const express = require('express');
const http = require('http');
const { Server } = require('socket.io');
const mineflayer = require('mineflayer');
const path = require('path');

const app = express();
const server = http.createServer(app);
const io = new Server(server, {
    cors: {
        origin: "*",
        methods: ["GET", "POST"]
    },
    pingTimeout: 60000,
    pingInterval: 25000
});

const PORT = process.env.PORT || 7860;

// Store active bots
const activeBots = new Map();

// Middleware
app.use(express.json());
app.use(express.static('public'));

// Health check endpoint
app.get('/health', (req, res) => {
    res.json({ status: true, uptime: process.uptime(), bots: activeBots.size });
});

// API Routes
app.get('/api/bots', (req, res) => {
    const bots = Array.from(activeBots.entries()).map(([id, data]) => ({
        id,
        username: data.bot?.username || 'unknown',
        host: data.host,
        port: data.port,
        connected: data.connected,
        players: data.players || []
    }));
    res.json(bots);
});

// Socket.IO Connection
io.on('connection', (socket) => {
    console.log('Client connected:', socket.id);

    let currentBot = null;
    let botId = null;
    let reconnectTimer = null;
    let reconnectAttempts = 0;
    const MAX_RECONNECT_ATTEMPTS = 5;
    const RECONNECT_DELAY = 5000;
    let botConfig = null;
    let isIntentionalDisconnect = false;

    // Connect bot to Minecraft server
    socket.on('connect-bot', (config) => {
        const { username, host, port = 25565, version } = config;

        if (!username || !host) {
            socket.emit('error', { message: 'Username and host are required' });
            return;
        }

        // Save config for reconnect
        botConfig = { username, host, port, version };
        isIntentionalDisconnect = false;
        reconnectAttempts = 0;

        // Disconnect existing bot for this socket
        if (currentBot) {
            isIntentionalDisconnect = true;
            currentBot.quit();
            activeBots.delete(botId);
        }

        // Clear any pending reconnect
        if (reconnectTimer) {
            clearTimeout(reconnectTimer);
            reconnectTimer = null;
        }

        botId = `${socket.id}_${Date.now()}`;

        createBotConnection(config, socket);
    });

    function createBotConnection(config, socket) {
        const { username, host, port = 25565, version } = config;

        try {
            console.log(`Creating bot ${username} for ${host}:${port}...`);

            const bot = mineflayer.createBot({
                host: host,
                port: parseInt(port),
                username: username,
                version: version || false,
                auth: 'offline',
                hideErrors: false,
                checkTimeoutInterval: 30000,
                closeTimeout: 10000,
                keepAlive: true,
                // Add some delay to avoid rate limiting
                connectTimeout: 30000
            });

            currentBot = bot;

            const botData = {
                bot: bot,
                socket: socket,
                host: host,
                port: port,
                connected: false,
                players: [],
                chatHistory: [],
                spawnTimeout: null,
                keepAliveInterval: null
            };

            activeBots.set(botId, botData);

            // Bot Events
            bot.on('login', () => {
                console.log(`Bot ${username} logged in to ${host}:${port}`);
                botData.connected = true;
                reconnectAttempts = 0;
                socket.emit('bot-status', {
                    status: 'online',
                    username: bot.username,
                    host: host,
                    port: port
                });
            });

            bot.on('spawn', () => {
                console.log(`Bot ${username} spawned`);
                socket.emit('bot-spawned', {
                    position: bot.entity?.position,
                    health: bot.health,
                    food: bot.food
                });
                updatePlayersList(bot, socket);

                // Start keep-alive mechanism
                startKeepAlive(bot, botData);

                // Clear spawn timeout
                if (botData.spawnTimeout) {
                    clearTimeout(botData.spawnTimeout);
                    botData.spawnTimeout = null;
                }
            });

            bot.on('chat', (username, message) => {
                if (username === bot.username) return;

                const chatData = {
                    username: username,
                    message: message,
                    timestamp: new Date().toISOString(),
                    type: 'chat'
                };

                botData.chatHistory.push(chatData);
                socket.emit('chat-message', chatData);
            });

            bot.on('message', (jsonMsg) => {
                const text = jsonMsg.toString();
                if (text && !text.includes(bot.username)) {
                    socket.emit('system-message', {
                        message: text,
                        timestamp: new Date().toISOString()
                    });
                }
            });

            bot.on('playerJoined', (player) => {
                socket.emit('player-joined', {
                    username: player.username,
                    timestamp: new Date().toISOString()
                });
                updatePlayersList(bot, socket);
            });

            bot.on('playerLeft', (player) => {
                socket.emit('player-left', {
                    username: player.username,
                    timestamp: new Date().toISOString()
                });
                updatePlayersList(bot, socket);
            });

            bot.on('health', () => {
                socket.emit('bot-health', {
                    health: bot.health,
                    food: bot.food
                });
            });

            bot.on('death', () => {
                socket.emit('bot-death', {
                    message: 'Bot died!',
                    timestamp: new Date().toISOString()
                });
            });

            bot.on('kicked', (reason) => {
                console.log(`Bot ${username} kicked:`, reason);
                const reasonStr = reason.toString ? reason.toString() : JSON.stringify(reason);
                socket.emit('bot-kicked', {
                    reason: reasonStr,
                    timestamp: new Date().toISOString()
                });

