/**
 * Gravity Bridge — VS Code Extension (SDK Edition)
 * 
 * Uses antigravity-sdk for:
 * - Real-time step/conversation monitoring via EventMonitor
 * - Full conversation content via LSBridge.getConversation()
 * - Message sending via CascadeManager.sendPrompt()
 * - Accept/Reject via CascadeManager.acceptStep()/rejectStep()
 * 
 * Communication with Discord via file-based bridge protocol.
 */

import * as vscode from 'vscode';
import * as fs from 'fs';
import * as path from 'path';
import * as os from 'os';
import * as cp from 'child_process';
import * as crypto from 'crypto';

// ─── File-based logging (AI can read directly) ───
function logToFile(msg: string) {
    const ts = new Date().toISOString().replace('T', ' ').substring(0, 19);
    const line = `${ts} ${msg}`;
    console.log(`Gravity Bridge: ${msg}`);
    try {
        if (!bridgePath) return;
        const logFile = path.join(bridgePath, 'extension.log');
        fs.appendFileSync(logFile, line + '\n', 'utf-8');
    } catch (e: any) {
        console.error(`Gravity Bridge LOG WRITE FAIL: ${e.message}`);
    }
}

// antigravity-sdk embedded locally (src/sdk/)
let AntigravitySDK: any;
let sdk: any;

let statusBar: vscode.StatusBarItem;
let bridgePath: string;
let projectName: string;
let isActive = false;
let deterministicPort = 0;  // derived from projectName, consistent across restarts
let watcher: fs.FSWatcher | null = null;
let commandsWatcher: fs.FSWatcher | null = null;

const sentPendingIds = new Set<string>();

// ─── Project Detection ───

function detectProjectName(): string {
    const config = vscode.workspace.getConfiguration('gravityBridge');
    const configName = config.get<string>('projectName');
    if (configName) { return configName; }

    const folders = vscode.workspace.workspaceFolders;
    if (folders && folders.length > 0) {
        const cwd = folders[0].uri.fsPath;
        try {
            const remoteUrl = cp.execSync('git remote get-url origin', {
                cwd, encoding: 'utf-8', timeout: 3000
            }).trim();
            const match = remoteUrl.match(/\/([^\/]+?)(?:\.git)?$/);
            if (match && match[1]) {
                return match[1].toLowerCase().replace(/[\s\-]+/g, '_');
            }
        } catch { }
        return path.basename(cwd).toLowerCase().replace(/[\s\-]+/g, '_');
    }
    return 'default';
}

// ─── Bridge File I/O ───

function ensureBridgeDir() {
    const dirs = ['', 'response', 'commands', 'chat_snapshots'];
    for (const d of dirs) {
        const p = path.join(bridgePath, d);
        if (!fs.existsSync(p)) { fs.mkdirSync(p, { recursive: true }); }
    }
}

// Module-level activeSessionId so writeChatSnapshot can register sessions lazily
let activeSessionId = '';

function writeChatSnapshot(text: string) {
    try {
        // Write to chat_snapshots/*.json for Bot's chat_snapshot_scanner to pick up
        const snapshotDir = path.join(bridgePath, 'chat_snapshots');
        if (!fs.existsSync(snapshotDir)) { fs.mkdirSync(snapshotDir, { recursive: true }); }
        const id = Date.now().toString();
        const data = {
            id,
            project_name: projectName,
            content: text,
            timestamp: Date.now() / 1000,
        };
        const filePath = path.join(snapshotDir, `${id}.json`);
        fs.writeFileSync(filePath, JSON.stringify(data, null, 2), 'utf-8');
        console.log(`Gravity Bridge: chat snapshot written (${text.length} chars) → ${id}.json`);
        // Lazily register session → project mapping (correct because projectName is per-window)
        if (activeSessionId) { writeRegistration(activeSessionId); }
    } catch (e: any) {
        console.log(`Gravity Bridge: snapshot write error: ${e.message}`);
    }
}


// ─── Command File Watcher (Discord → Antigravity) ───

function processCommandFile(filePath: string) {
    try {
        const content = fs.readFileSync(filePath, 'utf-8');
        const cmd = JSON.parse(content);

        // Skip already consumed commands
        if (cmd.consumed) {
            try { fs.unlinkSync(filePath); } catch { }
            return;
        }

        // Ignore commands for other projects
        if (cmd.project_name && cmd.project_name !== projectName) {
            console.log(`Gravity Bridge: skipping command for "${cmd.project_name}" (we are "${projectName}")`);
            return;
        }

        // Bot writes 'text' field, not 'message'
        const text = cmd.text || cmd.message || '';
        const action = cmd.action || '';

        console.log(`Gravity Bridge: command — text="${text}" action="${action}"`);

        if (action === 'approve' && sdk) {
            sdk.cascade.acceptStep().catch((e: any) =>
                console.log(`Gravity Bridge: approve error: ${e.message}`)
            );
        } else if (action === 'reject' && sdk) {
            sdk.cascade.rejectStep().catch((e: any) =>
                console.log(`Gravity Bridge: reject error: ${e.message}`)
            );
        } else if (action === 'approve_terminal' && sdk) {
            sdk.cascade.acceptTerminalCommand().catch((e: any) =>
                console.log(`Gravity Bridge: approve_terminal error: ${e.message}`)
            );
        } else if (text === '!stop') {
            // Cancel current operation
            vscode.commands.executeCommand('antigravity.agent.rejectAgentStep')
                .then(() => console.log('Gravity Bridge: ✅ stop sent'),
                    () => { });
        } else if (text.startsWith('!auto ')) {
            // Auto-approve mode toggle
            const mode = text.includes('on') ? 'true' : 'false';
            console.log(`Gravity Bridge: auto-approve → ${mode}`);
        } else if (text) {
            // Send message to Antigravity — use VS Code command (most reliable)
            vscode.commands.executeCommand('antigravity.sendPromptToAgentPanel', text)
                .then(() => console.log(`Gravity Bridge: ✅ sent "${text.substring(0, 50)}" via sendPromptToAgentPanel`),
                    (e: any) => console.log(`Gravity Bridge: sendPrompt failed: ${e.message}`));
        }

        // Remove processed command file
        try { fs.unlinkSync(filePath); } catch { }
    } catch (e: any) {
        console.log(`Gravity Bridge: command processing error: ${e.message}`);
    }
}

function watchCommandsDir() {
    const cmdDir = path.join(bridgePath, 'commands');

    // Process existing files
    try {
        for (const f of fs.readdirSync(cmdDir)) {
            if (f.endsWith('.json')) {
                processCommandFile(path.join(cmdDir, f));
            }
        }
    } catch { }

    // Watch for new files
    try {
        commandsWatcher = fs.watch(cmdDir, (event, filename) => {
            if (filename && filename.endsWith('.json') && event === 'rename') {
                const fp = path.join(cmdDir, filename);
                if (fs.existsSync(fp)) {
                    setTimeout(() => processCommandFile(fp), 200);
                }
            }
        });
    } catch { }
}

// ─── SDK Integration ───

async function initSDK(context: vscode.ExtensionContext): Promise<boolean> {
    try {
        const sdkModule = require('./sdk/index');
        AntigravitySDK = sdkModule.AntigravitySDK;
    } catch (err: any) {
        console.log(`Gravity Bridge: antigravity-sdk load failed: ${err.message}`);
        return false;
    }

    try {
        sdk = new AntigravitySDK(context);
        await sdk.initialize();
        console.log('Gravity Bridge: ✅ SDK initialized');
        return true;
    } catch (err: any) {
        console.log(`Gravity Bridge: SDK init failed: ${err.message}`);
        return false;
    }
}

// ─── Approval Observer via SDK IntegrationManager ───

async function setupApprovalObserver() {
    if (!sdk) { logToFile('[OBSERVER] no SDK'); return; }
    try {
        const integration = sdk.integration;
        if (!integration) { logToFile('[OBSERVER] sdk.integration unavailable'); return; }

        // 1. Start HTTP bridge server in Extension Host
        const bridgePort = await startObserverHttpBridge();
        if (!bridgePort) { logToFile('[OBSERVER] HTTP bridge failed'); return; }

        // 2. Register a TOP_BAR button so build() works
        try {
            integration.register({
                id: 'gravity_bridge_status',
                point: 'topBar',
                icon: '🌉',
                tooltip: 'Gravity Bridge Active',
            });
        } catch { /* already registered */ }

