import express, { Application } from 'express';
import cors from 'cors';
import { config } from 'dotenv';
import { Config } from './types/api';
import { generateRouter } from './routes/generate';
import { enhanceRouter } from './routes/enhance';
import { textToImageRouter } from './routes/textToImage';
import { imagesRouter } from './routes/images';
import { errorHandler, notFoundHandler } from './middleware/errorHandler';

// Load environment variables
config();

// Application configuration
export const appConfig: Config = {
  port: parseInt(process.env['PORT'] || '3000'),
  geminiApiKey: process.env['GEMINI_API_KEY'] || '',
  resultsDir: './results',
  uploadsDir: './uploads/temp',
  maxFileSize: 5 * 1024 * 1024, // 5MB
  maxFiles: 3
};

// Create Express application
export const createApp = (): Application => {
  const app = express();

  // Middleware
  app.use(cors({
    origin: process.env['CORS_ORIGIN'] || '*',
    credentials: true
  }));

  app.use(express.json({ limit: '10mb' }));
  app.use(express.urlencoded({ extended: true, limit: '10mb' }));

  // Request ID middleware for logging
  app.use((req, res, next) => {
    req.requestId = Math.random().toString(36).substr(2, 9);
    res.setHeader('X-Request-ID', req.requestId);
    next();
  });

  // Health check endpoint
  app.get('/health', (_req, res) => {
    const health = {
      status: 'healthy',
      timestamp: new Date().toISOString(),
      uptime: process.uptime(),
      environment: process.env['NODE_ENV'] || 'development',
      version: process.env['npm_package_version'] || '1.0.0'
    };

    console.log(`[${health.timestamp}] Health check - ${health.status}`);
    res.json(health);
  });

  // API info endpoint
  app.get('/api/info', (_req, res) => {
    const info = {
      name: 'Banatie - Nano Banana Image Generation API',
      version: '1.0.0',
      description: 'REST API service for AI-powered image generation using Gemini Flash Image model',
      endpoints: {
        'GET /health': 'Health check',
        'GET /api/info': 'API information',
        'POST /api/generate': 'Generate images from text prompt with optional reference images',
        'POST /api/text-to-image': 'Generate images from text prompt only (JSON)',
        'POST /api/enhance': 'Enhance and optimize prompts for better image generation'
      },
      limits: {
        maxFileSize: `${appConfig.maxFileSize / (1024 * 1024)}MB`,
        maxFiles: appConfig.maxFiles,
        supportedFormats: ['PNG', 'JPEG', 'JPG', 'WebP']
      }
    };

    console.log(`[${new Date().toISOString()}] API info requested`);
    res.json(info);
  });

  // Mount API routes
  app.use('/api', generateRouter);
  app.use('/api', enhanceRouter);
  app.use('/api', textToImageRouter);
  app.use('/api', imagesRouter);

  // Error handling middleware (must be last)
  app.use(notFoundHandler);
  app.use(errorHandler);

  return app;
};

// Extend Express Request type to include requestId
declare global {
  namespace Express {
    interface Request {
      requestId: string;
    }
  }
}