterns:`, message.patterns);
          attachDebuggerAndEnableFetch(tabId, message.providerName, message.patterns);
          sendResponse({ status: "Debugger attachment initiated" });
      } else {
          console.error(BG_LOG_PREFIX, "SET_DEBUGGER_TARGETS message received without valid sender.tab.id");
          sendResponse({ status: "Error: Missing tabId" });
      }
      return true; 
  } 
  else if (message.type === "CHAT_RELAY_READY") {
    console.log(`BACKGROUND: Content script ready in ${message.chatInterface} on tab ${sender.tab ? sender.tab.id : 'unknown'}`);
    if (sender.tab && sender.tab.id) activeTabId = sender.tab.id;
    sendResponse({ success: true });
    return true; // Indicate that sendResponse might be used (even if synchronously here)
  } else if (message.action === "RESPONSE_CAPTURED") {
    console.log(`BACKGROUND: Received captured response (OLD DOM METHOD) from content script on tab ${sender.tab ? sender.tab.id : 'unknown'} Request ID: ${message.requestId}`);
    
    if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
      console.log("BACKGROUND: Forwarding (OLD DOM) response to relay server:", message.response);
      relaySocket.send(JSON.stringify({
        type: "CHAT_RESPONSE", 
        requestId: message.requestId, 
        response: message.response,
        isFinal: true 
      }));
      sendResponse({ success: true });
      
      if (lastRequestId === message.requestId) {
          processingRequest = false;
          console.log("BACKGROUND: Reset processingRequest after (OLD DOM) RESPONSE_CAPTURED.");
          processNextRequest();
      }

    } else {
      console.error("BACKGROUND: Relay WS not connected, cannot forward (OLD DOM) response");
      sendResponse({ success: false, error: "Relay WebSocket not connected" });
      if (lastRequestId === message.requestId) {
          processingRequest = false;
      }
    }
    return true; 
  } else if (message.action === "GET_CONNECTION_STATUS") {
    const isConnected = relaySocket && relaySocket.readyState === WebSocket.OPEN;
    sendResponse({ connected: isConnected });
    return true; // Indicate that sendResponse might be used
  } else if (message.type === "CHAT_RESPONSE_FROM_DOM") {
    console.log(`BACKGROUND: Received CHAT_RESPONSE_FROM_DOM from tab ${sender.tab ? sender.tab.id : 'unknown'} for requestId ${message.requestId}`);
    const tabId = sender.tab ? sender.tab.id : null;
    const tabInfo = tabId ? debuggerAttachedTabs.get(tabId) : null;

    if (tabInfo && tabInfo.lastKnownRequestId === message.requestId && processingRequest) {
        if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
            relaySocket.send(JSON.stringify({
                type: "CHAT_RESPONSE_CHUNK",
                requestId: message.requestId,
                chunk: message.text,
                isFinal: message.isFinal !== undefined ? message.isFinal : true
            }));
            relaySocket.send(JSON.stringify({
                type: "CHAT_RESPONSE_STREAM_ENDED",
                requestId: message.requestId
            }));
            console.log(`BACKGROUND: Sent CHAT_RESPONSE_CHUNK (from DOM) and _STREAM_ENDED for app requestId: ${message.requestId}`);
            sendResponse({ success: true, message: "DOM Response forwarded to relay." });
        } else {
            console.error(`BACKGROUND: Relay WS not connected, cannot send DOM-captured response for requestId: ${message.requestId}`);
            sendResponse({ success: false, error: "Relay WebSocket not connected." });
        }
        // Finalize this request processing
        processingRequest = false;
        if (tabInfo) tabInfo.lastKnownRequestId = null; // Clear for this specific tab op
        console.log(`BACKGROUND: Reset processingRequest. Cleared lastKnownRequestId for tab ${tabId} after DOM response.`);
        processNextRequest();
    } else {
        console.warn(`BACKGROUND: Mismatched requestId or not processing for CHAT_RESPONSE_FROM_DOM. Current lastKnownRequestId: ${tabInfo ? tabInfo.lastKnownRequestId : 'N/A'}, processingRequest: ${processingRequest}, msg RequestId: ${message.requestId}`);
        sendResponse({ success: false, error: "Mismatched requestId or not processing." });
    }
    return true;
  } else if (message.type === "CHAT_RESPONSE_FROM_DOM_FAILED") {
    console.error(`BACKGROUND: Received CHAT_RESPONSE_FROM_DOM_FAILED from tab ${sender.tab ? sender.tab.id : 'unknown'} for requestId ${message.requestId}: ${message.error}`);
    const tabId = sender.tab ? sender.tab.id : null;
    const tabInfo = tabId ? debuggerAttachedTabs.get(tabId) : null;