        // 3. Write renderer script with HTTP fetch() approach
        const observerJS = generateApprovalObserverScript(bridgePort);
        const patcher = (integration as any)._patcher;
        if (patcher && typeof patcher.getScriptPath === 'function') {
            let baseScript = '';
            try { baseScript = integration.build(); } catch { baseScript = ''; }
            const combinedScript = baseScript + '\n' + observerJS;
            const scriptPath = patcher.getScriptPath();
            fs.writeFileSync(scriptPath, combinedScript, 'utf8');
            logToFile(`[OBSERVER] script written → ${scriptPath} (port=${bridgePort})`);
            if (!integration.isInstalled()) {
                patcher.install(combinedScript);
                logToFile('[OBSERVER] workbench.html patched (needs reload)');
            }

            // Also patch workbench-jetski-agent.html (Antigravity's actual entry point!)
            // IMPORTANT: vscode-file:// does NOT serve custom .js files (silent 404),
            // so we MUST inline the script directly into the HTML.
            const scriptDir = path.dirname(scriptPath);
            const jetskiHtml = path.join(scriptDir, 'workbench-jetski-agent.html');
            try {
                if (fs.existsSync(jetskiHtml)) {
                    let html = fs.readFileSync(jetskiHtml, 'utf8');

                    // Remove old external script tag if present
                    const extMarkerStart = '<!-- AG SDK [variet-gravity-bridge] -->';
                    const extMarkerEnd = '<!-- /AG SDK [variet-gravity-bridge] -->';
                    if (html.includes(extMarkerStart)) {
                        const extRe = new RegExp(
                            '\\n?' + extMarkerStart.replace(/[[\]]/g, '\\$&') +
                            '[\\s\\S]*?' +
                            extMarkerEnd.replace(/[[\]]/g, '\\$&') + '\\n?'
                        );
                        html = html.replace(extRe, '');
                        logToFile('[OBSERVER] removed external script tag from jetski HTML');
                    }

                    // Insert or update inline script
                    const inlineMarkerStart = '<!-- AG SDK INLINE [variet-gravity-bridge] -->';
                    const inlineMarkerEnd = '<!-- /AG SDK INLINE [variet-gravity-bridge] -->';

                    if (html.includes(inlineMarkerStart)) {
                        const re = new RegExp(
                            inlineMarkerStart.replace(/[[\]]/g, '\\$&') +
                            '[\\s\\S]*?' +
                            inlineMarkerEnd.replace(/[[\]]/g, '\\$&')
                        );
                        html = html.replace(re,
                            `${inlineMarkerStart}\n<script>\n${combinedScript}\n</script>\n${inlineMarkerEnd}`);
                        logToFile('[OBSERVER] jetski HTML inline script UPDATED');
                    } else {
                        html = html.replace('</html>',
                            `\n${inlineMarkerStart}\n<script>\n${combinedScript}\n</script>\n${inlineMarkerEnd}\n</html>`);
                        logToFile('[OBSERVER] jetski HTML inline script INSERTED');
                    }
                    fs.writeFileSync(jetskiHtml, html, 'utf8');
                }
            } catch (e: any) {
                logToFile(`[OBSERVER] jetski patch error: ${e.message}`);
            }
        }

        // 4. Update product.json checksums so vscode-file:// serves our patched files
        updateProductChecksums();

        try { integration.enableAutoRepair(); } catch { }
        setInterval(() => { try { integration.signalActive(); } catch { } }, 30_000);

        logToFile(`[OBSERVER] setup complete (HTTP bridge on port ${bridgePort})`);
        console.log(`Gravity Bridge: ✅ Approval observer installed (port ${bridgePort})`);
    } catch (err: any) {
        logToFile(`[OBSERVER] setup error: ${err.message}`);
    }
}

// ─── Product.json Checksum Auto-Update ───
// vscode-file:// protocol validates SHA256 checksums in product.json.
// If a file's checksum doesn't match, Electron serves the ORIGINAL cached version.
// This function recalculates checksums for files we modify (HTML files with <script> tags).

function updateProductChecksums() {
    try {
        // Find product.json (2 levels up from workbench dir: resources/app/product.json)
        const patcher = (sdk?.integration as any)?._patcher;
        if (!patcher || typeof patcher.getWorkbenchDir !== 'function') {
            logToFile('[CHECKSUM] no patcher/workbenchDir — skipping');
            return;
        }
        const workbenchDir = patcher.getWorkbenchDir();
        // workbenchDir = .../resources/app/out/vs/code/electron-browser/workbench
        // product.json = .../resources/app/product.json  (5 levels up from workbench)
        const appDir = path.resolve(workbenchDir, '..', '..', '..', '..', '..');
        const productJsonPath = path.join(appDir, 'product.json');

        if (!fs.existsSync(productJsonPath)) {
            logToFile(`[CHECKSUM] product.json not found at ${productJsonPath}`);
            return;
        }

        // Read product.json (may have BOM)
        let raw = fs.readFileSync(productJsonPath, 'utf8');
        if (raw.charCodeAt(0) === 0xFEFF) raw = raw.substring(1);
        const product = JSON.parse(raw);

        if (!product.checksums) {
            logToFile('[CHECKSUM] no checksums section in product.json');
            return;
        }

        // Files we may modify or create (relative key in product.json → absolute path)
        // CRITICAL: vscode-file:// only serves files with valid checksums in product.json.
        // Custom JS files MUST be added here or they'll silently 404.
        const filesToCheck: Record<string, string> = {
            'vs/code/electron-browser/workbench/workbench.html': path.join(workbenchDir, 'workbench.html'),
            'vs/code/electron-browser/workbench/workbench-jetski-agent.html': path.join(workbenchDir, 'workbench-jetski-agent.html'),
            'vs/code/electron-browser/workbench/ag-sdk-variet-gravity-bridge.js': path.join(workbenchDir, 'ag-sdk-variet-gravity-bridge.js'),
        };

        let updated = false;
        for (const [key, filePath] of Object.entries(filesToCheck)) {
            if (!fs.existsSync(filePath)) continue;

            const fileBytes = fs.readFileSync(filePath);
            const hash = crypto.createHash('sha256').update(fileBytes).digest('base64').replace(/=+$/, '');

            if (product.checksums[key] !== hash) {
                logToFile(`[CHECKSUM] updating ${key}: ${product.checksums[key].substring(0, 12)}... → ${hash.substring(0, 12)}...`);
                product.checksums[key] = hash;
                updated = true;
            }
        }

        if (updated) {
            fs.writeFileSync(productJsonPath, JSON.stringify(product, null, '\t'), 'utf8');
            logToFile('[CHECKSUM] product.json updated ✅');
        } else {
            logToFile('[CHECKSUM] all checksums already match ✅');
        }
    } catch (e: any) {
        logToFile(`[CHECKSUM] error: ${e.message}`);
    }
}

// ─── HTTP Bridge Server (Extension Host → Renderer communication) ───

let observerHttpServer: any = null;
const pendingResponses = new Map<string, { approved: boolean } | null>();

/** Derive a deterministic port from project name (range 10000-60000) */
function getDeterministicPort(name: string): number {
    let hash = 0;
    for (let i = 0; i < name.length; i++) {
        hash = ((hash << 5) - hash + name.charCodeAt(i)) | 0;
    }
    return 10000 + (Math.abs(hash) % 50000);
}

function startObserverHttpBridge(): Promise<number> {
    return new Promise((resolve) => {
        try {
            const http = require('http');
            const server = http.createServer((req: any, res: any) => {
                // CORS headers for renderer fetch()
                res.setHeader('Access-Control-Allow-Origin', '*');
                res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS');
                res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
                if (req.method === 'OPTIONS') { res.writeHead(200); res.end(); return; }

                const url = new URL(req.url, `http://127.0.0.1`);

                // POST /pending — renderer reports a detected approval button
                if (req.method === 'POST' && url.pathname === '/pending') {
                    let body = '';
                    req.on('data', (c: string) => body += c);
                    req.on('end', () => {
                        try {
                            const data = JSON.parse(body);
                            const rid = data.request_id || Date.now().toString();
                            // Write pending file for Discord bot
                            const pendingDir = path.join(bridgePath, 'pending');
                            if (!fs.existsSync(pendingDir)) fs.mkdirSync(pendingDir, { recursive: true });
                            const pending = {
                                ...data,
                                request_id: rid,
                                conversation_id: activeSessionId || '',
                                timestamp: Date.now() / 1000,
                                status: 'pending',
                                project_name: projectName,
                                auto_detected: true,
                                source: 'dom_observer',
                            };
                            fs.writeFileSync(path.join(pendingDir, `${rid}.json`), JSON.stringify(pending, null, 2));
                            logToFile(`[HTTP] pending created: ${rid} cmd="${data.command}" ctx="${(data.description || '').substring(0, 50)}"`);
                            res.writeHead(200, { 'Content-Type': 'application/json' });
                            res.end(JSON.stringify({ ok: true, request_id: rid }));
                        } catch (e: any) {
                            logToFile(`[HTTP] pending error: ${e.message}`);
                            res.writeHead(400); res.end(JSON.stringify({ error: e.message }));
                        }
                    });
                    return;
                }

