/**
 * Gravity Bridge — VS Code Extension
 * 
 * Bridges Antigravity IDE approval dialogs to the Discord bot via file-based protocol.
 * 
 * Multi-project routing:
 * - Each workspace has a project name (from settings or workspace folder name)
 * - Extension only processes commands/responses matching its project_name
 * - Pending approvals include project_name for Discord channel routing
 */

import * as vscode from 'vscode';
import * as fs from 'fs';
import * as path from 'path';
import * as os from 'os';

let watcher: fs.FSWatcher | null = null;
let commandsWatcher: fs.FSWatcher | null = null;
let statusBar: vscode.StatusBarItem;
let bridgePath: string;
let projectName: string;
let isActive = false;

// Track pending approvals we've already sent
const sentPendingIds = new Set<string>();

import * as cp from 'child_process';

/**
 * Detect project name from workspace.
 * Priority: settings > git remote repo name > workspace folder name
 */
function detectProjectName(): string {
    const config = vscode.workspace.getConfiguration('gravityBridge');
    const configName = config.get<string>('projectName');
    if (configName) { return configName; }

    // Try git remote URL → extract repo name
    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();
            // "https://gitea.example.com/Variet/gravity_control.git" → "gravity_control"
            // "git@github.com:user/repo.git" → "repo"
            const match = remoteUrl.match(/\/([^\/]+?)(?:\.git)?$/);
            if (match && match[1]) {
                const repoName = match[1].toLowerCase().replace(/[\s\-]+/g, '_');
                console.log(`Gravity Bridge: project from git remote → "${repoName}"`);
                return repoName;
            }
        } catch {
            // No git or no remote — fall through
        }

        // Fallback: workspace folder name
        return folders[0].name.toLowerCase().replace(/[\s\-]+/g, '_');
    }

    return 'unknown_project';
}

export function activate(context: vscode.ExtensionContext) {
    projectName = detectProjectName();
    console.log(`Gravity Bridge: activating for project "${projectName}"...`);

    // Determine bridge path
    const config = vscode.workspace.getConfiguration('gravityBridge');
    const configPath = config.get<string>('bridgePath');
    bridgePath = configPath || path.join(os.homedir(), '.gemini', 'antigravity', 'bridge');

    // Ensure bridge directories exist
    const dirs = ['pending', 'response', 'commands', 'register'];
    for (const dir of dirs) {
        const dirPath = path.join(bridgePath, dir);
        if (!fs.existsSync(dirPath)) {
            fs.mkdirSync(dirPath, { recursive: true });
        }
    }

    // Status bar
    statusBar = vscode.window.createStatusBarItem(vscode.StatusBarAlignment.Right, 100);
    statusBar.command = 'gravityBridge.start';
    statusBar.text = `$(radio-tower) ${projectName}: Off`;
    statusBar.tooltip = `Gravity Bridge — ${projectName}`;
    statusBar.show();
    context.subscriptions.push(statusBar);

    // Register commands
    context.subscriptions.push(
        vscode.commands.registerCommand('gravityBridge.start', startBridge),
        vscode.commands.registerCommand('gravityBridge.stop', stopBridge),
        vscode.commands.registerCommand('gravityBridge.connect', connectSession),
        vscode.commands.registerCommand('gravityBridge.approve', () => handleManualAction(true)),
        vscode.commands.registerCommand('gravityBridge.reject', () => handleManualAction(false)),
    );

    // Debug: enumerate ALL available antigravity + chat commands
    setTimeout(async () => {
        const allCmds = await vscode.commands.getCommands(true);
        const agCmds = allCmds.filter(c => c.includes('antigravity'));
        const chatCmds = allCmds.filter(c =>
            c.includes('chat') && !c.includes('chatEditing') &&
            (c.includes('send') || c.includes('open') || c.includes('new') ||
                c.includes('create') || c.includes('accept') || c.includes('submit') ||
                c.includes('input') || c.includes('message') || c.includes('prompt'))
        );
        console.log(`Gravity Bridge: === ANTIGRAVITY COMMANDS (${agCmds.length}) ===`);
        agCmds.sort().forEach(c => console.log(`  AG: ${c}`));
        console.log(`Gravity Bridge: === CHAT COMMANDS (${chatCmds.length}) ===`);
        chatCmds.sort().forEach(c => console.log(`  CHAT: ${c}`));
    }, 3000);

