import { existsSync, readFileSync, writeFileSync, mkdirSync } from "fs";
import { join, dirname } from "path";
import { homedir } from "os";
import { fileURLToPath } from "url";
import { 
    getNLAConfigDir, 
    getCurrentEnvironment, 
    setCurrentEnvironment, 
    getDeploymentPath 
} from "../utils.js";

// Get the directory of the current module
const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

// Colors for console output
const colors = {
    green: '\x1b[32m',
    blue: '\x1b[34m',
    red: '\x1b[31m',
    yellow: '\x1b[33m',
    reset: '\x1b[0m'
};

// Switch command
export function runSwitchCommand(env?: string) {
    console.log(`${colors.blue}════════════════════════════════════════════════════════${colors.reset}`);
    console.log(`${colors.blue}  Natural Language Agreement - Environment Switch${colors.reset}`);
    console.log(`${colors.blue}════════════════════════════════════════════════════════${colors.reset}\n`);

    // If no environment specified, show current
    if (!env) {
        const current = getCurrentEnvironment();
        console.log(`${colors.blue}Current environment:${colors.reset} ${colors.green}${current}${colors.reset}\n`);
        console.log('Available environments:');
        console.log('  • devnet       (local Anvil blockchain)');
        console.log('  • sepolia      (Ethereum Sepolia testnet)');
        console.log('  • base-sepolia (Base Sepolia testnet)');
        console.log('  • mainnet      (Ethereum mainnet)\n');
        console.log(`${colors.yellow}Usage:${colors.reset} nla switch <environment>`);
        console.log(`${colors.yellow}Example:${colors.reset} nla switch sepolia\n`);
        return;
    }

    // Validate environment
    const validEnvs = ['devnet', 'sepolia', 'base-sepolia', 'mainnet'];
    if (!validEnvs.includes(env)) {
        console.error(`${colors.red}❌ Invalid environment: ${env}${colors.reset}`);
        console.log('Valid environments: devnet, sepolia, base-sepolia, mainnet\n');
        process.exit(1);
    }

    // Switch environment
    const currentEnv = getCurrentEnvironment();
    
    if (currentEnv === env) {
        console.log(`${colors.yellow}⚠️  Already on ${env}${colors.reset}\n`);
        return;
    }

    setCurrentEnvironment(env);
    console.log(`${colors.green}✅ Switched to ${env}${colors.reset}\n`);
    
    // Show info about the environment
    if (env === 'devnet') {
        console.log('📝 Using local Anvil blockchain (http://localhost:8545)');
        console.log('   Run "nla dev" to start the development environment\n');
    } else if (env === 'sepolia') {
        console.log('📝 Using Ethereum Sepolia testnet');
        console.log('   Make sure you have deployed contracts and updated sepolia.json\n');
    } else if (env === 'base-sepolia') {
        console.log('📝 Using Base Sepolia testnet');
        console.log('   Make sure you have deployed contracts and updated base-sepolia.json\n');
    } else if (env === 'mainnet') {
        console.log('📝 Using Ethereum mainnet');
        console.log(`   ${colors.yellow}⚠️  WARNING: This is production! Use with caution.${colors.reset}\n`);
    }
}