                // GET /response/:rid — renderer polls for Discord approval
                if (req.method === 'GET' && url.pathname.startsWith('/response/')) {
                    const rid = url.pathname.split('/')[2];
                    const respFile = path.join(bridgePath, 'response', `${rid}.json`);
                    if (fs.existsSync(respFile)) {
                        try {
                            const data = JSON.parse(fs.readFileSync(respFile, 'utf8'));
                            fs.unlinkSync(respFile);
                            logToFile(`[HTTP] response sent: ${rid} approved=${data.approved}`);
                            res.writeHead(200, { 'Content-Type': 'application/json' });
                            res.end(JSON.stringify(data));
                        } catch {
                            res.writeHead(200); res.end(JSON.stringify({ waiting: true }));
                        }
                    } else {
                        res.writeHead(200); res.end(JSON.stringify({ waiting: true }));
                    }
                    return;
                }

                // GET /ping — health check
                if (url.pathname === '/ping') {
                    res.writeHead(200); res.end('pong');
                    return;
                }

                res.writeHead(404); res.end('not found');
            });

            // Listen on deterministic port (derived from projectName), fallback to random
            deterministicPort = getDeterministicPort(projectName);
            const tryListen = (targetPort: number) => {
              server.listen(targetPort, '127.0.0.1', () => {
                const port = server.address().port;
                observerHttpServer = server;
                logToFile(`[HTTP] bridge server started on port ${port}`);

                // Write port to shared ports JSON (multi-bridge support)
                const patcher = (sdk.integration as any)?._patcher;
                if (patcher && typeof patcher.getWorkbenchDir === 'function') {
                    const workbenchDir = patcher.getWorkbenchDir();
                    const portsFile = path.join(workbenchDir, 'ag-bridge-ports.json');
                    let portsData: Record<string, number> = {};
                    try {
                        if (fs.existsSync(portsFile)) {
                            portsData = JSON.parse(fs.readFileSync(portsFile, 'utf-8'));
                        }
                    } catch { }
                    portsData[projectName] = port;
                    fs.writeFileSync(portsFile, JSON.stringify(portsData), 'utf-8');
                    logToFile(`[HTTP] ports JSON updated → ${portsFile} (${projectName}=${port})`);
                }

                resolve(port);
              });
            };

            server.on('error', (e: any) => {
                if (e.code === 'EADDRINUSE' && deterministicPort > 0) {
                    logToFile(`[HTTP] deterministic port ${deterministicPort} in use, trying random...`);
                    deterministicPort = 0;
                    const server2 = require('http').createServer(server._events.request);
                    observerHttpServer = server2;
                    server2.on('error', (e2: any) => {
                        logToFile(`[HTTP] random port also failed: ${e2.message}`);
                        resolve(0);
                    });
                    server2.listen(0, '127.0.0.1', () => {
                        const port = server2.address().port;
                        logToFile(`[HTTP] bridge server started on RANDOM port ${port}`);
                        resolve(port);
                    });
                    return;
                }
                logToFile(`[HTTP] server error: ${e.message}`);
                resolve(0);
            });

            tryListen(deterministicPort);
        } catch (e: any) {
            logToFile(`[HTTP] server failed: ${e.message}`);
            resolve(0);
        }
    });
}

// ─── Renderer Script (uses fetch() — no Node.js APIs) ───

function generateApprovalObserverScript(_port: number): string {
    // Port is hardcoded as fallback, but renderer also reads ag-bridge-ports.json for multi-bridge
    return `
// ── Gravity Bridge v2: Approval Observer (MutationObserver-first, throttled) ──
(function(){
  'use strict';
  var BASE='',_obs=false,_sent={},_ready=false;
  var _scanScheduled=false,_lastScanTs=0;
  var THROTTLE_MS=100;
  var CLEANUP_MS=300000;

  function log(m){console.log('[GB Observer] '+m);}
  log('v2 Script loaded — discovering bridge port...');

  // ── Port Discovery: async fetch()-based (sync XHR blocked in Electron renderer) ──
  var HARDCODED_PORT=${_port};

  function tryPingAsync(port){
    return fetch('http://127.0.0.1:'+port+'/ping?t='+Date.now(),{signal:AbortSignal.timeout(2000)})
      .then(function(r){return r.text();})
      .then(function(t){return t==='pong';})
      .catch(function(){return false;});
  }

  function discoverPort(cb){
    log('Trying hardcoded port '+HARDCODED_PORT+'...');
    tryPingAsync(HARDCODED_PORT).then(function(ok){
      if(ok){log('Port discovered (hardcoded): '+HARDCODED_PORT);cb(HARDCODED_PORT);return;}
      log('Hardcoded port failed, retrying with backoff...');

      var attempts=0;
      var timer=setInterval(function(){
        attempts++;
        if(attempts>60){clearInterval(timer);log('Port discovery timeout after 2min');return;}
        tryPingAsync(HARDCODED_PORT).then(function(ok2){
          if(ok2){clearInterval(timer);log('Port discovered (retry #'+attempts+'): '+HARDCODED_PORT);cb(HARDCODED_PORT);}
        });
      },2000);
    });
  }

  discoverPort(function(port){
    BASE='http://127.0.0.1:'+port;
    fetch(BASE+'/ping').then(function(r){return r.text();}).then(function(t){
      if(t==='pong'){log('Bridge connected on port '+port);_ready=true;startObserver();}
      else log('Bridge ping failed: '+t);
    }).catch(function(e){log('Bridge unreachable: '+e.message);});
  });

  // ── Button patterns to detect (order matters: first match wins per scan) ──
  var PATS=[
    {re:/^Run/i,           type:'terminal_command'},
    {re:/^Accept all$/i,   type:'diff_review'},
    {re:/^Accept$/i,       type:'agent_step'},
    {re:/^Allow/i,         type:'permission'},
    {re:/^Approve/i,       type:'agent_step'},
    {re:/^Continue$/i,     type:'continue'},
    {re:/^Proceed$/i,      type:'continue'},
  ];

  // Reject button patterns for finding the counterpart
  var REJECT_RE=[/^reject$/i,/^reject all$/i,/^cancel$/i,/^deny$/i,/^stop$/i,/^decline$/i];

  // ── Stable button fingerprint (no getBoundingClientRect — scroll-safe) ──
  function btnId(b,type){
    // Use: type + button text + parent's first 40 chars of text content
    var txt=(b.textContent||'').trim();
    var parent=b.parentElement;
    var pctx=parent?(parent.textContent||'').substring(0,40).replace(/\\s+/g,' '):'';
    // Also use DOM position: nth-child among sibling buttons
    var idx=0;
    if(parent){
      var siblings=parent.querySelectorAll('button');
      for(var i=0;i<siblings.length;i++){if(siblings[i]===b){idx=i;break;}}
    }
    return type+'|'+txt+'|'+idx+'|'+pctx.substring(0,20);
  }

  // ── Context extraction — walk up DOM to find command/code description ──
  function extractContext(b){
    // Strategy 1: Look for code/pre/terminal blocks near the button
    var container=b.closest('[class*="step"]')
      ||b.closest('[class*="action"]')
      ||b.closest('[class*="tool"]')
      ||b.closest('[class*="cascade"]')
      ||b.closest('[class*="message"]');
    if(!container)container=b.parentElement;
    if(!container)return '';

    // Look for code blocks
    var codeEl=container.querySelector('pre,code,[class*="command"],[class*="terminal"],[class*="code-block"]');
    if(codeEl){
      var codeText=(codeEl.textContent||'').trim();
      if(codeText.length>0)return codeText.substring(0,500);
    }

    // Strategy 2: Get surrounding text (exclude button text itself)
    var full=(container.textContent||'');
    var btnText=(b.textContent||'');
    var desc=full.replace(btnText,'').trim();
    // Trim to reasonable length
    return desc.substring(0,500);
  }