    if (tabInfo && tabInfo.lastKnownRequestId === message.requestId && processingRequest) {
        if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
            relaySocket.send(JSON.stringify({
                type: "CHAT_RESPONSE_ERROR",
                requestId: message.requestId,
                error: `Failed to capture response from DOM on tab ${tabId}: ${message.error}`
            }));
        }
        sendResponse({ success: true, message: "DOM failure noted and error sent to relay." });
        // Finalize this request processing
        processingRequest = false;
        if (tabInfo) tabInfo.lastKnownRequestId = null;
        console.log(`BACKGROUND: Reset processingRequest. Cleared lastKnownRequestId for tab ${tabId} after DOM failure.`);
        processNextRequest();
    } else {
        console.warn(`BACKGROUND: Mismatched requestId or not processing for CHAT_RESPONSE_FROM_DOM_FAILED. Current lastKnownRequestId: ${tabInfo ? tabInfo.lastKnownRequestId : 'N/A'}, processingRequest: ${processingRequest}, msg RequestId: ${message.requestId}`);
        sendResponse({ success: false, error: "Mismatched requestId or not processing for DOM failure." });
    }
    return true;
  } else if (message.type === "FINAL_RESPONSE_TO_RELAY") {
      console.log(BG_LOG_PREFIX, `[REQ-${message.requestId}] RECEIVED FINAL_RESPONSE_TO_RELAY. FromTab: ${sender.tab ? sender.tab.id : 'N/A'}. HasError: ${!!message.error}. TextLength: ${message.text ? String(message.text).length : 'N/A'}. IsFinal: ${message.isFinal}. FullMsg:`, JSON.stringify(message).substring(0,500));
      const tabId = sender.tab ? sender.tab.id : null;
      const tabInfo = tabId ? debuggerAttachedTabs.get(tabId) : null;

      // Update lastSuccessfullyProcessedMessageText regardless of current processing state,
      // as this confirms a message text was fully processed by the AI.
      const details = pendingRequestDetails.get(message.requestId);
      if (details) {
          if (typeof details.messageContent === 'string') {
              lastSuccessfullyProcessedMessageText = details.messageContent;
              console.log(`BACKGROUND: Updated lastSuccessfullyProcessedMessageText to: "${lastSuccessfullyProcessedMessageText.substring(0,50)}..." for completed requestId ${message.requestId}`);
          } else {
              console.log(`BACKGROUND: RequestId ${message.requestId} (messageContent type: ${typeof details.messageContent}) completed. lastSuccessfullyProcessedMessageText not updated with non-string content.`);
          }
          pendingRequestDetails.delete(message.requestId);
      } else {
          console.warn(`BACKGROUND: Received FINAL_RESPONSE_TO_RELAY for unknown requestId ${message.requestId} (not in pendingRequestDetails). Cannot update lastSuccessfullyProcessedMessageText accurately.`);
      }

      // Check if this is the request we are currently processing for state reset
      if (processingRequest && lastRequestId === message.requestId) {
          if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
              if (message.error) { // Check if content.js sent an error (e.g., response too large)
                  console.error(BG_LOG_PREFIX, `Content script reported an error for requestId ${message.requestId}: ${message.error}`);
                  try {
                      relaySocket.send(JSON.stringify({
                          type: "CHAT_RESPONSE_ERROR",
                          requestId: message.requestId,
                          error: message.error
                      }));
                      console.log(BG_LOG_PREFIX, `Sent CHAT_RESPONSE_ERROR to server for requestId ${message.requestId} due to content script error.`);
                      sendResponse({ success: true, message: "Error reported by content script sent to relay." });
                  } catch (e) {
                      console.error(BG_LOG_PREFIX, `Error sending CHAT_RESPONSE_ERROR to relay for requestId ${message.requestId}:`, e);
                      sendResponse({ success: false, error: `Error sending CHAT_RESPONSE_ERROR to relay: ${e.message}` });
                  }
              } else { // No error from content.js, proceed to send data
                  try {
                      let responseText = message.text || "";
                      
                      // Decode text if it was encoded by content script
                      if (message.encoded) {
                          responseText = decodeURIComponent(responseText);
                      }
                      
                      console.log(BG_LOG_PREFIX, `Attempting to send FINAL CHAT_RESPONSE_CHUNK for requestId ${message.requestId}. Data length: ${responseText.length}`);
                      relaySocket.send(JSON.stringify({
                          type: "CHAT_RESPONSE_CHUNK",
                          requestId: message.requestId,
                          chunk: responseText,
                          isFinal: true
                      }));
                      console.log(BG_LOG_PREFIX, `Attempting to send CHAT_RESPONSE_STREAM_ENDED for requestId ${message.requestId}`);
                      relaySocket.send(JSON.stringify({
                          type: "CHAT_RESPONSE_STREAM_ENDED",
                          requestId: message.requestId
                      }));
                      console.log(BG_LOG_PREFIX, `Successfully sent FINAL CHAT_RESPONSE_CHUNK and _STREAM_ENDED for app requestId: ${message.requestId} to relaySocket.`);
                      sendResponse({ success: true, message: "Final response sent to relay." });
                  } catch (e) {
                      console.error(BG_LOG_PREFIX, `Error during relaySocket.send() for FINAL response (requestId ${message.requestId}):`, e);
                      sendResponse({ success: false, error: `Error sending final response to relay: ${e.message}` });
                  }
              }
          } else {
              console.error(BG_LOG_PREFIX, `Relay WS not OPEN (state: ${relaySocket ? relaySocket.readyState : 'null'}), cannot send final response/error for app requestId: ${message.requestId}`);
              sendResponse({ success: false, error: "Relay WebSocket not connected." });
          }

