// Load environment variables
require('dotenv').config();
const { checkAndUpdate } = require('./updater');

const Fastify = require('fastify');
const path = require('path');
const database = require('./database');
const config = require('./config');
const apiClient = require('./api-client');
const printer = require('./printer');
const PrintQueueWorker = require('./print-worker');

const fastify = Fastify({
  logger: true
});

const isDev = false;

// Order Poller Class
class OrderPoller {
  constructor(apiClient, database, printer) {
    this.apiClient = apiClient;
    this.db = database;
    this.printer = printer;
    this.intervalId = null;
    this.isPolling = false;
  }

  async start() {
    console.log('Starting order poller...');
    
    // Initial poll
    this.poll();
    
    // Schedule recurring polls
    this.scheduleNextPoll();
  }

  scheduleNextPoll() {
    const appConfig = config.getAll();
    const interval = parseInt(appConfig.pollingInterval, 10) || 15000;
    
    if (this.intervalId) {
      clearTimeout(this.intervalId);
    }
    
    this.intervalId = setTimeout(() => {
      this.poll();
      this.scheduleNextPoll();
    }, interval);
  }

  async poll() {
    if (this.isPolling) {
      console.log('Poll already in progress, skipping...');
      return;
    }

    this.isPolling = true;

    try {
      const appConfig = config.getAll();
      
      // Check if configured
      if (!appConfig.authToken || !appConfig.selectedBotId) {
        console.log('Not configured yet, skipping poll');
        this.isPolling = false;
        return;
      }

      // Check if token is expired
      if (apiClient.isTokenExpired(appConfig.tokenExpiry)) {
        console.log('Token expired, please re-login');
        this.isPolling = false;
        return;
      }

      // Get last synced order ID
      const lastOrder = this.db.getLastOrder();
      const afterId = lastOrder ? lastOrder.order_id : 0;

      console.log(`Polling for new orders (afterId: ${afterId})...`);

      // Fetch new orders from API
      const result = await this.apiClient.getOrders(
        appConfig.authToken,
        appConfig.selectedBotId,
        afterId,
        { includeCanceled: true, limit: 50 }
      );

      if (result.error) {
        console.error('Failed to fetch orders:', result.message);
        this.isPolling = false;
        return;
      }

      const orders = result.orders || [];
      console.log(`Received ${orders.length} orders from API`);

      // Process each order
      for (const order of orders) {
        const existingOrder = this.db.getOrderById(order.id);

        if (!existingOrder) {
          // New order - save and print
          console.log(`New order detected: #${order.id}`);
          this.db.insertOrder(order);
          
          // Initialize printer if needed
          if (!this.printer.printer) {
            this.printer.initializePrinter(appConfig);
          }

          // Add to print queue with deduplication check
          const newJobId = this.db.addToPrintQueue(order.id, 'new');
          if (!newJobId) {
            console.log(`Print job not created for order #${order.id} (duplicate prevention)`);
            continue;
          }
          
          this.db.markPrintJobProcessing(newJobId);
          
          try {
            // Use per-printer config system
            const printerConfigs = this.db.getEnabledPrinters();
            let result;
            
            if (printerConfigs && printerConfigs.length > 0) {
              result = await this.printer.printOrderReceiptWithPrinterConfigs(order, printerConfigs, 'new');
            } else {
              // Fallback to legacy system
              if (!this.printer.printer || !this.printer.config) {
                const currentConfig = require('./config').getAll();
                this.printer.initializePrinter(currentConfig);
              }
              result = await this.printer.printOrderReceipt(order, 'new');
            }
            
            if (result && result.success) {
              this.db.markOrderPrinted(order.id);
              this.db.markPrintJobCompleted(newJobId);
              // Cleanup any other pending jobs for this order+type
              this.db.cleanupDuplicateJobs(newJobId, order.id, 'new');
              console.log(`✓ Receipt printed for order #${order.id}`);
            } else {
              console.error(`✗ Print result indicates failure for order #${order.id}:`, result && result.error ? result.error : 'Unknown error');
              this.db.markPrintJobPending(newJobId);
            }
          } catch (error) {
            console.error(`✗ Failed to print order #${order.id}:`, error.message);
            console.log('  Order saved to database. You can reprint from dashboard.');
            this.db.markPrintJobPending(newJobId);
          }
        } else {
          // Check for status changes (cancellation status from backend)
          const statusChanged = existingOrder.status !== order.status;
          
          if (statusChanged) {
            console.log(`Order #${order.id} status changed: ${existingOrder.status} → ${order.status}`);
            
            this.db.updateOrder(order);

            // Print cancellation receipt if order was canceled
            if (order.status === 'canceled' && existingOrder.status !== 'canceled') {
              console.log(`Order #${order.id} was canceled - printing cancellation receipt...`);
              