  // ── Find the React app container (Antigravity's main UI root) ──
  function findPanel(){
    // Priority order of panel selectors (most specific first)
    var selectors=[
      '.antigravity-agent-side-panel',
      '#jetski-agent-panel',
      '.react-app-container',
      '[class*="agent-panel"]',
      '[class*="agentPanel"]',
    ];
    for(var i=0;i<selectors.length;i++){
      var el=document.querySelector(selectors[i]);
      if(el)return el;
    }
    return null;
  }

  // ── Core scan — finds actionable buttons and reports to bridge ──
  function scan(){
    if(!_ready)return;
    var now=Date.now();

    var panel=findPanel();
    // Expand search: panel-scoped first, then full body for review bars
    var searchRoots=[];
    if(panel)searchRoots.push(panel);
    // Always also scan body for diff review bar (Accept all/Reject all)
    // which lives outside the agent panel in the editor notification area
    if(document.body)searchRoots.push(document.body);
    if(!searchRoots.length)return;

    var seen={}; // dedupe buttons across search roots
    for(var r=0;r<searchRoots.length;r++){
    var allBtns=searchRoots[r].querySelectorAll('button');
    if(!allBtns.length)continue;

    for(var j=0;j<allBtns.length;j++){
      var b=allBtns[j];
      if(b.disabled||b.hidden)continue;
      // Check visibility (offsetParent null = hidden via CSS)
      if(!b.offsetParent&&b.style.display!=='fixed')continue;

      var txt=(b.textContent||'').trim();
      if(!txt)continue;

      // Match against patterns
      var matchedType=null;
      for(var p=0;p<PATS.length;p++){
        if(PATS[p].re.test(txt)){matchedType=PATS[p].type;break;}
      }
      if(!matchedType)continue;

      // Generate stable ID
      var bid=btnId(b,matchedType);
      if(_sent[bid])continue;

      // Extract context
      var desc=extractContext(b);
      var rid=now.toString()+'_'+Math.random().toString(36).substring(2,6);

      // Mark as sent
      _sent[bid]={rid:rid,ts:now};
      log('DETECTED '+matchedType+': "'+txt+'" → pending to bridge');

      // Send to bridge (closure to capture refs)
      (function(rid2,b2,bid2,txt2,desc2,type2){
        fetch(BASE+'/pending',{
          method:'POST',
          headers:{'Content-Type':'application/json'},
          body:JSON.stringify({
            request_id:rid2,
            command:txt2,
            description:desc2,
            step_type:type2
          })
        }).then(function(r){return r.json();}).then(function(d){
          log('Pending created: '+d.request_id+' for "'+txt2+'"');
          pollResponse(d.request_id,b2,bid2);
        }).catch(function(e){
          log('POST error: '+e.message);
          delete _sent[bid2];
        });
      })(rid,b,bid,txt,desc,matchedType);

      // Process ONE button per scan cycle (avoid flooding)
      return;
    }
    } // end searchRoots loop
  }

  // ── Poll for Discord response ──
  function pollResponse(rid,btn,bid){
    var polls=0;
    var maxPolls=600; // 5 minutes at 500ms interval
    var timer=setInterval(function(){
      polls++;
      // Check if button is still in DOM (step may have been resolved by other means)
      if(!document.body.contains(btn)){
        log('Button removed from DOM — stopping poll for '+rid);
        clearInterval(timer);
        delete _sent[bid];
        return;
      }
      if(polls>maxPolls){
        log('Poll timeout for '+rid);
        clearInterval(timer);
        delete _sent[bid];
        return;
      }
      fetch(BASE+'/response/'+rid).then(function(r){return r.json();}).then(function(d){
        if(d.waiting)return;
        clearInterval(timer);
        if(d.approved){
          log('✅ APPROVED '+rid+' → clicking "'+((btn.textContent||'').trim())+'"');
          btn.click();
        } else {
          log('❌ REJECTED '+rid+' → finding reject button');
          clickRejectButton(btn);
        }
        delete _sent[bid];
      }).catch(function(){});
    },500);
  }

  // ── Find and click the reject/cancel counterpart button ──
  function clickRejectButton(approveBtn){
    // Walk up to find the container, then search for reject buttons
    var container=approveBtn.closest('[class*="step"]')
      ||approveBtn.closest('[class*="action"]')
      ||approveBtn.closest('[class*="tool"]')
      ||approveBtn.parentElement;
    if(!container){log('No container for reject');return;}

    var siblings=container.querySelectorAll('button');
    for(var i=0;i<siblings.length;i++){
      var t=(siblings[i].textContent||'').trim();
      for(var r=0;r<REJECT_RE.length;r++){
        if(REJECT_RE[r].test(t)){
          log('Clicking reject: "'+t+'"');
          siblings[i].click();
          return;
        }
      }
    }
    log('No reject button found near approve button');
  }

  // ── Throttled scan — leading-edge: fires immediately, then locks ──
  function scheduleScan(){
    if(!_ready)return;
    var now=Date.now();
    if(now-_lastScanTs>=THROTTLE_MS){
      _lastScanTs=now;
      scan();
    } else if(!_scanScheduled){
      _scanScheduled=true;
      setTimeout(function(){
        _scanScheduled=false;
        _lastScanTs=Date.now();
        scan();
      },THROTTLE_MS-(now-_lastScanTs));
    }
  }

  // ── Periodic cleanup of stale _sent entries ──
  setInterval(function(){
    var now=Date.now();
    var keys=Object.keys(_sent);
    for(var i=0;i<keys.length;i++){
      var entry=_sent[keys[i]];
      if(entry&&entry.ts&&(now-entry.ts)>CLEANUP_MS){
        log('Cleanup stale entry: '+keys[i]);
        delete _sent[keys[i]];
      }
    }
  },60000);

  // ── Start observation ──
  function startObserver(){
    if(_obs)return;
    // PRIMARY: MutationObserver — reacts instantly to DOM changes
    new MutationObserver(function(mutations){
      // Only scan if mutations contain added nodes (new buttons potentially)
      for(var i=0;i<mutations.length;i++){
        if(mutations[i].addedNodes.length>0){
          scheduleScan();
          return;
        }
      }
    }).observe(document.body,{childList:true,subtree:true});

    // FALLBACK: periodic scan every 3s for any missed mutations
    setInterval(scheduleScan,3000);

    _obs=true;
    log('v2 Observer active — MutationObserver + 3s fallback');
  }
})();
`;
}

// Track last seen step per session to avoid re-fetching
const lastSeenStep = new Map<string, number>();
const lastSnapshotText = new Map<string, string>();
const registeredSessions = new Set<string>(); // track which sessions have been registered

/**
 * Write a registration file for the Bot to discover session → project mapping.
 * Called automatically on first step event per session.
 */
function writeRegistration(sessionId: string) {
    try {
        const regDir = path.join(bridgePath, 'register');
        if (!fs.existsSync(regDir)) { fs.mkdirSync(regDir, { recursive: true }); }
        const regFile = path.join(regDir, `${sessionId}.json`);
        // Always overwrite — the window that actively writes snapshots/approvals is the correct owner
        const data = {
            conversation_id: sessionId,
            project_name: projectName,
            timestamp: Date.now() / 1000,
        };
        fs.writeFileSync(regFile, JSON.stringify(data, null, 2), 'utf-8');
        console.log(`Gravity Bridge: registered session ${sessionId.substring(0, 8)} → ${projectName}`);
    } catch (e: any) {
        console.log(`Gravity Bridge: registration write error: ${e.message}`);
    }
}

function setupMonitor() {
    if (!sdk) { return; }
    // NOTE: SDK EventMonitor DISABLED to prevent ERR_CONNECTION_REFUSED spam.
    // Root cause: EventMonitor polls GetCascadeTrajectorySteps every 2s via rawRPC,
    // which has a 775-step hard limit and generates connection errors.
    // ALL relay is now handled by the GetAllCascadeTrajectories POLL below.
    console.log('Gravity Bridge: SDK monitor DISABLED (using GetAllCascadeTrajectories POLL instead)');