    // Chat document change listener — captures AI text responses
    context.subscriptions.push(
        vscode.workspace.onDidChangeTextDocument((event) => {
            handleChatDocumentChange(event);
        })
    );

    // Register @bridge Chat Participant for history relay
    try {
        const participant = vscode.chat.createChatParticipant(
            'gravity-bridge.gravity',
            bridgeChatHandler
        );
        participant.iconPath = new vscode.ThemeIcon('radio-tower');
        context.subscriptions.push(participant);
        console.log('Gravity Bridge: @bridge chat participant registered');
    } catch (err) {
        console.log('Gravity Bridge: chat participant API not available (OK)');
    }

    // Auto-watch brain/ for new conversations → auto-register
    watchBrainForNewSessions();

    // Auto-start
    startBridge();
}

function startBridge() {
    if (isActive) {
        vscode.window.showInformationMessage(`Gravity Bridge (${projectName}): already running`);
        return;
    }

    isActive = true;
    statusBar.text = `$(radio-tower) ${projectName}: On`;
    statusBar.tooltip = `Gravity Bridge — ${projectName} (Active)`;
    statusBar.command = 'gravityBridge.stop';

    // Watch bridge/response/ for Discord user responses
    const responsePath = path.join(bridgePath, 'response');
    const processedFiles = new Set<string>();  // Debounce
    try {
        watcher = fs.watch(responsePath, { persistent: false }, (eventType, filename) => {
            if (filename && filename.endsWith('.json') && !processedFiles.has(filename)) {
                processedFiles.add(filename);
                setTimeout(() => processedFiles.delete(filename), 2000);
                handleResponse(path.join(responsePath, filename));
            }
        });
        console.log('Gravity Bridge: watching response directory');
    } catch (err) {
        console.error('Gravity Bridge: failed to watch response dir', err);
    }

    // Watch for commands (user text input from Discord)
    const commandsPath = path.join(bridgePath, 'commands');
    try {
        commandsWatcher = fs.watch(commandsPath, { persistent: false }, (eventType, filename) => {
            if (filename && filename.endsWith('.json') && !processedFiles.has(filename)) {
                processedFiles.add(filename);
                setTimeout(() => processedFiles.delete(filename), 2000);
                handleCommand(path.join(commandsPath, filename));
            }
        });
        console.log('Gravity Bridge: watching commands directory');
    } catch (err) {
        console.error('Gravity Bridge: failed to watch commands dir', err);
    }

    vscode.window.showInformationMessage(`Gravity Bridge (${projectName}): Started`);
    console.log(`Gravity Bridge: started for project "${projectName}", bridge: ${bridgePath}`);
}

function stopBridge() {
    if (!isActive) { return; }

    isActive = false;
    statusBar.text = `$(radio-tower) ${projectName}: Off`;
    statusBar.tooltip = `Gravity Bridge — ${projectName}`;
    statusBar.command = 'gravityBridge.start';

    if (watcher) { watcher.close(); watcher = null; }
    if (commandsWatcher) { commandsWatcher.close(); commandsWatcher = null; }

    vscode.window.showInformationMessage(`Gravity Bridge (${projectName}): Stopped`);
}

/**
 * Handle a response from Discord (approve/reject).
 * Only processes responses — no project filtering needed since request_id is unique.
 */
async function handleResponse(filePath: string) {
    try {
        await new Promise(resolve => setTimeout(resolve, 200));

        if (!fs.existsSync(filePath)) { return; }

        const content = fs.readFileSync(filePath, 'utf-8');
        const response = JSON.parse(content);

        if (response.approved === undefined) { return; }

        console.log(`Gravity Bridge [${projectName}]: response — approved=${response.approved}`);

        if (response.approved) {
            await simulateApproval();
            vscode.window.showInformationMessage(`✅ Approved: ${response.request_id}`);
        } else {
            await simulateRejection();
            vscode.window.showInformationMessage(`❌ Rejected: ${response.request_id}`);
        }

        try { fs.unlinkSync(filePath); } catch (e) { /* ignore */ }
    } catch (err) {
        console.error('Gravity Bridge: error handling response', err);
    }
}

