import express from 'express';
import { WebSocketServer } from 'ws';
import cors from 'cors';
import { createServer } from 'http';

const app = express();
const PORT = 3001;

app.use(cors());
app.use(express.json({ limit: '5mb' }));

// ========== State ==========
const webClients = new Set();
const bridgeClients = new Set();

// Latest inventory state from the CC:Tweaked bridge
let inventoryState = {
  itemList: [],
  grandTotal: 0,
  chestCount: 0,
  totalSlots: 0,
  usedSlots: 0,
  freeSlots: 0,
  usedRatio: 0,
  dropperOk: false,
  barrelOk: false,
  furnaceCount: 0,
  furnaceStatus: {},
};

let activityState = {};
let alertsState = [];
let smeltingPaused = false;
let disabledRecipes = {};
let smeltableRecipes = {};
let craftableRecipes = [];
let craftTurtleOk = false;
let lastUpdate = 0;

// Pending commands for bridge HTTP polling (fallback)
let pendingCommands = [];

// ========== Helpers ==========

function broadcastToClients(data) {
  const message = JSON.stringify(data);
  webClients.forEach((client) => {
    if (client.readyState === 1) {
      client.send(message);
    }
  });
}

function pushCommandToBridge(command) {
  let sent = false;
  for (const bridge of bridgeClients) {
    if (bridge.readyState === 1) {
      bridge.send(JSON.stringify(command));
      sent = true;
    }
  }
  if (!sent) {
    // Fallback: queue for HTTP polling
    pendingCommands.push({ ...command, timestamp: Date.now() });
    console.log(`[Bridge] Queued command via HTTP poll (no WS bridge)`);
  }
}

// ========== HTTP Server ==========
const server = createServer(app);

// Health check
app.get('/api/health', (req, res) => {
  res.json({ status: 'ok', lastUpdate, uptime: process.uptime() });
});

// Get current inventory state
app.get('/api/inventory', (req, res) => {
  res.json({
    inventory: inventoryState,
    activity: activityState,
    alerts: alertsState,
    smeltingPaused,
    disabledRecipes,
    smeltable: smeltableRecipes,
    craftable: craftableRecipes,
    craftTurtleOk,
    lastUpdate,
  });
});

// Get just the item list
app.get('/api/items', (req, res) => {
  res.json({ items: inventoryState.itemList || [] });
});

// Get furnace status
app.get('/api/furnaces', (req, res) => {
  res.json({
    furnaceCount: inventoryState.furnaceCount,
    furnaceStatus: inventoryState.furnaceStatus,
    smeltingPaused,
  });
});

// Get alerts
app.get('/api/alerts', (req, res) => {
  res.json({ alerts: alertsState });
});

// Get recipes (smeltable + craftable)
app.get('/api/recipes', (req, res) => {
  res.json({
    smeltable: smeltableRecipes,
    craftable: craftableRecipes,
    disabledRecipes,
    smeltingPaused,
  });
});

// ========== Command Endpoints ==========

// Order an item from storage
app.post('/api/order', (req, res) => {
  try {
    const { itemName, amount, dropperName } = req.body;
    if (!itemName || !amount) {
      return res.status(400).json({ error: 'Missing itemName or amount' });
    }
    
    const command = {
      type: 'command',
      action: 'order',
      itemName,
      amount: parseInt(amount),
      dropperName: dropperName || null,
    };
    
    pushCommandToBridge(command);
    console.log(`📦 Order: ${itemName} x${amount}`);
    res.json({ success: true, message: `Order sent: ${itemName} x${amount}` });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Request inventory scan
app.post('/api/scan', (req, res) => {
  try {
    pushCommandToBridge({ type: 'command', action: 'scan' });
    console.log('🔍 Scan requested');
    res.json({ success: true, message: 'Scan requested' });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Toggle smelting pause
app.post('/api/smelting/toggle', (req, res) => {
  try {
    pushCommandToBridge({ type: 'command', action: 'toggle_pause' });
    console.log('🔥 Smelting toggle requested');
    res.json({ success: true });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Toggle a specific recipe
app.post('/api/recipes/toggle', (req, res) => {
  try {
    const { recipe } = req.body;
    if (!recipe) return res.status(400).json({ error: 'Missing recipe name' });
    