              // Update local status to 'canceled' so it shows on the dashboard
              this.db.updateOrderStatus(order.id, 'canceled');
              
              // Check if cancellation already printed to prevent duplicates
              if (this.db.hasPrintedCancellation(order.id)) {
                console.log(`Skipping duplicate cancellation print for order #${order.id}`);
              } else {
                // Add to print queue with deduplication check
                const jobId = this.db.addToPrintQueue(order.id, 'canceled');
                if (!jobId) {
                  console.log(`Cancellation job not created for order #${order.id} (duplicate prevention)`);
                } else {
                  this.db.markPrintJobProcessing(jobId);
              
                  try {
                    const cancelReason = order.cancellationReason || order.order?.cancellationReason || 'Order canceled';
                    
                    // Use per-printer config system
                    const printerConfigs = this.db.getEnabledPrinters();
                    let result;
                    
                    if (printerConfigs && printerConfigs.length > 0) {
                      result = await this.printer.printOrderReceiptWithPrinterConfigs(order, printerConfigs, 'canceled', { reason: cancelReason });
                    } else {
                      // Fallback to legacy system
                      if (!this.printer.printer || !this.printer.config) {
                        const currentConfig = require('./config').getAll();
                        this.printer.initializePrinter(currentConfig);
                      }
                      result = await this.printer.printOrderReceipt(order, 'canceled', { reason: cancelReason });
                    }
                    
                    if (result && result.success) {
                      this.db.markOrderPrinted(order.id);
                      this.db.markPrintJobCompleted(jobId);
                      // Cleanup any other pending jobs for this order+type
                      this.db.cleanupDuplicateJobs(jobId, order.id, 'canceled');
                      console.log(`✓ Cancellation receipt printed for order #${order.id}`);
                    } else {
                      console.error(`✗ Cancellation print failed for order #${order.id}:`, result && result.error ? result.error : 'Unknown error');
                      this.db.markPrintJobPending(jobId);
                    }
                  } catch (error) {
                    console.error(`✗ Failed to print cancellation for order #${order.id}:`, error.message);
                    console.log('  Order updated in database. You can reprint from dashboard.');
                    this.db.markPrintJobPending(jobId);
                  }
                }
              }
            }
          }
        }
      }

      // Reconciliation fetch: scan recent orders window to catch updates (e.g., cancellations)
      try {
        const recentResult = await this.apiClient.getOrders(
          appConfig.authToken,
          appConfig.selectedBotId,
          0,
          { includeCanceled: true, limit: 200 }
        );

        if (!recentResult.error) {
          const recentOrders = recentResult.orders || [];
          for (const order of recentOrders) {
            const existingOrder = this.db.getOrderById(order.id);
            if (!existingOrder) {
              // Skip new orders here; they are handled by the main afterId fetch
              continue;
            }

            // Check for status changes (cancellation status from backend)
            const statusChanged = existingOrder.status !== order.status;
            
            if (statusChanged) {
              console.log(`(reconcile) Order #${order.id} status changed: ${existingOrder.status} → ${order.status}`);

              this.db.updateOrder(order);

              // Print cancellation receipt if order was canceled
              if (order.status === 'canceled' && existingOrder.status !== 'canceled') {
                console.log(`(reconcile) Order #${order.id} was canceled - printing cancellation receipt...`);

                // Update local status to 'canceled' so it shows on the dashboard
                this.db.updateOrderStatus(order.id, 'canceled');

                // Check if cancellation already printed to prevent duplicates
                if (this.db.hasPrintedCancellation(order.id)) {
                  console.log(`(reconcile) Skipping duplicate cancellation print for order #${order.id}`);
                } else {
                  // Add to print queue with deduplication check
                  const jobId = this.db.addToPrintQueue(order.id, 'canceled');
                  if (!jobId) {
                    console.log(`(reconcile) Cancellation job not created for order #${order.id} (duplicate prevention)`);
                  } else {
                    this.db.markPrintJobProcessing(jobId);

                    try {
                      const cancelReason = order.cancellationReason || order.order?.cancellationReason || 'Order canceled';
                      
                      // Use per-printer config system
                      const printerConfigs = this.db.getEnabledPrinters();
                      let result;
                      
                      if (printerConfigs && printerConfigs.length > 0) {
                        result = await this.printer.printOrderReceiptWithPrinterConfigs(order, printerConfigs, 'canceled', { reason: cancelReason });
                      } else {
                        // Fallback to legacy system
                        if (!this.printer.printer || !this.printer.config) {
                          const currentConfig = require('./config').getAll();
                          this.printer.initializePrinter(currentConfig);
                        }
                        result = await this.printer.printOrderReceipt(order, 'canceled', { reason: cancelReason });
                      }
                      