          // Finalize this request processing
          console.log(BG_LOG_PREFIX, `Processing complete for command with app requestId: ${message.requestId} on tab ${tabId}`);
          processingRequest = false;
          if (tabInfo) tabInfo.lastKnownRequestId = null;
          console.log(BG_LOG_PREFIX, `Reset processingRequest. Cleared lastKnownRequestId for tab ${tabId}.`);
          processNextRequest();
      } else {
          console.warn(`BACKGROUND: Received FINAL_RESPONSE_TO_RELAY for requestId ${message.requestId}, but not currently processing it (current: ${lastRequestId}, processing: ${processingRequest}). Ignoring.`);
          sendResponse({ success: false, error: "Request ID mismatch or not processing." });
      }
      return true; // Indicate async response potentially
  } else if (message.type === "DUPLICATE_MESSAGE_HANDLED") {
    console.log(`BACKGROUND: Content script handled requestId ${message.requestId} as a duplicate of text: "${message.originalText ? message.originalText.substring(0,50) : 'N/A'}..."`);
    
    // Update last successfully processed text because this text was confirmed as a duplicate of it.
    lastSuccessfullyProcessedMessageText = message.originalText;
    pendingRequestDetails.delete(message.requestId); // Clean up details map
    console.log(`BACKGROUND: Updated lastSuccessfullyProcessedMessageText (due to duplicate) to: "${lastSuccessfullyProcessedMessageText ? lastSuccessfullyProcessedMessageText.substring(0,50) : 'N/A'}..."`);

    if (processingRequest && lastRequestId === message.requestId) {
        if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
            relaySocket.send(JSON.stringify({
                type: "CHAT_RESPONSE",
                requestId: message.requestId,
                response: `[ChatRelay Extension] Request to send duplicate message ("${message.originalText ? message.originalText.substring(0,100) : 'N/A'}") was detected and cleared from input. No message sent to AI.`,
                isFinal: true
            }));
            console.log(`BACKGROUND: Sent CHAT_RESPONSE (for duplicate) to server for requestId: ${message.requestId}.`);
        } else {
            console.error(`BACKGROUND: Relay WS not OPEN, cannot send CHAT_RESPONSE (for duplicate) for requestId: ${message.requestId}.`);
        }

        processingRequest = false;
        // lastRequestId remains, it's the ID of the last command *received*
        // currentRequestText (if used) would be nulled here.
        const tabInfo = sender.tab ? debuggerAttachedTabs.get(sender.tab.id) : null;
        if (tabInfo && tabInfo.lastKnownRequestId === message.requestId) {
             tabInfo.lastKnownRequestId = null;
        }

        console.log(`BACKGROUND: Reset processingRequest after DUPLICATE_MESSAGE_HANDLED for requestId: ${message.requestId}.`);
        processNextRequest();
    } else {
        console.warn(`BACKGROUND: Received DUPLICATE_MESSAGE_HANDLED for requestId ${message.requestId}, but not currently processing it or ID mismatch. Current lastRequestId: ${lastRequestId}, processing: ${processingRequest}. Still updated LSPMT.`);
        // If it was an older request, its details are cleaned, LSPMT updated. Server informed if possible.
         if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
            relaySocket.send(JSON.stringify({
                type: "CHAT_RESPONSE",
                requestId: message.requestId,
                response: `[ChatRelay Extension] An older/superseded request (ID: ${message.requestId}, Text: "${message.originalText ? message.originalText.substring(0,100) : 'N/A'}") was handled as a duplicate.`,
                isFinal: true
            }));
        }
    }
    sendResponse({ success: true, message: "Duplicate handling acknowledged by background." });
    return true;
  } else if (message.type === "USER_STOP_REQUEST") {
    const requestIdToStop = message.requestId;
    console.log(`BACKGROUND: Received USER_STOP_REQUEST for requestId: ${requestIdToStop}`);
    let responseSent = false; // To ensure sendResponse is called once

    // Case 1: The request to stop is the currently processing one.
    if (processingRequest && lastRequestId === requestIdToStop) {
        console.log(`BACKGROUND: Initiating stop for currently processing request: ${lastRequestId}. Content script will send FINAL_RESPONSE_TO_RELAY.`);
        if (activeTabId) {
            chrome.tabs.sendMessage(activeTabId, {
                action: "STOP_STREAMING",
                requestId: lastRequestId
            }, response => {
                if (chrome.runtime.lastError) {
                    console.error(`BACKGROUND: Error sending STOP_STREAMING to tab ${activeTabId} for requestId ${lastRequestId}:`, chrome.runtime.lastError.message);
                } else {
                    console.log(`BACKGROUND: Sent STOP_STREAMING to tab ${activeTabId} for requestId ${lastRequestId}. Content script ack:`, response);
                }
            });
        } else {
            console.warn(`BACKGROUND: Cannot send STOP_STREAMING for currently processing requestId ${lastRequestId}, activeTabId is null. This request might not be properly finalized by the provider.`);
            // If no active tab, we can't tell content.js to stop.
            // We should still inform the relay and clean up what we can,
            // though the provider state might remain for this request.
            if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
                relaySocket.send(JSON.stringify({
                    type: "CHAT_RESPONSE_ERROR",
                    requestId: lastRequestId,
                    error: "Request cancelled by user (no active tab to signal provider)."
                }));
            }
            // Since we can't rely on FINAL_RESPONSE_TO_RELAY, we have to clean up here.
            processingRequest = false;
            pendingRequestDetails.delete(lastRequestId);
            // lastSuccessfullyProcessedMessageText = null; // Consider if this should be reset
            console.log(`BACKGROUND: Forcefully reset processingRequest for ${lastRequestId} due to USER_STOP_REQUEST with no active tab.`);
            processNextRequest(); // Attempt to process next
        }