                // Try to reconnect if not intentional
                if (!isIntentionalDisconnect) {
                    attemptReconnect(socket, `Kicked: ${reasonStr}`);
                }
            });

            bot.on('error', (err) => {
                console.error(`Bot ${username} error:`, err.message);
                socket.emit('bot-error', {
                    message: err.message,
                    timestamp: new Date().toISOString()
                });

                // Only attempt reconnect for connection errors, not auth errors
                if (err.message && (
                    err.message.includes('ETIMEDOUT') ||
                    err.message.includes('ECONNRESET') ||
                    err.message.includes('ECONNREFUSED') ||
                    err.message.includes('timeout') ||
                    err.message.includes('disconnected')
                )) {
                    if (!isIntentionalDisconnect) {
                        attemptReconnect(socket, `Error: ${err.message}`);
                    }
                }
            });

            bot.on('end', (reason) => {
                console.log(`Bot ${username} disconnected. Reason:`, reason, 'Intentional:', isIntentionalDisconnect);

                // Stop keep-alive
                stopKeepAlive(botData);

                socket.emit('bot-disconnected', {
                    reason: reason || 'Connection closed',
                    timestamp: new Date().toISOString()
                });

                // Cleanup but keep the bot data for potential reconnect
                cleanupBotListeners(botId);

                // Attempt reconnect if not intentional disconnect
                if (!isIntentionalDisconnect) {
                    attemptReconnect(socket, reason || 'Connection closed');
                }
            });

            // Spawn timeout - if bot doesn't spawn within 30 seconds, reconnect
            botData.spawnTimeout = setTimeout(() => {
                if (!botData.connected) {
                    console.log(`Bot ${username} spawn timeout, reconnecting...`);
                    socket.emit('bot-error', {
                        message: 'Spawn timeout, reconnecting...',
                        timestamp: new Date().toISOString()
                    });
                    if (!isIntentionalDisconnect) {
                        bot.quit();
                        attemptReconnect(socket, 'Spawn timeout');
                    }
                }
            }, 30000);

        } catch (error) {
            console.error('Failed to create bot:', error);
            socket.emit('error', { message: error.message });

            if (!isIntentionalDisconnect) {
                attemptReconnect(socket, `Create error: ${error.message}`);
            }
        }
    }

    function attemptReconnect(socket, reason) {
        if (reconnectAttempts >= MAX_RECONNECT_ATTEMPTS) {
            console.log(`Max reconnect attempts reached for ${botConfig?.username}`);
            socket.emit('bot-error', {
                message: `Max reconnect attempts reached. Please check server details or try again later.`,
                timestamp: new Date().toISOString()
            });
            return;
        }

        reconnectAttempts++;
        console.log(`Reconnect attempt ${reconnectAttempts}/${MAX_RECONNECT_ATTEMPTS} for ${botConfig?.username} in ${RECONNECT_DELAY}ms`);

        socket.emit('bot-reconnecting', {
            attempt: reconnectAttempts,
            maxAttempts: MAX_RECONNECT_ATTEMPTS,
            delay: RECONNECT_DELAY,
            reason: reason,
            timestamp: new Date().toISOString()
        });

        reconnectTimer = setTimeout(() => {
            if (botConfig && !isIntentionalDisconnect) {
                console.log(`Executing reconnect for ${botConfig.username}...`);
                createBotConnection(botConfig, socket);
            }
        }, RECONNECT_DELAY);
    }

    function startKeepAlive(bot, botData) {
        // Send periodic position updates to keep connection alive
        botData.keepAliveInterval = setInterval(() => {
            if (bot && bot.entity) {
                // Small random movement to prevent AFK kick
                try {
                    const random = Math.random();
                    if (random < 0.1) {
                        // 10% chance to look around
                        const yaw = Math.random() * Math.PI * 2;
                        bot.look(yaw, 0, false);
                    }
                } catch (e) {
                    // Ignore look errors
                }
            }
        }, 15000); // Every 15 seconds
    }

    function stopKeepAlive(botData) {
        if (botData.keepAliveInterval) {
            clearInterval(botData.keepAliveInterval);
            botData.keepAliveInterval = null;
        }
        if (botData.spawnTimeout) {
            clearTimeout(botData.spawnTimeout);
            botData.spawnTimeout = null;
        }
    }

