package main

import (
	"bufio"
	"fmt"
	"io/ioutil"
	"log"
	"net"
	"os"
	"strings"
	"time"
)

const (
	port         = "43"
	whoisversion = "v0.01"
	dataDir      = "./data" // Directory where domain files are stored
	crlf         = "\r\n"
)

// Function to get metadata for a domain
func getDomainMetadata(domain string) (string, string, string, string, error) {
	metaFilePath := fmt.Sprintf("%s/%s.meta", dataDir, domain)
	file, err := os.Open(metaFilePath)
	if err != nil {
		return "", "", "", "", err
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	var registrar, registrationDate, expirationDate, status string
	if scanner.Scan() {
		registrar = scanner.Text()
	}
	if scanner.Scan() {
		registrationDate = scanner.Text()
	}
	if scanner.Scan() {
		expirationDate = scanner.Text()
	}
	if scanner.Scan() {
		status = scanner.Text()
	}

	if err := scanner.Err(); err != nil {
		return "", "", "", "", err
	}

	return registrar, registrationDate, expirationDate, status, nil
}

func handleConnection(conn net.Conn) {
	defer conn.Close()

	// Get the client's IP address
	clientIP := conn.RemoteAddr().String()

	// Read the domain name from the client
	reader := bufio.NewReader(conn)
	request, err := reader.ReadString('\n')
	if err != nil {
		log.Println("Error reading from connection:", err)
		return
	}

	// Clean up the request
	domain := strings.TrimSpace(request)

	// Get the current timestamp
	timestamp := time.Now().Format(time.RFC3339)

	// Check if the domain file exists
	filePath := fmt.Sprintf("%s/%s", dataDir, domain)
	domainInfo, err := ioutil.ReadFile(filePath)
	if err != nil {
		// Domain file not found, so check if metadata file exists
		metaFilePath := fmt.Sprintf("%s/%s.meta", dataDir, domain)
		if _, err := os.Stat(metaFilePath); err == nil {
			// Metadata file exists but domain file doesn't
			registrar, registrationDate, expirationDate, status, err := getDomainMetadata(domain)
			if err != nil {
				log.Println("Error reading metadata file:", err)
				conn.Write([]byte("Error reading domain metadata" + crlf))
				return
			}
			response := fmt.Sprintf("       __        __      ____            \n  ____/ /____   / /_    / __/__  __ _____\n / __  // __ \\ / __/   / /_ / / / // ___/\n/ /_/ // /_/ // /_ _  / __// /_/ // /      | \n\\__,_/ \\____/ \\__/(_)/_/   \\__,_//_/       |      dot.fur WHOIS Server\n _       __ __  __ ____   ____ _____       |  whois.fur | whois.dotfur.net\n| |     / // / / // __ \\ /  _// ___/       |         Version: %s\n| | /| / // /_/ // / / / / /  \\__ \\        |\n| |/ |/ // __  // /_/ /_/ /  ___/ /      \n|__/|__//_/ /_/ \\____//___/ /____/       \n                                         \n", whoisversion)
			response += fmt.Sprintf(
				"Domain: %s%sOrigin IP: %s%sTimestamp: %s%sRegistrar: %s%sRegistration Date: %s%sExpiration Date: %s%sStatus: %s%sNo WHOIS Info to show%s",
				domain, crlf,
				clientIP, crlf,
				timestamp, crlf,
				registrar, crlf,
				registrationDate, crlf,
				expirationDate, crlf,
				status, crlf,
				crlf)
			response += fmt.Sprintf("\n.fur WHOIS Server | https://git.fur/caramel/whois | Version: %s", whoisversion)
			response += crlf

			conn.Write([]byte(response))
		} else {
			// Both domain file and metadata file not found
			log.Println("Domain and metadata file not found")
			conn.Write([]byte("Domain not found" + crlf))
		}
		return
	}

	// Domain file found, get metadata for the domain
	registrar, registrationDate, expirationDate, status, err := getDomainMetadata(domain)
	if err != nil {
		log.Println("Error reading metadata file:", err)
		conn.Write([]byte("Error reading domain metadata" + crlf))
		return
	}

	// Format the response with additional fields, origin IP, and timestamp
	response := fmt.Sprintf("       __        __      ____            \n  ____/ /____   / /_    / __/__  __ _____\n / __  // __ \\ / __/   / /_ / / / // ___/\n/ /_/ // /_/ // /_ _  / __// /_/ // /      | \n\\__,_/ \\____/ \\__/(_)/_/   \\__,_//_/       |      dot.fur WHOIS Server\n _       __ __  __ ____   ____ _____       |  whois.fur | whois.dotfur.net\n| |     / // / / // __ \\ /  _// ___/       |         Version: %s\n| | /| / // /_/ // / / / / /  \\__ \\        |\n| |/ |/ // __  // /_/ /_/ /  ___/ /      \n|__/|__//_/ /_/ \\____//___/ /____/       \n                                         \n", whoisversion)
	response += fmt.Sprintf(
		"Domain: %s%sOrigin IP: %s%sTimestamp: %s%sRegistrar: %s%sRegistration Date: %s%sExpiration Date: %s%sStatus: %s%s%s",
		domain, crlf,
		clientIP, crlf,
		timestamp, crlf,
		registrar, crlf,
		registrationDate, crlf,
		expirationDate, crlf,
		status, crlf,
		string(domainInfo))

	// Add a final CRLF to signify the end of the response
	response += fmt.Sprintf("\n.fur WHOIS Server | https://git.fur/caramel/whois | Version: %s", whoisversion)
	response += crlf

	// Send the response back to the client
	conn.Write([]byte(response))

	log.Printf("Served domain: %s to %s at %s\n", domain, clientIP, timestamp)
}

func main() {
	// Start the TCP server
	listener, err := net.Listen("tcp", ":"+port)
	if err != nil {
		log.Fatalf("Error starting server: %s", err)
	}
	defer listener.Close()

	log.Printf("Whois server running on port %s\n", port)

	for {
		// Accept incoming connections
		conn, err := listener.Accept()
		if err != nil {
			log.Println("Error accepting connection:", err)
			continue
		}

		// Handle the connection in a new goroutine
		go handleConnection(conn)
	}
}