    pushCommandToBridge({ type: 'command', action: 'toggle_recipe', recipe });
    console.log(`🔄 Recipe toggle: ${recipe}`);
    res.json({ success: true });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Enable/disable all recipes
app.post('/api/recipes/enable-all', (req, res) => {
  pushCommandToBridge({ type: 'command', action: 'enable_all' });
  res.json({ success: true });
});

app.post('/api/recipes/disable-all', (req, res) => {
  pushCommandToBridge({ type: 'command', action: 'disable_all' });
  res.json({ success: true });
});

// Sort barrel
app.post('/api/sort-barrel', (req, res) => {
  try {
    const { barrelName } = req.body;
    if (!barrelName) return res.status(400).json({ error: 'Missing barrelName' });
    
    pushCommandToBridge({ type: 'command', action: 'sort_barrel', barrelName });
    console.log(`📦 Sort barrel: ${barrelName}`);
    res.json({ success: true });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Craft item
app.post('/api/craft', (req, res) => {
  try {
    const { recipeIdx } = req.body;
    if (recipeIdx === undefined) return res.status(400).json({ error: 'Missing recipeIdx' });
    
    pushCommandToBridge({ type: 'command', action: 'craft', recipeIdx: parseInt(recipeIdx) });
    console.log(`🔨 Craft request: recipe #${recipeIdx}`);
    res.json({ success: true });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// ========== Bridge Endpoints (for HTTP polling fallback) ==========

// Bridge sends inventory state
app.post('/api/bridge/state', (req, res) => {
  try {
    const data = req.body;
    updateStateFromBridge(data);
    res.json({ success: true });
  } catch (error) {
    console.error('❌ Error processing bridge state:', error);
    res.status(500).json({ error: error.message });
  }
});

// Bridge polls for pending commands
app.get('/api/bridge/commands', (req, res) => {
  try {
    const now = Date.now();
    // Clear old commands (>30s)
    pendingCommands = pendingCommands.filter(cmd => (now - cmd.timestamp) < 30000);
    
    const commands = [...pendingCommands];
    res.json({ commands });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Bridge acknowledges commands
app.post('/api/bridge/commands/ack', (req, res) => {
  try {
    const cleared = pendingCommands.length;
    pendingCommands = [];
    res.json({ success: true, cleared });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Bridge sends command result
app.post('/api/bridge/result', (req, res) => {
  try {
    const { action, success, message, error: err } = req.body;
    
    broadcastToClients({
      type: 'command_result',
      action,
      success,
      message,
      error: err,
    });
    
    console.log(`📩 Result: ${action} - ${success ? 'OK' : 'FAIL'}`);
    res.json({ success: true });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// ========== State Update ==========

function updateStateFromBridge(data) {
  if (data.cache) {
    inventoryState = {
      itemList: data.cache.itemList || [],
      grandTotal: data.cache.grandTotal || 0,
      chestCount: data.cache.chestCount || 0,
      totalSlots: data.cache.totalSlots || 0,
      usedSlots: data.cache.usedSlots || 0,
      freeSlots: data.cache.freeSlots || 0,
      usedRatio: data.cache.usedRatio || 0,
      dropperOk: data.cache.dropperOk || false,
      barrelOk: data.cache.barrelOk || false,
      furnaceCount: data.cache.furnaceCount || 0,
      furnaceStatus: data.cache.furnaceStatus || {},
    };
  }
  
  if (data.activity !== undefined) activityState = data.activity;
  if (data.alerts !== undefined) alertsState = data.alerts;
  if (data.smeltingPaused !== undefined) smeltingPaused = data.smeltingPaused;
  if (data.disabledRecipes !== undefined) disabledRecipes = data.disabledRecipes;
  if (data.smeltable !== undefined) smeltableRecipes = data.smeltable;
  if (data.craftable !== undefined) craftableRecipes = data.craftable;
  if (data.craftTurtleOk !== undefined) craftTurtleOk = data.craftTurtleOk;
  
  lastUpdate = Date.now();
  