    // ══════════════════════════════════════════════════════════════════════
    // PRIMARY RELAY: GetAllCascadeTrajectories (THE CORRECT API!)
    //
    // PROVEN VIA DIRECT RPC TESTING:
    // - GetCascadeTrajectorySteps: 775-step hard limit, startStepIndex IGNORED
    // - getDiagnostics.lastStepIndex: stale (can lag behind)
    // - GetAllCascadeTrajectories:
    //     stepCount: REAL-TIME (verified 1413→1429 live)
    //     latestNotifyUserStep: contains FULL notificationContent
    //     latestTaskBoundaryStep: contains FULL taskName/Status/Summary
    //     stepIndex on each → perfect for dedup
    // ══════════════════════════════════════════════════════════════════════
    let pollCount = 0;
    // activeSessionId is module-level (used by writeChatSnapshot for lazy registration)
    let activeSessionTitle = '';
    let lastKnownStepCount = 0;
    let lastNotifyStepIndex = -1;
    let lastTaskStepIndex = -1;
    let lastPendingStepIndex = -1; // dedup: don't re-create pending for same step
    let consecutiveIdleCount = 0; // debounce: require N consecutive stall polls
    let lastPendingTime = 0; // cooldown: minimum gap between pendings
    let sawRunningAfterPending = true; // gate: must see delta>0 before next pending
    let lastModTime = ''; // track lastModifiedTime to distinguish thinking vs approval
    let stallProbed = false; // prevent repeated step probes during same stall
    let lastRelayedTaskText = ''; // dedup TASK_BOUNDARY relay

    setInterval(async () => {
        pollCount++;
        if (pollCount <= 3 || pollCount % 12 === 0) {
            logToFile(`[POLL#${pollCount}] alive`);
        }
        try {
            const allTraj = await sdk.ls.rawRPC('GetAllCascadeTrajectories', {});
            if (!allTraj?.trajectorySummaries) {
                if (pollCount <= 3) logToFile('[POLL] no trajectorySummaries');
                return;
            }

            // ── Filter to sessions owned by THIS window ──
            // Each window claims sessions it sees first via writeRegistration().
            // Only process sessions registered to THIS projectName (or unclaimed ones).
            let bestSession: any = null;
            let bestSessionId = '';
            let bestModTime = '';
            const regDir = path.join(bridgePath, 'register');
            for (const [sid, data] of Object.entries(allTraj.trajectorySummaries) as [string, any][]) {
                // Check if this session is claimed by another project
                const regFile = path.join(regDir, `${sid}.json`);
                if (fs.existsSync(regFile)) {
                    try {
                        const reg = JSON.parse(fs.readFileSync(regFile, 'utf-8'));
                        if (reg.project_name && reg.project_name !== projectName) {
                            // Session belongs to another window — skip
                            continue;
                        }
                    } catch { }
                }

                const modTime = data.lastModifiedTime || '';
                if (!bestSession || modTime > bestModTime) {
                    bestSession = data;
                    bestSessionId = sid;
                    bestModTime = modTime;
                }
            }

            if (!bestSession) return;
            const currentCount = bestSession.stepCount || 0;
            const currentTitle = (bestSession.summary || 'Untitled').substring(0, 50);
            const isRunning = String(bestSession.status || '').includes('RUNNING');

            // Session changed?
            if (bestSessionId !== activeSessionId) {
                activeSessionId = bestSessionId;
                activeSessionTitle = currentTitle;
                lastKnownStepCount = currentCount;
                lastNotifyStepIndex = bestSession.latestNotifyUserStep?.stepIndex ?? -1;
                lastTaskStepIndex = bestSession.latestTaskBoundaryStep?.stepIndex ?? -1;
                lastPendingStepIndex = -1;
                stallProbed = false;
                // Don't register here — registration happens lazily in writeChatSnapshot/writePendingApproval
                // to avoid race conditions between multiple extension instances
                // Dump session keys + trajectoryMetadata on session change
                const allKeys = Object.keys(bestSession);
                logToFile(`[SESSION-INIT] id=${activeSessionId.substring(0, 8)} keys=[${allKeys.join(',')}]`);
                const trajMeta = bestSession.trajectoryMetadata;
                if (trajMeta) {
                    logToFile(`[SESSION-INIT] trajectoryMetadata=${JSON.stringify(trajMeta).substring(0, 500)}`);
                }
                console.log(`Gravity Bridge: [POLL#${pollCount}] session: ${activeSessionId.substring(0, 8)} "${currentTitle}" steps=${currentCount} ${isRunning ? 'RUNNING' : 'idle'}`);
                return;
            }

            const delta = currentCount - lastKnownStepCount;
            lastKnownStepCount = currentCount;

            if (delta > 0) {
                console.log(`Gravity Bridge: [POLL#${pollCount}] +${delta} steps (${currentCount}) "${currentTitle}"`);
            }

            // Log session state on EVERY poll for diagnostics
            const statusStr = String(bestSession.status || 'UNKNOWN');
            if (pollCount <= 10 || pollCount % 6 === 0 || delta > 0) {
                logToFile(`[POLL#${pollCount}] status=${statusStr} steps=${currentCount} delta=${delta}`);
            }

            // ── PRIMARY: Step-probe-based approval detection ──
            // On stall (idle=1, ~5s), probe GetCascadeTrajectorySteps to check WAITING.
            // 775-step limit: probe fails for long sessions → faster stall fallback.

            // ── STALL-BASED approval detection with step probe ──

            const currentModTime = bestSession.lastModifiedTime || (bestSession as any).lastModifiedTimestamp || (bestSession as any).modifiedTime || '';
            const modTimeChanged = currentModTime !== lastModTime;
            const isStall = isRunning && delta === 0;

            // Log modTime on stalls for debugging
            if (isStall && consecutiveIdleCount < 8) {
                logToFile(`[STALL-DBG] idle=${consecutiveIdleCount} modTime='${currentModTime}' changed=${modTimeChanged}`);
            }

            if (delta > 0) {
                consecutiveIdleCount = 0;
                sawRunningAfterPending = true;
                stallProbed = false; // allow re-probe on next stall
                lastModTime = currentModTime;
            } else if (isStall) {
                if (modTimeChanged) {
                    // lastModifiedTime is still changing = AI is thinking, NOT approval
                    consecutiveIdleCount = 0; // Reset!
                    stallProbed = false;
                    if (pollCount <= 10 || pollCount % 12 === 0) {
                        logToFile(`[THINK] step=${currentCount} modTime changing → not stall`);
                    }
                } else {
                    // lastModifiedTime frozen = real stall (approval waiting)
                    consecutiveIdleCount++;
                }
                lastModTime = currentModTime;

                // ── Step probe: on stall, fetch latest step via cascadeId (retry until WAITING found) ──
                // CONFIRMED: param='cascadeId', id=sessionId (map key from trajectorySummaries)
                // Retries every 2 polls (~10s) because RUN_COMMAND step may not be created yet
                if (consecutiveIdleCount >= 1 && !stallProbed) {
                    try {
                        const stepsResp = await sdk.ls.rawRPC('GetCascadeTrajectorySteps', {
                            cascadeId: bestSessionId,
                        });
                        if (stepsResp?.steps?.length > 0) {
                            const steps = stepsResp.steps;
                            // Diagnostic: compare returned steps vs trajectory stepCount
                            logToFile(`[STEP-PROBE] returned=${steps.length} vs trajectory.stepCount=${currentCount}`);
                            if (steps.length < currentCount) {
                                logToFile(`[STEP-PROBE] ⚠️ 775-limit hit! steps=${steps.length} < stepCount=${currentCount}`);
                            }
                            
                            // Scan last 5 steps backwards to find WAITING (RUN_COMMAND may not be last)
                            let foundWaiting = false;
                            for (let si = steps.length - 1; si >= Math.max(0, steps.length - 5); si--) {
                                const step = steps[si];
                                const stepStatus = step?.status || '';
                                const stepType = step?.type || '';

                                if (stepStatus === 'CORTEX_STEP_STATUS_WAITING') {
                                    foundWaiting = true;
                                    // Extract command from metadata.toolCall or direct fields
                                    const toolCall = step?.metadata?.toolCall;
                                    const toolName = toolCall?.name || stepType.replace('CORTEX_STEP_TYPE_', '').toLowerCase();
                                    let command = toolName;
                                    
                                    // Parse argumentsJson for command details
                                    if (toolCall?.argumentsJson) {
                                        try {
                                            const args = JSON.parse(toolCall.argumentsJson);
                                            if (args.CommandLine) {
                                                command = `${toolName}: ${args.CommandLine.substring(0, 150)}`;
                                            } else if (args.TargetFile) {
                                                command = `${toolName}: ${args.TargetFile.split(/[\\/]/).pop()}`;
                                            } else {
                                                command = `${toolName}: ${Object.keys(args).join(', ')}`;
                                            }
                                        } catch { command = toolName; }
                                    }

