require('dotenv').config();

const config = {
    // Server configuration
    port: parseInt(process.env.PORT) || 3000,
    host: process.env.HOST || '0.0.0.0',
    nodeEnv: process.env.NODE_ENV || 'development',
    
    // Database configuration
    database: {
        path: process.env.DB_PATH || './stl_storage.db',
        uploadDir: process.env.UPLOAD_DIR || './uploads'
    },
    
    // File upload configuration
    upload: {
        maxFileSize: parseInt(process.env.MAX_FILE_SIZE) || 100 * 1024 * 1024, // 100MB
        maxFiles: parseInt(process.env.MAX_FILES_PER_REQUEST) || 5,
        allowedExtensions: (process.env.ALLOWED_EXTENSIONS || '.stl,.STL').split(','),
        destination: './uploads/stl'
    },
    
    // Security configuration
    security: {
        sessionSecret: process.env.SESSION_SECRET || 'change-this-secret-key',
        bcryptRounds: parseInt(process.env.BCRYPT_ROUNDS) || 12,
        rateLimitWindow: parseInt(process.env.RATE_LIMIT_WINDOW_MS) || 15 * 60 * 1000,
        rateLimitMax: parseInt(process.env.RATE_LIMIT_MAX_REQUESTS) || 100
    },
    
    // Logging configuration
    logging: {
        level: process.env.LOG_LEVEL || 'info',
        file: process.env.LOG_FILE || './logs/app.log'
    }
};

// Validate required configuration
const requiredEnvVars = [];
const missingVars = requiredEnvVars.filter(varName => !process.env[varName]);

if (missingVars.length > 0) {
    throw new Error(`Missing required environment variables: ${missingVars.join(', ')}`);
}

module.exports = config;