        // Inform relay server about cancellation (can be done early)
        if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
            relaySocket.send(JSON.stringify({
                type: "CHAT_RESPONSE_ERROR", // Or a new type like "USER_CANCELLED_REQUEST"
                requestId: lastRequestId, // Use lastRequestId as it's the one being processed
                error: "Request cancelled by user."
            }));
            console.log(`BACKGROUND: Sent CHAT_RESPONSE_ERROR (user cancelled) to server for currently processing requestId: ${lastRequestId}.`);
        }
        
        // IMPORTANT: Do NOT set processingRequest = false or clear lastRequestId details here.
        // Let the FINAL_RESPONSE_TO_RELAY (triggered by provider.stopStreaming) handle the final state cleanup.
        sendResponse({ success: true, message: `Stop initiated for currently processing request ${lastRequestId}. Waiting for finalization from content script.` });
        responseSent = true;

    // Case 2: The request to stop is in the pending queue (not actively processing).
    } else {
        const initialQueueLength = pendingRequests.length;
        pendingRequests = pendingRequests.filter(req => req.requestId !== requestIdToStop);
        if (pendingRequests.length < initialQueueLength) {
            console.log(`BACKGROUND: Removed requestId ${requestIdToStop} from pendingRequests queue.`);
            pendingRequestDetails.delete(requestIdToStop); // Clean up details for the queued item

            if (relaySocket && relaySocket.readyState === WebSocket.OPEN) {
                 relaySocket.send(JSON.stringify({
                    type: "CHAT_RESPONSE_ERROR",
                    requestId: requestIdToStop,
                    error: `Request ${requestIdToStop} cancelled by user while in queue.`
                }));
                console.log(`BACKGROUND: Sent CHAT_RESPONSE_ERROR (user cancelled in queue) to server for requestId: ${requestIdToStop}.`);
            }
            if (!responseSent) sendResponse({ success: true, message: `Request ${requestIdToStop} removed from queue.` });
            responseSent = true;
        }
    }

    if (!responseSent) {
        console.warn(`BACKGROUND: USER_STOP_REQUEST for ${requestIdToStop}, but it was not actively processing nor found in the pending queue. Current active: ${lastRequestId}, processing: ${processingRequest}`);
        sendResponse({ success: false, error: "Request not found processing or in queue." });
    }
    return true;
  }
  // IMPORTANT: Add other top-level else if (message.action === "SAVE_SETTINGS") etc. here if they exist outside this snippet
});

// Listen for storage changes to update the server URL
chrome.storage.onChanged.addListener((changes, namespace) => {
  if (namespace === 'sync') {
    let needsReconnect = false;
    if (changes.serverHost || changes.serverPort || changes.serverProtocol) {
        needsReconnect = true;
    }
    
    if (needsReconnect) {
      console.log("BACKGROUND: Server settings changed, reconnecting...");
      if (relaySocket) {
        relaySocket.close(); 
      } else {
        loadSettingsAndConnect(); 
      }
    }
  }
});

// Initial setup
loadSettingsAndConnect();

// Placeholder for providerUtils if it's not globally available from another script.
// In a real extension, this would likely be imported or part of a shared module.
const providerUtils = {
    _providers: {}, // providerName -> { instance, domains }
    registerProvider: function(name, domains, instance) {
        this._providers[name] = { instance, domains };
        // console.log(BG_LOG_PREFIX, `Provider registered in background (simulated): ${name}`);
    },
    getProviderForUrl: function(url) {
        for (const name in this._providers) {
            if (this._providers[name].domains.some(domain => url.includes(domain))) {
                return this._providers[name].instance;
            }
        }
        return null;
    },
    // Simulate AIStudioProvider registration for isUrlSupportedByProvider
    // This would normally happen if provider-utils.js was also loaded in background context
    // or if this info was passed/stored differently.
    _initializeSimulatedProviders: function() {
        this.registerProvider("AIStudioProvider", ["aistudio.google.com"], { name: "AIStudioProvider" });
        this.registerProvider("GeminiProvider", ["gemini.google.com"], { name: "GeminiProvider" });
        this.registerProvider("GeminiProvider", ["chatgpt.com"], { name: "ChatGPTProvider" });
        this.registerProvider("GeminiProvider", ["claude.ai"], { name: "ClaudeProvider" });

    }
};
providerUtils._initializeSimulatedProviders(); // Call to populate for the helper

console.log("BACKGROUND: AI Chat Relay: Background Service Worker started.");