                                    const description = `Step #${si} (${stepType.replace('CORTEX_STEP_TYPE_', '')})`;
                                    logToFile(`[STEP-PROBE] ★ WAITING! step=${si} type=${stepType} cmd='${command}'`);

                                    if (si !== lastPendingStepIndex) {
                                        stallProbed = true; // found WAITING — stop retrying
                                        lastPendingStepIndex = si;
                                        lastPendingTime = Date.now();
                                        sawRunningAfterPending = false;
                                        writePendingApproval({
                                            conversation_id: activeSessionId,
                                            command,
                                            description,
                                            step_type: toolName,
                                            step_index: si,
                                            source: 'step_probe',
                                        });
                                    }
                                    break;
                                }
                            }
                            if (!foundWaiting) {
                                const lastStep = steps[steps.length - 1];
                                logToFile(`[STEP-PROBE] lastStep status=${lastStep?.status} type=${lastStep?.type} (not waiting)`);
                            }
                        }
                    } catch (e: any) {
                        logToFile(`[STEP-PROBE] error: ${e.message}`);
                    }
                }

                const now = Date.now();
                const cooldownOk = (now - lastPendingTime) > 60_000;

                const fallbackThreshold = (currentCount > 770) ? 4 : 8; // 775-limit: faster fallback
                if (consecutiveIdleCount >= fallbackThreshold && sawRunningAfterPending && cooldownOk) {
                    // Dynamic fallback: 20s (>770 steps) or 40s (normal)
                    lastPendingStepIndex = currentCount;
                    lastPendingTime = now;
                    sawRunningAfterPending = false;

                    const command = `Stall at step ${currentCount} (fallback)`;
                    const description = `승인 대기 감지 — fallback (${consecutiveIdleCount * 5}초 정지), Title: "${currentTitle}"`;

                    logToFile(`[STALL-FALLBACK] step=${currentCount} frozenCount=${consecutiveIdleCount} → pending`);
                    writePendingApproval({ conversation_id: activeSessionId, command, description, source: 'stall_fallback' });
                } else if (consecutiveIdleCount === fallbackThreshold) {
                    const reasons = [];
                    if (!sawRunningAfterPending) reasons.push('needDelta>0');
                    if (!cooldownOk) reasons.push(`cooldown(${Math.round((60000 - (now - lastPendingTime)) / 1000)}s)`);
                    if (reasons.length > 0) logToFile(`[STALL] SKIP: ${reasons.join(', ')}`);
                }
            } else if (!isRunning) {
                consecutiveIdleCount = 0;
                lastModTime = currentModTime;
            }

            // ── Process latestNotifyUserStep ──
            const notifyStep = bestSession.latestNotifyUserStep;
            if (notifyStep && notifyStep.stepIndex > lastNotifyStepIndex) {
                lastNotifyStepIndex = notifyStep.stepIndex;
                const content = notifyStep.step?.notifyUser?.notificationContent || '';
                // Filter: only relay meaningful notifications (skip trivial ones)
                if (content.length > 50) {
                    writeChatSnapshot(`📣 **알림** (step ${notifyStep.stepIndex})\n\n${content}`);
                    console.log(`Gravity Bridge: [POLL#${pollCount}] NOTIFY step=${notifyStep.stepIndex} ${content.length} chars`);
                } else if (content.length > 0) {
                    logToFile(`[POLL] NOTIFY skipped (too short: ${content.length} chars): ${content.substring(0, 80)}`);
                }
            }

            // ── Process latestTaskBoundaryStep ──
            const taskStep = bestSession.latestTaskBoundaryStep;
            if (taskStep && taskStep.stepIndex > lastTaskStepIndex) {
                lastTaskStepIndex = taskStep.stepIndex;
                const tb = taskStep.step?.taskBoundary;
                if (tb?.taskName) {
                    const mode = tb.mode ? tb.mode.replace('AGENT_MODE_', '') : '';
                    // Filter: skip status-only updates with same task name (noise)
                    const taskText = `${tb.taskName}|${tb.taskStatus || ''}`;
                    if (taskText !== lastRelayedTaskText) {
                        lastRelayedTaskText = taskText;
                        writeChatSnapshot(`📋 **[${mode}] ${tb.taskName}**\n${tb.taskStatus || ''}\n\n${tb.taskSummary || ''}`);
                        console.log(`Gravity Bridge: [POLL#${pollCount}] TASK step=${taskStep.stepIndex} "${tb.taskName}"`);
                    } else {
                        logToFile(`[POLL] TASK skipped (duplicate): "${tb.taskName}"`);
                    }
                }
            }
        } catch (e: any) {
            if (pollCount <= 5 || pollCount % 20 === 0) {
                console.log(`Gravity Bridge: [POLL#${pollCount}] error: ${e.message}`);
            }
        }
    }, 5000);
}

// ─── Response Watcher (Discord approval → Antigravity RPC) ───

let responseWatcher: fs.FSWatcher | null = null;

function setupResponseWatcher() {
    const responseDir = path.join(bridgePath, 'response');
    if (!fs.existsSync(responseDir)) {
        fs.mkdirSync(responseDir, { recursive: true });
    }

    try {
        responseWatcher = fs.watch(responseDir, (event, filename) => {
            if (filename && filename.endsWith('.json') && event === 'rename') {
                const fp = path.join(responseDir, filename);
                if (fs.existsSync(fp)) {
                    // Check if this response belongs to our project
                    const rid = filename.replace('.json', '');
                    const pendingFile = path.join(bridgePath, 'pending', `${rid}.json`);
                    if (fs.existsSync(pendingFile)) {
                        try {
                            const pending = JSON.parse(fs.readFileSync(pendingFile, 'utf-8'));
                            if (pending.project_name && pending.project_name !== projectName) {
                                logToFile(`[RESPONSE] skip ${rid} (project=${pending.project_name}, we=${projectName})`);
                                return; // Not our project
                            }
                        } catch { }
                    }
                    setTimeout(() => processResponseFile(fp), 300);
                }
            }
        });
        console.log('Gravity Bridge: response watcher started');
    } catch (e: any) {
        console.log(`Gravity Bridge: response watcher failed: ${e.message}`);
    }
}

async function processResponseFile(filePath: string) {
    try {
        const content = fs.readFileSync(filePath, 'utf-8');
        const resp = JSON.parse(content);
        const msg = `[RESPONSE] rid=${resp.request_id} approved=${resp.approved}`;
        console.log(`Gravity Bridge: ${msg}`);
        logToFile(msg);

        // Find matching pending request
        const pendingDir = path.join(bridgePath, 'pending');
        const pendingFile = path.join(pendingDir, `${resp.request_id}.json`);
        let sessionId = '';
        let isDomObserver = false;
        if (fs.existsSync(pendingFile)) {
            try {
                const pending = JSON.parse(fs.readFileSync(pendingFile, 'utf-8'));
                sessionId = pending.conversation_id || '';
                isDomObserver = pending.auto_detected === true
                    || pending.source === 'dom_observer';
            } catch { }
        }

        // ═══ MULTI-STRATEGY APPROVAL (v2.1) ═══
        // Tries multiple methods sequentially with detailed logging.
        // DOM observer: renderer handles clicking via pollResponse
        // Step probe/stall: try RPC → VS Code commands → log results

        const approved = resp.approved;

        if (isDomObserver) {
            // DOM observer path: renderer polls /response/:rid and clicks directly
            logToFile(`[RESPONSE] renderer-handled approval (rid=${resp.request_id})`);
        } else {
            // Step probe / stall path: try all approval strategies
            logToFile(`[RESPONSE] step_probe/stall → trying multi-strategy approval`);
            const approvalResult = await tryApprovalStrategies(approved, sessionId);
            logToFile(`[RESPONSE] approval result: ${approvalResult}`);
        }

        logToFile(`[RESPONSE] ${approved ? 'approve' : 'reject'} done (${isDomObserver ? 'dom' : 'step_probe'})`);

        // Cleanup response file — BUT NOT for DOM observer!
        if (!isDomObserver) {
            try { fs.unlinkSync(filePath); } catch { }
        }
    } catch (e: any) {
        const log = `[RESPONSE] error: ${e.message}`;
        console.log(`Gravity Bridge: ${log}`);
        logToFile(log);
    }
}

/**
 * Extract AI text from a PLANNER_RESPONSE step.
 * Known structure: {type, status, metadata, plannerResponse, ephemeralMessage, ...}
 * ephemeralMessage = system prompt (SKIP), plannerResponse = AI content
 */
function extractPlannerText(step: any): string | null {
    if (!step) { return null; }