/**
 * Handle a text command from Discord.
 * ONLY processes commands matching this project's name.
 */
async function handleCommand(filePath: string) {
    try {
        await new Promise(resolve => setTimeout(resolve, 200));

        if (!fs.existsSync(filePath)) { return; }

        const content = fs.readFileSync(filePath, 'utf-8');
        const command = JSON.parse(content);

        if (command.consumed || !command.text) { return; }

        // ★ PROJECT FILTER — only process commands for THIS project
        const cmdProject = command.project_name || '';
        if (cmdProject && cmdProject !== projectName) {
            console.log(`Gravity Bridge [${projectName}]: skipping command for "${cmdProject}"`);
            return;  // Not for us — leave file for the correct Extension instance
        }

        const text = command.text.trim();
        console.log(`Gravity Bridge [${projectName}]: command — "${text.substring(0, 50)}"`);

        // Special command: !stop — cancel AI work
        if (text === '!stop') {
            try {
                await vscode.commands.executeCommand('workbench.action.chat.stop');
                vscode.window.showWarningMessage(`⏹️ [${projectName}] AI 작업 중지됨`);
            } catch {
                vscode.window.showErrorMessage('AI 중지 명령 실행 실패');
            }
            command.consumed = true;
            fs.writeFileSync(filePath, JSON.stringify(command, null, 2), 'utf-8');
            return;
        }

        // Special command: auto-approve toggle
        if (text === '!auto on' || text === '!auto off') {
            const enabled = text === '!auto on';
            await toggleAutoApprove(enabled);

            command.consumed = true;
            fs.writeFileSync(filePath, JSON.stringify(command, null, 2), 'utf-8');
            return;
        }

        // General text: send directly to Antigravity agent panel
        try {
            await vscode.commands.executeCommand('antigravity.sendPromptToAgentPanel', command.text);
            console.log(`Gravity Bridge: ✅ sent via sendPromptToAgentPanel`);
        } catch (e1) {
            console.log(`Gravity Bridge: sendPromptToAgentPanel failed: ${e1}`);
            // Fallback: try sendChatActionMessage
            try {
                await vscode.commands.executeCommand('antigravity.sendChatActionMessage', command.text);
                console.log(`Gravity Bridge: ✅ sent via sendChatActionMessage`);
            } catch (e2) {
                console.log(`Gravity Bridge: sendChatActionMessage failed: ${e2}`);
                // Last resort: focus panel + clipboard paste
                try {
                    await vscode.commands.executeCommand('antigravity.agentPanel.focus');
                    await new Promise(resolve => setTimeout(resolve, 300));
                    const oldClip = await vscode.env.clipboard.readText();
                    await vscode.env.clipboard.writeText(command.text);
                    await vscode.commands.executeCommand('editor.action.clipboardPasteAction');
                    await vscode.env.clipboard.writeText(oldClip);
                    console.log('Gravity Bridge: clipboard paste fallback');
                } catch (e3) {
                    console.error('Gravity Bridge: all methods failed', e3);
                }
            }
        }

        // Always mark as consumed
        command.consumed = true;
        fs.writeFileSync(filePath, JSON.stringify(command, null, 2), 'utf-8');
    } catch (err) {
        console.error('Gravity Bridge: error handling command', err);
    }
}

/**
 * Toggle Antigravity's auto-approve settings.
 */
async function toggleAutoApprove(enabled: boolean) {
    const config = vscode.workspace.getConfiguration();

    try {
        await config.update('chat.tools.autoApprove', enabled, vscode.ConfigurationTarget.Global);
        await config.update('chat.agent.autoApprove', enabled, vscode.ConfigurationTarget.Global);

        if (enabled) {
            await config.update('chat.tools.terminal.enableAutoApprove', true, vscode.ConfigurationTarget.Global);
        }
        await config.update('autoAcceptV2.autoAcceptFileEdits', enabled, vscode.ConfigurationTarget.Global);

        statusBar.text = enabled
            ? `$(radio-tower) ${projectName}: Auto ✅`
            : `$(radio-tower) ${projectName}: Manual 🔒`;