// ===== DEBUGGER LOGIC =====
async function attachDebuggerAndEnableFetch(tabId, providerName, patterns) {
    if (!tabId || !patterns || patterns.length === 0) {
        console.error(BG_LOG_PREFIX, `attachDebuggerAndEnableFetch: Invalid parameters for tab ${tabId}. Patterns:`, patterns);
        return;
    }
    const debuggee = { tabId: tabId };
    const requiredVersion = "1.3";

    try {
        const existingAttachment = debuggerAttachedTabs.get(tabId);
        if (existingAttachment && existingAttachment.isAttached) {
            console.log(BG_LOG_PREFIX, `Already attached to tab ${tabId}. Ensuring Fetch is enabled with latest patterns.`);
        } else {
            console.log(BG_LOG_PREFIX, `Attempting to attach debugger to tab ${tabId}`);
            await new Promise((resolve, reject) => {
                chrome.debugger.attach(debuggee, requiredVersion, () => {
                    if (chrome.runtime.lastError) {
                        console.error(BG_LOG_PREFIX, `Error attaching debugger to tab ${tabId}:`, chrome.runtime.lastError.message);
                        debuggerAttachedTabs.delete(tabId);
                        return reject(chrome.runtime.lastError);
                    }
                    console.log(BG_LOG_PREFIX, `Successfully attached debugger to tab ${tabId}`);
                    debuggerAttachedTabs.set(tabId, {
                        providerName: providerName,
                        patterns: patterns,
                        isFetchEnabled: false,
                        isAttached: true,
                        lastKnownRequestId: null 
                    });
                    resolve();
                });
            });
        }
        
        const currentTabDataForPatterns = debuggerAttachedTabs.get(tabId);
        if (currentTabDataForPatterns) {
            currentTabDataForPatterns.patterns = patterns; 
            currentTabDataForPatterns.providerName = providerName; 
        }

        // Explicitly disable Fetch first, in case it's in a weird state
        try {
            console.log(BG_LOG_PREFIX, `Attempting to disable Fetch domain for tab ${tabId} before re-enabling.`);
            await new Promise((resolve, reject) => {
                chrome.debugger.sendCommand(debuggee, "Fetch.disable", {}, (disableResponse) => {
                    if (chrome.runtime.lastError) {
                        console.warn(BG_LOG_PREFIX, `Warning/Error disabling Fetch for tab ${tabId}:`, chrome.runtime.lastError.message);
                        // Don't reject, just log, as we want to proceed to enable anyway
                    } else {
                        console.log(BG_LOG_PREFIX, `Successfully disabled Fetch for tab ${tabId}. Response:`, disableResponse);
                    }
                    resolve();
                });
            });
        } catch (e) {
            console.warn(BG_LOG_PREFIX, `Exception during explicit Fetch.disable for tab ${tabId}:`, e);
        }

        console.log(BG_LOG_PREFIX, `Enabling Fetch domain for tab ${tabId} with patterns:`, patterns);
        await new Promise((resolve, reject) => {
            const fetchEnableParams = { patterns: patterns };
            console.log(BG_LOG_PREFIX, `Preparing to call Fetch.enable for tab ${tabId} with params:`, JSON.stringify(fetchEnableParams));
            chrome.debugger.sendCommand(debuggee, "Fetch.enable", fetchEnableParams, (response) => {
                if (chrome.runtime.lastError) {
                    console.error(BG_LOG_PREFIX, `Error enabling Fetch for tab ${tabId}:`, chrome.runtime.lastError.message);
                    return reject(chrome.runtime.lastError);
                }
                console.log(BG_LOG_PREFIX, `Successfully enabled Fetch for tab ${tabId}. Response from Fetch.enable:`, response);
                const currentTabData = debuggerAttachedTabs.get(tabId);
                if (currentTabData) {
                    currentTabData.isFetchEnabled = true;
                }
                resolve();
            });
        });
    } catch (error) {
        console.error(BG_LOG_PREFIX, `Error in attachDebuggerAndEnableFetch for tab ${tabId}:`, error);
        // Ensure flags are reset on error
        const currentTabDataOnError = debuggerAttachedTabs.get(tabId);
        if (currentTabDataOnError) {
            currentTabDataOnError.isFetchEnabled = false; // Ensure this is false
            // if (!currentTabDataOnError.isAttached) { // Commenting out: if attach failed earlier, it's already deleted. If attach succeeded but enable failed, we want to keep attachment info.
            //     debuggerAttachedTabs.delete(tabId);
            // }
        }
    }
}

async function detachDebugger(tabId) {
    if (!tabId) return;
    const attachmentDetails = debuggerAttachedTabs.get(tabId);
    if (attachmentDetails && attachmentDetails.isAttached) {
        console.log(BG_LOG_PREFIX, `Attempting to detach debugger from tab ${tabId}`);
        try {
            await new Promise((resolve, reject) => {
                chrome.debugger.detach({ tabId: tabId }, () => {
                    if (chrome.runtime.lastError) {
                        console.error(BG_LOG_PREFIX, `Error detaching debugger from tab ${tabId}:`, chrome.runtime.lastError.message);
                    } else {
                        console.log(BG_LOG_PREFIX, `Successfully detached debugger from tab ${tabId}`);
                    }
                    debuggerAttachedTabs.delete(tabId);
                    resolve(); // Resolve even if detach had an error, as we've cleaned up map
                });
            });
        } catch (error) { // Catch errors from the Promise constructor itself or unhandled rejections
            console.error(BG_LOG_PREFIX, `Exception during detach for tab ${tabId}:`, error);
            debuggerAttachedTabs.delete(tabId); // Ensure cleanup
        }
    } else {
        // If not attached or no details, still ensure it's not in the map
        debuggerAttachedTabs.delete(tabId);
    }
}