    // Fields to SKIP — not user-facing content
    const SKIP_FIELDS = new Set([
        'thinking', 'thinkingSignature', 'stopReason', 'type', 'status', 'metadata',
        'ephemeralMessage', 'generatorModel', 'requestedModel',
        'executionId', 'sourceTrajectoryStepInfo', 'stepIndex',
        'viewableAt', 'createdAt', 'finishedGeneratingAt',
        'lastCompletedChunkAt', 'source', 'stepGenerationVersion'
    ]);

    // plannerResponse can be string or object
    const pr = step.plannerResponse;
    if (typeof pr === 'string' && pr.length > 10) {
        return filterEphemeral(pr);
    }
    if (pr && typeof pr === 'object') {
        // Try known content fields first (NOT thinking/stopReason)
        const text = pr.content || pr.text || pr.summary || pr.message || pr.response || pr.output;
        if (typeof text === 'string' && text.length > 10) {
            return filterEphemeral(text);
        }
        // Search other fields, but skip non-content ones
        for (const key of Object.keys(pr)) {
            if (SKIP_FIELDS.has(key)) continue;
            const val = pr[key];
            if (typeof val === 'string' && val.length > 50) { // Higher threshold
                const filtered = filterEphemeral(val);
                if (filtered) {
                    console.log(`Gravity Bridge: [DEBUG] planner text in plannerResponse.${key} (${filtered.length} chars)`);
                    return filtered;
                }
            }
        }
    }

    // Try other step fields (skip known non-content)
    for (const key of Object.keys(step)) {
        if (SKIP_FIELDS.has(key) || key === 'plannerResponse') continue;
        const val = step[key];
        if (typeof val === 'string' && val.length > 50) {
            const filtered = filterEphemeral(val);
            if (filtered) {
                console.log(`Gravity Bridge: [DEBUG] planner text in step.${key}`);
                return filtered;
            }
        }
    }
    return null;
}

/** Filter out system ephemeral messages and non-content strings. */
function filterEphemeral(text: string): string | null {
    if (!text || text.length < 10) { return null; }
    // Skip system prompt metadata
    if (text.includes('<EPHEMERAL_MESSAGE>') || text.includes('<ephemeral_message>')) { return null; }
    if (text.includes('artifact_reminder') || text.includes('active_task_reminder')) { return null; }
    if (text.includes('no_active_task_reminder')) { return null; }
    // Skip base64/crypto strings (no spaces, mostly alphanumeric)
    if (!text.includes(' ') && /^[A-Za-z0-9+/=_\-]{50,}$/.test(text)) { return null; }
    return text;
}

/** Extract human-readable command from a tool call step's data. */
function extractToolCommand(stepData: any): string {
    // Try common step data shapes from protobuf
    if (stepData.runCommand) {
        return stepData.runCommand.commandLine || stepData.runCommand.command || 'Run Command';
    }
    if (stepData.writeToFile) {
        const target = stepData.writeToFile.targetFile || stepData.writeToFile.filePath || 'file';
        return `Write: ${target.split(/[\\/]/).pop()}`;
    }
    if (stepData.codeAction) {
        const fp = stepData.codeAction.filePath || '';
        return `Edit: ${fp.split(/[\\/]/).pop() || 'file'}`;
    }
    if (stepData.replaceFileContent || stepData.multiReplaceFileContent) {
        const d = stepData.replaceFileContent || stepData.multiReplaceFileContent;
        const fp = d.targetFile || d.filePath || '';
        return `Edit: ${fp.split(/[\\/]/).pop() || 'file'}`;
    }
    if (stepData.sendCommandInput) {
        return `Send Input: ${(stepData.sendCommandInput.input || '').substring(0, 50)}`;
    }
    // Generic fallback: use first key name
    const keys = Object.keys(stepData).filter(k => k !== 'status' && k !== 'stepStatus');
    return keys.length > 0 ? keys[0] : 'Unknown tool call';
}

/** Extract description from a tool call step for Discord display. */
function extractToolDescription(stepData: any, sessionTitle: string, stepIndex: number): string {
    const parts = [`Step #${stepIndex}`, `Session: "${sessionTitle}"`];
    // Try to get code/command content for context
    if (stepData.runCommand) {
        const cmd = stepData.runCommand.commandLine || stepData.runCommand.command || '';
        if (cmd) parts.push(`Command: ${cmd.substring(0, 200)}`);
    }
    if (stepData.writeToFile?.targetFile) {
        parts.push(`File: ${stepData.writeToFile.targetFile}`);
    }
    if (stepData.codeAction?.filePath) {
        parts.push(`File: ${stepData.codeAction.filePath}`);
    }
    return parts.join('\n');
}

/** Write a pending approval file matching Bot's ApprovalRequest dataclass. */
function writePendingApproval(data: { conversation_id: string; command: string; description: string; step_type?: string; step_index?: number; source?: string }) {
    try {
        const pendingDir = path.join(bridgePath, 'pending');
        if (!fs.existsSync(pendingDir)) { fs.mkdirSync(pendingDir, { recursive: true }); }
        const id = Date.now().toString();
        const payload = {
            request_id: id,
            conversation_id: data.conversation_id,
            command: data.command,
            description: data.description,
            timestamp: Date.now() / 1000,
            status: 'pending',
            discord_message_id: 0,
            project_name: projectName,
            ...(data.step_type ? { step_type: data.step_type } : {}),
            ...(data.step_index !== undefined ? { step_index: data.step_index } : {}),
            ...(data.source ? { source: data.source } : {}),
        };
        fs.writeFileSync(path.join(pendingDir, `${id}.json`), JSON.stringify(payload, null, 2), 'utf-8');
        console.log(`Gravity Bridge: pending approval written → ${id}.json`);
        // Register session → project mapping (correct because projectName is per-window)
        if (data.conversation_id) { writeRegistration(data.conversation_id); }
    } catch (e: any) {
        console.log(`Gravity Bridge: pending write error: ${e.message}`);
    }
}

// ─── Multi-Strategy Approval Execution ───

/**
 * Try multiple approval methods sequentially.
 * Returns a string describing which method succeeded (or all failed).
 * 
 * Strategy order (most reliable first):
 * 1. HandleCascadeUserInteraction RPC (cross-platform, no focus)
 * 2. VS Code accept/reject commands (focus-dependent)
 * 3. Log failure for manual intervention
 */
async function tryApprovalStrategies(approved: boolean, sessionId: string): Promise<string> {
    const action = approved ? 'APPROVE' : 'REJECT';
    logToFile(`[APPROVAL] Starting ${action} strategies for session ${sessionId.substring(0, 8)}`);

    // ── Strategy 1: HandleCascadeUserInteraction RPC ──
    if (sdk) {
        // Try variant A: { cascadeId, approved }
        try {
            logToFile(`[APPROVAL-1A] HandleCascadeUserInteraction { cascadeId, approved: ${approved} }`);
            const rpcResult = await sdk.ls.rawRPC('HandleCascadeUserInteraction', {
                cascadeId: sessionId,
                approved: approved,
            });
            logToFile(`[APPROVAL-1A] ✅ SUCCESS: ${JSON.stringify(rpcResult).substring(0, 200)}`);
            return `RPC-1A:HandleCascadeUserInteraction(approved=${approved})`;
        } catch (e: any) {
            logToFile(`[APPROVAL-1A] ❌ FAIL: ${e.message}`);
        }

        // Try variant B: { cascadeId, stepAction }
        try {
            const stepAction = approved ? 'STEP_ACTION_ACCEPT' : 'STEP_ACTION_REJECT';
            logToFile(`[APPROVAL-1B] HandleCascadeUserInteraction { cascadeId, stepAction: '${stepAction}' }`);
            const rpcResult = await sdk.ls.rawRPC('HandleCascadeUserInteraction', {
                cascadeId: sessionId,
                stepAction: stepAction,
            });
            logToFile(`[APPROVAL-1B] ✅ SUCCESS: ${JSON.stringify(rpcResult).substring(0, 200)}`);
            return `RPC-1B:HandleCascadeUserInteraction(stepAction=${stepAction})`;
        } catch (e: any) {
            logToFile(`[APPROVAL-1B] ❌ FAIL: ${e.message}`);
        }