        const mode = enabled ? '자동 승인 ON 🟢' : '수동 승인 OFF 🔴';
        vscode.window.showInformationMessage(`Gravity Bridge (${projectName}): ${mode}`);

        const statusPath = path.join(bridgePath, 'commands', `auto-status-${Date.now()}.json`);
        fs.writeFileSync(statusPath, JSON.stringify({
            id: `auto-status-${Date.now()}`,
            project_name: projectName,
            text: `[SYSTEM] Auto-approve: ${enabled ? 'ON' : 'OFF'}`,
            timestamp: Date.now() / 1000,
            consumed: true,
            auto_approve: enabled,
        }, null, 2), 'utf-8');

    } catch (err) {
        console.error('Gravity Bridge: failed to toggle auto-approve', err);
    }
}

async function simulateApproval() {
    try {
        await vscode.commands.executeCommand('workbench.action.acceptSelectedCodeAction');
    } catch {
        try {
            await vscode.commands.executeCommand('type', { text: '\n' });
        } catch {
            await vscode.commands.executeCommand('workbench.action.terminal.focus');
        }
    }
}

async function simulateRejection() {
    try {
        await vscode.commands.executeCommand('workbench.action.closeQuickOpen');
    } catch {
        try {
            await vscode.commands.executeCommand('cancelSelection');
        } catch {
            console.log('Gravity Bridge: rejection sent but no active dialog found');
        }
    }
}

/**
 * Manual approve/reject from command palette.
 */
function handleManualAction(approved: boolean) {
    const requestId = `manual-${Date.now()}`;
    const responsePath = path.join(bridgePath, 'response', `${requestId}.json`);

    const response = {
        request_id: requestId,
        approved: approved,
        user_input: '',
        timestamp: Date.now() / 1000,
    };

    fs.writeFileSync(responsePath, JSON.stringify(response, null, 2), 'utf-8');

    if (approved) { simulateApproval(); }
    else { simulateRejection(); }
}

/**
 * Write a pending approval request to bridge/pending/ for Discord bot to pick up.
 * Includes project_name for correct channel routing.
 */
export function writePendingApproval(
    conversationId: string,
    command: string,
    description: string
): string {
    const requestId = `req-${Date.now()}`;
    const pendingPath = path.join(bridgePath, 'pending', `${requestId}.json`);

    const request = {
        request_id: requestId,
        conversation_id: conversationId,
        project_name: projectName,  // ★ Project routing
        command: command,
        description: description,
        timestamp: Date.now() / 1000,
        status: 'pending',
        discord_message_id: 0,
    };

    fs.writeFileSync(pendingPath, JSON.stringify(request, null, 2), 'utf-8');
    sentPendingIds.add(requestId);

    console.log(`Gravity Bridge [${projectName}]: pending approval — ${requestId}`);
    return requestId;
}

/**
 * Register a conversation → project mapping in bridge/register/.
 * The bot reads these files to route brain events to the correct channel.
 */
function registerConversation(conversationId: string) {
    const registerDir = path.join(bridgePath, 'register');
    if (!fs.existsSync(registerDir)) {
        fs.mkdirSync(registerDir, { recursive: true });
    }

    const filePath = path.join(registerDir, `${conversationId}.json`);
    const data = {
        conversation_id: conversationId,
        project_name: projectName,
        timestamp: Date.now() / 1000,
    };

    fs.writeFileSync(filePath, JSON.stringify(data, null, 2), 'utf-8');
    console.log(`Gravity Bridge [${projectName}]: registered ${conversationId.substring(0, 8)}`);
}

/**
 * Read the title (first # heading) from a conversation's task.md or implementation_plan.md.
 */
function getConversationTitle(convDir: string): string {
    for (const fname of ['task.md', 'implementation_plan.md']) {
        const fpath = path.join(convDir, fname);
        if (fs.existsSync(fpath)) {
            try {
                const lines = fs.readFileSync(fpath, 'utf-8').split('\n').slice(0, 5);
                for (const line of lines) {
                    const match = line.match(/^#\s+(.+)/);
                    if (match) { return match[1].trim().substring(0, 50); }
                }
            } catch { /* ignore */ }
        }
    }
    return '';
}