                      if (result && result.success) {
                        this.db.markOrderPrinted(order.id);
                        this.db.markPrintJobCompleted(jobId);
                        // Cleanup any other pending jobs for this order+type
                        this.db.cleanupDuplicateJobs(jobId, order.id, 'canceled');
                        console.log(`✓ Cancellation receipt printed for order #${order.id}`);
                      } else {
                        console.error(`✗ Cancellation print failed for order #${order.id}:`, result && result.error ? result.error : 'Unknown error');
                        this.db.markPrintJobPending(jobId);
                      }
                    } catch (error) {
                      console.error(`✗ Failed to print cancellation for order #${order.id}:`, error.message);
                      console.log('  Order updated in database. You can reprint from dashboard.');
                      this.db.markPrintJobPending(jobId);
                    }
                  }
                }
              }
            }
          }
        }
      } catch (reconcileErr) {
        console.error('Reconciliation fetch error:', reconcileErr.message);
      }

    } catch (error) {
      console.error('Poll error:', error.message);
    }

    this.isPolling = false;
  }

  stop() {
    if (this.intervalId) {
      clearTimeout(this.intervalId);
      this.intervalId = null;
    }
    console.log('Order poller stopped');
  }

  restart() {
    this.stop();
    this.start();
  }
}

// Main initialization
async function main() {
  try {
    // Initialize database
    database.init();
    console.log('Database initialized');

    // Register plugins
    await fastify.register(require('@fastify/view'), {
      engine: {
        ejs: require('ejs')
      },
      root: path.join(__dirname, 'views')
    });

    await fastify.register(require('@fastify/static'), {
      root: path.join(__dirname, 'public'),
      prefix: '/public/'
    });

    await fastify.register(require('@fastify/cookie'), {
      secret: process.env.COOKIE_SECRET || 'kitchen-agent-secret-key-change-in-production',
      hook: 'onRequest'
    });

    await fastify.register(require('@fastify/formbody'));

    await fastify.register(require('@fastify/multipart'), {
      limits: {
        fileSize: 5 * 1024 * 1024 // 5MB limit for logo uploads
      }
    });

    // Register routes
    await fastify.register(require('./routes/auth'));
    await fastify.register(require('./routes/dashboard'));
    await fastify.register(require('./routes/settings'));
    await fastify.register(require('./routes/orders'));

    // Initialize printer with config
    const appConfig = config.getAll();
    if (appConfig.printerType && appConfig.printerPath) {
      try {
        printer.initializePrinter(appConfig);
        console.log('Printer initialized successfully');
      } catch (error) {
        console.error('Failed to initialize printer:', error.message);
        console.log('Printer can be configured later in Settings');
      }
    } else {
      console.log('Printer not configured - configure in Settings');
    }

    // Start order poller
    const poller = new OrderPoller(apiClient, database, printer);
    const printWorker = new PrintQueueWorker(database, config, printer);
    
    // Make poller available globally for restart after settings change
    fastify.decorate('orderPoller', poller);
    fastify.decorate('printWorker', printWorker);

    // Start server
    const port = parseInt(process.env.PORT, 10) || 3000;
    const host = process.env.HOST || '0.0.0.0';
    
    await fastify.listen({ port, host });
    
    const addresses = fastify.server.address();
    console.log('\n=================================================');
    console.log('Think Link AI Kitchen Agent is running!');
    console.log(`Access at: http://localhost:${port}`);
    console.log(`Or use your computer's IP address from other devices`);
    console.log('=================================================\n');

    // Kick off auto-update check (at boot and on interval)
    if (isDev) {
      console.log('Dev mode detected: skipping auto-update checks');
    } else {
      try { checkAndUpdate(); } catch (_) {}
      const envIntervalRaw = process.env.UPDATE_CHECK_INTERVAL_MS;
      const envIntervalMs = envIntervalRaw ? parseInt(envIntervalRaw, 10) : NaN;
      const updateIntervalMs = (!Number.isNaN(envIntervalMs) && envIntervalMs > 0) ? envIntervalMs : (5 * 60 * 1000);
      setInterval(() => { try { checkAndUpdate(); } catch (e) { fastify.log.error(e); } }, updateIntervalMs);
    }

    // Start polling after server is up
    poller.start();
    // Start print queue worker
    printWorker.start();

    // Handle shutdown gracefully (PM2 reload-friendly)
    const gracefulShutdown = async () => {
      console.log('\nShutting down gracefully...');
      poller.stop();
      try { printWorker.stop(); } catch (_) {}
      try { database.close(); } catch (_) {}
      try { await fastify.close(); } catch (_) {}
      process.exit(0);
    };

    process.on('SIGINT', gracefulShutdown);
    process.on('SIGTERM', gracefulShutdown);
    process.on('message', (msg) => { if (msg === 'shutdown') gracefulShutdown(); });

  } catch (error) {
    console.error('Failed to start server:', error);
    process.exit(1);
  }
}

// Start the application
main();