  // Broadcast to all web clients
  broadcastToClients({
    type: 'state_update',
    inventory: inventoryState,
    activity: activityState,
    alerts: alertsState,
    smeltingPaused,
    disabledRecipes,
    craftTurtleOk,
    lastUpdate,
  });
}

// ========== WebSocket Server ==========

const wss = new WebSocketServer({ server });

console.log(`🚀 Inventory Manager Web Server starting...`);
console.log(`📡 HTTP Server: http://localhost:${PORT}`);
console.log(`🔌 WebSocket Server: ws://localhost:${PORT}/ws`);

wss.on('connection', (ws, req) => {
  const url = req.url || '';
  
  // ---- Bridge WebSocket connection ----
  if (url.startsWith('/ws/bridge')) {
    console.log('🌉 CC:Tweaked bridge connected via WebSocket');
    bridgeClients.add(ws);
    
    ws.on('message', (raw) => {
      try {
        const data = JSON.parse(raw);
        
        if (data.type === 'ping') {
          ws.send(JSON.stringify({ type: 'pong' }));
          return;
        }
        
        if (data.type === 'state') {
          // Full state update from bridge
          updateStateFromBridge(data);
        } else if (data.type === 'command_result') {
          // Command result from bridge
          broadcastToClients({
            type: 'command_result',
            action: data.action,
            success: data.success,
            message: data.message,
            error: data.error,
          });
        }
      } catch (error) {
        console.error('❌ Bridge WS message error:', error.message);
      }
    });
    
    ws.on('close', () => {
      console.log('🌉 CC:Tweaked bridge disconnected');
      bridgeClients.delete(ws);
    });
    
    ws.on('error', (error) => {
      console.error('❌ Bridge WS error:', error);
      bridgeClients.delete(ws);
    });
    
    return;
  }
  
  // ---- Web client WebSocket connection ----
  console.log('🌐 New web client connected');
  webClients.add(ws);
  
  // Send current state to new client
  ws.send(JSON.stringify({
    type: 'initial_state',
    inventory: inventoryState,
    activity: activityState,
    alerts: alertsState,
    smeltingPaused,
    disabledRecipes,
    smeltable: smeltableRecipes,
    craftable: craftableRecipes,
    craftTurtleOk,
    lastUpdate,
  }));
  
  ws.on('message', (message) => {
    try {
      const data = JSON.parse(message);
      console.log('📨 Received from web client:', data);
      
      if (data.type === 'command') {
        // Forward command to bridge
        pushCommandToBridge(data);
      }
    } catch (error) {
      console.error('❌ Error processing web client message:', error);
    }
  });
  
  ws.on('close', () => {
    console.log('👋 Web client disconnected');
    webClients.delete(ws);
  });
  
  ws.on('error', (error) => {
    console.error('❌ WebSocket error:', error);
  });
});

// ========== Start Server ==========

server.listen(PORT, () => {
  console.log(`✅ Inventory Manager Web Server ready on port ${PORT}`);
  console.log(`\nBridge HTTP endpoint: http://localhost:${PORT}/api/bridge/state`);
  console.log(`Bridge WebSocket: ws://localhost:${PORT}/ws/bridge`);
  console.log(`Web client WebSocket: ws://localhost:${PORT}/ws`);
});

// Graceful shutdown
process.on('SIGINT', () => {
  console.log('\n🛑 Shutting down server...');
  process.exit(0);
});