    // Send chat message
    socket.on('send-chat', (message) => {
        if (currentBot && currentBot.chat && botConfig) {
            try {
                currentBot.chat(message);
                socket.emit('chat-sent', {
                    username: currentBot.username,
                    message: message,
                    timestamp: new Date().toISOString()
                });
            } catch (e) {
                socket.emit('error', { message: 'Failed to send chat: ' + e.message });
            }
        }
    });

    // Send command
    socket.on('send-command', (command) => {
        if (currentBot && currentBot.chat && botConfig) {
            try {
                currentBot.chat(command);
            } catch (e) {
                socket.emit('error', { message: 'Failed to send command: ' + e.message });
            }
        }
    });

    // Bot actions
    socket.on('bot-action', (action) => {
        if (!currentBot || !botConfig) return;

        try {
            switch(action.type) {
                case 'jump':
                    currentBot.setControlState('jump', true);
                    setTimeout(() => currentBot.setControlState('jump', false), 500);
                    break;
                case 'sneak':
                    currentBot.setControlState('sneak', true);
                    setTimeout(() => currentBot.setControlState('sneak', false), 1000);
                    break;
                case 'look':
                    if (action.x !== undefined && action.y !== undefined && action.z !== undefined) {
                        const Vec3 = require('vec3');
                        currentBot.lookAt(new Vec3(action.x, action.y, action.z));
                    }
                    break;
                case 'move':
                    if (action.direction) {
                        currentBot.setControlState(action.direction, true);
                        setTimeout(() => currentBot.setControlState(action.direction, false), 500);
                    }
                    break;
            }
        } catch (e) {
            socket.emit('error', { message: 'Action failed: ' + e.message });
        }
    });

    // Disconnect bot
    socket.on('disconnect-bot', () => {
        isIntentionalDisconnect = true;

        if (reconnectTimer) {
            clearTimeout(reconnectTimer);
            reconnectTimer = null;
        }

        if (currentBot) {
            try {
                currentBot.quit();
            } catch (e) {}
            cleanupBot(botId);
            currentBot = null;
            botId = null;
        }

        socket.emit('bot-disconnected', {
            reason: 'Disconnected by user',
            timestamp: new Date().toISOString()
        });
    });

    // Get players list
    socket.on('get-players', () => {
        if (currentBot) {
            updatePlayersList(currentBot, socket);
        }
    });

    // Disconnect handler
    socket.on('disconnect', () => {
        console.log('Client disconnected:', socket.id);
        isIntentionalDisconnect = true;

        if (reconnectTimer) {
            clearTimeout(reconnectTimer);
            reconnectTimer = null;
        }

        if (currentBot) {
            try {
                currentBot.quit();
            } catch (e) {}
            cleanupBot(botId);
        }
    });
});

function updatePlayersList(bot, socket) {
    if (!bot.players) return;

    const players = Object.values(bot.players).map(p => ({
        username: p.username,
        ping: p.ping,
        uuid: p.uuid
    }));

    socket.emit('players-list', players);
}

function cleanupBotListeners(id) {
    if (activeBots.has(id)) {
        const data = activeBots.get(id);
        stopKeepAlive(data);
        if (data.bot) {
            try {
                data.bot.removeAllListeners();
            } catch (e) {}
        }
        activeBots.delete(id);
    }
}

function cleanupBot(id) {
    if (activeBots.has(id)) {
        const data = activeBots.get(id);
        stopKeepAlive(data);
        if (data.bot) {
            try {
                data.bot.quit();
                data.bot.removeAllListeners();
            } catch (e) {}
        }
        activeBots.delete(id);
    }
}

function stopKeepAlive(botData) {
    if (botData) {
        if (botData.keepAliveInterval) {
            clearInterval(botData.keepAliveInterval);
            botData.keepAliveInterval = null;
        }
        if (botData.spawnTimeout) {
            clearTimeout(botData.spawnTimeout);
            botData.spawnTimeout = null;
        }
    }
}

// Start server
server.listen(PORT, () => {
    console.log(`🎮 Minecraft Bot Controller running on port ${PORT}`);
    console.log(`🌐 Access the web interface at http://localhost:${PORT}`);
});

// Graceful shutdown
process.on('SIGTERM', () => {
    console.log('SIGTERM received, shutting down gracefully');
    activeBots.forEach((data, id) => {
        cleanupBot(id);
    });
    server.close(() => {
        process.exit(0);
    });
});

process.on('SIGINT', () => {
    console.log('SIGINT received, shutting down gracefully');
    activeBots.forEach((data, id) => {
        cleanupBot(id);
    });
    server.close(() => {
        process.exit(0);
    });
});