chrome.tabs.onRemoved.addListener((tabId, removeInfo) => {
    console.log(BG_LOG_PREFIX, `Tab ${tabId} removed. Detaching debugger if attached.`);
    detachDebugger(tabId);
});

chrome.runtime.onSuspend.addListener(() => {
    console.log(BG_LOG_PREFIX, "Extension suspending. Detaching all debuggers.");
    for (const tabId of debuggerAttachedTabs.keys()) {
        detachDebugger(tabId);
    }
});

chrome.debugger.onDetach.addListener((source, reason) => {
    if (source.tabId) {
        console.log(BG_LOG_PREFIX, `Debugger detached from tab ${source.tabId} (e.g. DevTools closed) due to: ${reason}. Cleaning up.`);
        debuggerAttachedTabs.delete(source.tabId);
    }
});

chrome.debugger.onEvent.addListener((debuggeeId, message, params) => {
    if (!debuggeeId.tabId) return;
    const tabId = debuggeeId.tabId;
    const tabInfo = debuggerAttachedTabs.get(tabId);

    // DEVELOPER ACTION: This parsing function needs to be robustly implemented
    // based on consistent observation of the AI Studio response structure.
    function parseAiStudioResponse(jsonString) {
        try {
            const parsed = JSON.parse(jsonString);
            let combinedText = "";
            if (Array.isArray(parsed)) {
                for (const topLevelEntry of parsed) {
                    if (topLevelEntry && topLevelEntry[0] && topLevelEntry[0][2] && Array.isArray(topLevelEntry[0][2])) {
                        for (const candidateBlock of topLevelEntry[0][2]) {
                            if (candidateBlock && candidateBlock[0] && candidateBlock[0][0] && candidateBlock[0][0][0] && Array.isArray(candidateBlock[0][0][0][0])) {
                                for (const innerMostArray of candidateBlock[0][0][0][0]) {
                                    if (Array.isArray(innerMostArray) && innerMostArray.length > 1 && typeof innerMostArray[1] === 'string') {
                                        const textSegment = innerMostArray[1];
                                        // Basic heuristic to filter out "thought process" or similar meta-commentary.
                                        // This will need refinement based on actual response variations.
                                        if (!textSegment.toLowerCase().includes("thinking process") &&
                                            !textSegment.toLowerCase().includes("thought process") &&
                                            !textSegment.startsWith("1.") && // Avoid numbered list from thoughts
                                            !textSegment.startsWith("2.") &&
                                            !textSegment.startsWith("3.") &&
                                            !textSegment.startsWith("4.") &&
                                            !textSegment.startsWith("5.") &&
                                            !textSegment.startsWith("6.") &&
                                            textSegment.trim() !== "**") {
                                            combinedText += textSegment; // Concatenate, newlines are part of the text
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
            // Cleanup common markdown/formatting that might not be desired for relay
            let cleanedMessage = combinedText.replace(/\*\*/g, "").replace(/\\n/g, "\n").replace(/\n\s*\n/g, '\n').trim();
            
            if (cleanedMessage) {
                console.log(BG_LOG_PREFIX, "Parsed AI Studio response to (first 100 chars):", cleanedMessage.substring(0, 100));
                return cleanedMessage;
            } else {
                console.warn(BG_LOG_PREFIX, "Parsing AI Studio response yielded empty text. Original (first 200 chars):", jsonString.substring(0,200));
            }
        } catch (e) {
            console.error(BG_LOG_PREFIX, "Error parsing AI Studio response JSON:", e, "Original string (first 200 chars):", jsonString.substring(0, 200));
        }
        console.warn(BG_LOG_PREFIX, "Failed to extract clean text from AI Studio response, returning raw data.");
        return jsonString;
    }

    if (message === "Fetch.requestPaused") {
        // Log immediately upon entering Fetch.requestPaused
        console.log(BG_LOG_PREFIX, `ENTERED Fetch.requestPaused for tab ${tabId}, URL: ${params.request.url}, Debugger NetworkRequestId: ${params.requestId}, Stage: ${params.responseErrorReason || params.requestStage}, Headers:`, params.request.headers);

        if (!tabInfo) {
            console.warn(BG_LOG_PREFIX, `Fetch.requestPaused for tab ${tabId} but NO tabInfo found in debuggerAttachedTabs. Continuing request.`);
            chrome.debugger.sendCommand(debuggeeId, "Fetch.continueRequest", { requestId: params.requestId });
            return;
        }
        if (!tabInfo.isFetchEnabled) {
            console.log(BG_LOG_PREFIX, `Tab ${tabId} not actively monitored or Fetch not enabled (tabInfo.isFetchEnabled is false). Continuing request.`);
            chrome.debugger.sendCommand(debuggeeId, "Fetch.continueRequest", { requestId: params.requestId });
            return;
        }