/**
 * Manual connect: scan brain/ for recent conversations and let user pick.
 * Shows task.md titles for readability. Offers auto-connect for new projects.
 */
async function connectSession() {
    const brainPath = path.join(os.homedir(), '.gemini', 'antigravity', 'brain');
    if (!fs.existsSync(brainPath)) {
        vscode.window.showErrorMessage('Brain 디렉토리를 찾을 수 없습니다.');
        return;
    }

    // Get conversation dirs sorted by modification time (newest first)
    const dirs = fs.readdirSync(brainPath)
        .filter(d => {
            const fullPath = path.join(brainPath, d);
            return fs.statSync(fullPath).isDirectory() && d.includes('-');
        })
        .map(d => {
            const fullPath = path.join(brainPath, d);
            return {
                name: d,
                mtime: fs.statSync(fullPath).mtimeMs,
                title: getConversationTitle(fullPath),
            };
        })
        .sort((a, b) => b.mtime - a.mtime)
        .slice(0, 10);

    // Build QuickPick items
    const items: (vscode.QuickPickItem & { convId?: string })[] = [];

    // Always offer auto-connect option first
    items.push({
        label: '$(sync) 새 대화 자동 연결',
        description: '다음에 시작하는 대화가 자동으로 이 프로젝트에 연결됩니다',
        detail: `프로젝트: ${projectName}`,
    });

    // Add conversation items with titles
    for (const d of dirs) {
        const titleLabel = d.title || '(제목 없음)';
        const timeStr = new Date(d.mtime).toLocaleString();
        items.push({
            label: `$(comment-discussion) ${titleLabel}`,
            description: d.name.substring(0, 8),
            detail: `${d.name} · ${timeStr}`,
            convId: d.name,
        } as any);
    }

    const selected = await vscode.window.showQuickPick(items, {
        placeHolder: `프로젝트 "${projectName}"에 연결할 세션을 선택하세요`,
    });

    if (!selected) { return; }

    if (!('convId' in selected) || !selected.convId) {
        // Auto-connect mode
        vscode.window.showInformationMessage(
            `🔄 ${projectName}: 다음 대화가 자동으로 연결됩니다`
        );
        return;
    }

    registerConversation(selected.convId);
    vscode.window.showInformationMessage(
        `✅ ${selected.description} → ${projectName} 연결됨`
    );
}

/**
 * Auto-watch brain/ for new conversation directories → auto-register.
 */
function watchBrainForNewSessions() {
    const brainPath = path.join(os.homedir(), '.gemini', 'antigravity', 'brain');
    if (!fs.existsSync(brainPath)) { return; }

    // Track known dirs
    const knownDirs = new Set(
        fs.readdirSync(brainPath).filter(d =>
            fs.statSync(path.join(brainPath, d)).isDirectory()
        )
    );

    try {
        fs.watch(brainPath, { persistent: false }, (eventType, filename) => {
            if (!filename || !filename.includes('-')) { return; }
            const fullPath = path.join(brainPath, filename);

            // Check if it's a new directory
            if (!knownDirs.has(filename) && fs.existsSync(fullPath) &&
                fs.statSync(fullPath).isDirectory()) {
                knownDirs.add(filename);
                registerConversation(filename);
                console.log(`Gravity Bridge [${projectName}]: auto-registered new session ${filename.substring(0, 8)}`);
            }
        });
        console.log(`Gravity Bridge [${projectName}]: watching brain/ for new sessions`);
    } catch (err) {
        console.error('Gravity Bridge: failed to watch brain dir', err);
    }
}

/**
 * Monitor text document changes for chat panel content.
 * VS Code chat documents have special URI schemes (vscode-chat-response, etc.).
 * We capture significant changes and relay to Discord.
 */
let lastChatContent = '';
let chatDebounceTimer: NodeJS.Timeout | null = null;

function handleChatDocumentChange(event: vscode.TextDocumentChangeEvent) {
    const doc = event.document;
    const scheme = doc.uri.scheme;

    // Log ALL schemes to discover chat-related ones (debug mode)
    if (scheme !== 'file' && scheme !== 'git' && scheme !== 'output' &&
        scheme !== 'vscode-userdata' && scheme !== 'untitled') {
        console.log(`Gravity Bridge [${projectName}]: doc change scheme="${scheme}" uri="${doc.uri.toString().substring(0, 80)}"`);
    }