        // Try variant C: { cascadeId, userAction } (experimental)
        try {
            const userAction = approved ? 'USER_ACTION_APPROVED' : 'USER_ACTION_REJECTED';
            logToFile(`[APPROVAL-1C] HandleCascadeUserInteraction { cascadeId, userAction: '${userAction}' }`);
            const rpcResult = await sdk.ls.rawRPC('HandleCascadeUserInteraction', {
                cascadeId: sessionId,
                userAction: userAction,
            });
            logToFile(`[APPROVAL-1C] ✅ SUCCESS: ${JSON.stringify(rpcResult).substring(0, 200)}`);
            return `RPC-1C:HandleCascadeUserInteraction(userAction=${userAction})`;
        } catch (e: any) {
            logToFile(`[APPROVAL-1C] ❌ FAIL: ${e.message}`);
        }
    }

    // ── Strategy 2: VS Code Commands — step-type-specific (focus-dependent) ──
    // Per SDK research (2026-03-09):
    //   Run button = terminal command → terminalCommand.run / terminalCommand.accept
    //   Code changes = agent step → agent.acceptAgentStep
    //   General commands = command.accept
    // Previously only tried acceptAgentStep (Silent Success) — now tries ALL 7

    // Try to focus the panel first (required for command.accept / acceptAgentStep)
    try {
        logToFile(`[APPROVAL-2] focusing panel...`);
        await vscode.commands.executeCommand('antigravity.agentPanel.focus');
        await new Promise(resolve => setTimeout(resolve, 300));
        await vscode.commands.executeCommand('antigravity.agentSidePanel.focus');
        await new Promise(resolve => setTimeout(resolve, 300));
        logToFile(`[APPROVAL-2] panel focus attempted (agentPanel + agentSidePanel)`);
    } catch (e: any) {
        logToFile(`[APPROVAL-2] panel focus failed: ${e.message}`);
    }

    // All 7 approval commands in priority order (terminal first for Run button)
    const commands = approved
        ? [
            // Terminal commands (Run button) — UNTESTED INDIVIDUALLY (devlog-004)
            'antigravity.terminalCommand.run',      // SDK: TERMINAL_RUN
            'antigravity.terminalCommand.accept',   // SDK: TERMINAL_ACCEPT
            // General command approval
            'antigravity.command.accept',            // SDK: COMMAND_ACCEPT
            // Agent step approval (known: Silent Success with focus)
            'antigravity.agent.acceptAgentStep',     // SDK: ACCEPT_AGENT_STEP
            // Cascade action (experimental)
            // 'antigravity.executeCascadeAction',   // SDK: needs action param — skip
        ]
        : [
            'antigravity.terminalCommand.reject',   // SDK: TERMINAL_REJECT
            'antigravity.command.reject',            // SDK: COMMAND_REJECT
            'antigravity.agent.rejectAgentStep',     // SDK: REJECT_AGENT_STEP
        ];

    for (let i = 0; i < commands.length; i++) {
        const cmd = commands[i];
        try {
            const t0 = Date.now();
            logToFile(`[APPROVAL-2${String.fromCharCode(65 + i)}] executing: ${cmd}`);
            const result = await vscode.commands.executeCommand(cmd);
            const dt = Date.now() - t0;
            logToFile(`[APPROVAL-2${String.fromCharCode(65 + i)}] returned: ${JSON.stringify(result)} (${dt}ms)`);
        } catch (e: any) {
            logToFile(`[APPROVAL-2${String.fromCharCode(65 + i)}] ❌ FAIL: ${e.message}`);
        }
    }

    // ── Strategy 3: ResolveOutstandingSteps (REJECT ONLY — this CANCELS!) ──
    if (!approved && sdk) {
        try {
            logToFile(`[APPROVAL-3] ResolveOutstandingSteps (REJECT/CANCEL only!)`);
            const rpcResult = await sdk.ls.rawRPC('ResolveOutstandingSteps', {
                cascadeId: sessionId,
            });
            logToFile(`[APPROVAL-3] ✅ SUCCESS: ${JSON.stringify(rpcResult).substring(0, 200)}`);
            return `RPC-3:ResolveOutstandingSteps(cancel)`;
        } catch (e: any) {
            logToFile(`[APPROVAL-3] ❌ FAIL: ${e.message}`);
        }
    }

    logToFile(`[APPROVAL] ⚠️ ALL strategies attempted — check logs for results`);
    return `ALL_ATTEMPTED:${action}`;
}

// ─── Activation ───

export async function activate(context: vscode.ExtensionContext) {
    console.log('Gravity Bridge: activating...');

    // Project detection
    projectName = detectProjectName();
    console.log(`Gravity Bridge: project "${projectName}"`);

    // Bridge path
    const config = vscode.workspace.getConfiguration('gravityBridge');
    const configPath = config.get<string>('bridgePath');
    bridgePath = configPath || path.join(os.homedir(), '.gemini', 'antigravity', 'bridge');
    ensureBridgeDir();
    console.log(`Gravity Bridge: bridge path: ${bridgePath}`);

    // Status bar
    statusBar = vscode.window.createStatusBarItem(vscode.StatusBarAlignment.Left, 100);
    statusBar.text = '$(sync~spin) Bridge';
    statusBar.tooltip = `Gravity Bridge: ${projectName}`;
    statusBar.show();
    context.subscriptions.push(statusBar);

    // Initialize SDK
    const sdkReady = await initSDK(context);

    if (sdkReady) {
        setupMonitor();  // Now just logs that monitor is disabled
        setupApprovalObserver();  // DOM observer via SDK IntegrationManager
        statusBar.text = '$(check) Bridge';
        statusBar.tooltip = `Gravity Bridge: ${projectName} (POLL + Observer active)`;

        // Register SDK-powered commands
        context.subscriptions.push(
            vscode.commands.registerCommand('gravityBridge.approve', async () => {
                try {
                    await sdk.cascade.acceptStep();
                    vscode.window.showInformationMessage('Gravity Bridge: Step approved');
                } catch (e: any) {
                    vscode.window.showErrorMessage(`Approve failed: ${e.message}`);
                }
            }),
            vscode.commands.registerCommand('gravityBridge.reject', async () => {
                try {
                    await sdk.cascade.rejectStep();
                    vscode.window.showInformationMessage('Gravity Bridge: Step rejected');
                } catch (e: any) {
                    vscode.window.showErrorMessage(`Reject failed: ${e.message}`);
                }
            })
        );
    } else {
        statusBar.text = '$(warning) Bridge (no SDK)';
        console.log('Gravity Bridge: SDK not available, file-based mode only');
    }

    // Watch commands directory
    watchCommandsDir();

    // Watch response directory for approval interactions
    setupResponseWatcher();
    // Register basic commands
    context.subscriptions.push(
        vscode.commands.registerCommand('gravityBridge.start', () => {
            isActive = true;
            statusBar.text = sdkReady ? '$(check) Bridge SDK' : '$(sync~spin) Bridge';
            vscode.window.showInformationMessage(`Gravity Bridge started for "${projectName}"`);
        }),
        vscode.commands.registerCommand('gravityBridge.stop', () => {
            isActive = false;
            // SDK monitor is disabled, no need to stop
            statusBar.text = '$(circle-slash) Bridge OFF';
            vscode.window.showInformationMessage('Gravity Bridge stopped');
        }),
        vscode.commands.registerCommand('gravityBridge.connect', async () => {
            if (!sdk) {
                vscode.window.showErrorMessage('SDK not initialized');
                return;
            }
            try {
                const sessions = await sdk.cascade.getSessions();
                const items = sessions.map((s: any) => ({
                    label: s.title || 'Untitled',
                    description: `step ${s.stepCount} • ${s.id?.substring(0, 8)}`,
                    sessionId: s.id,
                }));
                const pick = await vscode.window.showQuickPick(items, {
                    placeHolder: 'Select a conversation to connect'
                });
                if (pick) {
                    await sdk.cascade.focusSession((pick as any).sessionId);
                    vscode.window.showInformationMessage(`Connected to: ${(pick as any).label}`);
                }
            } catch (e: any) {
                vscode.window.showErrorMessage(`Connect failed: ${e.message}`);
            }
        })
    );

    // Cleanup
    context.subscriptions.push({
        dispose: () => {
            if (sdk) { try { sdk.dispose(); } catch { } }
            if (watcher) { watcher.close(); }
            if (commandsWatcher) { commandsWatcher.close(); }
        }
    });

    console.log('Gravity Bridge: ✅ activated');
    isActive = true;
}

export function deactivate() {
    if (sdk) {
        try { sdk.dispose(); } catch { }
    }
}