        // This is the application's requestId (e.g., 0, 1, 2...)
        // It's CRITICAL that tabInfo.lastKnownRequestId is correctly set when the command was initially forwarded.
        const currentOperationRequestId = tabInfo.lastKnownRequestId;

        if (currentOperationRequestId === null || currentOperationRequestId === undefined) {
            console.warn(BG_LOG_PREFIX, `Fetch.requestPaused for tab ${tabId} (URL: ${params.request.url}) but tabInfo.lastKnownRequestId is null/undefined. Cannot associate with an operation. Continuing request.`);
            chrome.debugger.sendCommand(debuggeeId, "Fetch.continueRequest", { requestId: params.requestId });
            return;
        }
        
        // Check if the URL matches any of the patterns for this tab
        const matchesPattern = tabInfo.patterns.some(p => {
            try {
                // Ensure the pattern is treated as a string and properly escaped for regex construction.
                // Basic wildcard to regex: replace * with .*? (non-greedy)
                const patternRegex = new RegExp(String(p.urlPattern).replace(/[.*+?^${}()|[\]\\]/g, '\\$&').replace(/\\\*/g, '.*?'));
                return patternRegex.test(params.request.url);
            } catch (e) {
                console.error(BG_LOG_PREFIX, `Error creating regex from pattern '${p.urlPattern}':`, e);
                return false;
            }
        });

        if (!matchesPattern) {
            // console.log(BG_LOG_PREFIX, `Fetch.requestPaused for URL ${params.request.url} did NOT match stored patterns for tab ${tabId}. Continuing request. Patterns:`, tabInfo.patterns);
            chrome.debugger.sendCommand(debuggeeId, "Fetch.continueRequest", { requestId: params.requestId });
            return;
        }
        console.log(BG_LOG_PREFIX, `Fetch.requestPaused for URL ${params.request.url} MATCHED pattern. App RequestId: ${currentOperationRequestId}. Proceeding...`);
        
        console.log(BG_LOG_PREFIX, `[DEBUG_STAGE_STATUS] For matched URL ${params.request.url}, appReqId: ${currentOperationRequestId}, debugger netReqId: ${params.requestId}:`);
        console.log(BG_LOG_PREFIX, `  - params.requestStage: ${params.requestStage}`);
        console.log(BG_LOG_PREFIX, `  - params.responseStatusCode: ${params.responseStatusCode}`);
        console.log(BG_LOG_PREFIX, `  - params.responseErrorReason: ${params.responseErrorReason}`);

        // Additional pre-condition logging
        console.log(BG_LOG_PREFIX, `[PRE-CONDITION CHECK] For AppReqId: ${currentOperationRequestId}, Debugger netReqId: ${params.requestId}`);
        console.log(BG_LOG_PREFIX, `  - tabInfo (raw):`, tabInfo); // Log the raw tabInfo object
        console.log(BG_LOG_PREFIX, `  - tabInfo.patterns:`, tabInfo ? JSON.stringify(tabInfo.patterns) : "tabInfo is null");
        console.log(BG_LOG_PREFIX, `  - tabInfo.lastKnownRequestId: ${tabInfo ? tabInfo.lastKnownRequestId : "tabInfo is null"} (should be currentOperationRequestId)`);
        console.log(BG_LOG_PREFIX, `  - currentOperationRequestId (derived from tabInfo.lastKnownRequestId): ${currentOperationRequestId}`);

        // Scenario 1: Network error before even getting a response status (e.g., DNS failure)
        if (params.responseErrorReason) {
            console.error(BG_LOG_PREFIX, `Response error for ${params.request.url} (debugger netReqId ${params.requestId}): ${params.responseErrorReason}. AppReqId: ${currentOperationRequestId}.`);
            const messageToContent = {
                type: "PROVIDER_DEBUGGER_EVENT", // Ensure this type is handled by content.js
                detail: {
                    requestId: currentOperationRequestId,
                    networkRequestId: params.requestId,
                    error: `Network error: ${params.responseErrorReason}`,
                    isFinal: true
                }
            };
            chrome.tabs.sendMessage(tabId, messageToContent, response => {
                if (chrome.runtime.lastError) console.error(BG_LOG_PREFIX, `Error sending debugger error event (responseErrorReason) to content script for tab ${tabId}:`, chrome.runtime.lastError.message);
                else console.log(BG_LOG_PREFIX, `Sent debugger error event (responseErrorReason) to content script for tab ${tabId}, appReqId: ${currentOperationRequestId}, ack:`, response);
            });
            chrome.debugger.sendCommand(debuggeeId, "Fetch.continueRequest", { requestId: params.requestId });
            return;
        }