    // Capture chat-related documents
    // Known chat schemes: vscode-chat-response, vscode-copilot-chat, etc.
    const isChatDoc = scheme.includes('chat') || scheme.includes('copilot') ||
        scheme.includes('notebook') || doc.uri.path.includes('chat');

    if (!isChatDoc) { return; }

    const content = doc.getText();
    if (!content || content === lastChatContent) { return; }

    // Debounce: wait 2s for content to stabilize (AI streams text)
    if (chatDebounceTimer) { clearTimeout(chatDebounceTimer); }
    chatDebounceTimer = setTimeout(() => {
        const finalContent = doc.getText();
        if (finalContent && finalContent !== lastChatContent && finalContent.length > 20) {
            lastChatContent = finalContent;
            writeChatSnapshot(finalContent);
        }
    }, 2000);
}

/**
 * Write a chat content snapshot to bridge for the bot to relay.
 */
function writeChatSnapshot(content: string) {
    const snapshotDir = path.join(bridgePath, 'chat_snapshots');
    if (!fs.existsSync(snapshotDir)) {
        fs.mkdirSync(snapshotDir, { recursive: true });
    }

    const id = `chat-${Date.now()}`;
    const filePath = path.join(snapshotDir, `${id}.json`);
    const data = {
        id,
        project_name: projectName,
        content: content.substring(0, 4000),  // Limit size
        timestamp: Date.now() / 1000,
    };

    fs.writeFileSync(filePath, JSON.stringify(data, null, 2), 'utf-8');
    console.log(`Gravity Bridge [${projectName}]: chat snapshot written (${content.length} chars)`);
}

/**
 * @bridge Chat Participant handler.
 * Reads conversation history and sends to Discord via bridge.
 */
const bridgeChatHandler: vscode.ChatRequestHandler = async (
    request: vscode.ChatRequest,
    context: vscode.ChatContext,
    stream: vscode.ChatResponseStream,
    token: vscode.CancellationToken
) => {
    const command = request.prompt.trim().toLowerCase();

    if (command === 'stop' || command === '중지') {
        // Cancel current AI work
        try {
            await vscode.commands.executeCommand('workbench.action.chat.stop');
            stream.markdown('⏹️ AI 작업 중지 요청을 보냈습니다.');
        } catch {
            stream.markdown('⚠️ 중지 명령을 실행할 수 없습니다.');
        }
        return;
    }

    // Collect conversation history
    const historyLines: string[] = [];
    historyLines.push(`# 대화 히스토리 (${projectName})\n`);

    for (const entry of context.history) {
        if (entry instanceof vscode.ChatRequestTurn) {
            historyLines.push(`## 👤 사용자\n${entry.prompt}\n`);
        } else if (entry instanceof vscode.ChatResponseTurn) {
            let responseText = '';
            for (const part of entry.response) {
                if (part instanceof vscode.ChatResponseMarkdownPart) {
                    responseText += part.value.value;
                }
            }
            if (responseText) {
                historyLines.push(`## 🤖 AI\n${responseText}\n`);
            }
        }
    }

    if (historyLines.length <= 1) {
        stream.markdown('대화 히스토리가 비어있습니다. AI와 대화를 먼저 진행한 후 `@bridge`를 호출하세요.');
        return;
    }

    // Write to bridge for Discord relay
    const fullHistory = historyLines.join('\n');
    const cmdId = `bridge-history-${Date.now()}`;
    const cmdPath = path.join(bridgePath, 'commands', `${cmdId}.json`);

    const data = {
        id: cmdId,
        project_name: projectName,
        text: `[HISTORY]\n${fullHistory}`,
        timestamp: Date.now() / 1000,
        consumed: false,
    };

    fs.writeFileSync(cmdPath, JSON.stringify(data, null, 2), 'utf-8');

    stream.markdown(`✅ 대화 히스토리 (${context.history.length}개 턴)를 Discord에 전송했습니다.`);
    console.log(`Gravity Bridge [${projectName}]: sent ${context.history.length} turns to Discord`);
};

export function deactivate() {
    stopBridge();
}