        // Scenario 2: We have response headers (indicated by params.responseStatusCode being present).
        if (params.responseStatusCode) {
            if (params.responseStatusCode >= 200 && params.responseStatusCode < 300) {
                // SUCCESS: We have a 2xx status, attempt to get the response body.
                console.log(BG_LOG_PREFIX, `Attempting Fetch.getResponseBody for ${params.request.url}, appReqId: ${currentOperationRequestId}, debugger netReqId: ${params.requestId} (Stage: ${params.requestStage}, Status: ${params.responseStatusCode})`);
                chrome.debugger.sendCommand(debuggeeId, "Fetch.getResponseBody", { requestId: params.requestId }, (responseBodyData) => {
                    let errorMessageForContent = null; 
                    if (chrome.runtime.lastError) {
                        errorMessageForContent = `Error calling Fetch.getResponseBody: ${chrome.runtime.lastError.message}`;
                        console.error(BG_LOG_PREFIX, `${errorMessageForContent} for tab ${tabId}, appReqId: ${currentOperationRequestId}, debugger netReqId: ${params.requestId}`);
                    }
                    
                    console.log(BG_LOG_PREFIX, `[getResponseBody CB] appReqId: ${currentOperationRequestId}, netReqId: ${params.requestId}. responseBodyData raw:`, responseBodyData);
                    if (responseBodyData) {
                        console.log(BG_LOG_PREFIX, `[getResponseBody CB] responseBodyData.body (first 100): ${responseBodyData.body ? String(responseBodyData.body).substring(0,100) : 'N/A'}, .base64Encoded: ${responseBodyData.base64Encoded}`);
                    }
                    console.log(BG_LOG_PREFIX, `[getResponseBody CB] errorMessageForContent before check: '${errorMessageForContent}'`);

                    if (!responseBodyData && !errorMessageForContent) { 
                        errorMessageForContent = "No response body data and no explicit error from getResponseBody.";
                        console.warn(BG_LOG_PREFIX, `${errorMessageForContent} for tab ${tabId}, appReqId: ${currentOperationRequestId}, debugger netReqId: ${params.requestId}`);
                    }
                    console.log(BG_LOG_PREFIX, `[getResponseBody CB] errorMessageForContent AFTER check: '${errorMessageForContent}'`);

                    // Text encoding fix: properly decode base64-encoded response bodies
                    let processedData = null;
                    if (responseBodyData && responseBodyData.body) {
                        if (responseBodyData.base64Encoded) {
                            try {
                                processedData = new TextDecoder('utf-8').decode(Uint8Array.from(atob(responseBodyData.body), c => c.charCodeAt(0)));
                            } catch (error) {
                                console.error(BG_LOG_PREFIX, `Error decoding base64 response body for requestId ${params.requestId}:`, error);
                                processedData = responseBodyData.body; // Fallback to original
                            }
                        } else {
                            processedData = responseBodyData.body;
                        }
                    }

                    const messageToContent = {
                        type: "PROVIDER_DEBUGGER_EVENT",
                        detail: {
                            requestId: currentOperationRequestId,
                            networkRequestId: params.requestId,
                            data: processedData,
                            base64Encoded: false, // Always false since we've decoded it
                            error: errorMessageForContent,
                            isFinal: true 
                        }
                    };
                    console.log(BG_LOG_PREFIX, `Sending PROVIDER_DEBUGGER_EVENT (body/error) to content script for tab ${tabId}, appReqId: ${currentOperationRequestId}. Error: ${errorMessageForContent}, Data (first 100): ${messageToContent.detail.data ? String(messageToContent.detail.data).substring(0,100) + "..." : "null"}`);
                    chrome.tabs.sendMessage(tabId, messageToContent, response => {
                         if (chrome.runtime.lastError) console.error(BG_LOG_PREFIX, `Error sending/acking debugger event (body/error) to content script for tab ${tabId}:`, chrome.runtime.lastError.message);
                         else console.log(BG_LOG_PREFIX, `Sent debugger event (body/error) to content script for tab ${tabId}, appReqId: ${currentOperationRequestId}, ack:`, response);
                    });
                });
            } else { // Non-2xx status code
                const httpErrorMessage = `HTTP error ${params.responseStatusCode} for ${params.request.url}`;
                console.error(BG_LOG_PREFIX, `${httpErrorMessage}. AppReqId: ${currentOperationRequestId}, Debugger netReqId: ${params.requestId}.`);
                const messageToContent = {
                    type: "PROVIDER_DEBUGGER_EVENT",
                    detail: {
                        requestId: currentOperationRequestId,
                        networkRequestId: params.requestId,
                        error: httpErrorMessage,
                        isFinal: true
                    }
                };
                chrome.tabs.sendMessage(tabId, messageToContent, response => {
                    if (chrome.runtime.lastError) console.error(BG_LOG_PREFIX, `Error sending debugger HTTP error event to content script for tab ${tabId}:`, chrome.runtime.lastError.message);
                    else console.log(BG_LOG_PREFIX, `Sent debugger HTTP error event to content script for tab ${tabId}, appReqId: ${currentOperationRequestId}, ack:`, response);
                });
                chrome.debugger.sendCommand(debuggeeId, "Fetch.continueRequest", { requestId: params.requestId });
            }
        } else {
            // No response headers yet (no params.responseStatusCode), and no responseErrorReason.
            // This could be an earlier stage of the request or one not relevant for body capture.
            console.log(BG_LOG_PREFIX, `Request for ${params.request.url} (debugger netReqId: ${params.requestId}, appReqId: ${currentOperationRequestId}) does not have responseStatusCode. Stage: ${params.requestStage}. Continuing request.`);
            chrome.debugger.sendCommand(debuggeeId, "Fetch.continueRequest", { requestId: params.requestId });
        }
    }
});